Inorganic Chemistry of the Transition Elements: v. 3: A Review of Chemical Literature (Specialist Periodical Reports)

A Specia Iist PeriodicaI Report Inorganic Chemistry of the Transition Elements Volume 3 A Review of the Literature Pu...

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A Specia Iist PeriodicaI Report

Inorganic Chemistry of the Transition Elements Volume 3

A Review of the Literature Published between October 1972 and September 1973

Senior Reporter 6. F. G. Johnson, University Chemical Laboratory, Cambridge University Rep0rters

R. Davis. Kingston Polytechnic C. D. Garner, Manchester University L. A. P. Kane-Maguire, University of Wales, Cardiff J. A. McCleverty, University of Sheffkld

@ Copyright 1974

The Chemical Society Burlington House, London, W I V OBN

ISBN: 0 85186 520 8 Library of Congress Catalog Card No. 72-83458

Printed in Gt. Britain by Page Bros (Norwich) Ltd, Norwich

Preface _

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This, the third volume of the series,covers the period October 1972to September 1973 and follows the layout adopted in the two previous volumes. Chapter 1 contains an account of the Chemistry of the Early Transition Metals, excluding Scandium, Yttrium, and the Lanthanides. The Chemistry of the Elements of the first transition series from Manganese to Copper is discussed in Chapter 2. Chapter 3 deals with the Noble Metals (Ru, Os, Rh, Ir, Pd, Pt, Ag, and Au) and Chapter 4 with the Lanthanides (includingSc, Y, and La) and the Actinides. We thank readers for their advice and constructive criticisms of Volumes 1 and 2, and we have attempted to put some of the suggested modifications into practice. We hope to receive further constructive criticisms of this volume. B. F. G. JOHNSON

Contents

Chapter 1 The Early Transition Metals By C. D. Garner

1

1 Titanium Introduction Binary Compounds and Related Systems Halides and Oxyhalides Oxides Chalcogenides Carbides, Silicides, and Germanides Titanium (11) Titanium(rr1) Halides and Oxyhalides 0-Donor Ligands S-Donor Ligands N-Donor Ligands Mixed N-Donor and 0-Donor Ligands P-Donor Ligands Cyclopentadienyl Complexes Titanium (IV) Halides and Oxyhalides 0-Donor Ligands S-Donor Ligands N-Donor Ligands Mixed N-donor and 0-donor Ligands Organometallic Titanium(1v) Compounds Titanium-Carbon o-Bonded Complexes Cyclopentadienyl Complexes

5 6 6 7 8 8 9 10 10 12 12 13 20 21 22 23 23 26

2 Zirconium and Hafnium Introduction Binary Compounds and Related Species Halides and Oxyhalides Oxides and Chalcogenides Compounds with Elements of Group V and with Silicon

27 27 28 28 28 29

V

1 1

3 3 4

4 5

Contents

vi

Zirconium(I1) and Hafnium(1r) Zirconium(n1) and Hafnium(rI1) Zirconium(rv) and Hafnium(1v) Halides and Oxyhalides 0-Donor Ligands S-Donor Ligands N-Donor Ligands Mixed N-donor and 0-donor Ligands Organometallic Zirconium(1v)and Hafnium(1v) Compounds o-Bonded Complexes n-Bonded Complexes Zirconium(1v) and Hafnium(1v) Hydrido-compounds 3 Vanadium Introduction Carbonyl and other Lowoxidation State Compounds Nitrosyl Complexes Binary Compounds and Related Species Halides Oxides Chalcogenides Compounds with Elements of Group V Hydrides Vanadium(r1) Vanadium(rr1) Halides and Oxyhalides 0-Donor Ligands S-Donor Ligands N-Donor Ligands Mixed N-donor and 0-donor Ligands Cy ano-complexes Organometallic Vanadium(rI1) Compounds Vanadium(1v) Halides and Oxyhalides 0-Donor Ligands Complexes with Ligands containing Oxygen and other Donor Atoms S-Donor and Se-donor Ligands N-Donor Ligands Sb-Donor Ligands Organometallic Compounds Mixed-valence Compounds Vanadium(v) Halides and Oxyhalides 0-Donor Ligands

29

29 30 30 30 36 37 37 38 38

39 39 40 40 41 42 42 42 42 43 43 44 44 45 45 45 47 47 47 48 48 48 48 49 53 56 58 58 58

61) 61

61 64

Contents

vii

N-Donor and Mixed N-donor and 0-donor Ligands Organometallic Compounds

67 68

4 Niobium and Tantalum Introduction Carbonyl Complexes Binary Compounds and Related Systems Halides Oxides Chalcogenides Compounds with Elements of Group V, with Silicon, and with Germanium Hydrides Compounds with Nb-Nb or Ta-Ta Bonds Niobium(II1) and Tantalum(rr1) Niobium(rv) and Tantalum(1v) Niobium(v) and Tantalum(v) Halides and Oxyhalides 0-Donor Ligands S-Donor and Se-donor Ligands N-Donor and Mixed N-donor and 0-donor Ligands Organometallic Complexes

68 68 70 70 70 70 72

5 Chromium Introduction Carbonyl Complexes Organometallic n-Complexes Trifluorophosphino-complexes Dinitrogen Complexes Nitrosyl Complexes Binary Compounds and Related Systems Halides Oxides Chalcogenides Compounds with Elements of Group V Carbides and Silicides Borides and Gallides Hydrides Chromium(I1) Halides 0-Donor Ligands N-Donor Ligands Organometallic Compounds Chromium(II1) Optically Active Complexes

72 73 73 74 74 76 76 78 85 85 86 87 87 88 92 94 94 94 95 95 96 96 97 97 97 98 98 98 98 99 100 100 100

. ..

Contents

Vlll

Halide and Oxyhalide Complexes 0-Donor Ligands Polymeric Complexes containing Bridging Oxygen Atoms Complexes with S-donor, Se-donor, or Te-donor Ligands N-Donor Ligands Mixed N-donor and Other Donor Atom Ligands P-Donor Ligands Cyano-complexes Organometallic Compounds Chromium(1v) Chromium(v) Chromium(v1) Halides and Oxyhalides 0-Donor Ligands N-Donor Ligands

6 Molybdenum and Tungsten

Introduction Carbonyl Complexes Trifluorophosphino-complexes Dinitrogen Complexes and Nitrogen Fixation Nitrosyl Complexes Cyano- and Isocyano-complexes Hydrido-complexes Binary Compounds and Related Systems Halides Oxides Chalcogenides Other Binary and Related Systems Compounds containing Mo-Mo or W-W Bonds Molybdenum(r1) and Tungsten@) Molybdenum(II1) and Tungsten(II1) Molybdenum(1v) and Tungsten(1v) Molybdenum(v) and Tungsten(v) Mononuclear Complexes Dinuclear and Polynuclear Complexes Molybdenum and Tungsten Bronzes Molybdenum(v1) and Tungsten(v1) Halide, Oxyhalide, and Related Complexes 0-Donor Ligands Iso- and Hetero-polyanions S-and Se-Donor Ligands

101 102 105 108 109 111 113 113 115 116 116 116 117 117 118 120 120 120 122 128 128 131 133 134 135

135 137 137 138 138 142 142 144 146 146 148 150 151 151 154 162 165

ix

Contents

N-Donor Ligands Organometallic Compounds

166 166

7 Technetium and Rhenium Introduction Carbonyl Complexes Dinitrogen Complexes Nitrosyl Complexes Cyanide Complexes Hydrido-complexes Binary Systems and Related Compounds Halides Oxides Nitrides and Borides Compounds with Tc-Tc or Re-Re Bonds Technetium@) and Rhenium(@ Technetium@) and Rhenium(1v) Technetium(v) and Rhenium(v) Rhenium(v1) Technetium (VII)and Rhenium(vI1)

167 167 168 171 172 172 173 173 173 174 174 175 176 176 178 179 179

8 Appendix

181

Chapter 2 Elements of the First Transitional Period By R. Davis

185

1 Manganese Carbonyl Compounds Nitrosyl Compounds Other Manganese(1) Complexes Manganese(@ Halides and Pseudohalides Complexes N-Donor ligands 0-Donor ligands S-Donor ligands Mixed donor ligands Oxides Manganese@) Halides and Pseudohalides Complexes N-Donor ligands 0-Donor ligands S-Donor ligands Mixed donor ligands

185 185 190 191 191 191 191 191 193 195 195 197 197 197 197 197 198 198 198

Contents

X

Higher Oxidation States of Manganese 2 Iron

Carbonyl Compounds Nitrogenyl and Nitrosyl Compounds Other Iron(0) and Iron(1) Compounds Iron(r1) Halides and Pseudohalides Hydrides Complexes Pyridine and related ligands Macrocyclic N-donor ligands Other N-donor ligands 0-Donor ligands S-Donor and P- donor ligands Mixed donor ligands Iron(111) Halides and Pseudohalides Complexes N-Donor ligands 0-Donor ligands S-Donor and Se-donor ligands Mixed donor ligands Iron(rv) Compounds Higher Oxidation States of Iron Oxides, Hydroxides, and Sulphides

3 Cobalt Carbonyl Compounds Nitrogenyl and Nitrosyl Compounds Cobalt(1) Cobalt(I1) Halides and Pseudohalides Hydrides Complexes Amine complexes Pyridine and related ligands Imidazole, pyrazole, and related ligands Macrocyclic N-donor ligands Other N-donor ligands 0-Donor ligands S-Donor and Se-donor ligands P-Donor and As-donor ligands

199 200 200 210 21 1 21 1 21 1 212 213 213 214 217 218 220 221 222 222 223 223 224 226 226 227 227 227

228 228 232 234 235 235 236 236 236 237 238 239 240 241 245 245

xi

Contents

Mixed donor ligands Other Cobalt@) Compounds Cobalt(Ir1) Halides and Pseudohalides Complexes Ammine and monoamine complexes Diamine complexes Polyamine complexes Macrocyclic N-donor ligands and vitamin B analogues Oximato-complexes Other N-donor ligands 0-Donor, S-donor, Se-donor, and As-donor ligands Amino-acid complexes Schiff-base ligands Other mixed donor ligands Polynuclear anion-bridged complexes Cobalt@) and Cobalt(v) Oxides Cobalt- Oxygen Compounds

4 Nickel

Carbonyl, Nitrosyl, Nitrogenyl, and Oxygenyl Compounds Halides and Pseudohalides Nickel(0) Nickel(1) Nickel(1.5) Nickel(I1) Complexes Ammine, Amine, and Related Ligands Pyridine and Related Ligands Imidazole and Pyrazole Ligands Macrocyclic N-donor Ligands Other N-donor Ligands 0-donor Ligands S-Donor and Se-donor Ligands P-Donor and As-donor Ligands Mixed Donor Ligands Other Compounds Nickel(rI1) Nickel(1v) Oxides

247 252 252 252 253 253 254

256 258 260 26 1 262 263 265 266 268 268 268 268

270 270. 270 27 1 27 1 272 27 3 273

27 5 275 276

279 280 284 285 287 296 296 297 297

xii

Contents

5 Copper coPPer(1) Halides Complexes N-Donor and 0-donor ligands S-Donor and Se-donor ligands P-Donor ligands Mixed donor ligands Other Copper(1) Compounds Copper(I1) Halides Complexes N-Donor ligands 0-Donor ligands S-Donor and Se-donor ligands Mixed donor ligands Copper(II1) Oxides and Hydroxides

298 298 298 298 298 299 300 301 30 1 30 1 301 303 303 309 313 314 325 325

6 Ligands

325

7 Formation and Stability Constants

328

8 Bibliography

333

Chapter 3 The Noble Metals By L. A. P. Kane-Maguire 1 Ruthenium Cluster Compounds Ruthenium(0) and Ruthenium(1) Rut henium(I1) Group VII Donors Halogeno-carbonyl and -phosphine complexes Hydridophosphine complexes Group VI Donors 0-Donor and S-donor ligands Group V Donors Molecular nitrogen complexes Nitrosyl complexes Other N-donor ligands Sb-Donor ligands Group IV Donors Si-Donor and Sn-donor ligands Mixed Oxidation State Ruthenium

337 337 337 339 340 340 340 341 342 342 343 343 344 345 347 347 347 348

...

xi11

Contents

Ruthenium(rI1) Group VII Donors Halide donor ligands Halogenophosphine complexes Group VI Donors 0-Donor ligands S-Donor ligands Group V Donors N-Donor ligands Group IV Donors C-Donor ligands Ruthenium(1v) Group VII Donors Other Donor Ligands Ruthenium(1v) and Ruthenium(vI1r) 2 Osmium

Cluster Compounds Osmium(0) Osmium(I1) Group V Donors Molecular nitrogen complexes Other N-donor ligands Other Group Donors Osmium(rI1) Osmium(1v) Osmium(v) Osmium(v1)

3 Rhodium Cluster Compounds Rhodium( -I) Rhodium(1) Group VII Donors Hydrido-carbonyl and -phosphine complexes Halogeno-carbonyl and -phosphine complexes Group VI Donors 0-Donor ligands S-Donor ligands Group V Donors N-Donor ligands P- and As-donor ligands Group IV Donors Rhodium(I1) Group VI Donors

349 349 349 349 349 349 349 352 352 353 353 353 353 354 354 354 354 356 356 356 356 358 359 3 59 360 361 36 1 36 1 36 1 362 363 363 363 364 365 365 366 367 367 369 370 370 370

Contents

xiv 0-Donor ligands Group V Donors Rhodium(rI1) Group VII Donors Halogeno-complexes Halogeno-carbonyl and -phosphine complexes Group VI Donors 0-Donor ligands S-Donor ligands Group V Donors N-Donor ligands P- and As-donor ligands

370 371 371 372 372 372 372 372 373 374 374 378

4 Iridium Cluster Compounds Iridium( -I) Iridium(1) Group VII Donors Halogeno-carbonyl and -phosphine complexes Group VI Donors 0-Donor and S-donor ligands Group V Donors N-Donor ligands P-Donor ligands Iridium(II1) Group VII Donors Halogeno-complexes Halogeno-carbonyl and -phosphine complexes Group VI Donors 0-Donor ligands S-Donor ligands Group V Donors Group IV Donors C-Donor and Sn-donor ligands Iridium(1v)

379 379 379 380 380 380 38 1 38 1 382 382 383 384 384 384 384 386 386 386 387 390 390 39 1

5 Palladium Palladium(0) Palladium(I1) Group VII Donors Halide and hydride donor ligands Halogeno-phosphine and -phosphite complexes Group VI Donors 0-Donor ligands Mixed 0-donor and N-donor ligands

393 393 393 393 393 394 394 394 395

xv

Contents

S-Donor ligands Se-Donor ligands Group V Donors N-Donor ligands P-Donor and As-donor ligands Group IV Donors C-Donor ligands Sn-Donor and Pb-donor ligands Palladium(1v) 6 Platinum Cluster Compounds Platinum(0) Platinum(11) Group VII Donors Halogeno-complexes Halogenophosphinecomplexes Group VI Donors 0-Donor ligands Mixed 0-donor and N-donor ligands S-Donor ligands Se-Donor ligands Group V Donors N-Donor ligands P-Donor and As-donor ligands Group IV Donors C-Donor ligands Si-Donor, Sn-donor, and Pb-donor ligands Group I11 Donors B-Donor ligands Platinum(1v) Group VII Donors Group VI Donors Group V Donors Group IV Donors Platinum(v)

7 Silver Silver(1) Group VII Donors Group VI Donors 0-Donor ligands S-Donor ligands Group V Donors N-Donor lieands

396 400 400 400 402 403 403 404 404 406 406 406 409 409 409 409 41 1 41 1 412 413 417 417 417 420 42 1 421 421 422 422 422 422 423 423 423 424 426 426 426 430 430 43 1 432 432

Contents

xvi

P-Donor, As-donor, and Sb-donor ligands Group IV Donors Silver-Metal Bonded Compounds Silver@) Silver(n1)

433 434 434 434 435

8 Gold Cluster Compounds Gold(r) Group VII Donors Group VI Donors Group IV Donors Gold(r1r) Group VII Donors Group VI Donors Group V Donors Gold(v)

436 436 439 439 439

9 Reviews

443

440 440 440 440 44 1 442

Chapter 4 Scandium, Yttrium, the Lanthanides, and the Actinides By J. A. McCleverty 446 1 Scandium and Yttrium Structural Studies Chemical Studies

446 446 446

2 The Lanthanides Structural Studies Chemical Studies Lanthanide Shift Reagents

448 449 45 1 460

3 TheActinides Structural Studies Chemical Studies

463 463 466

4 Uranyl and Related Compounds Structural Studies General Chemistry

472 472 475

Author Index

48 1

1 The Early Transition Metals BY C. D. GARNER 1 Titanium Introduction.-A text describing the chemistry of titanium has been published' and the organometallic chemistry of titanium reported during 1971 has been reviewed.2 The compound C8H,TiC,Ph, has been prepared by treating TiCl, with Pr'MgBr in ether containing cyclo-octatetraene and diphenylacetylene. This green compound is diamagnetic and air-stable in the solid state and its i.r., mass, and 'H n.m.r. spectra are consistent with a structure involving .n-bonded cyclo-octatetraene and tetraphenylcyclobutadiene rings.3 A new type of fluxional process for an organometallic system has been described4 for bis(cyc1o-octatetraene)titanium(u) in which formal oxidation and reduction occur for the planar and bent C8H8 rings, (I), respectively, through reciprocal ring bending and flattening with an activation energy of 70 f 1 k.T mol-'.

Cyclopentadienyl(cycloheptatrieny1)titanium has been shown by an X-ray diffraction study to be a sandwich compound, the dihedral angles between the C,H5 and C7H7 rings being 2.2". Although the distance of the titanium atom from the carbon atoms of the former ring (232 pm) is normal, that from the carbon atoms of the latter (219 pm) is unusually short5 Tris(cyc1opentadieny1)titanium involves two h5- and one h2-C5H, groups (2); it is suggested that in the bonding of this latter group to the metal, the cyclopentadienyl radical acts as a three-electron ligand thus giving the titanium a 17-electron G . P. Luchinskii, 'The Chemistry of Titanium', Khimiya, Moscow, 1971 F. Calderazzo, J. Organometallic Chem., 1973,53, 179. H. 0.Van Oven, J . Organometallic Chem., 1973,55, 309. J. Schwartz and J. E. Sadler, J.C.S. Chem. Comm., 1973, 172. J. D. Zeinstra and J. L. de Boer, J . Organometallic Chem., 1973,54. 207.

1

Inorganic Chemistry of the Transition Elements

2

configuration. This three-electron h2-C,H, arrangement may serve as a model for the intermediate state in the 1,2-shift mechanism in fluxional 7t-C5H5 systems.6 The fixation of dinitrogen by organic compounds in the presence of titanocene derivatives has been accomplished, and amines can be obtained directly by treatment of the corresponding aldehyde, a-keto-ester, acid chloride, or anhydride with a mixture of [(n-Cp),TiCl,] and Mg-Mgl, (or EtMgBr) in a current of d i n i t r ~ g e nThe . ~ paramagnetic complex [{(7c-Cp),Ti),N2MgC1] has been isolated at - 60 "C in the system [(n-Cp),TiCl,]- Pr'MgC1-N, in ether. This complex affords hydrazine when decomposed by HC1.' A model olefin polymerization catalyst previously characterized as [(C,H,),TiA1Et,12 has been studied by X-ray diffraction, 'H n.m.r., and mass spectral techniques. The compound contains ( l-%-C5H5) andp(1-5q :o-C,H,) rings and is the first well-characterized dimeric titanium-aluminium hydride : structure (3) has been suggested.' Alkyl exchange between a polymeric alkyltitanium compound and alkylaluminium compound, present in excess, is

usually assumed to be the main transfer process in Ziegler-Natta olefin polymerization. Such an exchange process has been identified" between TiMe, and A1,Me6. M O calculations have been performed along the reaction coordinate for the insertion of ethylene into a titanium-carbon o-bond' and also for the titanium-aluminium-ethylene complex (4).' I b These latter results showed that the Ti-olefin bond involves no back-bonding and that the .n*-orbital of the olefin acquires little stability on co-ordination to titanium. The Ti-Me bond of (4)is localized almost completely in the highest bonding level of the complex, with the metal contribution being almost pure d in character. The results of these calculations suggest that the R,Al group in the

lo

C. R . Lucas, M. Green, R. A. Forder, and K. Prout, J.C.S. Chem. Comm., 1973.97. A. Dormond, J. C. Leblanc. F. Le Moigne, and J. Tirouflet, Compt. rend., 1972,274, C . 1707. Yu. G. Borodko, 1. N. Tvleva, L. M. Kachapina, E. F. Kvashina, A. K. Shilova, and A. E. Shilov, J.C.S. Chem. Comm., 1973, 169. F. N. Tebbe and L. J. Guggenberger, J.C.S. Chem. Comm., 1973,227. A. S. Khachaturov, L. S. Bresler, and 1. Ya. Poddubnyi, J . Organometallic Chem., 1972,42, C18. (a) P. Cossee, P. Ros, and J. H. Schachtschneider, Proceedings of the 4th International Congress on Catalysis, 1968, 1, 207 (Chem. A h . 1972, 77, 88946m); (6) D. R. Armstrong, P. G. Perkins, and J. J. P. Stewart, J.C.S. Dalton. 1972, 1972.

The Early Transition Metals

3

molecular catalyst functions merely as a substrate which maintains a high co-ordination number at the titanium site. Calculations along the reaction co-ordinate indicate that the negatively charged methyl group may readily migrate to the olefin, which carries a net positive charge, consistent with the phenomenon of catalysis. Binary Compounds and Related Systems.- -Halides and Oxyhalides. Thermal decomposition of NH,TiF, in a H, or Ar atmosphere at 6 0 0 4 5 0 ° C has been shown to afford a convenient route to high-purity TiF,.', The thermodynamic relationships between the chlorides of titanium have been investigated and standard heats and entropies of formation of TiC13(l), Ti2C16(l), and TiOCl(s) determined as - 525 kJ mol-' and 328 e.u., - 1180 kJ mol-' and 520 e.u., and - 760 kJ mol-' and 75 e.u., re~pectively.'~ The preparation of TiCl, or TiBr, by the reaction of titanium metal with molten metal halides such as PbX,, AgX (X = C1 or Br), or CuCl has been studied at 450-550 "C. The reaction of titanium with an excess of molten PbCl, at 530°C affords pure TiC1, in 9.8 % yield after 15 min.I4 The vacuum-u.v. electronic spectrum of TiCl,(g) has been recorded and discussed in comparison with available photoelectron data and theoretical results.' The energy required to reorganize TiC1, from tetrahedral to various other geometries has been evaluated by the self-consistent MO method. The results suggest that the tetrahedral geometry is a consequence of nuclear repulsions rather than bonding interactions.I6 An equilibrium diagram has been constructed for the TiC1,-TiBr, system and the crystallization temperatures of the mixed halides TiCl,Br, TiCl,Br,, and TiClBr, were shown to be - 19.4, -5.7, and 13.4 "C, respectively. These liquids have standard heats of formation of - 760, - 710, and - 660 kJ mol-', re~pective1y.l~ The chemical shift data for the 47Ti and ,'Ti n.m.r. of TiCl,, TiBr,, [TiF6]'-, and binary mixtures of TiCl, with both TiBr, and TiI, have been determined. The order of increasing shielding of the titanium nucleus by the halogens is 1,Br < C1. The resonance absorptions for TiCl, and TiBr, are unshifted on dilution in inert solvents, thus suggesting that the neat liquids of these halides involwe monomeric molecules. Mixtures of TiCl, and TiBr, exhibit one resonance signal, the chemical shift of which varies linearly with the mole fraction of the components, consistent with rapid halogen exchange between the TiCl,Br,_, (x = 0-4)molecules. A similar exchange process probably takes place between two or more species in TiC1,Til, mixtures since again only one signal is observed.lSa Raman spectra of TiCl, solutions in BrCH,OMe show lines typical of the TiCl,,Br,-,, (n = 1 - 4 ) molecules.' 8 b l2 l3

l4 l6 l7 l8

K. Koyama and Y. Hashimoto, Nippon Kagaku Kaishi, 1973,195 (Chem. A h . , 1973,78,91916~). L. D. Polyachenok, G. I. Novikov, and 0. G. Polpchenok, Obshchei priklad Khim., 1972, 34, 45. H. Elias and F. Al-Khafagi, 2. anorg. Chem., 1972,393,207. A. A. Iverson and B. A. Russell, Spectrochim. Actu, 1973,29A, 715. B. Hessett and P. G. Perkins, Rev. Roumaine Chim., 1972,17, 611. G. P. Luchinskii, Zhur.fiz. Khim., 1972,46,2959. (a) R. G. Kidd, R.W. Matthews, and H. G. Spinney, J . Amer. Chem. SOC., 1972 94,6686; (b) V. P. Makridin and S. 1. Chistyakov, Z h u r ohslichei Khim.. 1972.42, 1871.

Inorganic Chemistry of the Transition E Eements

4

Oxides. The structures and properties of titanium dioxide have been reviewed1' and the bonding in anatase has been suggested to be more ionic than that in rutile from a study of their K X-ray emission spectra.20 The structure of the Tin02n-1oxides has been classified as an infinitely adaptive one in crystallographic shear phases (4 < n < 9 and 16 < n < 3 9 . 2 1 The linewidths of the e.s.r. spectra of these oxides has been shown22to be a sensitive indicator of their stoicheiometry, for 2 d n d 10, The structural aspects of the metal-insulator transition in Ti407 have been investigated by X-ray crystallography. The triclinic structure of this oxide consists of rutile-like layers of TiO, octahedra extended in the ab-plane and four octahedra thick along the c-axis. At 120 K there is a clear separation into strings of TiIn or Ti" ions running parallel to the c-axis; the Ti'' centres are paired to form Ti-Ti bonds, whereas the Ti" atoms are strongly bonded to one oxygen, T i 4 = 178-179 Chalcogenides. The composition of TiS, has been shown to be 1 :3.00 by X-ray diffraction and density measurement~,~ and its vibrational spectra have been rep~rted.~' The mixed cation disulphides Ti0.05V1.00S2, Tio.84Vo.16S2, Tio~70Cro~ogS2, and Ti0.92Cro,09S2 have been prepared by grinding a mixture of TiS, with the appropriate metal and sulphur, followed by prolonged heating at 950 OC.,, Ti,.,,,NbS, has been shown to have a structure in which the titanium atoms occupy octahedral sites between the NbS, prisms, the site symmetries of the re~pectively.~~ The compounds Ni,TiS, metal atoms being C,, and (x = 0.25, 0.33, 0.40, or 0.75) have been characterized in the Ni-TiS, system by X-ray diffraction studies. These compounds probably involve nickel atoms inserted into octahedral sites of the host lattice.28 TiS, reacts with solutions of K'(naphtha1ene)- to give a metal intercalation derivative KnTiS2.29Layer intercalation compounds of TiS, with NH,, N,H4, NH,NHMe, MeNHNHMe, and py, other nitrogen heterocyclics, and their N-oxides have been prepared, and the layer expansions determined.30 The phase diagrams of the Ti-Hg-Se and TiSe-HgSe systems have been constructed using X-ray and thermal analyses and a compound of composition Ti,Hg7Selo was identified in the latter.31

2o 21

22

23

24 25 26

27 28 29

30 31

B. G. Hyde and B. N. Figgis, Gout. Report Announce. (U.S.A.),1972,72, 177. M . Pessa and E. Suoninen, Phys. Letters (A), 1972,40,407. J. S. Anderson, J.C.S. Dalton, 1973, 1107. J. F. Houlihan and L. N. Mulay, Materials Res. Bull., 1971. 6, 737. M. Marezio, P. D. Dernier, D . B. McWhan, and J. P. Remeika, Materials Res. Bull., 1970, 5, 1015; J . Solid State Chem., 1973, 6, 213. L. Brattas and A. Kjekshus, Acta Chem. Scand., 1972,26, 3441. C. Perrin, A. Perrin, and J. Prigent, Efrll. SOC.chim. France, 1972, 3086. L. E. Conroy and K. R. Pisharody, Nat. Efrr. Stand (U.S.A.)Spec. Publ. N o . 364,1972,663. A. Royer, A. Le Blanc-Soreau, and J. Rouxel, Compt. rend., 1973,276, C , 1021. M. Danot, J. Bichon, and J. Rouxel, Efill. SOC. Chim. France, 1972,3063. E. Bayer and W. Riidorff, Z . Naturforsch, 1972,27b, 1336. R. Schollhorn and A. Weiss, Z . Naturforsch., 1972, 274 1273, 1275, 1277; 1972. 27% 1428. A. A. Kuliev, Z. G. Kagramanyan, and D. M. Suleimanov, Ref Zhur. met.. 1972, Abs. 6138 (Chem. Abs.. 1973,78. 1026075).

The Early Transition Metals

5

Carbides, Silicides, and Germanides. The standard heat of formation and the dissociation energy of TiC,(g) have been determined as - 730 k 9 and 160 f 8 kJ mol-l, respectively, using the mass spectrometric Knudsen effusion technique.32 The standard heat and entropy of formation of Ti,Si,(s) have been reported as - 580 kJ mol-' and 272 e.u., re~pective1y.l~ A thermodynamic analysis of the co-reduction of TiO, with SiO, by carbon at elevated temperatures has shown that the formation of TiSi is more probable than TiSi2.33Phase equilibria in the Ti-Nb-Ge ternary system have been investigated.34 Titanium@).-Pulse radiolysis of aqueous solutions of titanium(rI1) containing formic acid affords Ti" ziia reduction of Ti"' by -C02H.35Density determinations of molten NaCl solutions (800-950 "C) of TiCl, suggest that substantial amounts of [TiCl,]- are formed in such media.36 The d-d spectrum of Ti" ions isolated in NaCl crystals have been obtained, and absorption maxima identified at ca. 8000 and 15000 cm-' and assigned to ,Tlg -,3T2gand Tlg -+ Tlgtransitions, respectively. The samples were prepared from CdC1, and titanium metal in NaCl at 950 0C.37 Titanium@) complexes, ArTiC1,,A1,C16 (Ar = tetra-, penta-, or hexa-methylbenzene), may be prepared by the reduction of TiCl, with metallic A1 in the presence of AlC1, in benzene containing the polymethylbenzene. These compounds, together with the analogous pentamethylbenzene derivative, may also be prepared by ligand exchange reactions from C6H6TiC1,,A12C16.This study3* has provided further support for the n-interaction between titanium and the aromatic molecules suggested earlier. New evidence has been presented indicating the participation of Ti" in various dinitrogen-fixing systems, although other studies of these systems (p. 10) indicate that Ti"' is also involved. An investigation of the systems [(7c-Cp),TiC12]-Li(NaFHg, [(n-Cp),TiC1,-J-[(7cc-Cp)Fe(CO),],, and [(n-C&TiCl,]-Na[(n-Cp)Fe(CO),] has led to the conclusion that the active species for dinitrogen absorption is probably titanocene, with perhaps more than one molecule of dinitrogen bonded to each titanocene dimer.39 The kinetics and stoicheiometry of dinitrogen fixation by TiC1,-Mg mixtures in T H F solution have been reported. These systems react with N, at 25 "C (1 atm) to form a species believed to be TiNMg,Cl,(THF),, and it is proposed that the mechanism involves the complexing of N, with a dimeric Tin species, followed by a ratedetermining reaction with metallic Mg.40 The reactions of transition-metal 32 33

34

35 36

37 38 39 40

D. L. Cocke and K. A. Gingerich, J. Chem. Phys., 1972,57, 3654. G. G. Papin, 1. V. Ryabchikov, N. M. Dekhanov, V. G. Mizin, and G. V. Serov, 2hur.jiz. Khim., 1972,46, 1558. W. Heller, 2. Mettalk., 1973,64, 124. J. D. Ellis, M. Green, A. G. Sykes, G. V. Buxton, and R. M. Sellers, J.C.S. Dalton, 1973, 1724. D. J. MacDonald, P. R. Bremner, and A. E. Raddatz, J . Chem. Eng. Data, 1973,18, 187. W. E. Smith, J.C.S. Chem. Comm., 1972, 1121. S. Pasynkiewicz,R. Giezynski, and S. Dzierzgowski,J . Organometallic Chem., 1973,54, 203. C. Ungurenasu and E. Streba, J . Inorg. Nuclear Chem., 1972,34, 3753. A. Yamamoto, S. Go, M. Ookawa, M. Takahishi, S. Ikeda, and T. Keii, Bill. Chem. SOC.Japan, 1972,45,3110.

Inorganic Chemistry of the Transition Elements

6

complexes with azo-compounds are also of interest in connection with dinitrogen fixation. [(n-Cp),Ti(CO),] reacts during two days at 25 "C with azobenzene to form black-maroon crystals of [(n-Cp),Ti(Ph-N=N-Ph)] which are thermally stable, soluble in aromatic hydrocarbons but readily hydrolysed : structure (5)has been suggested.,'

(5)

Oxidative additions of alkyl and acyl halides to [(n-Cp),Ti(CO),] affording Ti" derivatives have been reported42 (p. 25). Titanocene has been shown to reduce a variety of organic molecules including alcohols, aldehydes, ketones, and organic halides.43 Titanium(Irr).-HaZides and Oxyhalides. Semi-empirical MO calculations on [TiF6I3- using a new parameter-free method have been published, and the calculated and experimental values of the ligand-field splitting, super-hyperfine coupling constants, and spin densities were in excellent agreement.44 Density determinations of NaCl solutions (800-950°C) containing TiC1, have led to the suggestion that substantial quantities of [TiCl,]- are formed under these condition^.,^ The phase diagram for the TiC1,-NaC1-AlCl, system has been presented; Na,TiCl6 is the only compound formed.45 A thermal analysis of the TiCl,-VCl,-KCl system has been performed and the only compounds identified were K,MC16 (M = Ti or V).46 Treatment of TiBr, with B,(NMe,), produces TiBr,,B,Br,(NMe,),, which has been characterized by i.r. and electronic spectral and magnetic studies as a dinuclear species: structure (9 has been suggested. The compound reacts or TiBr3,2NMe,, reswith HBr or NMe, to form TiBr,,B,Br,(NMe,H), pectively ; pyrolysis affords B,Br,(NMe,),.47 Br Me,NBHBr

/

I

Br

Br

\Ti'

I

\Br/ Br

'Ti

I /Br\BNMe, / I \Br- BNMe,

Br

(6 1 G. Fachinetti, G. Fochi, and C. Floriani, J . Organometakc Chem., 1973, 57, C51. C. Floriani and G. Fachinetti, J.C.S. Ckern. Comm., 1972, 790. 43 A. Merijanian, T. Mayer, J. F. Helling, and F. Klemick, J . Org. Chem., 1972. 37.3945; A. Merijanian, T. Maver. and J. F. Helling, Reu. Latinoamer. Quim.. 1972.3.62(Chem. Abs. 1973,78,4324s). 44 A. Dutta-Ahmed and E. A. Boudreaux, Znorg. Chem., 1973, 12, 1597. 4 5 E. N. Ryabov, I. V. Vasil'kova, L. P. Starikova, R. A. Sandler, and I. V. Godun, Zhur. neorg. Khim., 1927, 17, 1759. 46 R. A. Sandler, E. N. Ryabov, I. V. Vasil'kova, and E. A. Cherepanova, Zhur. neorg. Khim., 1972, 17, 3111. 47 (a) M. R. Suliman and E. P. Schram Inorg. Chem., 1973, 12, 923. (b) M. R. Suliman, Diss. Abs. (B), 1972.33. 621. 41

42

The Early 'TLansitionMetals

7

0-Donor Ligands. YTiO, has been prepared from Ti,O, and Y,O, and its X-ray diffraction characteristics have been reported.48 TiTaO, has been obtained from the corresponding oxides by ceramic techniques under an inert atmosphere ; X-ray and neutron diffraction and magnetic measurements indicate that the metal atoms are distributed statistically over the metal sites of the rutile structure.49 Treatment of an aqueous HCl solution of titanium(@ chloride with alkali affords a dark-brown precipitate of Ti,O,,nH,O, which is rapidly oxidized to TiO,,nH,O via a blue-black intermediate. The reflectance spectrum of the latter is very similar to that of the corresponding iron system and therefore the intermediate probably involves oxygen bridging between Ti"' and Ti" centres." The electrochemical behaviour of the Ti"-Ti'" couple has been investigated in methanol solutions containing H,O (0.02-7.00 moll- ') and C1- (0.020.22 moll- '), and the presence of two electrochemically distinct titanium (111) complexes was observed. Polarographic and e.s.r. data were interpreted in terms of the species [TiCl,(MeOH),] +,[TiCl(MeOH)5]Z+,and [TiCl(MeOH),. H,O]' +,the former two complexes equilibrating rapidly on an electrochemical t i m e - s ~ a l e . Analogous ~~" results were obtained for TiCl, in MeOD containing D,O ( 0 4 . 1 moll- ').'Ib However, conductance and electronic spectral data indicate that TiC1, in ROH (R = Me or Et) also produces [Ti(ROH),I3+, and crystalline [Tj(MeOH),]Cl, has been prepared by refluxing a 5 % solution of TiC1, in MeOH under Ar, concentrating, and cooling to -80°C. Solutions of TiCl, in Me,CHOH appear to contain [Ti(Me2CHOH)4C12]+ ions." Photoreduction of a titanium(1v)alkoxide in aqueous solution containing an alcohol or a glycol has been shown to generate Ti'= species and alkoxyl radicals ria homolytic cleavage of a Ti"-OR bond.53The polymeric alkoxides (RO)TiCl,,2ROH (R = Me or Et), (MeO)TiBrZ,2.7MeOH,and (EtO)TiBr,,2EtOH have been prepared by the reaction of the appropriate alcohol with [(1t-Cp)TiX,1 (X = C1 or Br). These alkoxides are diamagnetic; their electronic spectra are consistent with octahedral co-ordination about the metal, and their i.r. spectra with bridging a l k o x y - g r ~ u p s . ~ ~ E ~ , N [ T ~ C ~ , ( A C O Hhas ) ~ ~been prepared by refluxing TiC1,,6H,O in AcCl until all the solid was dissolved, followed by addition of Et,NCl. Coordination of neutral acetic acid molecules is consistent with analytical and spectroscopic data.55 Refluxing titanium(1v) salts with Na-Hg in 1 : 1 glacial acetic acid-acetic anhydride for 1-2 h affords an easy route to titanium(Ir1) 48

49

51

52

53 54 55

G. P. Shveikin and G. V. Bazuev, Zhur. nrorg. Khirn., 1973, 18, 291. D. N. Astrov, N. A. Kryukova, R. B. Zorin, V. A. Makarov, R. P. Ozerov, F. A. Rozhdestvenskii, V. P. Smironov, A. M. Turchaninov, and N. V. Fadeeva, KristallograJiya, 1972, 17, 1152. G. C. Allen, M. B. Wood, and J. M. Dyke, J . Inorg. Nuclear Chem., 1973,35,2311. (a) E. P. Parry, 1. B. Goldberg, D. H. Hern, and W. F. Goepplinger, J . Phys. Chem., 1973, 77, 678; (b) I. B. Goldberg and W. F. Goepplinger, Inorg. Chem., 1972. 1 1 . 3129. B. Pittel and W. H. E. Schwars 2.anorg. Chem., 1973, 3%, 152; Ber. BunsengeseZlschajt Phys. chem., 1972,76,1025, (Chem. Abs. 1972,37,158285~). F. E. McFarlane and G. W. Tindall, Inorg. Nuclear Chem. Letters, 1973,9, 907. R.S. P. Coutts, R. L. Martin, and P. C. Wailes, Inorg. Nuclear Chem. Letters, 1973,9, 981. L. P. Podmore, P. W. Smith, and R. Stoessiger, J.C.S. Dalton, 1973, 209.

8

Inorganic Chemistry of the nansition Elements

acetate. 5 6 The reduction of titanium(1v) carboxylates and their DMF adducts by hydrogen has been shown to afford Ti" species which act as catalysts for the hydrogenation of unsaturated organic molecules. In aqueous solution at 25"C, the heat of the reaction

Ti"'

+ 2H,C204 + Ti(C,04), + 4H'

at infinite dilution of Ti"', has been estimated5*as -6 kJ rnol-'. TiC1, reacts with OP(OBu'), at elevated temperatures to afford" [TiC12(OP(OBui),)], the electronic spectrum of which is consistent with hexaco-ordinated Ti"'. The crystal structure of [Ti(urea),](C10,), at 90 K is almost identical with that at room temperature with T i 4 bonds of length 200(2) rather than 204(1) pm.60 The magnetic anisotropy of [Ti(urea),]X, (X = I or ClO,) has been measured between 80 and 300K and interpreted with the aid of a trigonally distorted = octahedral ligand-field model.61 TiIn and alizarin form a 1: 1 complex (A, 430nm) in aqueous solution.62 The sulphoxides R,SO (R = Bu, Ph, Bz, or p-C1C,H4) and Me(Ph)SO are reduced to the corresponding sulphides in 68-91 % yield by refluxing with TiC1, in MeOH-CHCl, under nitrogen.63 S-Donor Ligands. The X-ray diffraction characteristics of La,TiBe2S14 have been reported.64 N-Donor Ligands. The electronic spectra, magnetic susceptibility, and e.s.r. spectra of [Ti(N(SiMe,),} 3] have been determined and interpteted using a crystal-field model for D,, symmetry.65 The crystal structure of trichlorotris(pyridine)titanium(m)-1-pyridine has been shown to involve irregular coordination about the metal (7,the bond length variations appear to be a

c1\

I.. / p y T1 h

PY?

56

57

58

59

60 61

62 63 64 65

(d'cl

n = 239.9 pin b = 235.1 pm c = 221.4 pm d = 231.8 pm

R. C. Paul, T. Raj, and R. Parkash, Zndian J . Chem., 1972,10,939. V. V. Abalyaeva, 0. N. Efimov, and M. L. Khidekel, Zzvest. Akad. Nauk S.S.S.R., Ser. khim., 1972, 1490, 1496. K. Pan, S. Hsin, and T. Huang, J . Chinese Chem. SOC. (Formosa), 1972, 19, 1, (Chem. Abs., 1972, 77, 66924a). C. M. Mikulski, L. L.Pytlewski, and N. M. Karayannis, J fnorg. Nuclear Chern., 1973,352102. B. N. Figgis and L. G . B. Wadley, Austral. J . Chem., 1972,25, 2233. B. N. Figgis, L. G. B. Wadley, and M. Gerloch, J.C.S. Dalton, 1973, 238. S. S. A. Rizvi and N. Ahmad. J . lndian Chem. SOC., 1972,49, 909. T.-L. Ho and C. M. Wong. Synthesis Comm., 1973,3, 37 (Chem. Abs. 1973,78, 124 1972). G . Colin and J. Flahaut. Bull. Soc. chim. France, 1972,2207. E. C. Alyea, D. C. Bradley, R. G. Copperthwaite, and K. D. Sales, J.C.S. Dalton, 1973, 185; D. C. Bradley, R. G. Copperthwaite, S. A. Cotton, K. D. Sales, and J. F. Gibson, J.C.S. Dalton, 1973, 191

The Early nunsition Metals

9

consequence of steric rather than electronic effects.66 E.s.r. and electronic spectra of [TiCl,(MeCN),] have been shown to be more consistent with a mer- than fac-octahedral arrangement of the ligands. [TiCl,(MeCN),] -t has been prepared by the addition of a chloride acceptor (e.g.AlCl, or TiCI,) to a solution of anhydrous TiC1, in MeCN and the e.s.r. and electronic spectra of this ion have been reported.67 14N-contact shifts have been measured for the complexes formed in MeCN solutions of TiCl,, and the observed negative coupling constants taken as evidence that spin-density is transferred from the metal to the ligands via n-orbital overlap.68 The triplet-state X-band e.s.r. spectrum of dinuclear Ti"'-chelates of tetrakis(srminomethy1)methane has been recorded for frozen aqueous-glycol solutions (77 K). The spiro-conformation of the methylene groups of this ligand ensures that the two metal centres in each dinuclear unit will have a non-parallel alignment of their g-tensor axes. Interpretation of the spectrum has afforded a value of 560(30)pm for the Ti"'Ti" separation in these d i m e r ~ E.s.r. . ~ ~ spectra have also been recorded for solutions of TiCl, in a wide range of organic bases (e.g. MeCN, Et,N, py, or DMSO) and the data discussed in terms of monomer-dimer complex equilibria.7 The i.r. spectra of [Ti(bipy),]"+ complexes, in which the formal oxidation state of the metal ranges from 111 to -I, have been described in some detail11 Since the Ti-N stretching frequencies remain fairly constant over this range of oxidation states, it is suggested that on reduction an increasing fraction of the electron population resides on the ligands, with the electron density at the metal remaining approximately constant. This view is supported by the fact that the ligand spectra (1625-1475 and 1000-900 cm-') of the lower oxidation state complexes are similar to that of Li+(bipy)-. Mixed N-donor and 0-Donor Ligands. Tris(quinolin-8-olato)titanium(111)has been prepared7, by the reaction of a-TiC1, and quinolin-8-01 in MeCN and characterized by magnetic susceptibility and e.s.r., electronic, and X-ray diffraction spectral studies. Since the compound is isomorphous with the corresponding Al"' and Cr" derivatives it would appear to consist of mer-octahedral monomeric units, rather than dimeric units as previously suggested. TiC1, reacts with diethyl 6-methylpyridine-2-phosphonate at elevated temperatures (111). Spectral to form tris(ethoxy-6-methylpyridine-2-phosphonato)titanium data suggest that the ligand acts as a bidentate NO-chelate to give monomeric complexes which have a distorted octahedral geometry.73 6h

67

6a

69 'O

'' 73

R. K. Collins and M. G B Drew, Inorg. Nuclear Chem. Letters, 1972,8,975. H. K. Ostendorf, Rec Trau. chim., 1972,91,809 (Chem. Abs., 1972,77, 54457n). V. K. Kapur and B. B. Wayland, J . Phys. C h e m , 1973,77,634. S. G. Carr, P. D . W. Boyd, and T. D. Smith, J.C.S. Dalton, 1972, 1491. J. B. Raynor and A. W. L. Ball, Inorg. Chim. Acta, 1973,7,315. (a) Y . Saito, J. Takemoto, B. Hutchinson, and K. Nakamoto, Inorg. Chem., 1972, 11, 2003; (6) E. Koenig and E. Lindner, Spectrochim. Acta, 1972,28A, 1393. F. B. Taylor and T. A. Wilkins, J.C.S. Dalton, 1973, 87. A. N . Speca, R. Mink, N. M. Karayannis, L. L. Pytlewski, and C. Owens, J . Inorg. Nuclear Chem., 1973,35, 1833.

10

Inorganic Chemistry of the lhmsition Elements

P-Donor Ligands. TiC1,,2PEt3 and TiC1,,2PHflMe,-,, (n = 0-2) have been prepared by the direct combination of the components in toluene at elevated temperatures ; however, attempts to prepare complexes of the weaker Lewis bases PX, (X = F, C1, or Ph) failed. The bis(alky1phosphine) derivatives are air-sensitive and soluble in benzene, and TiC1,,2PEt3 has been shown to be monomeric in this medium. E m . and electronic spectral studies have shown that a 1:3 mixture of TiCl, and the PR, molecules form TiC1,,3PR3 at ca. - 20 "C, but on warming one phosphine becomes detached.74 [TiCl,,PMe,PMe,,TiCl,] has been isolated and extensively characterized following the reaction between TiCl, and Me,PPMe, in MeCN, THF, or benzene.75 Cyclopentadienyl Complexes. The range of monocyclopentadienyltitanium(I1I) complexes has been extended.76 [(n-Cp)Ti(O,CR),] (R = Me, Et, Pr, Ph, or CF,) have been prepared by two methods. The reaction of [(~-cp)TiCl,J and Na0,CR under anaerobic conditions in THF followed by evaporation to dryness and sublimation of the residue at 180 "C affords these compounds as a green sublimate only when R = Me, Et, or CF,. However, the alternative route from [(n-Cp)TiCl,] and RCO,H, in the presence of two moles of amine, gives all five derivatives. Molecular weight studies in benzene for the R = Me and Bu derivatives have shown that the compounds are dimeric. The diamagnetic nature of all of the compounds is considered to arise from a superexchange interaction between the two Ti"' centres in such dimers via the n-systems of bridging carboxylato-groups. [(n-Cp)TiX,],nL (X = C1 or Br; n = 1 when L = 1,2-dimethoxyethane, or n = 2 when L = MeOH or EtOH) have been prepared by dissolving [(n-Cp)TiX,],nTHF (n = 0 or 1) in the appropriate, dry, oxygen-free solvent. Magnetic (p = 1.7-1.9 BM) and electronic spectral properties have been recorded and interpreted on the basis of discrete, hexaco-ordinate titanium(Ir1) centres. Attempts to prepare the analogous dioxan adduct yielded non-stoicheiometric complexes. and pdiketones afforded the corresponding tris(P-diketonat0)titanium (111)complex. [(n-Cp),TiF] has been prepared by reduction of [(n-Cp),TiF,] in THF with activated A1 foil, and thus the complete series of [(n-Cp),TiX] (X = F, C1, Br, or I) molecules is now known. These complexes, which may also be prepared by ligand exchange reactions with boron halides in the presence of A1 foil, appear to exist as diamagnetic, halogeno-bridged d i m e r ~The . ~ ~analogous aryl derivatives [(x-Cp),TiR] (R = Ph, Bz, C6F,, 0-, m-, or p-MeC6H4, 2,6Me,C6H,, or 2,4,6-Me,C,H2) are monomeric with one unpaired electron per Ti"'. These very air-sensitive complexes, prepared from [(n-Cp),TiCl] and RMgX under argon, react with dinitrogen to afford the deep-blue diamagnetic complexes [((n-Cp),TiR),N,] (R = Ph, Bz, C,H,, o-, m-, or p-MeC6H& which have heats of formation of - 38 to - 84 kJ mol- 1.78 Since the i.r. spectra 74

75 77

78

C. D. Schmulback, C. H. Kolich, and C. C. Hinckley, lnorg. Chem., 1972,11,2841. K. Issleib, U. Giesder, and H. Hartung, 2. anorg. Chem., 1972,390, 239. R.S. P. Coutts, R . L. Martin, and P. C. Wailes. Austral. J . Chem., 1973,26, 47; 941. R. S. P. Coutts, P. C. Wailes, and R L. Martin, J . Organometallic Chem., 1973,47, 375. J. H. Teuben and H. J. de Liefde Meijer, J . Organometallic Chem., 1972, 46, 313; J. H. Teuben, J Organornetallic Chem.. 1973, 57. 159.

The Early Transition Metals

11

of these complexes contain no absorption characteristic of v(N-N) stretching it is concluded that they have a centrosymmetric structure. The complexed dinitrogen can be completely reduced with Na+(naphthalene) -, and subsequent hydrolysis affords NH, and N2H4. The blue colour of these complexes is not a function of their dinitrogen content since [(n-Cp),TiR] (R = Me or Ph), which are initially green in THF, afford such blue solutions under N, or Ar atmospheres, or in O U C U O . ~ ~ The direct fixation of dinitrogen by organic compounds in the presence of titanocene derivatives has been reported. Thus, PhNH,, BzNH,, and other amines have been obtained by treatment of the corresponding aldehydes, a-keto-esters, acid chlorides and anhydrides, or organolithium compounds with a mixture of [(n-Cp),TiCl,] and Mg-Mgl, (or EtMgBr) and a current of d i n i t r ~ g e n .An ~ intermediate paramagnetic complex [((n-Cp),Ti),N,MgCl] has been isolated at - 60 "C in the system [(n-Cp),TiCl,]-PriMgCl-N, in ether. This dark complex is stable in U ~ C U Oat room temperature, but is rapidly oxidized by air and affords N2H4 on addition of HCl. [{(n-Cp),Ti),N,MgCl] is paramagnetic ( p = 2.2 BM, g = 1.975)and has an i.r. absorption at 1255 cmwhich has been attributed to v(N=N) stretching: structure (8), involving (n-Cp),Ti-N-N=Ti(x-Cp),

I

MgCl

c*

(n-Cp),Ti+-N=N -Ti(n-Cp),

I

MgCl

(8)

resonance hybrids, has been suggested.8 A new intermediate complex, [(nCp),TiN;Ti(n-Cp),], has been isolated at low temperatures from the system [(n-Cp),TiCl,]-MeMgI-N,. The complex is stable at room temperature but loses N, above 40"C, it is apparently a di-imide derivative and initially affords N,H, when decomposed with HCl. [(n-Cp),TiN,Ti(.n-Cp),] is paramagnetic ( p = 1.45 BM) and exhibits a v(N=N) stretching absorption at 1280 cm-I ; the non-centrosymmetric structure (9) has been proposed,80 and this is clearly different from the isomeric species described last year (Vol. 2, p. 2). The reactivity of titanocene derivatives towards N, and H, has been investigated, and several highly reactive titanocene complexes have been isolated. A yellow intermediate which forms in the Volpin-Shur system has been characterized as [((x-Cp)TiC,H,] ,,6MgC1,,2Et20]. This intermediate appears to be the reactive com79

T. Chivers and E. D. Ibrahim, Canad. J . Chern., 1973,51, 815. Yu. G. Borodko, 1. N. lvleva, L. M. Kachapina, S. I. Salienko, A. K. Shilova, and A. E. Shilov, J.C.S. Cheni. Cornm.. 1972, 11 78.

12

Inorganic Chemistry of the Transition Elements

ponent of the mixture and reacts with N, in ethereal media to give a titanocene nitride derivative which affords NH, on hydrolysis.8 The crystal structure of [(n-Cp),Ti(BH,)] has been determined by X-ray diffraction studies and shown to involve molecular units in which the BH, group is co-ordinated through two bridging hydrogen atoms [Ti-H = 175(8) pm], thus producing quasi-tetrahedral co-ordination of the The vibrational spectrum of [(n-Cp),Ti(BH,)] is consistent with the bidentate co-ordination of this tetrahydroborato-group.83A model olefin polymerization catalyst, previously characterized as [(C,H,),TiHAlEt,] , has been shown by 'H n.m.r. studies to be [(C,H,)(C,H,)TiHAlEt,12. This is the first wellcharacterized dimeric titanium-aluminiumalkyl hydride and structure (3) has been suggested.' Titanium(Iv).-The role of non-bonded intramolecular donor-atom interactions in octahedral titanium@) complexes has been discussed, and such interactions were shown to be important in determining the detailed structure of such complexes and the preferential formation of certain isomers.84 Halides and Oxyhalides. The 47Ti, 49Ti, and ''F n.m.r. signals observed for TiF, dissolved in 48% aqueous H F solutions have been shown'*" to be due to [TiF,I2- ; no evidence was found for the previously noted instability of this ion in such media The crystal structure of Li2TiF,,2H,O has been shown by X-ray diffraction methods to consist of a hexagonal close-packed array of fluoride ions and water molecules containing the metal ions in distorted ~ formation constants of a series of octahedral sites, Ti-F = 1 9 4 ~ m . 8The (HA),[TiF,] (A = py, PhNH,, or piperidine) salts have been determined by an ion-exchange method.86 AgTiF, has been prepared by the fluorination of a mixture of TiO, and Ag,O (or Ag2S0,)87 and (HgI),[TiF,] by the addition of iodide to a solution of HgO and [TiF6I2- in 40% aqueous HF.88 The reaction of XeF, with TiC1, has been shown to afford TiF,,2XeF,.89 A new oxyfluoride perovskite KTi0,F has been prepared by the direct reaction of K F with TiO, under high pressure and its chemical and physical properties have been investigated." Mixtures of Na,TiF, and SiO, afford either Na,TiOF, or Na6Ti,0,F,, on heating, depending on the proportion of the reactants, and X-ray diffraction studies have indicated that these products are specific

substance^.'^

81

82 83 84 85 86

87

89 90 91

R. H. Marvich, Diss. Abs. (9,1972,32, 6280. K. M. Melmed, D. Coucouvanis, and S. J . Lippard, Inorg. Chem.. 1973,12, 232. T. J. Marks, W. J. Kennelly, J. R. Kobb, and L. A. Shimp, Inorg. Chem., 1972,l , 2540. R. F. Zahrobsky, J . Coord. Chem., 1972,1, 301. E. A. Marseglia and I . D. Brown, Acta Cryst., 1973, B29, 1352. N. A. Parpiev, Uzbek. khim. Zhur., 1972, 16, 17(Chem. Abs., 1973.78, 102621fl. B. Miiller and R. Hoppe, 2. anorg. Chem., 1972,392, 37. D. Breitinger and K. Kohler, Inorg. Nuclear Chem. Letters, 1972,8. 957. V. A. Legasov and A. S. Marinin, Zhur. neorg. Khim., 1972, 17, 2408. B. L. Chamberland, Materials Res. Bull., 1971,6, 31 1. R. V. Chernovand 1. G. Kovzun, Ukrain. khim. Zhur., 1972,38,421 (Chem. Abs., 1972,77.157065n).

The Early I).ansition Metals

13

D.t.a. studies have shown9,= that, in the TiCl,-PCl, system, a 1 : 1 complex is formed whose heat of fusion is 16 kJ mold' ; the i.r. and Raman spectra of (PCl,),[Ti,Cl, have been reported and partially assigned assuming D,, symmetry for the anion.92b The standard enthalpy of formation of TiCl, solutions in HCl (2-5mol1-l) has been shown calorimetrically to be -690 kJ mo1-l at 25°C;93a when TiO, is dissolved in a NaCl-KCl melt [TiOC1,I2- is formedg3' with a T i 4 stretching frequency of 950 cm- '. The vapour pressure curve for the TiOC1,-NOCl system has indicated the formation of NO[TiOCl,] which has been isolated as a golden yellow, hygroscopic, crystalline solid. This dissociates into its components at temperatures above 50°C, and the heat of dissociation below 40°C has been estimatedg4 as 26 kJ mol-'. The addition compounds NO[TiCl,(RCO,)] (R = Me, Et, Pr, Pr', or Bu') have also been reported in the TiCl,(RCO,)-NOCl systems but no evidence of NOCl addition to the corresponding TiCl,(RCO,), complexes could be obtained.95 Reduction of methanolic or ethanolic solutions of TiCl, in the presence of hydrogenation catalysts such as PtO, or (Ph,P),RhCl at atmospheric pressure, followed by application of dinitrogen at > 100 atm and MgCl, in alkali leads to the formation of detectable amounts of N2H4. This process can be made cyclic by subsequent acidification, and re-reduction of the TiIVby hydrogen.96 TiBr, reacts47b with (Me,N),BBr to produce [{TiBr,},{(Me,Nj,BBr}2], for which the structure (10) has been proposed on the basis of its i.r. spectrum and unusual s t ~ i c h e i o m e t r y The . ~ ~ new complex (Et,N)[Ti,Br9] may be precipitated following the slow addition of a CH,Cl, solution of Et,NBr to a well-stirred solution of TiBr, in CH,Cl, (Et,N+ :Ti 6 1 :4).98

0-Donor Ligands. Table 1 summarizes the results of some studies concerning titanates and TiIV mixed oxide compounds. The corrosion of titanium metal by liquid sodium containing dissolved oxygen has been shown to take place Q2

y3

y4 y5

9h

97

'*

(a) M. K. Chikanova and E. S. Vorontsov, Zhur. obshchei. Khim., 1972, 42, 721; (b) D. Nicholls and K. R. Seddon, Spectrochim. Acta, 1972,28A, 2399. (a) V. P. Vasil'ev, P. N. Vorob'ev, and 1. B. Khvostova, lzvest. V . U . Z . Khim. i khim. Tekhnol., 1972, 15, 855 (Chem. Abs., 1972,77, 80271s); (b) L. M. Gurevich and A. B. Bezukladnikov, Zhur. neorg. Khim., 1973, 18, 116. B. Viard, J. Amaudrut, and C. Devin, Compt. rend., 1973,276, C, 1279. J. Amaudrut, Bull. SOC. chim. France, 1972,2228. V. V. Abalyaeva, N. T. Denisov, M. L. Khidekel, and A. E. Shilov, lzoest. Akad. Nauk S.S.S.R., Ser. khim., 1973, 196. M R Suliman and E. P. Schram, lnorg. Chem., 1973,12,920. R . J. H. Clark and M. A. Coles. J.C.S. Dalton, 1972,2454.

Inorganic Chemistry of the Transition Elements

14

Table 1 Some studies on titnnates and Ti" mixed oxides Compound

Source

P-Li,TiO, y-Li,TiO, a- and P-Li,TiO,

Li,O-Ti0

Na,TiO, Na,TiO, Na6Ti,07 Na,Ti, 0,

,

M2Ti601

3

I

(M = Na or K) M6Ti,07 (M = K, Rb, or Cs) CaTi,O, CaTiO, Ca,Ti,O, Ca,Ti,O P-Ba,TiO,

,,

BaTi,O,, 7H,O BaTi,O, K,TiSi, 0,

,

Na,TiSi,O, (narsarsukite)

,

Na, 0-Ti0

,

Re$

map.1535 "C

a

a

X X, m.p. 1030 "C

M,O-TiO, B,O, melt

-

b

M,O + TiO, (8-4:1) at 45&650°C CaO-TiO,

I

Properties reported

X, isotypic with

C

K6C0207

X

d

X , i.r. TiO, octahedral units

CaO-TiO,

st. TiO, tetrahedra Ti-0 = 180.8 pm BaC1,-TiC1,-NH,OH-H,O heptahydrate at 700 "C KOH-TiO,-SiO,

g

X st, TiO, octahedra

NaF-Ti0,-SO,-H,O

PbTiO,

f

h 1

X,perovskite structure j k

PbTiP,O,

X

TiO,

Ti,Sb,O

,

+ Sb,O,

at > 900°C

t.d.

1

Ti,Bi,O, Ti,Bi,O,, TiBi 0,,

Ti0,-Bi,O,-KF-H,O

X

m

Ti, BizO9 Ti3Bi,0,, TiBi,O,

TiIv + Bill1 hydroxide coppts. heated > 500°C

i.r., t.d., X

n

,,

TiOSe0,,3H,O Ti(SeO,), TiTe,O,

t.d. TiO,

+ TeO,

CrFeTi, O7

X,fluorite structure X,isostructural with

0

p

q

Cr,Ti,O, BaTiMIPO,), (M = Cr or Fe) NifNiTiO,)

BaCO, + TiO, + 4-M203 3(NH,),HPO, NiO + TiO, at 2 1500°C

Cu,Ti, 0

CuO-TiO,

Cu ,Ti0

+

X

r

X,spinel lattice X

S

exothermic cpd., stable at > 980 "C

U

t

The Early Pansition Metals

15

Table 1 (contd.) Compound

Source

FeTiTaO,

Fe,03 + TiO,-Ta,OS at 1150-1250 "C under pressure

fTio.04Moo.,,)0,.,o

Properties reported

Ti02-Mo0,-Mo0,

R crf: V

X ,t.d.,

W

decomp. ca. 765 'C Li,Ti( Moo4),

Li, Mo04-Ti0,-Mo0,

La,Ti 0, Nd,TiO,

Nd,O,

+ TiO, at m.p.

MTiNbO, copptn. of hydroxides (M = Ce, Pr, or Nd) heated at 1150 "C M' NdTiM' 0, IM' = Cd or Pb, M2 = Nb or Ta)

X X

x

k

st, isotypic with La,TiO, Y Ti-0 = 177-199pm

X,eschynite structure

z

X,pyrochlore structure

aa

(a) Ref. 996. (b) A. J. Easteal and D. J. Udy, J. Inorg. Nuclear Chem., 1973,35, 3041. (c) W. Schartau and R. Hoppe, Naturwiss., 1973, 60, 105. (d) N. G. Kisel, T. F. Limar, and 1. F. Cheredruchenko, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972, 8, 1782. (e) 0. Matsumoto, K. Ishida, and Y . Mitsuya, Denki Kagaku, 1972,40, 641 (Chem. Abs. 1972,77, 169805s). (fj K. K. Wu and I. D. Brown, Acta Cryst., 1973, B29, 2009. ( g ) A . 1. Savos'kina, T. F. Limar, and N. G. Kisel, Zhur. neorg. Khim., 1972, 17, 2578. ( / I ) N. G . Shurnyatskaya. V. A. Blinov, A. A. Voronkov, V. V. llvukhin, and N. V. Belov, Doklady Akad. Nauk S.S.S.R., 1973, 208, 591. (i) V. A. Blinov, 0. K. Mel'nikov, V. V. Ilyukhin, A. A. Voronkov, and N. V. Belov, lzvest. Akad. Nauk S.S.S.R.. neorg. Materialy, 1973, 9, 530. (1) G. M. H. Van de Velde, U. Spitsbergen, and P. J. Gellings, J. lnorg. Nuclear Chew.. 1973, 35, 675. (k) B. M. Wanklyn, J . Materials Sci., 1972, 7, 813. (0 A. I. Sheinkman, L. M. Gol'dshtein, V. N. Turlakov, and G. V. Kleshchev, Zhur. priklad Khim., 1972, 45, 940. (m) M. L. Barsukova, V. A. Kuznetsov, A. N. Lobachev, and T. N. Tanakina, Kristallografiya, 1972,17,846.(n) C . G. Macarovici and G. Morar, Z . anorg. Chem., 1972, 393,275. (0)B. I. Danil'tsev, T. T. Mityureva, and I. A. Sheka, Ukrain. khim. Zhur., 1972, 38, 526 (Chem. Abs., 1972, 77, 169788~).(p) J. Galy, Nat. Bur. Stand (U.S.A.),Spec. Publ. No. 364, 1972, 29. (4)I. E. Grey and W. G. Mumme, J. Solid State Chem., 1972, 5, 168. (r) R. Masse. Bull. SOC.franc. Minkral. Crist., 1972, 95, 405. (s) G. Bayer and 0. W. Florke, Naturwiss., 1973,60, 102. (t) A. 1. Sheinkman. V. G. Mukhin, L. M. Gol'dshtein, and G. V. Kleshchev, Ref: Zhur. khim., 1972, Abs. 6B842 (Chem. Ahs., 1973, 78, 48847~).(u) A. A. Slobodyanyuk. Yu. D. Tret'yakov, and A. F. Bessonov, fzuest. W.Z., Tsvet. Met., 1972, IS, 18 (Chem. Abs., 1972,77, 131 549y). (u) E. I. Krylov, F. A. Rozhdestvenskii, and V. A. Zavol'skii, U.S.S.R. P. 340622 (Cl.C.0lg) (Chem. Abs., 1973, 78, 60442). ( w ) T. Ekstrom, Acta Chem. Scand., 1972, 26, 1843. (x) P. V. Klevtsov and E. A. Zolotova, lzoest. Akad. Nauk S.S.S.R. neorg. Materialy, 1973, 9,79. (y) H.Miiller-Buschbaum and K. Scheunemann, J . Inorg. Nuclear Chem., 1973, 35, 1091. (z) A. K. Borisov, E. I. Krylov, and F. A. Rozhdestvenskii, Ref: Zhur. khim., 1971, Abs. 21B643 (Chem. Abs., 1972,77, 96319~).(aa) L. N. Aver'yanova, V. M. Ezhov, and D. V. Balashov, Zhur. neorg. Khim., 1972, 17, 2842.

by the formation of non-adherent ternary oxides, in addition to the wellknown binary oxides and oxygen solid solutions in the metals. Na,TiO, has been identified on the surface of titanium after immersion in liquid sodium containing dissolved oxygen at temperatures close to 600 "C. The compound has been prepared by other routes and its composition confirmed by t.g.a.; its X-ray powder diffraction pattern indicates that it is a member of the iso-

16

Inorganic Chemistry of the TransitionElements

structural Na,MO, (M = Ti, Sn, or Pb) The preparation and properties of potassium titanates have been re~iewed."~The crystal structure of Li,TiO, has been redetermined and shown to be a derivative of the NaCl= 195 pm. In Bi,Ti,O,, the T i 0 6 octahedra resemble those type with found in orthorhombic BaTiO,, with the T i 4 bond lengths ranging from 173 to 241 pm.' O0 A new cation-exchanger, titanium-zirconium phosphate, has been reportedlo' and the new thermally stable and highly strontiumspecific ion-exchanger, titanium(1v) vanadate, has been prepared' O 2 by mixing 0.5M aqueous solutions of TiCI, and Na,VO, (pH 0-1). The new heteropolytungstates M4[Ti'VW802s] (M = Na, NH,, or T1) have been synthesized from aqueous media (pH 5 . 5 4 . 5 ) . ' 0 3 The oxidation of Ti"' to Ti" by OH radicals has been observed35 on pulse radiolysis of Ti"' solutions at pH 1.4. Stability constants have been reported for Ti(O€Q3+, Ti(OH)Z+, and Ti(OH); as 9.3 x l O I 3 1mol-l, 1.5 x lo2' l2 ~ ~ the extent of polymer mol-2, and 2.5 x lo3' l3 mol-,, r e s p e ~ t i v e l y , 'and formation in the hydrolysis products of Ti'" has been studied by thin-layer gel-chromatography.' O 5 The crystal structures of two mononuclear peroxotitanium(1v) chelates, the red diaquoperoxotitanium(1v) dipicolinate, and the orange difluoroperoxotitanium(1v) dipicolinate, have been determined. Analogous to earlier results (Vol. 1, p. 3) the titanium atoms are co-ordinated approximately pentagonal bipyramidally, with the peroxo- and dipicolinato-chelates occupying the equatorial sites and the aquo- or fluoro-ligands the apical ones.lo6 The crystal structure of Nenadkevichite from Saint-Hilaire, Quebec, Na3. 76K0.2 4Ca0. 11Mn0.03(Nb2. 7 6Til. 18)02.f30(oH) 1.20Si8024,H20 has been described : l o 7 other minerals in this series contain progressivelv more TiIVfor NbV. The mass spectrum of Ti(NO,), has been reported and, although no parent ion peak was observed, those corresponding to Ti(N0,); and TiO(NO,)+ were identified."' However, no substantial evidence could be provided for the ready loss of NO,. radicals which has been postulated to explain the reactions of Ti(NO,), with organic molecules, The stepwise formation constants of TiOP,O; - at 20 "C in aqueous solution have been

'' (a) M. G . Barker and D. J. Wood, J.C.S. Dalton. 1972, 2448, 2451; (b) C. Gicquel, M. Mayer, and R. Bouaziz, Compr. rend., 1972, 275, C , 1427. A. J. Easteal and D. J. Udy, High Temp. Sci., 1972, 4. 487. l o ' J. F. Dorrian, Diss. Abs. ( B ) , 1972,32, 6587. lo' (a) S. A. Marei and S . K. Shakshooki. Radiochem. Radioanalyt. Letters, 1972, 11, 187 (Chem. Abs., 1973. 78, 172043~);(6) M. Qureshi, K. G. Varshney, and S. K. Kabiruddin. Canad. J . Chem., 1972,50,2071. l o 3 G. Marcu, R. Vatulescu, and T. Budiu, Stud. Unia. Babes-Bolyai, Ser. Chem., 1972, 17, 87 (Chem. Abs., 1973, 78, 790792). C. Liegeois, J. Chim. Phys. Physicochem., Biol., 1972,69, 1531 (Chem. A h . , 1973, 78. 10864j). lo' M. Sinibaldi, J . Chromatogr., 1973,76,280. l o 6 D. Schwarzenbach, Hell). Chim. Acta, 1972. 55, 2990. lo' G. Perrault, C. Boucher, J. Vicat, E. Cannillo. and G. Rossi, Acta Cryst., 1973. B29, 1432. l o 8 L. Dauerman and G . E. Salser, J . Inorg. Nuclear Chern., 1973, 35, 304.

loo

The Early nunsition Metals

17

determined as 10'' 1 mol-' and 8.5 x lo31' mol-', respecti~ely.'~~ A new and cubic phase of KTi,(POJ, has been prepared which is isotypic with langbeinite. The substitution of (K' + Ti'V) by MV(M = Sb, Nb, or Ta) in the rhombohedra1 form of KTi,(PO,), has been shown to lead to the isotypic compounds MTi(POJ,.' l o TiCl, dissolves in disulphuric acid to form H,[Ti(HSO,),], which behaves as a weak acid in this system."' The system Ti0,-Cr,O,-SO,-H,O in 80% H,SO, has been studied at its boiling point and shown to form a range of double salts (Ti0,),(Cr02),S0, (n = 0 . 1 4 . 8 and rn = 1.4-1.3), whose X-ray diffraction characteristics have been obtained."' The lattice parameters and i.r. spectra of the double sulphates MTi(SO,), (M = Mg, Mn, Fe, Co, Ni, Zn, or Cd) have been reported."3 Similarly, Ti,O(SOJ,,nM,SO, (M = Na and n = 2 or 4; M = K and n = 0.33, 1, 2, or 4) and their hydrates have been studied by spectroscopic and thermal analytical methods and it has been concluded from the results that these salts involve -Ti-O-Ti-Ochains.' l4 Light-scattering data have been obtained'15 which support the formation of Ti(S0J2,MS0, (M = Ca or Ba) double salts from their constituents dissolved in 98 % H'SO,. TiOSO, reacts'16 with LiCl in aqueous solution to form LiTiO(OH)SO, with a formation constant of 4.9 x 10- 1 molRongalite, CH,OH SO,Na, forms'17 a yellow (A, = 335 nm) 2 :1 complex with TiO'+ in aqueous H,SO, with an overall formation constant of 1.6 x lo31' mol-'.

'

/OCH2CH2\ BuOTi -OCH,CH,-N \OCH,CH,/

'.

-

+ /OCH,CH,\ ROTi -OCH2CH2 -NH 0 ' CH,CH,/ (12) R = CH,P(O)(O-)(OH) ( I 3) R = CH,P(CH,OH)(OH)(O-)

Io9

'12 '13 '14

'I5

'I6 11'

B

L. Sucha, Sbornik Vyscke Skoly Chem.-Technol. Praze Analit. Chem., 1972, 97 (Chem. Abs., 1972, 77, 52895e). R. Masse, A. Durif, J. C. Guitel, and 1. Tordjman, &ll. Soc.fr.anG. Minkral Crist., 1972, 95, 47. R. C. Paul, J. K. Puri, V. P. Kapila, and K. C. Malhotra. J . Inorg. Nuclear Chem., 1972,34, 2141. L. 1. Bekkerman and 1. N. Zadrodin, Zhur. neorg. Khim., 1972,17,2387. R . Perret and P. Couchot, Compt. rend., 1973,276, C , 507. R. V. Chernov, L. T. Savchenko, and A. M. Kalinichenko, Ukrain. khim. Zhur., 1972, 38, 550, 745 (Chem. Abs., 1973,78, 2 3 4 4 3 ~ 1972,77, ; 169812s); A. M. Sych and V. V. Garbuz, ibid., 1972, 38. 1206 (Chem. Abs., l973,78,51863b). Ya. G. Goroshchenko and L. Soliev, Ukrain khim. Zhur., 1972, 38, 544 (Chem. Abs., 1973, 77, 169420n). Ya. G. Goroshchenko and 1. A. Sidorenko, Zhur. neorg. Khim., 1972,17, 1608. I. M. Ryazantseva and N. N. Sel'manshuk, Izvest. K U.Z . Khim. i. khim. Technol., 1972,15, 947 (Chem. Abs., 1972,77, 131 403w).

Inorganic Chemistry of the TransitionElements

18

POC1, reacts with TiOCl, or [TiCl,(O,CR)] (R = Me, Et, Pr, Pr', or But) to afford TiOC12,20PC13.118The phase diagram of the TiBr,-POCl, system has been constructed and 1:1, 1:2, and 2: 1 compounds identified with melting points of 94, 104, and 84"C,respe~tively."~TiCl, reacts with OP(OBu), to give a 1 :1 addition compound whose i.r. spectral and conductance characteristics have been obtained. Treatment of the l-titaniabicyclo[3,3,3]undecane (11) with HOCH,P(O)PH (or its anilinium salt) or (HOCH,),P(O)OH affords (12) or (13), respectively. The action of (HOCH2),P(O)(OH),2PhNH, upon The complexes of dialkylphosphinous acids, TiX,, (14) affords (15). 2R,P(O)H (X = C1 or Br and R = Bu, Ph, or cyclohexyl), have been prepared in benzene solution and their i.r. spectra determined.',," The dialkyl phosphite derivatives TiCl,_,[OP(O)R(OR)], (n = 1 - 4 and R = Et, Pr, or Bu) have been isolated following the reactions of TiCl, with the dialkyl phosphites in differing molar ratios in benzene solution under reduced pressure. Their insolubility and i.r. spectra suggest that these compounds are polymeric with bridging (RO)RP(O)O Hexamethyldisiloxane reacts with TiCl, to afford TiC1,-,(OSiMe3), (n = 1-3), which have formation constants of > l o 5 1 mol-', 8 1, rnol-,, and lo-' l3 mol-,, re~pective1y.l~~ The complexes [TiCl,(O,CR),] (R = Me, Ph, Bz, naphthyl, CF,, or CCl,) dissociate in DMF solution to form the ions [TiCl(RCO,),]+ and [TiCl, (RCO,)]-, and the uptake of hydrogen by these solutions in the presence of PtO, has been studied.57 Bi,[TiO(C20,),],,4H20, (BiO),[TiO(H,L), 3, 4H,O, (BiO)2[(Ti0)2(H,L),],2H,0, and Bi,[(TiO),L3],4H2O (H,L = tartaric acid) have been prepared by mixing solutions of Bi(NO,), and H,[TiO(C,O,),], or H,[TiO(H,L),]. The i.r. spectra of these bismuth salts have been reported for the hydrated and anhydrous forms, the latter being obtained by heating the former at 110-120 "C; further heating affords mixed oxides.'24 A 1:1 Ti'v-2,4-dihydroxybenzoic acid complex'25 of stability constant 3 x lo6 1 moland the TiIV-cyc1ohexanediaminetetra-aceticacid (H,Y) complexes126 [TiO(H,Y)], [TiO(HY)] -, and [TiOYI2-, of stability constants 2.1 x lo8, 1.4 x lo", and 1.7 x 10l8 1 mol-l, respectively, have been characterized. Dry CO, (1 atm) reacts smoothly with Ti(OBu), at 30°C to give a mixture of partially carboxylated products.127 Formylation of methyl 2,4-dihydroxy-

','

'

'19

lZo

lZ2 lZ3 lZ4 lZ5 lZ6

12'

B. Viard and J Amaudrut, Compt. rend., 1972,274, C , 2175 A. V. Suvorov and D. Sharipov, Zhur. neorg. Khim., 1973,18, 1143. T. D. Ibraeva, Yu. A. Nevskaya, and T. A. Sumarokova, Ref: Zhur. khim. 1972, Abs. 5B1479 (Chem. Abs., 1973,78, 10989d). E V. Kuznetsov and E. K. Ignat'eva, Khirn. Primen. Fosjororg. Soedin, Tr. Konf: 4th, ed N. P. Grechkin, Nauka, Moscow, 1969, p. 221 (Chem. Abs., 1973,78, 148036~). (a) A. A. Muratova, E. G. Yarkova V. P. Plekhov, R. G. Zagetova, and A. N. Pudovik, Zhur. obshchei Khim., 1972,42,976; (b) D. M. Pun and A. Parkash, J . Indian Chem. SOC., 1972,49,833 V. V. Yastrebov, Zhur.fiz. Khim., 1972,46,2922 C . Gh. Macarovici and Gh. Morar, Reti. Roumaine Chim., 1972, 17, 847; Stud. Unio. BabesBolyai, Ser. C h e w 1972,17, 5 (Chem. Abs., 1973,78,66432j). A. I. Astakhov, E. N. Knyazeva, and S. Ya Schnaiderman, Zhur. obshchei Khim., 1972,42,2505. P. P. Nenova, B. P. Karadakov, and D. St. Kuncheva, Zhur. neorg. Khim., 1972,17, 1856. M Hidai, T. Hikita, and Y. Uchida, Chem. Letters, 1972, 521.

The Early Transition Metals

19

benzoate and related compounds with C1,CHOMe and TiC1, affords the 3-formyl derivative as the major product, presumably via intermediates such as (16) which induce selective substitution ortho to the hydroxy-group.'28

OMe

1:1, 1:2, and 1:4 or 1:3 TiIv-pyrocatechol complexes have been identified in the presence of 4-aminopyrldine or salsoline, respe~tive1y.l~~ The i.r. and = Pr or Bu; Raman spectra of (BuO),TiL,-, (n = 1, L = O,CC,H,CO,R,R n = 2, L = O,CC,H,CO,Bu or 0,CC6H,(N0,)C02Bu; n = 4) have been recorded and the data discussed in terms of the structure of these compounds.' 30 The standard heat of formation of Ti(OEt), (s) has been determined',' calorimetrically as - 1480 +_ 8 kJ mol- '. Ti(OEt),, or Ti(OCHMe,),, reacts with MeCOCH2C02(CH2),0,CCH2COMe(H,L; n = 2,4, or 5) in 2 : l and 1:1 molar ratios with substitution of one and two alkoxide groups, respectively, to give co-ordination polymers.' 3 2 Polyglycol ethers R(OCH,CH2),0H (HL') (R = C6Hl3--C9HI9;n = 3-9), or (RC0,CH2)2C[CH,(OCH,CH2)nOH]2 (H2L2) (R = C,Hg-C,H,,; n = 25-29), react with TiCl, to afford TiCl,L',xTiCl, (x = 1-3), or (TiC1,),L2,yTiC14 (y = 10-16), respectively. Similar complexes were also observed with other large polyether molecules.' 33 The reaction of TiCl, with NH, followed by treatment with 2 : l R'OH-H20 (R' = Me, Pr, Bu, Ph, EtCO, or n-C,,H,,O) or MeCOCH,COR2-H20 (R2 = Me or Et) affords (R'O),TiO or (R2COCH=CMeO),Ti0, respectively.'34 The chloro(alkoxy)bis-(2,4-pentanedionato)titanium(1v) complexes, [Cl(RO)Ti(acac),] (R = Me, Et, Pr, Pri, or allyl), and the corresponding alkoxypentachlorotitanium(rv)salts (pyH),[(RO)TiCl,J have been reported. Addition of a 1:1 solution of ROH and py to a suspension of [Cl,Ti(acac)] in CH2C1, slowly affordsa precipitate of (pyH),[(RO)TiCl,] ; filtration, followed by the addition of hexane, produces [Cl(RO)Ti(acac),]. The 'H n.m.r. spectra of these latter complexes contain only one peak at room temperature, but at lower temperatures in CHC1, solution the patterns observed are consistent T. M. Cresp, M. V. Sargent, J. A. Elix, and D. P. H. Murphy, J.C.S. Perkin I , 1973, 340. U. Dustov, N. Kh. Maksudov, Sh. T. Talipov, and R. Kh. Dzhiyanbaeva, Zhur. analit. Khim., 1972 27, 2272; D. Kh. Petkova, S. Ya. Schnaiderman, and E. N. Knyazeva, Zhur. obshchei Khim., 1972,42,2236. lJo G. A. Semerneva, M. P. Tsvetkova, and A. L. Suvorov, Ref: Zhur. khim., 1972, Abstr. No. 13B218 (Chem. Abs., 1972,77, 145901~). 13' Yu. Kh. Shaulov, V. G. Genchel, R. M. Arzatullova, and N. V. Petrova, Zhur.fiz. Khim., 1972, 46, 2382. 13' U. B. Saxena, A. K. Rai, and R. C. Mehrotra, Z . Naturforsch, 1972, B27, 1145. l J 3 A. D. Pomogailo, D. V. Sokol'skii, U. A. Mambetov, E. M. Gluzman, and G. G. Kochurovskaya Doklady Akad. Nauk S.S.S.R., 1972,207, 882. 13* K. J. Bramekamp, Ger. Offen., 2 137633 (Chem. Abs., 1973,78, ll0560a). 12*

lZ9

20

Inorganic Chemistry of the nansition Elements

with the cis-octahedral isomer being the dominant solution species.'35 A similar geometry has been identified by X-ray diffraction studies for three bischelate complexes of bis-(2,6-di-isopropylphenoxo)titanium(rv) with two 2,4pentanedionato-, 8-quinolato-, or 2-methyl-8-quinolato-groups as the other ligands. All three compounds are monomeric with distorted octahedral coordination about the titanium(Iv1 and all have approximately two-fold molecular symmetry. The lengths of the T i 4 bonds involving the phenoxyligands range from 183.4 pm in the acetylacetonate to 181.6 pm in the quinIV), and its bis-dioxan aldate. 36 Di-p -oxo-bis-(2,4-pentanedionato)titanium( adduct, have been characterized by X-ray crystallographic studies and shown to be cyclic dimers, the two metal centres being linked by two oxygen atoms. The di-p-0x0-dititanium ring is planar with L OTiO and L TiOTi 83 and 97", respectively.137 Some fourteen crystalline 1 :1 and 1 :2 TiC1,-cycloalkanone complexes have been prepared and their carbonyl stretching frequencies shown to be 40-77 cm-' lower than those exhibited by the uncomplexed groups; the integrated intensities of the carbonyl stretching modes were shown to be a measure of the relative basicities of the ketones towards TiC1,. The enthalpies of addition of these complexes were seen to be dependent on the number of carbon atoms in the cycloalkanone ring and steric effects of methyl substituents ct to the 1:1 and 2: 1 TiIV-purpurin and 1 :2 TiIv-naphthazarin carbonyl complexes have been characterized spectrophotometrically.'3g 1 :1 and 1 :2 neutral addition complexes between TiCl, and several and between (BuO),TiCl,-, ( n = 0-4) and THF, dioxan, and tetrahydr~pyran'~'have been characterized. Low-temperature "F n.m.r. spectra of solutions containing TiCl,, TiF,, and 1,2-dimethoxyethane (DME) have shown that halogen redistribution occurs to produce all possible mixed-halide complexes containing a single cis-chelated DME ligand. These results, together with those of the analogous THF system suggest that, in the absence of steric interactions, the preferred orientation involves fluoride trans to the 0-donor ligand, presumably because of the enhanced n-bonding ability of the fluorine in this orientation. 142a Related systems involving TiI, gave very poor spectra apparently because of rapid ligand exchange effects.142b

'

S-Donor Ligands. The 'H and I3C n.m.r. spectra of [Ti(S,CNPr,),] have been obtained as part of a general study of ligand inequivalence in eight-co-ordinate 13' 13' 13' 13*

139 140

14'

14*

D. W. Thompson, W. R. C. Munsey, and T. V. Harris, lnorg. Chem., 1973,12,2190. P. H. Bird, A. R. Fraser, and C. F. Lau, Inorg. Chem., 1973,12, 1322. G. D. Smith, C. N. Caughlan, and J. A. Campbell, lnorg. Chern., 1972,11,2989. A. Pagliardini, L. Elegant, and M. Azzaro, Tetrahedron Letters. 1972. 4563; L. Elegant, A. Pagliardini, G. Torri, and M. Azzaro, Bull. SOC. chim. France, 1972,4422. R. S. Bottei and R. G. Schneggenburger. J . lnorg. Nuclear Chem., 1973,35, 1645, 1711. M. Basso-Bert, D. Gervais, and B. J. P. Laurent, J. Chim. Phys., 1972,69, 982 (Chern. Abs., 1972, 77,66819~). Yu. A. Lysenko, V. N. Marchenko, L. I. Khokhlova, and A. I. Pletnev, Zzvest, V.U.Z. Khim. i khim. Technol., 1973,16, 177 (Chem. Abs., 1973,78, 152 150x). N. Yoshino and T. Yoshino, Ml. Chem. SOC.Japan, 1972,45, 3172. (a) R. S. Borden, P. A. Loeffler, and D. S. Dyer, lnorg. Chem., 1972, 11, 2481; (b) R. S. Borden, Gout. Rep. Announce. (U.S.A.) 1972,72, 66.

The Early Pansition Metals

21

c0mp1exes.l~~ Seven-co-ordinatetris(dialkyldithiocarbamato)titanium(Iv) halides, [(R,NCS,),TiX] (R = Me, Et, Pr', or But, X = C1; R = Me or Et, X = Br), may be obtained by addition of the stoicheiometric quantity of anhydrous NaS2CNR2 to a solution of TiX, in CH2C12.These complexes appear to exist as monomeric molecular units, from molecular weight and mass spectral data, and their i.r. spectra are consistent with the presence of bidentate S2CNR2 groups. The 'H n.m.r. spectra of the R = Me and Et complexes in CH2C12 at room temperature indicate that they are non-rigid on an n.m.r. time-s~a1e.l~~ Difluorophosphinic acid, F,PS2H, reacts with TiCl, to afford [C1,TiS2PF,], whose 'F n.m.r. spectrum contains only the sharp doublet expected from this formulation. The complex is air- and solventsensitive and its low volatility has been ascribed to a chloride-bridged polynuclear s t r u c t ~ r e . 'Series ~ ~ of 1 : l and 1:2 TiC1, adducts with dithiol and thiol, respectively, have been isolated and characterized. In each case T i 4 bonding occurs, with retention of the S-H bond, and the i.r. spectrum is consistent with a cis-octahedral structure.14' Stable TiC1,-R$3i(CHJnSR2 [R' = Me or Et; n = 1-3; and R2 = H or CHS(CHJ,SiRi] adducts have been formed in solution ; however, the analogous R' = vinyl derivatives, once formed, undergo further reaction.147 N-Donor Ligands. (Me,Si),N reacts with TiCl, to yield the novel heterocyclic [Cl,TiNSiMe,],, isolated as orange c r y ~ t a 1 s . lR,N),TiBr ~~ (R = Me or Et) reacts with N-metalled cyclic amines to afford the corresponding [(R,N),Ti{ N(CH2),)] (n = 2-49 complexes.'49 Tetrakis(diethylamin0)- or tetrakis(pyrro1idino)-titanium(1v)tetrahydrochloride, (Et2N),Ti,4HCl or (C,H8N),Ti, 4HC1, react with diethylketone to form TiO,, the corresponding amine, and enamines.' 5 0 TiX4,n(3-cyanopyridine)(X = C1 or Br and n = 1 or 2) complexes have been prepared from their constituent molecules by mixing in a chlorinated hydrocarbon solvent. 1.r. spectra suggest that, for the n = 2 complexes, the ligands are co-ordinated via the pyridine nitrogen only, but that when n = 1 the cyano-nitrogen is also involved.' 5 1 The complexes TiCl,L, have been characterized, where L is a unidentate, aromatic Schiff base derived from benzaldehyde, anisaldehyde, or salicylaldehyde and amines such as aniline, o-, m-,or p-toluidine or other substituted anilines. The electronic and i.r. spectra of these complexes are consistent with octahedral stereochemistry 143

144

145 146

14'

14'

lS1

E. L.Muetterties, Inorg. Chem., 1973, 12, 1963. E. C. Alyea, B. S. Ramaswamy, A. N. Bhat, and R. C. Fay, lnorg. Nuclear Chem. Letters, 1973, 9, 399. R. G. Cavell and A. R. Sanger, lnorg. Chem., 1972, 11, 2016. J. A. Douek and J. T. Spickett, J . lnorg. Nuclear Chem., 1973, 35, 511. E. N. Kharlamova, E. N. Gur'yanova, F. P. L'vova, N. N. Vlasova, and N. V. Komarov, Zhur. strukt. Khim., 1973, 14, 70. M. Pierce-Butler and G. R. Willey, J . Organometallic Chem., 1973.54, C19. H. Burger and U. Dammgen, 2.anorg. Chem., 1972,394,209. G. E. Manoussakis and J. A. Tossidis, J . lnorg. Nuclear Chem., 1972,34,2449. S. C. Jain, J . lnorg. Nuclear Chem., 1973,35, 505.

Inorganic Chemistry of the 7kansition Elements

22

about the Ti" involving N-bonded ligands L.' 5 2 The complexes [TiOCl,L,] (L = 0- and p-anisidine, 0-and p-phenetidine, nicotinamide, benzidine, a- and P-naphthylamine, or acridine) have been prepared by mixing THF solutions of TiC1,,6H20 and the appropriate aromatic nitrogen base.' 53 Mixed N-donor and 0-donor Ligands. The five-co-ordinate bis(a1koxy)titanium(1v) complexes [(PriO),Ti(OCHR'CH,NMeJ] (R' = H or Me) and [(R20),Ti(NMeCH,CH,NMeJ] (R2 = Et or P?) have been prepared by the addition of the lithium salt of the appropriate bidentate ligand to [(RO),TiCl] in a suitable solvent under a nitrogen atmosphere. These compounds are all liquids and molecular weight, conductance, 'H n.m.r., and i.r, data are all consistent with covalent, monomeric units containing chelated ligands. The analogous [(EtO),Ti(OCHRCH,NMe,)] complexes are dimeric and are presumed to involve tris-octahedral Ti" centres linked by bridging ethoxygroups. 54 Bis(che1ate)dialkoxytitanium(~ v derivatives ) have been prepared by treating Ti(OR), compounds with ligands such as 7-allyl-8-hydroxyquinoline.' 55 Tris(quinolin-8-olato)titanium(1v)reacts7, with oxygen at room temperature to form {Ti(ox),},O. Titanyl perchlorate dissolved in the minimum quantity of aqueous alcohol reacts with a-benzoinoxime (H,L) 1 :2 to precipitate the dimeric [TiL,], complex whose i.r. and 'H n.m.r. spectra have been obtained.lS6"Aldoximes (HL), under analogous conditions, react to give monomeric [TiOL,] complexes and i.r. spectral studies suggest that these complexes are five co-ordinate, with a trigonal-bipyramidal structure.' 56b A five-co-ordinatesquare pyramidal structure has been proposed'57 for the 1 :1 complexes formed by T i 0 2 + and the Schiff bases (17). These compounds have been obtained from methanolic solution as dark, microcrystalline solids which are soluble in DMF and DMSO, and their i.r. spectra contain a band at ca. 1090 cm-' which has been attributed to v(Ti=O) stretching. TiL, complexes have been obtained for the Schiff bases (18)--(20); the i.r. spectra of (18) show that the nitrogen of the azomethine group is bonded to the titanium(IV), the co-ordination geometry being trans-octahedral.' 1 :1 and 1 :2 acylhydrazine complexes of TiF, and TiCl, have been prepared and characterized.' 5 9 Their i.r. spectra indicate that acylhydrazines such as

'

15'

153 154

15' 156

157

15*

lS9

N. S. Biradar and V. H. Kulkarni, lndian J. Chem., 1972, 10, 1193; D. Negoiu and A. Kriza, Ann. Unio. Bucaresti, Chem., 1971,20, 39 (Chem. Abs., 1973,78, 5 1 9 0 9 ~ ) . M. M. Khan, lnorg. Nuclear Chem., 1972,34,3589. E. C. Alyea and P. H. Merrell, lnorg. Nuclear Chem. Letters, 1973,9, 69. A. L. Suvorov, A. A. Pozdeev, and S. S. Spaskii, U.S.S.R. p. 330174 (Chem. A h . , 1972,77,48638f). (a) N. S. Biradar, V. B. Mahale, and V. H. Kulkarni, J . Znorg. Nuclear Chem., 1973, 35, 2565; (6) N. S. Biradar and V. B. Mahale, J . Less-Common Metals, 1973, 31, 159. N. S. Biradar, V. B. Mahale, and V. H. Kulkarni, Znorg. N u c l e a Ckem. Letters, 1972, 8, 997. (a) N. S. Biradar, V. B. Mahale, and V. H. Kulkarni, Znorg. Chim. Acta, 1973, 7, 267; (b) L. 1. Kuznetsova, A. D. Garnovskii, 0. A. Osipov, Yu. V. Kolodyazhnyi, and N. N. Viranovskaya, Zhur. obshchei Khim., 1972,42,566. (a) R. C . Aggarwal, B.N. Yadav, and T. Prasad, lndian J. Chem., 1972,10,671; (6)R. C. Aggarwal, B. N. Yadav, and T Prasad. J Inorg. Nuclear Chem.. 1973. 35.653

The Early Pansition Metals

23

R1vcH

R2

OHH

I

R3

(18) R' = R2 = H, R3 = H, Me, or OMe R' R 3 = H. R Z = Me R2 = R3 = H, R ' = Me

R (17) R

R =

H or Me

RCONHNH, (R = Me or Ph), which form the 1:1 complexes, behave as bidentate NO-donor ligands, and that diacylhydrazines such as RCONHNHCOR (R = H or Me), which form the 1:2 complexes, act as quadridentate ligands. Refluxing a mixture of TiCl, and an acylhydrazine produces a condensation compound whose i.r. spectrum contains a band due to isocyanate-groups but not one due to carbonyl groups. Thus enolization of the ketonic group($ of these molecules seems to occur during the condenati ion.''^' The aminodibutoxysilanes, (BuO),RSiNH, (R = H or Ph) form 1 :1 adducts with TiCl, which appear to be polymeric.16' Organometallic Titanium(1v) Compounds.-As in previous Volumes only selected aspects of this chemistry are presented. Titanium-Carbon cr-Bonded Complexes. A full report of the mono- and dinuclear anionic derivatives of MeTiX, (X = C1 or Br) has now been published, together with a discussion of the structure of MeTiC1, in the solid state, and a brief report of both 0, and SO, insertions into T i 4 bonds.98 Pb(CH=CHa, reacts with TiCl, (1:1)to form (CH,=CH)TiCl,. This purple compound is less stable than MeTiC1, and decomposes rapidly at temperatures above -30°C ; however, 1:2 THF and 1:1 dimethoxyethane adducts may be prepared, and these moisture-sensitive green solids are more thermally stable than the parent compound. The observed thermal decomposition products of (CH,=CH)TiCl,, ethylene, butadiene, and a little acetylene, are more consistent with a mechanism involving homolytic fission of the Ti-vinyl bond than with p-elimination. Wolfsberg-Helmholtz calculations have 160

161

R. C. Paul, K. S. Dhindsa, S. C. Ahluwalia, and S. P. Narula, Pruc. 2nd Chem.Symp., 1970, 1, 163 (Chem. Abs., l972,77,96376r). B. J. Hewitt, A K Holliday, and R.J. Puddephat, J C.S. Dalton, 1973, 801.

24

Inorganic Chemistry of the nunsition Elements

been performed162"to assess the effect of donor ligands on the nature of T i 4 bonds in Me,TiCl,-, (n = 04),MeTiC1,,2L (L = THF, py, or PPh,) and Me4Ti,2py.The mechanism of decomposition of MeTiC1, in co-ordinating solvents has been investigated and shown not to involve free radicals in e.g. ether.162bThe interaction of MeTiC1, with organoaluminium compounds such as AIR, and A1R2(OEt) (R = Me, Et, or Pr) activates and splits the Ti-Me bond, the rate of the reaction being first order in MeTiC1,. This labilization of transition-metal alkyls by organoaluminium compounds seems to be a general phenomenon which is obviously important in connection with Ziegler-Natta c a t a 1 y ~ i s . lMethyl ~~ group exchange between TiMe, and Al,Me, has been observed" on adding a solution of the latter in toluene to a solution of Ti(CD,), in this solvent at - 75 "C. Li[TiMe5J,2dioxan has been prepared by the addition of dioxan t o the yellow-green solution obtained by mixing TiMe, with LiMe in diethyl ether. The compound is stable in the absence of air at < 0 "C and is a 1:1 electrolyte in THF. The analogous adducts, Li[RTiMe4],2dioxan (R = Ph or Bz) and Li[Ph3TiMe,],2dioxan, have also been obtained.' 64 The preparation and physical and chemical properties of tetrakis(neopentyl)titanium(iv)have now been reported in detail. The compound seems to be more reactive than its analogues in the neighbouring group, aerobic oxidation in benzene affords Ti(OCH,CMe,),, and CO (1 atm) reacts to give a product whose i.r. spectrum contains bands typical of terminal carbonyl groups. However, Ti(CH,CMe,), does not react with ethylene, propylene, or hydrogen at room t e r n p e r a t ~ r e . ~ , ~ n.m.r. spectra have been recorded for Ti(CH,Ph), and the CH, l H and chemical shifts contrasted with those of other benzyl compounds.'66 Ti(CH,Ph), has been shown to react with aldehydes, ketones, esters, and acyl chlorides, as does PhCH,MgCl.' 67 (PhCH,),Ti,bipy is a most effective homogenous catalyst for the cyclodimerization of ethylene and buta-1,3-diene to vinylcyclobutane.168 Studies of the preparation and properties of (C6F5)"TiC14-"(n = 1-4) have been rep~rted.'~'(C,F,)TiCl, is monomeric in benzene, its T i 4 bond does not appear to be labile and the compound forms a 1 :2 adduct with ~yridine.',~" [(n-Cp),TiCl,] reacts with Me,SO at 70°C to give a 7t- to o-rearrangement of the cyclopentadienyl groups. This rearrangement may be followed by 'H n.m.r. spectroscopy, the 7t-Cp signal being replaced by a new one at 3.45z 16'

16' 164

16' 16' 168 169

(a) 0. S. Roshchupkina S. M. Vinogradova, and Yu. G. Borod'ko, Z h u r . j z . Khim.. 1972, 46, 2715; (b) J. D. McCowan, Canad. J. Chem., 1973,51, 1083. T. Yamamoto and A. Yamamoto. J Organometallic Chem., 1973,57. 127. K. H. Thiele, K. Milowski, P. Zdunnek, J. Muller, and H. Rau, Z . Chem., 1972, 12, 186. (a) P. J. Davidson, M. F. Lappert, and R. Pearce, J. Organometallic Chem., 1973, 57, 269; (b) W. Mowat and G. Wilkinson, J.C.S. Dalton, 1973, 1120. L. Zetta and G. Gatti, Org. Magn. Resonance, 1972,4, 585. J. Causse, R. Tabacchi, and A. Jacot-Guillarmod, Hell,. Chim. Acta, 1972,5S, 1560. L. G. Cannell, J . Amer. Chem. SOC.,1972,94,6867. (a) G. A. Razuvaev, V. N. Latyaeva and G. A. Kilyakova, Doklady Akad. Nauk S.S.S.R..1972, 103, 126; (b) P. Lahuerta and R. Uson, Rev. Cienc. Exactas, Fis-Quim. Natur., Zarugosa, 1972, 27,75 (Chem A h . 1972.77. 164813111

The Early Pansition Metals

25

after 6 h. Addition of Et,O to the mixture at the end of the reaction precipitates a pale-violet compound of composition Cp2TiC1,,4Me,SO.' 70 Mono- and di-lithioferrocene react with dialkylaminotitanium(1v) bromides, (R,N),TiBr (R = Me or Et) and (Et,N),TiBr,, to form the h'-ferrocenyltitanium(1v) dialkylamides (n-Cp)Fe(C, H4)Ti(NR,),, Fe { (C, H-i)Ti(NEt ,), } , and { (nCp)FeC,H,),Ti(NEt&, by simple salt-elimination reactions. The ix. and 'H and 13C n.m.r. spectra of these compounds were recorded, the molecules being rigid on an n.m.r. time-scale. The reaction of [(n-Cp),TiCl,] with Me,MCH,Li (M = Si or Ge) affords a convenient synthesis of [(n-Cp),Ti(CH,MMe,),] : similarly, TiCl, and (R,Me, -,SiCH,),Mg (n = 0 - 2 and R = Ph or Bz) afford Ti(CH,SiMe, -,R,J4. These complexes have a greater thermal stability than their methyl analogues. The relative oxidative stabilities of the latter compounds correlate with the degree of shielding at the metal centre.' 7 2 Bis(n-indeny1)titanium dihalides react with appropriate organolithium reagents to form the dimethyl and diphenyl derivatives which appear to be more stable than the corresponding n-cyclopentadienyl derivatives. This study also reported the preparation and properties of bis(n-indenyl)bis(o-pentafluoropheny1)titanium and the new titanium metallocycle 5,5-bis(n-indenyl)dibenzotitanole(21).' 7 3

''

(TI.

-Cp)

(TI.

-Cp)

\Ti/C=CPh INiCO / \ I

CzzCPh

(22 ) (21 1

Transition-metal acetylides react readily with metal carbonyls to form derivatives. Thus (x-Cp),Ti(C=LPh), and Ni(CO), afford (22)' 74 The oxidative additions of alkyl and acyl halides, RCOCl (R = Me or Ph), to [(n-Cp),Ti(CO),] yield the corresponding [(n-Cp),Ti(Cl)C(O)R] compounds, and 9,lO-phenanthraquinone affords (23).", [(n-Cp),TiPh,] and [(n-Cp),Ti(Me)Cl) have been shown to be active hydrogenation catalysts175and the 'H n.m.r. spectra of several [(n-Cp),TiR,] and [(n-Cp),Ti(R)Cl] compounds have been re-investigated and previous interpretations of such data questioned.' 76

170 17'

173 174

176

M. Tsutsui and C. E. Hudman, Chem. Letters, 1972, 777. H Burger and C Kluess, J . Orqanornetallic Chem.. 1973.56.269. M K. Collier, M. F. Lappert, and R. Pearce, J.C.S. Dalton, 1973, 445. E. Samuel and M. D. Rausch, J . Amer. Chem. Soc., 1973,956263. K. Yasufuku and H. Yamazaki, Bull. Chem. SOC.Japan, 1972,452664. P. C. Wailes, H. Weigold, and A. P. Bell, J . Organometallic Chem., 1972,43, C32. A. Glivickv and J D McCowan. Cnnad. J . Chem.. 1973.51.2609

Inorganic Chemistry of the nunsition Elements

26

Cyclopentadienyl Complexes. An X-ray diffraction study of [(n-Cp)(nMe,C,)TiCl,] has shown that the ligands are arranged about the metal centre in a distorted tetrahedral manner with two staggered five-membered rings n-bonded to the titanium atom and tilted at an angle of 130".Other dimensions agree closely with those of [(x-Cp),TiCl,] and it is concluded that the angle of tilt of the K-CP rings in such compounds is sensitive to steric effects.'77 A description of the preparati~n'~'"and the full report'78b of the crystal structure of (l,l'-trimethylene-di-~-cyclopentadienyl)titaniumdichloride, (KC,H4)(CHz),(7c-C,H4)TiClzhave been published. [(mCp),TiCl,] reacts with o-mercaptophenol, o-HSC,H,OH, in the presence of Et,N to give [(nCp),Ti(OC,H,S-o)], which has been characterized by i.r. and electronic spectra. The crystal structure of [(K-Cp),Ti(S,C,H,-o)] has been deter(e.g. mined.' 79b Pairs of diastereoisomers of [(K-C~)(K-C,H,R)T~(C~)X] R = CMe,Ph and X = OPh) complexeshave been prepared and characterized by 'H n.m.r. spectroscopy.' Similarly, [(K-C~)(~-C,H,)T~CI(SCHM~,)] shows diastereotopic methyl resonances, and the diastereoisomers of [(n-Cp)( K - M ~ C , H , ) T ~ C ~ ( ~ C , , H(24) , , ) ~have been separated by fractional crystallization.'80b

'''

c1

17'

T. L. Khotsyanova and S. 1. Kuznetsov, J . OrganometalZic Chem., 1973.57, 155. M. Hillman and A: J. Weiss, J . Organometallic Chem., 1972, 42, 123; (b) E. F. Epstein and I . Bernal, lnorg. Chim. Acta, 1973,7, 21 1. (a) K. Andrae and W. Rolka. Z . anorg. Chem., 1972,391, 19; (b)A. Kutoglu, ibid.. 1972,390, 195. (a)F. Le Moigne, A. Dormond, J. C. Leblanc, C. Moise, and J. Tirouflet, J. OrganometaflicChem., 1973,54, C13; J. Tirouflet, A. Dormond, J. C. Leblanc, and F. Le Moigne, Tetrahedron Letters, 1973, 257. (b) H. Brunner and H. D. Schindler, J . Organometallic Chem., 1973, 55, C71. (a)

179

The Early nansition Metals

27

[(n-Cp),TiCl,] in THF at -78°C reacts with Ph,GeLi in MeO(CH3,OMe to yield [(n-Cp),Ti(GePh,),] in 60-70 % yield; this compound reacts with CCl, to give [(n-Cp),TiCl(GePh,)], which may also be obtained by pyrolysis of [(n-Cp),Ti(GePh,),] followed by treatment of the products with dry HCl in dioxan.18' 35Cl N.q.r. spectra have been reported for [(n-Cp),-,,TiCl,J ( n = 2--4)18, and dipole moments and i.r. spectra obtained for [(n-Cp),TiX,] (X = C1, NCS, or OCN).lS3 1.r. and Raman spectra (600-50cm-') have been recorded for [(n-Cp)TiX,] and [(n-Cp),TiX,] (X = F, Cl, Br, I, or Me) and the comparisons afforded by this extensive study have allowed the metalring and metal-ligand stretching modes to be a~signed.'~,The titanoxanes [(n-Cp)Ti(X)O], (X = C1, Br, or I and n = 4 for X = C1) have been prepared by stirring [(n-Cp)TiX,] in acetone under anaerobic conditions, oxygen abstraction from the solvent affording mesityl oxide.' 8 5

2 Zirconium and Hafnium Introduction.-The half-life of 17,Hf has been determined as 1.9 0.3 years.f86 The electronic spectrum of Zr5+ has been re-analysed and the ionization potential of this ion estimated as 95.8 0.6eV.'87 The vapour pressures of solid and liquid zirconium and hafnium have been determined and used to calculate the enthalpies of sublimation at 298.15 K as 621 and 600 kJ mol-', respectively.f88 A text describing the chemistry of hafnium has been publishedf8' and the organometallic chemistry of zirconium and hafnium reported during 1971 has been reviewed., The dicyclo-octatetraene complexes of zirconium and hafnium, [M(cot),], (M = Zr or Hi) have been prepared'" by the reduction of the tetrachlorides by Mg metal, Mg or A1 anodes, or by treating tetra-alkoxyor tetra-allyl-zirconium with AM,, in the presence of cot. [Zr(cot),J and Hf(cot), readily dissolve in Et,AlH to give the adducts [(cot),Zr(HAlEtJ,] ( n = 1 or 2) which involve M---H---A1 linkages. Zr(cot), forms 1 :1 adducts with HMPA and THF190Cand X-ray diffraction studies have shown that the latter exists as discrete molecules which contain h8- and h4-C8H8rings and a G. A. Razuvaev, V. N. Latyaeva, G. A. Vasil'eva, and L. 1. Vyshinskaya, Zzvesf. Akad. Nauk S.S.S.R., Ser. khim., 1972,1658; G. A. Razuvaev, V. N. Latyaeva, G. A. Vasil'eva, L. I. Vyshinskaya, and G. Ya. Mal'kova, Doklady Akad. Nauk S.S.S.R., 1972, 206, 1127. A. N. Nesmeyanov, E. V. Bryukhova, 1. M. Alymov, 0.V. Nogina, and V. A. Dubovitskii, Izvest. Akad. Nauk S.S.S.R., Ser. Khim., 1972, 1671. l S 3 A. Jensen, V. H. Christiansen, J. F. Hansen, T. Libowski, and J. L. Burmeister, Acta. Chem. Scand., 1972,26,2898. lS4 E. Samuel, R. Ferner, and M. Bigorgne, Znorg. Chem., 1973,12,881. l E 5 R. S. P. Coutts, R. L. Martin, and P. C. Wailes, Znorg. Nuclear Chem. Letters, 1973,9,49. C. J. Orth, H. A. O'Brien, M. E. Schillaci, and B. J. Dropesky, Inorg. Nuclear Chem. Letters, 1973,9, 61 1 . J. 0. Ekberg, J. E. Hansen, and J. Reader, J Opt. SOC.Amer., 1972,62,1134, 1139, 1143. R. J. Ackermann and E. G . Rauh, J . Chem. Thermodynam., 1972,4, 521. 1. A. Sheka and K . F. Karlysheva, 'The Chemistry of Hafnium', Nauk Dumka, Kiev, 1972. (u) H. Lehmkuhl, S. Kintopf, and K. Mehler, J. Organometallic Chem., 1972, 46, C1; (b) H. J. Kablitz, R. Kallweit, and G. Wilke, ibid., 1972, 44, C49; (c) H. J. Kablitz and G. Wilke, ibid.. 1973,51,241

''' "'

28

Inorganic Chemistry of the nunsition Elements

co-ordinated THF molecule, with the Z r 4 bond of 244.7(4) pm being rather Binary Compounds and Related Species.-Halides and Oxvhalides. The reaction of metallic Zr with ZrBr, at 6 7 0 4 2 0 ° C affords ZrBr which has a rhombohedral 1 a t t i ~ e . l ’An ~ ~ alternative preparation by electrolysis of fused ZrBr,NaBr-KBr mixtures affords the compound with a hexagonal unit cell.192b ZrCl,, prepared by the disproportionation of ZrCl, under 5 atm pressure, has been shown to have stoicheiometry ZrC1, with 1.84 ,< x < 1.95. The crystal structure of the compound where x = 1.87 i-0.2 is analogous to those of MS, (M = Nb, Ta, Mo, or Re), and contains Z r 4 1 distances of 259 pm.lg3 The chemistry of the halides and oxyhalides of zirconium(n1)and hafnium(Ir1) has been reviewed,lg4and the magnetic properties of crystalline ZrX, (X = Cl or Br) have been described. Antiferromagnetic coupling along the infinite chains of Zr”’ ions parallel to the c-axis, and ferromagnetic coupling between ions in the same ab-plane were invoked to explain the magnetic properties of these compounds. Separation of the monoclinic, tetragonal, and cubic polymorphs of HfF, has been achieved on crystallization and the vapour pressure of the compound examined as a function of temperat~re.”~The rates of formation of ZrX, (X = C1 or Br) from metallic Zr and PbX,, AgX, or CuCl have been examined and the majority of these reactions shown not to proceed to c~mpletion.’~ Oxides and Chalcogenides. The crystal structure of monoclinic ZrO, has been redetermined,19’ the results being in good agreement with those of earlier studies. HfPo, ( x = 0.91-1.09) has been synthesized by heating these elements at temperatures between 630 and 900 K. Some dissociation of the compound occurs above 700 K.19* Layer intercalation compounds of ZrS, and HfS, with NH,, N2H4, and RNHNHMe (R = H or Me) have been obtained and the corresponding layer expansions determined.30 The non-stoicheiometric zirconium and hafnium ditelluride phases ZrTe, (x = 1.74-1.45) and HfTe1.94have been characterized by X-ray diffraction studies. The non-stoicheiometry of the latter compound appears to be in the anion ~ub-lattice.’~~ The compositions of the diamagnetic ZrX, and HfX, (X = S, Se, or Te) have

19’

D. J. Brauer and C. Kruegger, J . Organometallic Chem . 1972.42. 129. (a) S. I. Troyanov, G. S. Marek, and V. I. Tsirel’nikov, Zhur. neorg. Khim., 1973,18,259;( b ) L. E. lvanovskii and R. 1. Novikov, ibid., 1972, 17, 2572.

19’

S. I. Troyanov and V. I. Tsirel’nikov, Vestnik M o s k m Univ., Khim., 1973, 14, 67 (Chem. Abs., 1973,78, 1656052). D. A. Miller and R. D. Bereman, Coord. Chem. Rev., 1972,9.107. M. J. Camp, Diss. Abs. (B), 1972,32, 5670. Yu.M. Korenev, 1. D. Sorpkin, N. A. Chirina, and A. V. Novoselova, Zhur. neorg. Khim., 1972, 17, 1195. A. Ono, Mineral. J., 1972,6, 433. Z. V. Ershova and E. S. Prokin, Radiokhimiya, 1973, 15,252. A. Gleizes and Y. Jeannin, J . Solid State Chem., 1972, 5, 42; J. G. Smeggil and S. Bartram, ibid.,

194

lg5 196

19’ 19’ 199

p. 391

The Early Il).ansitionMetals

29

been shown to be 1 :3.00 by X-ray diffraction and density determination^.,^ The vibrational spectra of ZrS, have also been reported.,, Compounds with Elements of Group V and with Silicon. The reaction of nitrogen with zirconium at 1440°C and 2-10 mTorr has been followed and the initial stage shown to lead to the formation of a thin ZrN layer.,’’ The phases Zr,PSb and Hf,PSb crystallize with the H-Ti,SC structure,201and ZrSb, and HfSb, with the TiAs, structure.202 A thermodynamic analysis of the co-reduction of ZrO, and SiO, by carbon at 1500-3000K has suggested that the formation of ZrSi is more probable than that of ZrSi,.,, Zirconium(I1) and Hafnium(n).-Studies of the diffusion coefficients of Zr” dissolved in fused alkali-metal chloride melts have led to the suggestion that [ZrCl,]’- ions are formed.203ZrAlCl, has been isolated as a pure brown powder following the disproportionation of ZrC1, in AlCl,. Zirconium tetra-alkoxides react with cot and Et,AlH to form [(cot)ZrH,]. The electrolysis of ZrC1, at an aluminium anode in the presence of cot and Bu4NBrinTHF at 20°C has been shown to produce [(cot)ZrCl,],THF. [Hf(cot),] reacts with two equivalents of HCl in THF to afford [(cot)HfCl,],THF, the molecule of solvent is removed on heating to 70°C. [(cot),ZrCl,] may be prepared similarly and the reactions of these dihalides with Grignard reagents have afforded the corresponding [(cot)MR,] (M = Zr and R = Me, Et, allyl, or crotyl; M = Hf and R = allyl) derivatives. [(cot)Zr(allyl),] catalyses the stereospecific dimerization of butadiene to octa- 1,3-trans-6-cis-triene and the crystalline complex [(cot)ZrC,H,,] has been isolated as an intermediate in this reaction.lgo ZrC14 reacts over 2 h with LiPh (1 :4) in Et,O at - 30 to -40°C to afford a brown solution of ZrPh,, but evaporation of this solution affords the black crystalline product [Ph,ZrOEt,],. This compound is spontaneously inflammable in air and produces PhZrOEt when thermally decomposed.204 Evidence has been presented for the formation of Zr(CH,Ph), by the thermal decomposition of Zr(CH,Ph),.205 Zirconium(r1r) and Hafnium(rn).-The complexes formed by the halides and oxyhalides of zirconium(II1) and hafnium(Ir1) have been reviewed.lg4 [ZrCl,(3,5-lutidine),1, has been prepared from its constituents and its structure is presumed to be a chloride-bridged dimer. 2,6-Lutidine does not react with ZrC1, and 2,4-lutidine (L) affords [ZrCl,L,,] (y ca. 1.1-1.33) together with a

.

2oo 201

’O’

’03

204

’05

R. A. Sallach, J . Phys. Chem., 1972,76,2156. H. Boller, Monatsh., 1973, 104, 166. A. Kjekshus, Acta Chem. Scand., 1972,26,1633. M. V. Smirnov, V. E. Komarov, and N. P. Borodina, Fiz. Khim. Elektrokhim. Rasplau. Solei. Shlakov, Tr. Vses.Soveshch. 4th, ed. A. V. Gorodyskii, ‘Naukova Dumka’, Kiev, 1970,2,3(Chem. A h . , 1972. 77, 92 969p). G. A. Razuvaev, V. N. Latyaeva, L. I. Vishinskaya, and A. M. Rabinovitch, J . Organometallic Chem., 1973,49,441. K. H. Thiele, E. Kohler, and B. Adler, J . Organometallic Chem., 1973,50, 153.

30

Inorganic Chemistry of the TransitionElements

black product which contains [ZrC14L]?06 Refluxing ZrIVsalts with Na-Hg in 1 :1 glacial acetic acid-acetic anhydride for 1-2 h affords a convenient synthesis of Zr(0,CMe)3.56 Zirconium(Iv) and Hafnium").-Halides and Oxyhalides. A new X-ray structural determination of Li,ZrF, has resolved ambiguities in the position of the Li' ions. Each Zr" is co-ordinated to six F- ions at the corners of a regular octahedron (Zr-F = 201.6 pm) each corner of which is shared by two edge-sharing Li' co-ordination octahedra.,07 The formation constants of [ZrF8I2- and [HfF6I2- in the respective MF,-HF-H,O systems have been determined by ion-exchange methods.86 AgZrF, and AgHT, have been prepared by the fluorination of MOC1, (M = Zr or Hf) and Ag,O (or Ag,SOJ mixtures, and shown to contain strong magnetic exchange between the Ag" ions.87A remarkable versatility of structural units has been identified in the CU"-H,O-[Z~F,]~system. Crystals of CuZrF6,4H,0 involve infinite chains of - - [ZrF,l2- - - -[Cu(H,0),I2+ - -- distorted octahedral units. K,CuZrF6,2H,0 contains [Zr,Fl,]4- ions which are composed of two ZrF, pentagonal bipyramids sharing an equatorial edge. Cu,(ZrF7),,16H,0 crystals possess [Zr,Fl4I6anions, which result from the association of two ZrF, square antiprisms sharing an edge, and crystals of Cu2ZrF,,12H,O contain individual [ZrF,I4square antiprisms.208 The reaction of M3U0,F, (M = Rb or Cs) with MF and ZrO, for 6 h at 700 "C affords Ml2ZrU3O8FI8,X-ray diffraction characteristics of which were reported.209 Studies of the diffusion coefficients of ZrIV in fused alkali-metal chloride melts have indicated that [ZrCl6I2- ions are formed.203A full report of the preparation and crystal-structure determination of BiBi9[HfC1,], has been The compound ZrOC1,,1.75CdC1,,10H20 has been identified in the ZrOC1,-CdC1,-H,O system and the properties of this system at 25 "C have been obtained.," Under certain conditions in aqueous HCl solutions, ZrO, can be formed as oligomers, or as chain polymers, both of which give hydrochlorides with a ZrO, :HCl ratio of 1 :1. The hydrochloride oligomer, (Zr0,,4H,0,4HC1),12H20,4HC1, has been crystallized from such media and the latter H 2 0 and HCl molecules have been identified as guests in the crystal lattice of the other components.'12 0-Donor Ligands. Table 2 summarizes some of the data reported on zirconates, hafnates, and related mixed oxide systems, and the physicochemical properties of mixed oxide systems involving ZrO, have been reviewed.,13 The corrosion of zirconium metal by liquid sodium containing dissolved oxygen takes place '06

207 208

'09

'lo 211 '12 'I3

T. E. Henzler, Diss. Abs. (4, 1972,33, 618. G. Brunton, Actu Cryst., 1973, B29, 2294. J. Fischer and R. Weiss, Actu Cryst., 1973, B29, 1955, 1958, 1963, 1967. J. Fleckenstein, S . Kemmler-Stack, and W. Rudorff, Z . Nuturforsch., 1972, 27b, 1272. R. M. Friedman and J. D. Corbett, Znorg. Chem., 1973,12, 1134. I . N. Belyaev, L. M. Lobas, and L. 1. Efimushkina, Zhur. neorg. Khim., 1972,17,3075. W. B. Blumenthal, J . Less-Common Metals, 1973,30, 39. S. F Pal'guev, A. D. Neuimin, V. N. Strekalovskii, A. G. Kotlyar, V. N. Chebotin, S. L. Fridman, and V. N. Zubankov, Vysokoternp. Khim. Silikat. Okislov, Tr. Vses. Soveshch., 3rd, 1968, ed. E. K. Keler, 'Nauka' Leningrad Otd., Leningrad, (Chem Abs., 1972,77, 93 886w).

The Early Bansition Metals

31

by the formation of non-adherent ternary oxides, in addition to the well-known binary oxides, and oxygen solid-solution in the metal. Na2Zr03 has been identified on the surface of zirconium after immersion in sodium containing dissolved oxygen at temperatures close to 600°C. This compound has been prepared by other routes and its composition confirmed by t.g.a. and X-ray diffraction studies.99aThe superstructure of the M20,,6Zr02-type phases in the M20,-ZrO, (M = Nb or Ta) systems has been described and shown214 to occur for the range of M 2 0 5:Zr02 ratios 2 :9 to 2 :15. The structure and intergrowth of the polymorphs of Zr02,12Nb205 have also been investigated.2 The crystal structures of Zr(OH),CrO, and Zr4(OH),(Cr04),(H20), (x ca. 1) have been described.216 The former consists of infinite nets of [Zr,(OH),CrO,]~"+ ions, in which Zr" exhibits both trigonal-dodecahedra1 and pentagonal-bipyramidal co-ordination. Crystals of the latter compound possess infinite chains of approximate composition [Zr4(OH),(CrOJ8]:"+, in which Zr"' is at the centre of a somewhat distorted pentagonal bipyramid. The new heteropolytungstates M1(M2W8028) (M1 = Na, NH,, or TI; M2 = Zr or Hf) have been prepared from aqueous media (pH 5 . 5 4 . 5 ) containing tungstate anions and the appropriate metal cations.103Zirconium and hafnium have been separated by the complete precipitation of the former as the pyridinium salt of molybdozirconophosphate.2' The values of the thermodynamic quantities of Cl--NO, and SOZ--NO, anion exchanges on hydrous zirconia have been determined.218The degree of hydration of zirconium precipitates2" and the extent of polymer formation in these hydrolysis products lo5 have been studied. Zirconium(1v) and hafnium(1v) hydroxides have been shown by l H n.m.r. spectral and acid-base titration studies to contain both OH and H 2 0 groups; the latter may be selectively removed by heating at < 150"C.220 Heating a-zirconium phosphate for long periods has led to the formation of the new 6- and q-phases and refluxing in H3PO4 solutions (15.7 moll-l) to the &phase, initially, and the &-phase,subsequently.221The crystal structure of a-Zr(NH,POJ,,H,O has been shown to be essentially the same as that of a-Zr(HP04),,H20, with the layers spread apart to accommodate the ammonium ions, thus producing cavities in the lattice.222The thermal decomposition

'I4

'I5

'I7 'I9 *'O

'''

'''

R. S. Roth, J. I,. Waring, W. S. Brower, and H. S. Parker, Nat. Bur. Stand. (U.S.A.).,Spec. Publ. No. 364, 1972, 183. N. C. Stephenson, J. P. Beale, and D. C. Craig Nat. Bur. Stand (U.S.A.) Spec. Publ. No. 364, 1972, 165; B. Nolander and R. Novin, Acta Chem. Scand., 1972,26, 3814. W. Mark, Acta Chem. Scand., 1972,26, 3744; 1973.27, 177. K. Murata, S. Takernoto, and S. lkeda, Chem. Letters, 1972, 751. A. Lj. Ruvarac and M. I. Trtanj, J . lnorg. Nuclear. Chem., 1972,34, 3893. P. Mouron, C. Reynaud, and G. Vuillard, Compt. rend., 1972,275, C , 1371. 2.N. Prozorovskaya, V. F. Chuvaev, L.N. Komissarova, N. M. Kosinova, and Z. A Vladirnirova, Zhur. neorg. Khirn., 1972, 17. 1524 A. Clearfield, A. L. Landis, A. S. Medina, and J. M. Troup, J . lnorg. Nuclear Chem., 1973,35,1099. A Clearfield and J. M Troup. J . Phvs. Chem.. 1973.77. 243.

Inorganic Chemistry of the TransitionElements

32

Table 2 Zirconates, hafnates, and related mixed oxide systems Compound

Source

Mg2Hfs01 2 CaHf409

MgO-HfO, CaO-HfO,

Na,Zr,Si,O,

,

Cs,ZrSi,O, Cs,Zr Si O9 Cs,ZrSi,O,,

I

,

BaZrSi,O, Ba,Zr,Si 0

1

, , Ba,Zr,Si,O, ,

Properties reported

Re$ a

st

b

CsOH-Zr02-Si02 under hydrothermal conditions (270-340 "C)

X

C

BaC0,-Zr0,-SiO, 135G1450 "C

X

d

AHo = - 6431 kJ mol-' e

Hf(SOJ,PH,O Hf(SOJ2,4D,O

t.d., X X

f

t.d., X

As 9

Zr0,-TeO, HfO,-TeO,

X,fluorite lattice X

h

ZrO, + V,OS in a Pt crucible at 650 "C for 15 h

i.r.. X

i

X,cubic X

j

f

Li,MoO,-ZrO, (or Hf0,)MOO, system

t.d., X

k

SrZr 0,-LaTaO,

X, pyrochlore structure 1

FeZr ,O M2Hf6017

(M = Nb or Ta) zr(MOO,), H~(MoO,)~ Li,Zr( MOO,), Li,Hf(MoO,), SrLaZrTaO,

I

KBa,ZrNb90,0 Li,La,Zr2Nb,030

X

MLaZrTaO, (M = Ca, Sr, Ba, Cd, or Pb)

X, pyrochlore structure n

Ce2Zr30

10

M2Hf207

m

Ce0,-ZrO,

c,

x

0

heating M(NO&Hf(NO,),

m.p., d

P

(M = La, Nd-Lu) (a) C. Delamarre, Rev. Internat. Hautes Temp. Refract., 1972, 9, 209 (Chem. Abs., 1973, 78, 8 8 0 4 ~ ) . (6) R. G. Sizova, A. A. Voronkov, N. G. Shumvatskaya, V. V. Ilyukhin, and N. V. Belov, Doklady Akad. Nauk S.S.S.R., 1972, 205, 90.(c) K. V. Alyamovskaya and V. G. Chukhlantsev, tzuest. Akad. Nauk S.S.S.R., neorg. Maferialy, 1973, 9, 76. (d) R. Masse and A. Durif, Compt. rend., 1973, 276, C , 1029. (e) E. V. Shibanov and V. G. Chukhlantsev. 2hur.fiz. Khim., 1972,46,2683.(A H. A. Papazian, P. J. Pizzolato, and R. R. Orrell, Thermochirn. Acta, 1972,4,97; F. L. Chan, and G. G. Johnson, jun., Develop. Appl. Spectroscopy, 1972, 10, 307 (Chem. Abs., 1973, 78, 141 335k). ( g ) B. I. Danil'tsev, T. T. Mityureva, and 1. A. Sheka, Ukrain. khim. Zhur., 1972, 38, 526 (Chem. Abs., 1972, 77, 169788~). (h) J. Galy, Nat. f i r . Stand. (U.S.A.),Spec. Publ. No. 364, 1972, 29. (3 J. C. Pedregosa, E. J. Baran, and P. J. Aymonino, Anales Asoc. quint. Argentina, 1972, 60. 397 (Chem. Abs.. 1973. 78. 21 112p).

The Early Tfansition Metals

33

of such salts as Zr(MPO,),.xH,O

(M = H, Li, Na, K, or NH,) is consistent with the water moleciiles being held in a zeolitic environment. For the ammonium salt, the first stage of thermal decomposition affords Zr(NH,PO,)(HPOJ via loss of NH, and H,0.223 The thermodynamic equilibrium constants, enthalpies, and entropies of Na+-H+ ion exchange in crystalline a-Zr(HPOJ,,H,O have been determined. This exchange occurs in two stages, the first affording Zr(HP04)(NaPOJ,5H,0 (AH = 125 & 3 kJ mol-l, AS = - 115 2 13e.u., and K,,., = 2.0 x lo-, 1mol-') and the second Zr(NaP0J2,3H,O (AH = 17 k 3 kJ mol-', AS = -34 f 1 e.u., and K,,., = 1.8 x 1 mol-I). K+-H+ exchange on a-and y-Zr(HPO,),,H,O takes place in ewentially the same manner.,,, Na+-K+ ion exchange on mZr(HPO,),,nH,O has also been studied in detail and the phases Zr(NaPO,),,aH,O, Zr(NaPO,)(KPOJ,bH,O, and Zr(KPOJ,,cH,O, which have partial phase solubility, have been shown to be involved in this exchange.225X-Ray diffraction studies have dhown that Ca2+-H+ and Sr2+-H+ exchanges on crystalline zirconium phosphate occur with the formation of Zr{Ca(POJ),.,,(HP0,)o.7,,3H,0 and Zr{Sr(POJ2)o~,o(HP04),3.5H20, respectively. These processes are therefore not single-step ones, in contrast to Ba2+-H+ exchange.226 Zirconium(1v) monobutyl phosphate, Zr(BuOPO,),, has been prepared and characterized by i.r. q p e c t r o ~ c o p yThe . ~ ~ dialkylphosphinous ~ acid complexes [{R,P(O)H),ZrX,] (R = Bu, Ph, or cyclohexyl; X = C1 or Br) have been prepared from ZrX, and R,P(O)H in benzene and their i.r. spectra reported.'22a The extraction of zirconium and hafnium from aqueous HClO, and H2S04 solutions by the chelates bis-di-n-hexylphosphinylmethaneand di-n-octyl-20x0-propanephosphate has been extensively investigated,,' and the extraction of zirconium from aqueous nitric acid by tributyl phosphate shown to produce [ZrOH(NO,),,TBP], and [Zr(0H),(NO3),,TBP], (n = 2 - 4 ) in the organic phase.229'H and 31Pn.m.r. spectral studies of the cation hydration in ZrOX,(X = NO, or ClO&H,O-HMPA-Me,CO mixtures at ca. - 70°C have 223

224 225

226 221

228 229

S E. Horsley and D. W. Nowell, Proceedings of the 3rd International Conference on Thermal Analysis, 1971, 2, 611 (Chem. Abs., 1973, 78, 131562t). A. S. Medina, Diss. Abs. (B), 1972, 32,6331; J. M. Garcb-Muiioz, ibid., 1973, 33,3533. G. Alberti, U. Constantino, S. Allulli, and M. A. Massucci, J . lnorg. Nuclear Chern., 1973, 35, 1339; A. Clearfield and A. S. Medina, ibid., p. 2985. G. Alberti, U. Constantino, and M. Pelliccioni, J . Inorg. Nuclear Chem., 1973, 35, 1327. A. S.Solovkin, E. G. Teterin, M. N. Shesterikov, and S. A. Kokanov, Zhur. neorg. Khim., 1973, 18, 120. P. Bronzan and 2. Meider-Gorican, J . Less-Common Metals, 1972, 29, 407. V. M. Klyuchnikov, L. M. Zaitsev, S. S. Korovin, and 1. A. Apraksin, Zhur. neorg. Khim., 1972, 17. 3030.

(1) D. A. Braganza and K. R. Rao, Current Sci., 1972.41, 564. (k) P. V. Klevtsov and

E. A. Zolotova, Izoest. Akad. Nauk S.S.S.R., neorg. Materialy, 1973, 9, 79. (0 I. N. Belyaev, L. N. Aver'yanova, and V. M. Ezhov, Zhur. neorg. Khim., 1973, 18, 1141. (m) M. Kestigian and W. R. Bekebrede, Materials 1973,8, 319. (n) L. N. Aver'yanova, V. M. Ezhov, and D. V. Balashov, Zhur. neorg. Khim.. Res. BU., 1972, 17, 2842. (0)S. Roitti and V. Longo, Ceramurgiu, 1972, 97 (Chem. Abs., 1973, 78, 89127~). (p) K. I. Portnoi, S. E. Salibekov, and N. I. Timofeeva, Vysokotemp. Khim. Silikat. Okislou., Tr. Vses. Soueshch., 3rd, 1968,43 (Chem. Abs., 1972,77, 694919.

Inorganic Chemistry of the Dansition Elements

34

been reported. These data are consistent with the formation of metal cation (Zr02+) polymers, perhaps tetramers, containing four tightly bound ligands per cation. These ligands are normally water molecules; however, they may be substituted by HMPA or NO, Zr(OH)AsO,,xH,O, which may be useful as an ion-exchange matrix, has been obtained by heating arsenious acid, zirconium(1v)oxychloride, and potassium persulphate in aqueous HCl., 31 K,Zr(S0,),,2H20 contains the dimeric anions, [(SOJ,(H,0),Zr(S04),Zr(H20)2(S04)2]4-,in which each ZrIVis co-ordinated to seven oxygen atoms; four from two bidentate sulphate groups, one from a bridging sulphato-group, and two from water molecules.232Broad-line 'H n.m.r. and i.r. spectral studies have been reported for Na,Hf(S0,),,3H20, K,HqS0,)4,H,0, and (NH,),Hf(SOJ3,2H,0 and interpreted in terms of possible structures of these compound~.~~~ Tetrakis(&-caprolactim-O-sulphonato)zirconium(rv) has been prepared by A 1 :1 ZrIV-oheating a solution of ZrC1, in caprolactim-0-sulphonic nitronaphthosulphonic acid complex with a formation constant of 5.1 x lo8 1 mol- 'has been characterized.234b ZrC1, reacts with MeC0,H in CCl, at elevated temperatures to give very pure Zr(O,CMe), (m.p. 190 f 1"C) and the X-ray diffraction characteristics of this compound have been recorded. The reaction of ZrCl, with Ac,O affords mainly ZrC1(02CMe)3.235The syntheses, i.r. spectra, and thermal decomposition of Zr(O,CR), and Hf(O,CR), (R = Me, CH,Cl, or CC1,) have been described.236The stability constants of the 1 :1 complexes between Zr" or Hf" and acetate, ZrIV and mercapt~proprionate,~~' and between Zr02+ and ~ i t r a c o n a t e ~have , ~ been reported. The hydroxyglycolates, [M O(0H), (HOCH CO,),I ,nH ,O and [M(OH)(H OCH CO2)3],nH 0 (M = Zr or Hf, n = 3-7), have been synthesized and the nature of hydrogenbonding involved considered on the basis of their i.r. spectra.239The i.r. spectra of deuteriated (d,) and protonated tetrakis-(dI-mande1ato)-zirconium(w) and -hafnium(Iv) (ML,) are indicative of structures which contain considerable hydrogen-bonding These neutral, stoichieometric products are obtained only

,

,

,

,

230

A. fratiello. G. A. Vidulich, and F. Mako. Inorg. Chem., 1973. 12. 470.

231

P.Sanchez-Batanero, M. Rodriguez-Ponce, and F. Burriel-Marti, Inform. Quim. Anal., 1972, 26,

232

84 (Chem. Abs., 1972, 77, 83050e). M. A. Porai-Koshits, V. I. Sokol, and V. N. Vorotnikova, Zhur. strukt. Khim., 1972, 13, 874. N. F. Savenko, L. I. Fedoryako, 1. A. Sheka, 1. V. Matyash, and A. M. Kalinichenko, Ukrain.

233

234

235

236

237 238 23y

khim. Zhur., 1972,38,410 (Chem. Abs., 1972,77, 158214~). M. Masaki, K. Fukui, J. Kita, and I. Uchida, -Ger. OffPn, 2 221 497 (Chem. Abs., 1973. 78. 29273n); (b) 0.Makitie and R. Pelkonen, Suornen Kemi. (B), 1972,45,243 (Chem. Abs., 1972,77, 118 9390. V. L. Pavlov, Yu.A. Lysenko, and A. A. Kalinichenko, Zhur. neorg. Khim., 1972, 17, 3366. Yu. A. Lysenko and A. A. Kalinichenko, Zhur. neorg. Khim., 1972, 17, 2404. Z. A. Vladimirova, Z. N. Prozorovskaya, and L. N. Komissarova, Zhur. neorg. Khim., 1973, 18, 704; S. K. Srivastava, P. C. Srivastava, and H. L. Nigam, lndian J. Chem., 1972,10, 223. J. Krishnamacharyulu and U. V. Seshaiah, lndian J. Chem. 1972, 10, 1192. Z. N. Prozorovskaya, I. V. Potapova, S. S. Kalinina, V. F. Chuvaev, K. 1. Petrov, and L. N. Komissarova, Zhur. neorg. Khirn.,1972, 17. 2940. (a)

The Early Dunsition Metals 35 with the racemic ligand, suggesting that the dl-ligand pairs provide a stereospecificity, suitable for the formation of stable hydrogeg-bonds, which is not provided by d- or I-ligands alone. Zr(d2-L), is insoluble in both polar and nonpolar solvents sand a polymeric structure containing bridging ligand pairs between the metal ions has been proposed. However, mandelic acid reacts with ZrC1, in MeCN to form ClZrL, and Zr(dl-L),, both of which are considered to consist of seven-co-ordinate monomers.24o 1 :1 Complexes between ZrO’+ and 3-nitro-, 5-nitro-, 3,5-dinitro-, and 5-bromo-salicylicacid have been identified.’,’ 1.r. and X-ray-induced photoelectron spectra of the complexes [M,(OH),(NH,CH,C0,)s]X,,12H,0 (M = Zr or Hf; X = C1, Br, or NO,) have shown that the glycine molecules are 0-bonded to the metal A similar conclusion has been deduced from i.r. spectral studies of the Zr,O(OH),(NH,CH,C0,),,(14 - n)H,O (n = 4-12) complexes.242bStepwise stability constants have been reported for the complexes of zirconium(1v) with diphenylamine-2,2’-dicarboxylic asparagine, and g l ~ t a m i n e . ’ ~ ~ ~ Dry CO, (1 atm) reacts smoothly with Zr(OR), (R = Et or Bu) to give the corEesponding partially carboxylated products. 2 7 A large number of mixed alkoxide-acetoacetate-p-diketonato-or -p-keto-ester complexes of ZrIV have been prepared by refluxing the corresponding hexa-alkoxydizirconium alkylene-bis(acetoacetate)with the appropriate f3-diketone or fi-keto-e~ter,’~~ Alcoholysis of ZrC1, or HfC1, in the presence of pyridine has been studied, and the resulting halogeno-alkoxides were characterized by their i.r. and X-ray diffraction spectra.245 The tetraisopropoxides of ZrW and HfIVmay be prepared in 50-90 % yield by the reaction of the metal tetrachloride with anhydrous Pr’OH at pH 9. Alkoxide exchange with Am‘OH affords the corresponding tetra-t-amyl compounds.246 The extraction of ZrW and HfIV from aqueous HCl by CHCl, solutions of 1-nitroso-naphthol (HA) alone, and in the presence (M = Zr of other chelating agents, has been investigated; the [MA,(OH),Cl, -,,l or Hf, n = 0-2) complexes have been identified in each case.2474,5-Dihydroxyfluoroscein and ZrIVform 1: 1 and 1:2 complexes, the latter being insoluble in water. Several ligand distribution equilibria for eight-co-ordinate p-diketonatozirconium(1v) complexes in solvents of low donor ability have been studied by ’H n.m.r. spectroscopy. These results, together with data from other studies,

’

242

243

244 245 246

248

E. M. Larsen and E. H. Horneier, lnorg. Chem. 1972, 11, 2687. C. S. Pande and G. N. Misra, Indian J . Chem., 1973,11,292. (a) G. S. Kharitonova, V. 1. Nefedov, and L. N. Pankratova Zhur. neorg. Khim., 1972.17, 3134; L. N. Pankratova and G. S. Kharitonova, ibid., p. 2653; (b) Z. N. Prozorovskaya, S. S. Kalinina, L. N. Komissarova, K. I. Petrov, and V. I. Spitsyn, Doklady Akad. Nauk. S.S.S.R., 1972,207, 359. (a) P. N. M. Das, 0. P. Sunar, and C. P. Trivedi, Zndian J . Chem., 1973, 11, 69; (b) R. C. Tewari and M. N. Srivastava, Talanta, 1973, 20, 360. U. B. Saxena, A. K. Rai, and R. C. Mehrotra, Indian J Chem., 1973, 11, 178. G. M. Toptygina, 1. B. Barskaya, and I. Z. Babievskaya, Zhur. neorg. Khim., 1972,14, 2119, 2123. M. 0. Hoch, Ger. Offen., 2 153 354 (Chem. Abs., 1972,77,64 128v). N. P. Rudenko and R. G. Naier, Radiokhimiya, 1972, 14, 478, 645. P. Sun and C. Liu, J . Chinese Chem. SOC.(Formosa), 1972, 19, 35 (Chem. Abs., 1972, 77, 6 6 8 2 8 ~ ) .

36

lnorganic Chemistry of the ?FansitionElements

indicate that, when Hiketonates possess protonated terminal groups, the equilibrium constants for the exchange process are similar to those expected for a random distribution of ligands. However, when one P-diketonate is protonated and the other fluorinated, the equilibrium constants are 102-105 times larger than expected for random exchange, largely because of favourable enthalpy changes. These have been attributed to the differences in the mean Z r 4 bond energies between the mixed and the parent complexes.249 Structural information has been obtained for solid H E , (L = tropolone, N-benzoyl-, or N-nitroso-N-phenylhydroxylamine)complexes by obtaining the nuclear quadrupole interactions of IslTa, produced by the P-decay of IgoHf.Two ls'Ta sites were observed for the last two ligands suggesting that they exist in two isomeric forms. For the tropolonato-complex, a rapid interconversion between isomeric forms appears possible, and [Hf(tropolone),]CHCl, seems to involve an interaction between the occluded solvent molecule and the ligand aromatic rings.250 The extraction of Zr'" and Hfv thiocyanates from aqueous HC1 solutions by acetophenone (HL) has been shown to lead to the formation of the corresponding [M(OH),(NCS),-,(HL),] (n = 2 or 3) complexes.251 The mixed P-diketonates [MC1,-,-nL~L~] (M = Zr or Hf; m = 0,2, or 3; n = 4,2, or 1; L1 and Lz = acac, bzac, or dbm) have been prepared by the reaction of the corresponding P-diketones with MCl, in THF solutions containing Et,N.252 The complexes formed between ZrIV and Hf'" and naphthazarin (1:2), 1,2,4trihydroxyanthraquinone (1: 1 and 1 :2),139and arsenazo I ( 1 : 1)253and between Zr'" and 5-hydroxy-1,4-naphthaquinone (1 :1 and 1: 2)254 have been characterized. S-Donor Ligands. T12Pt3ZrS6has been prepared by heating the constituent binary sulphides for 2-4 days at 400--60O0C in the absence of air.255ZrCl, r?acts with o-mercaptophenol to afford H,[Zr(o-SC,H,O),] and the i.r. spectrum of this complex has been obtained.' 7 9 a Other complexes involving S-donor ligands which have been reported include [ZrL;(NO,),] (HL' = 2,3dimercaptoquinoxaline),256"and ZrLi and HE: (HL' = 3-thianaphthenoyltrifluoroacetone)? 5 6 b This latter chelate has potential for solvent extraction of these elements.

24y

250

251

252

253 254 255 256

T. J. Pinnavaia, M. T. Mocella, B. A. Averill, and J. T. Woodward, lnorg. Chem., 1973. 12, 763. P. Boyer, A. Tissier, and J. 1. Vargas, Inorg. Nuclear Chem. Letters, 1972, 8, 813; P. Boyer, A. Tissier, J. I. Vargas, and P. Vulliet, Chem. Phys. Letters, 1972, 14, 601. I. V. Vinarov, A. 1. Orlova, L. P. Grigor'eva, and L. I. Il'chenko, Zhur. neorg. Khim., 1972, 17, 3035. M. Kh. Minacheva and E. M. Brainina, Izvest. Akad. Nauk S.S.S.R., Ser. Khim., 1973, 689. L. A. Kvichko, V. N. Tolmachev, and V. D. Konkin, Ukrain. khim. Zhur., 1973, 39, 131 (Chem. Abs., 1973, 78, 141 OlSj). T. B. Denisova, Re$ Zhur. khim., 1972, Abs. 24G87 (Chem. Abs. 1973.78, 167 9 5 6 ~ ) . V. Schmidt and W. Rudorff, 2.anorg. Chem., 1973,397, 51. (a) D. Negoiu and N. Muresan, Ann. Uniu. Bucaresti, Chim., 1971,20, 133 (Chem. A h . , 1973,78, 131 536n); (6) J. R. Johnston, W. J. Holland, and J. Gerard, Mikrochim. Acta, 1972, 608 (Chem. Abs., 1972, 77, 147 200p).

The Early ?).ansitionMetals

37

N-Donor Ligands. The isocyanato-complexes of Zr" and HPv, (Et,N),[M(NCO),], have been prepared by the reaction of MCl, with Et,NNCO (1 :2), followed by the addition of AgNCO (4 moles). The i.r. and Raman spectra of these complexes are consistent with N-bonded l i g a n d ~ . , ~The ~" analogous N-bonded selenocyanato-derivatives, K,[M(NCSe),], have been prepared by the extraction of MCl, into a MeCN solution of KNCSe.2576 [M(bipy),(NCS),] and [M(phen),(NCS),] (M = Zr or Hf) have been prepared in THF-MeCN solutions and their i.r. and X-ray diffraction spectra reported.258 The 1:1 and 1 :2 adducts of MX, (M = Zr or Hf; X = C1 or Br) with 3-cyanopyridine have been prepared by mixing chlorinated hydrocarbon solutions of the tetrahalide and the ligand. Their i.r. spectra suggest that the pyridine nitrogen atoms are co-ordinated in both the 1 :2 and the 1:1 adducts, but that only the latter contain co-ordinated cyano nitrogen.'" ZrX,L, (X = C1 or Br; L = 2,4 or 3,5-lutidine) and ZrX,L (X = C1, Br, or I ; L = 2,6-lutidine) have been reported and the former was shown to have a trans-octahedral structure by i.r. spectroscopy.206Several mixed adducts of ZrC1, containing both ethylacetate and N-donor ligands, such as py, 2-a-, 2-8-, or 2-y-picoline, 3-benzylpyridine, EtNH,, or Pr'NH,, have been reported. The ZrC1,,4-ptoluidine and HfC1,,2L (L = py and a-picoline) adducts have also been separated from solutions of the constituent molecules in ethyl acetate.259 Mixed N-donor and O-donor Ligands. The addition of acetone to aqueous solutions containing ZrOC1, and serine (HA) precipitates complexes of the type ZrO,(OH),Cl,,nHA,(14 - n)H,O (n = 4-12), the i.r. spectra of which are consistent with the co-ordination of the amino-acid by carbonyl- and amino-m~ieties.~~~~ ZrL, (HL = phenylbenzohydroxamic acid) has been prepared by treating an aqueous solution containing Zr" with an alcoholic solution of HL; the i.r. spectrum was recorded.,,' A structural study of HfL, (L = N-benzoyl- or N-nitroso-N-phenylhydroxylamine)complexes using 'Ta as a probe is discussed on p. 36 ) . 2 5 0 1 :1 and 1 :2 acylhydrazine complexes of ZrF, and ZrC1, have been prepared and characterized. Their i.r. spectra are consistent with acylhydrazines RCONHNH, (R = Me or Ph) functioning as bidentate NO-donor ligands in the 1: 1 complexes, and diacylhydrazines RCONHNHCOR (R = H or Me) acting as quadridentate ligands in the 1 :2 complexes.' 5 9 A 1 :3 ZrIv-diantipyrylmethane complex, with a stability constant of 8.4 x lo', l3 r n ~ l has - ~ been reported,,' and the relative efficiency of this ligand

'

257

(a) E. J. Peterson, A. Galliart, and T. M. Brown, Znorg. Nuclear Chem. Letters, 1973, 9, 241 ; (6) A. Galliart and T. M. Brown, J . Inorg. Nuclear Chem., 1972,34, 3568.

258

A, M. Golub, T. P. Lishko, G. V. Tsintsadze, and V. V. Skopenko, Zhur. neorg. Khim., 1972, 17, 2115. Ts. B. Konunova and M. F. Frunze, Ref: Zhur. khim., 1972, Abs. 5V93, (Chem. A h . , 1972, 77, 172 0522). K. Bhatt and Y . K. Agrawal, Synth. Znorg. Metal-Org. Chem., 1972,2,175. M. I. Shtokalo and T. S.Chernukha, Izuest. K U.Z., Khim. i khim. technol., 1972,15,670, (Chem. A h . , 1972, 77, 66 8512).

259

260 261

Inorganic Chemistry of the Transition Elements

38

at extracting aqueous Zr'" and Hf" shown to be ca. 10:1.262ZrIVcomplexes with the Schiff bases (25)2b3"and those derived from the condensation of aminocarbazole with 2-hydro~yarylaldehydes,~~~~ have been isolated and characterized. OH

i. (25) X X X

=

SO,H H, Y

=

H, S 0 3 H , C1, or NO2

Y = NO2 or S 0 3 H = SO3H, Y = NO2

=

Organometallic Zirconium(Iv) and Hafnium(rv) Compounds.-o-Bonded CompZexes.Tetrakis(neopenty1)-zirconium(1v) and -hafnium(rv) have been obtained in good yield by treating the anhydrous metal chlorides with neopentyl-lithium in ether solutions at 0 "C. The compounds are readily purified by sublimation in vucuo at ca. 50°C. The zirconium derivative is an active catalyst for the polymerization of a-olefins and dienes. Zr(CH,CMe,), reacts with CO at 25 "C and 1atm, to give products which have i.r. bands characteristic of terminal carbonyl groups.16' CO also reacts with Zr(CH,R), (R = vinyl or Ph) by successive insertion into the Z r - C bonds.264 Further characterization of Zr(CH,Ph), has been reported, including 'H and 13Cn.m.r. spectral studies,166 and its dark-red 1:l adduct with 2,2'-bipyridyl has been isolated. The addition of alkylchloroaluminium derivatives to ZrR, (R = PhCH, or allyl) produces active catalysts for the preparation of C,-C,, a-olefins from ethylene.26sThe reaction of ZrC1, and LiPh (1:4)in Et,O at - 30 to - 40 "C for 2 h under argon, affords a brown solution thought to contain LiPh,. The compound was not isolated because of its thermal instability but its reactions, e.g. with HgCl,, were consistent with its formulation.204 The isoleptic compounds M(CH,SiMe,-,,RJ (R = Ph or PhCH, ;n = 0-2) have been obtained from reactions between MCl, and Mg(R,Me, -,SiCHJ, in hexane; the 'H n.m.r. spectra of these complexes were recorded. The compounds are thermally more stable than their methyl analogues and their oxidative stabilities correlate with the degree of steric shielding at the metal centre.Zr(CH,SiMe,), reacts with acacHin the ratio 1:2 to form [(Me,SiCH,),Z~facac),] and in the ratio 1 : 1 to give a 7 :I :0.3mixture of [(Me,SiCH,),Zr(acac),-J (n = 3,2, and 4, respectively). [(n-Cp),M'(CH,M2Me,),] (M1 = Zr 262

263

264

2b5

R G Naier and N. P Rudenkn. Radiokhirniya. 1972, 14, 480. (a) N. N. Basargin, V. A. Goloanitskaya, A. V. Kodorntseva, and R. M. Saginashvili, Zauod. Lab.. 1972,38,773(Chem. A h . , 1972,77, 169416r); (6) T. M. Kulikova, V.D. Chistola, and V.I. Shishkina, Ref: Zhur. khim., 1971, Abs. 24634 (Chem. A h . , 1972,77, 147 1lOj). C. 1. Attridge, B. Dobbs, and S. J. Maddock, J . OrganometalZic Chem., 1973, 57, (255. C . J. Attridge, R. Tackson, S. J Maddock. and D. T. Thompson. J.C.S. Chem. Cnmm.. 1973, 132.

The Early Transition Metals

39

or Hf; M2 = Si or Ge) have been prepared from Me,M2CH,Li and [(n-Cp),M'Cl,] in ether.172 The use of low temperatures and long reaction times enables some metalcarbon o-bonded compounds to be prepared by the reversal of p-elimination reactions. [(n-Cp),ZrRCl] (R = CHMeCHMe,, cyclohexyl, or p-CH,CH,C,H,Ph) have been obtained from [(n-Cp),ZrHCl] and the corresponding are hydrogenaolefin. [(z-Cp),ZrHCl] and [(n-Cp),ZrMeX] (X = Me or tion catalysts.l Z 5[(n-Cp),ZrCl,] and [(n-Cp),HfCl,] react with the appropriate organolithium reagents to form stable dimethyl and diphenyl derivatives. The bisrn-indeny1)halides of these elements likewise react with these reagents to form the corresponding dimethyl and diphenyl compounds, which appear to be more stable than their n-cyclopentadienyl analogues.' 73 The optimum conditions for forming tetracyclopentadienylzirconium(1v)have been described266" and the crystal structure of tetracyclopentadienylhafnium(1v) has been determined.266b n-&nded Complexes. The i.r. and Raman spectra (600-50 cm-l) have been reported for [(n-Cp),ZrX,] and [(n-Cp),HfX,] (X = Me, F, C1, Br, or I) and the comparisons afforded by this detailed study have allowed the metal-ring and metal-ligand stretching modes to be assigned.' 84 (1,l'-Trimethylene-di-ncyclopentadieny1)-zirconiumand -hafnium dichlorides have been prepared by treating Na2[C,H4(CH2),C,H4] with the corresponding metal tetrachloride ; 'H n.m.r., i.r., and electronic spectra were r e ~ 0 r d e d . l ~The ~ " dipole moments and i.r. spectra of [(n-Cp),Zr(NCS),] and [(n-Cp),Zr(OCN),] have been determined,' 83 and [(n-Cp),Zr(SC,H,O-o)] has been prepared by treating [(n-Cp),ZrCl,] with o-mercaptophenol in the presence of Et, N.l 79" [(nCp)MLX] (M = Zr or Hf; X = C1 or Br; L = acac, bzac, or dbm) derivatives have been prepared from [(n-Cp),MX,] and ML,. The 'H n.m.r. spectra of these compounds in CCl, from - 25 to 70 "C have been obtained and discussed in terms of possible structures for these molecules?67 The mechanism of interchange of the syn- and anti-protons of [Zr(h3-C,H,),] has been studied by determining the temperature dependence of the 'H n.m.r. spectrum of the compound dissolved in CFCl,. This has demonstrated that the mechanism involves allyl-group interchange.268 spectra of Zirconium(1v) and Hafnium(I v) Hydrido-Compounds.-The Zr(BHJ4, Zr(BD,),, Hf(BHJ,, and Hf(BDJ, vapours have been re-investigated and the Raman spectra of Zr(BHJ, and HqBHJ, dissolved in benzene have been reported for the first time. In all cases the results are consistent with a 3 structure containing triple hydrogen-bridged tetrahydroboratoThe vibrational spectra of [(n-Cp),Zr(BHJ,] and [(n-Cp),ZrH-

a)

Zhh

267

268

269

(a) A. V. Medvedeva and D. N. Ryabenko, Zhur. priklad Khim., 1972,45,1296 (Chem. Abs., 1972.

77, 75 301x); (b) V. 1. Kulishov, N. G. Bokii and Yu. T. Struchkov, Zhur. strukt. Khim., 1972, 13, 11 10. Z. M. Brainina, M. Kh. Minacheva, and L. A Fedorov, lzvest. Akad. Nauk S.S.S.R., Ser. khim., 1972, 2356. J . K. Krieger, J. M. Deutch, and G. M. Whitesides, Inorg. Chem., 1973,12, 1535. N.Davies, M.G. H. Wallbridge, B. E. Smith, and B. D. James, J.C.S. Dalton, 1973. 162.

40

Inorganic Chemistry of the nunsition Elements

(BH,)] have been described and interpreted in terms of double hydrogenbridged bonding of the tetrahydroborato-gro~ps.~~ Dropwise addition of AlMe, to a stirred slurry of [(n-Cp),ZrH,] (1 :1) in benzene at room temperature rapidly produces a clear violet solution, from (

x - C P ) ~Zr-H-A1Me3

/\ \/

H

H

__

(

x -Cp)2Zr-H-A1Me3

which the pale blue compound (26) may be obtained in essentially quantitative yield. The proposed structure is consistent with the lH n.m.r. spectrum of the compound. The compound is thermally unstable and decomposes at room temperature, via interaction of methyl groups and the bridging hydrogen atoms, to give CH,, H,, and a crimson compound.270

3 Vanadium Introduction.-The possibility of allotropy in vanadium metal at sub-ambient temperatures has been investigated by measuring the electrical resistivity in the [llO] direction of a single crystal, the elastic constants, and by X-ray diffraction studies. The results were consistent with no allotropy.271 The information available on vanadium chemistry has been indexedz7, and the organometallic chemistry of this element reported during 1971 has been reviewed.273 Dicyclopentadienylpentacarbonyldivanadium has been shown

(27) Distances in pm

270

P. C. Wailes, H. Weigold, and A. P. Bell, .I Organometallic . Chem., 1972, 43, C29. D. G. Westlake. S. T. Ockers. M H Miiller. and K. D. Anderson. Met. Trans.. 1972.3.1711 (Chern.

Abs., 1972, 77, 61 2 2 8 ~ ) . Gmelin’s Handbook of Inorganic Chemistry, System Nos. 48/49/50, Vanadium-NiobiumTantalum Index,Gmelin Institute, Max Planck Institute. 1973. VI. 2 7 3 F. Calderazzo, J . Organometallic Chem., 1973, 53, 207.

272

The Early Dunsition Metals

41

by X-ray diffraction methods to involve grossly unsymmetrical carbonyl bridges between the two metal centres (27). Each vanadium atom is bonded to a .n-cyclopentadienyl ring and the other vanadium; however, one atom is bonded to one terminal carbonyl group and strongly attached to two bridging carbonyls, whilst the other atom is less strongly bonded to the carbon atoms of the latter, but has two terminal carbonyl The first structural elucidation of a naturally occurring vanadium compound has been achieved. Amavadine, which has been isolated from the fly Arnanita rnuscaria, has been shown by degradative, synthetic, and spectroscopic studies to ~ ~ 'use of the vanadyl group as a new spectrohave the structure (32) ( ~ . 5 4 ) . The scopic probe of metal binding sites in proteins has been demonstrated by its incorporation into insulin. Em., optical, and i.r. spectra of the protein-bound V 0 2 + have indicated that it is held on two types of site; the co-ordination geometry about the metal was determined in each case. This approach should be valuable in the study of other metal lop rote in^.^^^ Carbonyl and other Low Oxidation State Compounds.-Bu 4N[V(C0)6] has been obtained by electrochemical reduction of VCl, or [V(acac),] at an A1 anode in an aprotic solvent containing Bu,NBr and saturated with CO at low to medium pressures. BU4N[V(CO)6] is readily converted into V(CO), by mixing with 99 % H,P04 and P,OI0 at 30-35 "C under reduced pressure, the carbonyl distilling from the reaction mixture.277 The magnetic susceptibility of V(CO), has been determined between 4.2 and 300 K. Above 66 K the data are consistent with octahedral V(CO), molecules but below this temperature both axial distortion and magnetic exchange between pairs of molecules seem to occur.278 The structure of dicyclopentadienylpentacarbonyldivanadium(27) is described above. There is no simple way in which the electronic structure of the compound can be rationalized, although the atomic structure offers a good basis for the interpretation of its complex reactions and fluxional properties.274 Carbonyl exchange of [(7c-Cp)V(CO),] with 13C0, CI80, or 13C180 has been followed by i.r. spectroscopy; all the various v(C=O) stretching frequencies were assigned.279"[(7c-Cp)V(CO),] and [(n-Cp)V(CO),PPh, J are protonated by CF,CO,H or HCl in CH2C12solution and their basicities have been assessed in relation to those of related compounds.279b Dicycloheptatrienevanadium(0)has been prepared, by treating VCl, with Pr'MgCl in ether in the presence of cycloheptatriene, and its magnetic, mass,

274

275

276

277

278

'''

F. A. Cotton, B. A. Frenz, and L. Kruczynski, J . Amer. Chem. SOC.,1973,95, 951. H. Kneifel and E. Bayer, Angew. Chem. Internat. Edn., 1973, 12, 508; Z . Naturjorsch., 1972, 27b, 207. N. D. Chasteen, R. J. Dekoch, B. L. Rogers, and M. W. Hanna, J . Amer. Chem. SOC.,1973,95,1301. G. Silvestri, S. Gambino, M. Guainazzi, and R. Ercoli, J.C.S. Dalton, 1972,2558. J. C. Bernier and 0. Kahn, Chem. Phys. Letters, 1973, 19, 414. (a) I. S. Butler and A. E. Fenster, J . Urganometallic Chem., 1973, 51, 307; (6) B. V. Lokshin, A. A. Pasinsky, N. E. Kolobova, K. N. Anisimov, and Yu. V. Makarov, ibid., 1973, 55, 315.

42

Inorganic Chemistry of the nunsition Elements

and 'H n.m.r. spectral properties were reported. This compound reacts with Ph,CBF, to give [(C,H7)2V](BF,)2.280 Nitrosyl Complexes.-K,[V(CN),NO],H,O has been prepared by passing H2S into vanadate(v) solutions containing CX- and NH,OH, and characterized in magnetic and i.r., electronic, and X-ray diffraction spectral studies.,' la The i.r. spectra of this and related complexes have been described and discussed.281b Binary Compounds and Related Species.-Halides. The electronic spectra of VX, (X = C1, Br, or I) crystals have been studied at various temperatures and, whilst the gross features are consistent with isolated V" centres, sharp fine structure and intense spin-forbidden bands are indicative of some antiferromagnetic exchange between these centres.282 VF, has been synthesized in almost quantitative yield by the reduction of VF, on a heated vanadium filament.283.The electronic spectrum of VCl, in the vacuum U.V. has been reported for gas-phase samples at room temperature and the spectral results compared with relevant photoelectron and theoretical data. The results indicate that the higher-energy transitions are due to chlorine non-bonding electrons.' Oxides. The crystal structures of solid solutions of oxygen in vanadium near the composition V,O have been determined by X-ray and electron diffraction. The oxygen atoms occupy the octahedral interstitial sites in a regular manner, forming a body-centred, tetragonal super-lattice of stoicheiometry ca. V, 603.2 84 The superstructure of VO, (1.15 < x ,< 1.25) has been shown to involve a regular arrangement of cation-vacancy clusters.285 The crystallography of the compounds V,O, n- (3 < n d 8) have been determined; the lattice n = 4-8 can be systematically described on the basis of the parent rutile lattice and that The of V,O, is related to this structure by a choice of 2a as cell metal-insulator transitions in V,07 and VO, have been investigated by X-ray diffraction techniques and the lattice parameters of v407 determined between 77 and 298 K.23 A consideration of the electronic structures of v307 and V,O, has led to the conclusion that the former cannot contain V'" ions and that the real formula of the latter is probably close to V,08(OH).2'7 The hydrothermal reduction of V 2 0 , by SO, yields a series of oxides in which the oxidation state of vanadium

'" J . Miiller and B. Mertschenk, Chem. Ber., 1972, 105, 3346. (a) A. Miiller, P. Werle, E. Diemann, and P. J. Aymonino, Chem. Ber., 1972, 105, 2419; (b) J. Ziolkowski, B. Jezowska-Trzebiatowska, and B. B. Kedzia, Bull. Acad. polon. Sci.,Sir. Sci.chim., 1972,20, 231. (Chem. Abs.. 1973.78, 54449q). 2 8 2 W. E. Smith, J.C.S. Dalton, 1972, 1634. l B 3W. E. Falconer, G. R. Jones, W. A. Sunder, I. Haigh, and R. D. Peacock, J . lnorg. Nuclear Chem., 1973, 35, 751. 284 K. Hiraga and M. Hirabayashi, J . Phys. SOC. Japan, 1973,34,965 (Chem. Abs., 1973,78,141215~). 2 8 5 M. Saeki and M. Nakahira, Materials Res. Bull. 1971,6, 603 (Chem. Abs., 1972,77, 805222). 2 8 6 H. Horiuchi, M. Tokonami, N. Morimoto, K. Nagasawa, Y. Bando. and T. Takada, Materials Res. Bull. 1971,6, 833 (Chem. Abs., 1972,77, 80564q). A Casalot. Materials Rrs. Bull. 1972 7, 903. (Chem. Abs., 1972, 77, 131 719d) 281

'"

The Early llansition Metals

43

varies from 4.8 to 3.0, according to the initial ratio of reactants, V,O,,H,O and V204.8,nH20have been prepared crystallographically pure by such reductions.288The introduction of MOO, into the V205lattice results in the formation of VIVcentres by encouraging the release of electrons into the conduction band. These effects, which are important in understanding the catalytic properties of V205-MOO, systems, have been monitored by electronic and i.r. spectroscopy.289 The vapour pressure of V 2 0 , has been determined between 973 and 1473 K, and the enthalpy of evaporation calculated as ca. 143 kJ mol-'.290 The electrical conductivity of liquid V 2 0 , has been measured as a function of both temperature and partial pressure of oxygen.291Raman and i.r. spectra or oriented single-crystals of V20, have been recorded and the absorption frequencies compared with those calculated using a simple transferred forcefieid.292 Chakogenides. A review has been presented in which the distortions of the VS structure are discussed.293Tio.84Vo.16S2 and Ti,.,,V,.,S2 have been prepared by grinding a mixture of TiS,, V, and S prior to heating at 950 "C for 1 week; the X-ray diffraction and magnetic properties of these disulphides were obtained.26 The structure of patronite, V(S2),, has been refined. Each vanadium atom is surrounded by four dumbell-shaped S , groups, each of which is bonded by two vanadium atoms. In this manner V(S2, chains are formed, the V-V distances alternating between 284 and 321 pm. The eight V-4 distances about each metal centre range from 239 to 250 pm, the S-S separations being 203.8 pm.294The vibrational spectra of V(S3, have been studied and the S 4 stretching modes shown to occur between 500 and 600 ~ r n - l . ~ , Layer intercalation compounds of VSe, with NH,, N2H4, N2H4,H,0, and NHRNHMe (R = H or Me) have been reported and the corresponding layer expansions determined.,' FeV2Te4 has been prepared and shown to be a metallic compound with the monoclinic defect NiAs-type structure.295 Compounds with Elements of Group V. The phase V,N has been characterized in the V-N system296and the phase diagram of the V-N-0 system con~tructed.~'~ Phase equilibria in the V-P-C system have been investigated at 1O0O"C and a new compound, V4P,, has been identified and shown to be of the Nb4As,289

290 291

292

293 294

295

296 29'

M. Tachez, F. Theobald, J. Tudo, and G. LaPlaLe, Compt. rend., 1973, 276, C , 1187. A. Bielanski, K. Dyrek, and A. Kozlowska-Rog. Bull. Acad. Polon. Sci., Skr. Sci. chim., 1972, 20, 1057 (Chem. Abs., 1973,78, 64 629e). T. A. Pak, Zhur.Jiz. Khim., 1972,46, 2121. R. C. Kerby and J. R. Wilson, Canad. J . Chem.. 1972, 50,2865. T. R. Gilson, 0. F. Bizri, and N. Cheetham, J.C.S. Dalton, 1973, 291. F. Jellinek, Nut. Bur. Stand. (U.S.A.)Spec. Publ. No. 364, 1972, 625. A. Kutoglu and R. Allman, Neues Jahrb. Mineral. Monatsh., 1972, 339 (Chem. Abs., 1972, 77, 157 447p). R. H. Plovnick, J . Solid State Chem., 1972,5153. D. Potter and R. Geils, Scr. Met., 1972,6, 395 (Chem. Abs., 1972,77, 53343k). G. Brauer and H. Reuther, Z onorq. Chem.. 1973,395, 151.

44

Inorganic Chemistry ofthe Transition Elements

type.," X-Ray diffraction studies have shown that VP has the NiAs-type structure and neutron diffraction studies that VAs has the MnP-type structure. The magnetic electrical properties of these phases have also been examined.299 V,As, has been shown by X-ray diffraction studies to beisotypic with N~,As,.~" V,P,S, has been prepared by prolonged heating of a stoicheiometric mixture of the elements at 3 2 0 4 0 0 "C and its X-ray diffraction characteristics have been reported.301 The crystal structure of V,P,C, identified in the V-P-C system, is of a new type which contains both trigonal prismatic and octahedral units.298 Hydrides. The phase diagram and thermodynamic data for the V-H system have been pre~ented.~" Vanadium@).-The compounds RbVCl, (m.p. 1078 "C) and Rb,VCl, have been identified in the RbCl-VC1, system and both were shown to contain octahedrally co-ordinated V11.303The alkali bromovanadate (11) salts, MVBr3,6H,0 (M = K, Rb, Cs, or NHJ, have been prepared by electrolytic reduction of V,O, in dilute HBr solutions, followed by the addition of MBr. These hexahydrates are all very hygroscopic, oxygen-sensitive compounds. CsVBr3,3H,0 has also been prepared and all these Rb, Cs, and NH, salts were dehydrated to the anhydrous compounds by heating to 230 "C in uacuo.304 The y-picoline (L) complexes [VX2L,] (X = Cl, Br, or I) have been obtained by the reaction of VX,,nH,O with L in EtOH or acetone, and their effective magnetic moments and V-X stretching frequencies determined.,05 The reactions of azo-compoundq with transition-metal complexes are of interest in connection with atmospheric nitrogen fixation. Vanadocene has been shown to react during one day at room temperature with azobenzene in toluene to give black-maroon crystals of [(n-Cp),V(PhN=NPh)]. The structure of these molecules would appear to be analogous to that of the titanium derivative ( 5 ) (p. 6).41 The fixation of nitrogen in protic media containing V" has been achieved by mixing solutions of VS0,,7H20 containing NaOH with pyrocatechol under N,, NH, being formed and Na,SO, precipitated. The reduction may proceed via NzH4 formation, since N2H4 is reduced to NH, under these conditions. The optimum yields were obtained in 50% alcohol solutions.306The kinetics of the reduction of N, to NzH4 by Zn in alkaline media containing V". V"', and and the fixation of N, by 298 299

300 301

302 303

304 305

306

307

H. Boller, M o w t s h . , 1973, 104, 48. K. Selte, A. Kjekshus, and A. F. Andresse, Acta Chem. Scnnd., 1972, 26, 4057. K. Yvon and H. Boller, Monatsh., 1972, 103, 1643. W. Klingen, R. Ott, and H. Hahn, Z . anorg. Chem., 1973,3%, 271. R. Griffiths, 3. A. Pryde, and A. Righini-Brand, J.C.S. Faraday 1, 1972,68,2344. E. K. Lupenko, A. I. Efimov, and 1. I. Kozhina, Vestnik Leningrad Univ., Fiz. Khim., 1972, 114 (Chem. Abs., 1973,78,49 156e). H. J. Seifert and A . Wuesteneck, lnorg. Nuclear Chem. Letters, 1972, 8, 949. M. M. Kharnar and L. F. Larkworthy, Chem. Ind. (London) 1972, 807. L. A. Nikonova, A. G. Ovcharenko. 0. N. Efimov, V. A. Avilov, and A. E. Shilov, Kinetika i Katalitz, 1972,13, 1602 (Chem. Abs., l973,78,91995c). D. V. Sokol'skii, Ya. A. Dorfrnan, Yu. M. Shindler, and V. S. Ernel'yanov, Zhur.$z. Khim., 1972, 46,2929.

The Early Transition Metals

45

VC1,-Mg systems in THF,40 have been investigated; both were shown to involve VI'I-V'I redox equilibria. Some mixed valence V*rr-Vrl complexes are described in the following section. Vanadium(rII).--HaZides and OxyhaZides. All of the compounds VX,,6H20 (X = C1 or Br), RbVC1,,6H,O, and Cr,VX,,nH,O (X = C1, n = 4; X = Br, n = 5) have been shown to contain the green trans-[VX,(H,O),]+ ion. A new method of preparing the compounds M,VCl,,H,O (M = K, Rb, Cs, or NHJ has been described and involves dehydrating the corresponding diaquocomplexes in vamo at ca. 50°C. These monohydrates contain the red [VC1,(H,0)]2- ion and may themselves be dehydrated at ca. 170 "C to afford the corresponding intensely coloured, violet M,VCl, salt, the magnetic properties of which have been interpreted in terms of a weak antiferromagnetic interaction in a polymeric structure.308 A d.t.a. study of the VC1,-TiC1,-KCl system has failed to identify any compounds other than K,VCl, and K3TiC1,.46 [VCl,]- has been prepared in benzene solution using long-chain quaternary ammonium cations to give solubility, and the ligand-field and far4.r. spectra of the anion have been recorded., O9 M3VOCl, (M = K, Rb, or Cs) have been prepared by treating M3VC1, with Sb,03 (3 ;1) for up to 30 h in an inert-gas atmosphere and the partially oxidized products obtained on chlorination of these compounds have been characterized.,' 0-Donor Ligands. NaVO, has been obtained by the 1 :1 reaction of Na,O and V,O,, and its X-ray diffraction pattern indicates that it has a structure similar to that of a-NaFeO,. NaVO, may also be prepared by reducing VO, with liquid sodium at 150 "C; this reagent reacts with V,O, at 600°C to afford NaVO, plus Na,VO,, and with V,O, to produce NaVO, plus VO. This latter binary oxide may be oxidized by a solution of oxygen in liquid sodium to form NaV02.31' YV0348and VTa0,49 have been prepared from the corresponding oxides by ceramic techniques. The former compound has been characterized by X-ray diffraction studiesand the latter by X-ray and neutron diffraction,and magnetic measurements, which have indicated that the V"' and TaVatoms are distributed statistically with respect to the Ti" positions of the rutile structure. Oxidation states in the spinel FeCoVO, have been characterized by Mossbauer, magnetic, and diffraction studies ;Co"(Fen'V"')O, is suggested as the most probable formula.31 V(OH)SO, has been obtained by the reduction of V20, by SO, and its properties compared with those of VOS04.288HV(S04),,4H,0 has been 308

309 310

311

312

L. P. Podmore and P. W. Smith, Austral. J . Chem., 1972,25, 2521 E. F. King and M. L. Good, Spectrochim. Acta, 1973,29A, 707. A. I. Morozov and E. V. Karlova, U.S.S.R. P., 352844; A. I. Morozov, 1. S. Morozov, and E. V. Karlova, ibid., 361 145 (Chem. Abs., 1973, 78, 74 275a,113442z). M. G. Barker and A. J. Hooper, J.C.S. Dalton, 1973, 1517, 1520. 5. C. Bernier and E. Both, Materials Res Bull., 1973. 8, 253 (Chem. Abs., 1973,78, 117331k).

46

Inorganic Chemistry of the Transition Elements

crystallized from aqueous H2S04 solutions of V"'. Heating this compound in an atmosphere of moist oxygen affords HV(S0,J2,2H20 at 110"C, (H,O)V(S04)2at 160°C, and V,(SOJ3 at 230°C. The X-ray diffraction patterns of all these vanadium(II1) sulphates have been recorded,,', as have those of the anhydrous vanadium(Ix1) alums, MV(S0,J2 (M = Na, NH,, T1, or Ag). These NH, and Tl salts were prepared by dehydrating the corresponding hydrates in U ~ C U Oat 250 "Cand the Na and Ag ones by heating finely powdered mixtures of V2(S04), and M2S04at cu. 300 "Cfor up to 3 days., Ag3V(S04), may be prepared in the latter manner, using the appropriate proportions of reactants.31 4b Refluxing vanadium(v) salts with Na-Hg in 1 :1 glacial acetic acid-acetic anhydride for 1-2 h provides an easy route to vanadium(II1) acetate.56Basic vanadium(II1) acetate has been re-investigated. The compound was prepared by refluxing anhydrous VC13 under dry nitrogen for 8 h with a four-fold excess of glacial MeC0,H. The i.r. spectrum of the product favours the formulation [V30(02CMe),(02CMe)2,2MeC02H]~, i.e. the vanadium analogue of 'manganic acetate', and the magnetic properties of the compound are also consistent with this formulation. Therefore, vanadium(rI1) can form carboxylato-complexes which are based on the [M,0(O2CR),L3]+ unit.315 The complexes A[VX4(MeC0,H)2] (A = Me,N, Et,N, or pyH; X = C1 or Br) have been prepared by refluxing VX,,3H20 in MeCOX until dissolved, and then adding AX. The co-ordination of neutral acetic acid molecules has been demonstrated by analytical and spectroscopic methods, the latter suggesting that the anions have a cis-octahedral c ~ n f i g u r a t i o nVanadium(Ir1) .~~ reacts with an excess of P-resorcylic acid to form 1 :1 and 1 :2 complexes having A,, values of 322 and 380 nm, re~pectively.~' Thermal decomposition of vanadium(rI1) oxalates has been shown to proceed via electron transfer and C - 0 bond fission to afford CO, and a smaller amount of C0.,17 Vanadium(Ix1) squarate trihydrate has been prepared by mixing an aqueous solution of VC1,,6H20 with one of squaric acid. Electronic, i.r,, and X-ray diffraction spectra have been obtained and t.g.a. showed that the complex loses up to three water molecules on heating. The hydroxo-bridged dimeric structure (28) has been proposed from these data. The effective magnetic moments of 2.80 BM for these hydrates are normal for such d2-systems,but the value of 2.60 BM for anhydrous vanadium(xr1) squarate suggests this contains some spin-coupling between the metal centre^.^' * The temperature-dependent 'H n.m.r. spectra of tris-(a-isopropyltropo1onato)- and tris-(a-isopropyltropo1onato)-vanadium(II1)have shown that they 313 31J

315

316

317

318

J. Tudo and G. LaPlace. Compt. rend.. 1973.276, C. 277. (a) R . Perret, A. Thierr-Sorel, and P. Couchot, Bull., SOC.franc. Mintral. Crist., 1972, 95, 521 ; (b) R. Perret and P. Couchot, Compt. rend., 1972, 274, C, 1735. B. J. Allin and P. Thornton, Inorg. Nuclear Chem. Letters, 1973,9,449. S. Ya. Shnaiderman and G. N. Prokofeva, Zhur. analit. Khim., 1972, 27, 697. K. Nagase, h l l . Chern. SOC. Japan, 1973,46, 144. S. M. Condren and H. 0. McDonald, Inorg. Chem., 1973, 12, 5 7 ; S. M. Condren, Diss.Abs. (4, 1972.32. 6889

47

T h e Early Ransition Metals

(28) n = 2 01'3

are stereochemically non-rigid complexes which attain the fast-exchange limit of inversion and/or isomerization below 0 OC.,I9 An analysis of the isotopically shifted l H n.m.r. signals of the labile complex tris-[( + )-3-acetylcamphorato-]vanadium(II1) in various media has revealed how the number of isomers present and their relative abundances change from solvent to solvent.320 The structure of [V(urea),]I, is almost identical with that of the analogous Ti'" compound, involving VO, octahedra distorted by a 7" twist about the three-fold axis. At 300 K the V - 0 bond lengths are 198(2) pm and at 90 K 193(1) pm. Each [V(urea),13+ ion comprises two sets of three urea molecules with strong hydrogen-bonding with each set. The magnetic susceptibility of this compound has been measured between 300 and 80K and the results were interpreted in terms of a 'Tlgground state using a point-charge model.321 S-Donor Ligands. La,VBe,S,, has been prepared and its X-ray diffraction pattern recorded.,, VCl, reacts with K(S(S)AsPh,) in alcohol to afford [V{ S(S)AsPh,),], the magnetic, i.r., and electronic spectral properties of which have been obtained.,,, N-Donor Ligands. VCl,,H,C(NMe,), has been identified as one of the products of the reaction between VCl, and B,(NMe,),, and characterized by i-r. and electronic spectroscopy. This compound reacts with py to afford V C 1 , , 2 ~ y . ~ ~ ~ The electronic structure of some intense purple-coloured complexes initially thought to contain [L,V"(OH),Vn'L,]4+ (L = bipy or phen) ions have been investigated, the complexes being isolated as SO:- or mixed PFi-Cl- salts. Electronic and photoelectron spectra and magnetic and e.s.r. measurements have shown that these complexes are in fact novel examples of dinuclear mixed-valence species containing both V" and Vn'.,,, The i.r. spectra of [V(bipy)J+ complexes, in which the formal oxidation state of the metal ranges from 111 to -I, indicate that the electron density on the ligands increases with decreasing oxidation state whereas that at the metal remains essentially ~onstant.~' Mixed N-Donor and 0-donor Ligands. V"'-Schiff base complexes, [VLCl],py [L = salen or NN'-phenylbis(salicylideneiminato)] and [V(salen)C1],2py, 319 320 321 322 323 324

S. S. Eaton, G. R . Eaton. R. H Holm, and E. L. Muetterties, J . Amer. Chrrn. SOC.. 1973, 95, 1 1 16. R. M. King and G. W. Everett, j u n , Inorg. Chim. Acta, 1973,7,43. B. N. Figgis and L. G. B. Wadley, J.C.S. Dalton, 1972, 2182. A. Muller and P. Werle, Chem. Ber., 1971,104, 3782. R. F. Kiesel, Dim Abs. (B), 1972, 32, 6276. K. S. Murray and R. M. Sheahan, J C.S. Dalton, 1973, 1182.

48

Inorganic Chemistry of the l'fansition Elements

have been synthesized by allowing VCl, and the appropriate ligand to react in py solution; the corresponding bromo-complexes were obtained by exchange with LiBr. The magnetic and spectral properties of all these complexes are generally consistent with tetragonally distorted octahedral structures.325VCl, at elevated temperatures to reacts with diethyl 6-methylpyridine-2-phosphate precipitate tris(ethoxy-6-methylpyridine-2-phosphonato)vanadium(111),and spectral evidence suggests that the ligand functions as a bidentate NO-chelate to afford a distorted octahedral complex.73 Cyano-complexes. K4[V(CN),],2H20 has been prepared by passing H,S into vanadate(v) solutions containing CN- . This compound has been characterized by i.r. and electronic spectra and magnetic measurements,281aand an X-ray diffraction study has shown that it contains discrete [V(CN),]"- anions with an approximately pentagonal-bipyramidal structure. The lengths of the equatorial V--C bonds are not significantly different, but these distances of 214.4 and 214.9 pm, respectively, are longer than those of other 3d-transition-metal 26 cyano-c~mplexes.~ Organometallic Vanadium (111) Compounds. A wide range of x-cyclopentadienyl dicarboxylates has been prepared327aand their magnetic properties have been interpreted on the basis of monomeric units or dimers of the [(x-Cp)V(O,CCF,),], type.327bThis latter structure has been confirmed for bis-(xcyclopentadienyl)vanadium(m) die-furancarboxylate by X-ray diffraction methods: the four bridging carboxylato-groups span a V - - - V distance of 362.5pm.328 Polarographic reduction of [(x-Cp),VS,CNR,]+ (R, = Me,, Et,, Pri, Bu,, or MeH) has been shown to yield the corresponding neutral V"' complex. These molecules are susceptible to dissociation, releasing free S,CNR, ions, a process which is enhanced by the presence of oxygen.329 Vanadium(Iv).--Halides and Oxyhalides. The formation constant of [VOF,]has been determined by an ion-exchange method.86 The d-d spectrum of the pentachlorovanadate(1v) ion in [PCl,] [VCl,] has been analysed in terms of the angular-overlap model, and a square-pyramidal C,, structure suggested as a result of this analysis.330V 0 2 + substitutes in the (NHJ,SbCl, lattice on the antimony(m) sites which have approximately C,, symmetry. MO and ligand-field calculations strongly suggest that [VOC1,]2 ions are formed in this ~ituation.~,'Substitution of chloride ions for the water molecules in [VO(H20)5]2' has been studied by e.s.r. spectroscopy :resonances 325 326

327

328 329 330 331

K. S. Murray, G. R. Simm, and B. 0. West, Austral. J . Chem., 1973,26, 991. R. L. R. Towns and R. A. Levenson, J . Amer. Chem. Soc., 1972.94, 4345. (a) V. T. Kalinnov, V. V. Zelentsov, G. M. Larin, A. A. Pasynskii, and 0. D. Ubozhenko, Zhur. obshchei Khim., 1972, 42, 2692; (b) G. M. Larin, V. T. Kalinnikov, G. C . Alexandrov, Yu. T. Struchkov, A. A. Pasynskii, and N. E. Kolsbova, J . Organometallic Chem., 1971, 27, 53. N. 1. Kirillova, A. I. Gusev, A. A. Pasynskii, and Yu. T. Struchkov, Zhur. strukt. Khim., 1972, 13, 880. A. M. Bond, A. T. Casey, and J. R Thackeray, Inorg. Chem., 1973, 12, 887. C. W. G. Russell and D. W. Smith, lnorg. Chim. Acta, 1972,6, 677. J M. Flowers. J. C. Hempel, W. E. Hatfield, and H. H. Dearman, J . Chem. P h y s , 1973,58, 1479.

The Early Pansition Metals

49

for the species [VO(H,0)5-,C1,]2-" (n = 1-4) were observed, the water molecule trans to the V==O bond being displaced first.332The reduction of VC1,by trimeth ylamine and by dimethylaminodichloroborane has been studied ; the former is converted into [Me,N=CH,]Cl and the latter into MeN=CH,,BCl, and Me2NH,BC1,.333 0-Donor Ligands. Three crystalline polymorphic modifications of VO(OH), have been prepared by the reaction between V and V 2 0 5(1 :2) under hydrothermal conditions. These polymorphs are pink, wine-red, and blue in colour and their i.r. spectra have been obtained.334Studies of the hydrolysis of V 0 2 + ions have revealed that only VO(OH)+ and VO(OH), are formed in dilute solutions and their formation constants have been determined.335The heats of formation of KHVO,(g) and K2V0,(g) have been determined as - 725 & 20 and - 850 20 kJ mol- respectively, from mass spectrometric investigations involving vanadium with potassium-seeded molecular hydrogen-oxygen flames., 36 Crystalline CaV,09 has been shown to contain VO, square-pyramidal units which share their basal edges to form infinite sheets of [V,09],2"- ions. The Ca" ions are inserted between these sheets in square antiprismatic sites; the phasesMV,O, (M = Ca, Sr, or Cd), which form an isomorphous series, are similarly constructed.337VSbO, has been prepared from V,O, and Sb203 by heating for 15 min at 1050 "C in a sealed Pt crucible. It has a monoclinic crystal structure which is similar to that of rutile and its magnetic properties are consistent with the presence of V1v.338TeVO, has been prepared in two different crystalline forms. The low-temperature a-modification contains isolated [V04]:"- chains composed of regular, edge-sharing, VO, octahedra. These chains are linked by Te"' atoms, each of which is co-ordinated to three oxygen atoms which have a one-sided co-ordination of three oxygen atoms. In the high-temperature P-modification each V" atom is at the centre of a square pyramid of oxygens, with an additional oxygen weakly co-ordinated ( V - 0 = 277 pm). These distorted octahedra share corners to form puckered sheets which are held together by [Te,O6I4- ions in which each TeN atom is at the apex of a square pyramid with a base of four oxygen atoms.339CuVO, has been shown to have a distorted ilmenite structure in which the interatomic distances suggest the electronic structure Cu'V"0, ; the anomalous magnetic properties of the compound have been attributed to VIV-VN interaction^.^^' The first measurement of the sign and the magnitude of the quadrupole moment of "V, -0.10 & 0.06, has been obtained from forbidden e.s.r. lines

',

332 333 334 335

336 337 338 339 340

C

N. N. Kalinichenko, 1. N. Marov, and A. N. Ermakov, Zhur. neorg. Khim. 1972,17, 3250. R. Kiesel and E. P. Schram, Inorg. Chem., 1973, 12, 1090. E. Schwarzmann, R. Bak, and R. Birkenberg, 2. Naturforsch.. 1972,27b, 1003. (a) R.P. Henry, P. C. H. Mitchell,andJ.E.Prue, J.C.S. Dalton,1973,1156;(b)N. A. Krasnyanskaya, 1.1. Eventova, N. V. Mel'chakavo, and V. M. Peshkova, Zhur. analit. Khim., 1972,27, 1842. M. Farber and R. D. Srivastava, Combust. Flame, 1973, 20, 43 (Chem. A h . : 1973, 78, 115970~). J.-C. Bouloux and J. Galy, Acta Cryst., 1973, B29,269, 1335. H. Schuer and W. Klemm, Z . anorg. Chem., 1973,395,287. G. Meunier, J. Darriet, and J. Galy, J . Solid State Chem., 1972, 5, 314; 1973, 6,67. J. R. Rea, P. W. Bless, and E. Kostiner. J . Solid Stare Chem, 1972. 5, 446.

Inorganic Chemistry of the TransitionElements

50

of VIV,as either [VW,0,,]4- or V 0 2 +ions doped in crystals of Na,(MeNH,),[V2W40,,],6H,0 or [Pd(bzac),], respectively.341 Three new tungstovanadate(w) heteropolyanions have been prepared (Scheme 1) and characterized by i.r., electronic, e.s.r., and X-ray diffraction spectra. The [H,V, W4019]6-n and [VW,01g]4- ions appear to possess the Lindqvist-Aronsson [Nb6Ol9I8type structure, whereas [H2VW, appears to have a Keggin structure related to metatungstate. Their electronic spectra show that these three ions are analogues of heteropoly-blue species with low-energy intervalence chargetransfer bands in addition to the expected d-d transitions.342

w:v = 2

pH 5-6

w:v = 5

[HnV2W40,,16-n brown-orange

a

(*V, W)

- [vW5ol9]4-

w:v >5

+ W"' pH 4-5

7 - [HzVWi i 0 4 1 3 -Wv' pH 7-8 purple-pink wine-red I p H 2-3

colloids

V02+,[H,W1 2 0 , , 1 6 -

Scheme 1 The optica1ande.s.r. spectraofthe heteropoly-blue analogue [PVW, 10,0]5 -, prepared either by the electrolytic reduction of the corresponding Vv ion, or by treatment of V 0 2 + with [PW,,039]7- at pH 4.5, have been recorded in The electronic spectrum of this deep red-purple complex contains bands at 20000 and 25000 cm-l, attributed to VIV + W"' 'intervalence transitions', in addition to d-d bands of V 0 2 + at 12000 and 14500cm-I. A single-crystale.s.r. study has confirmed that the V" atom in this anion occupies one of the Wvl positions in a normal Keggin structure. [ZnVW,,04,]8- has been prepared344 by the substitution of Vw for Znn in [Zn2W,,040H2]8-. The phase composition of the VOS0,-K2S04 system at 360 and 500°C has been investigated using X-ray diffraction and i.r. spectroscopy ; the formation of 2:1, l :1, and l :2 double salts was confirmed.345E.s.r. spectroscopy has been used to follow the extraction of V 0 2 + , from aqueous solutions by di-n-butyl phosphate in hexane, and monomeric and trimeric VO{ O,P(OBu),}, complexes were identified. [VO{ O,P(OBu),),], was isolated as a crystalline solid from the hexane solution and shown to contain a magnetic exchange interaction between the three metal centres.346The hypophosphito-complex, 341

342 343 344 345

346

R. L. Belford, D. T. Huang, and H. So, Chem. Phys. Letters, 1972, 14, 592. C. M. Flynn, jun., and M. T. Pope, Inorg. Chem., 1973, 12, 1626. D. P. Smith, H. So, J. Bender, and M. T. Pope, Inorg. Chem., 1973,12,685. M. Bauchet, C. Tourne, and G. Tourne, Compt rend., 1972, 275, C, 407. Z. 1. Ezhkova, B. E. Zaitsev, L. I. Konysheva, V. A. Matveevicheva, N. I. Nekhorosheva, 0. Ya. Polotnyuk, and S. P. Chaikovskii, Kinetika i Katalitz, 1972, 13, 1288 (Chem. A h . . 1973, 78, 34 797r). M. Sato. T. Takayanagi. Y. Fumita and T. Kwan, Bull. Chem. Sor Japon. 1973.46. 727.

The Early Transition Metals

51

[VO(O,PH,),H,O], has been prepared and its magnetic, i.r., and e.s.r. spectral properties determined. 47 Contrary to predictions based on spectroscopic evidence, crystals of (NHJ,[VO(C,OJ,H,O] contain a distorted octahedral arrangement of oxygen atoms about each VIv atom with a cis rather than a trans arrangement of oxalato-groups, in addition to a co-ordinated water [VO(C,O,)],-nH,O (n = 1, 1.5, or 2) have been prepared by treating V,05 with oxalic acid in glacial acetic acid at ca. 110 0C.349Complex formation between V 0 2 + and oxalate in aqueous media has been investigated using the pressure-jump techniq~e.~ The formation of a 1 :1 V02+-citraconate complex has been identified and the stability constant determined as 2.1 x lo5 1 mol- by the pH titration method.238Interactions between V 0 2+ and malonate, L-tartrate, and racemic tartrate have been studied using a pressure-jump apparatus. With malonate three relaxation times were identified and associated with the ccjmplexes [( VO(OH)},malonate], [VO(malonate)], and [VO(malonate),]2 - Relaxation times associated with the formation of [VO(tartrate)] and [VO(tartrate)], were also observed, the dimeric complex forming stereospecifically such that no mixed complex containing d- and I-tartrato-groups was obtained for the r a ~ e m a t e . ~The ~ ' varying rates and products of uptake of 0, by solutions of V'" tartrato-complexes have been studied as a function of the isomeric form of the ligand. The rate of 0, uptake in the pH range 3-7 was shown to be meso > D > DL, i.e. the converse of the stability of the dimeric tartrato-bridged V" complexes.351This, together with the increase in the rate of oxidation with increasing pH in all three systems, suggests that the active species in these reactions are the monomeric hydroxo-complexes.The temperature dependence of the magnetic moments of some oxovanadium(1v) tartrato-, citrato-, and trihydroxyglutarato-complexes have been determined352 and the nature of the complexes formed between this cation and such carboxylates in aqueous media have been studied by anion exchange and electronic spectroscopy. These latter results suggested that [VO(lactate),] has a trans-configuration containing co-ordinated carboxylate and hydroxy-groups of this ligand.353 The formation constants of the 1:1 complex between VOz+ and diglycolate,35" and the 1 :1 and 1 :2 complexes between V 0 2 and ~ a l i c y l a t have e~~~~ been determined as lo5 1 mol-l, 2.5 x 10'' 1 mol-l, and 1.5 x 10' 1' mol-',

'

+

347

348 349 350

351 352

353 354

J. Sala-Pala, R. Kergoat, and J. E. Guerchais, Compt. rend., 1972, 274, C , 595. G. E. Form E. S. Raper, R. E. Oughtred, and H. M. M. Shearer, J.C.S. Chem. Comm., 1972, 945. W. N. Smith, jun., U.S. P., 3689515 (Chem. Abs., 1973,78, 15533k). H. Hoffmann and W. Ullbricht, Ber. Bunsengesellschuft Phys. Chem., 1972,76,1052 (Chem. Abs., 1972,77, 169 280s). R. D. Gillard and R. A. Wiggins, J.C.S. Dalton, 1973, 125. V. T. Kalinnikov, V. V. Zelentsov, 0. D. Ubozhenko, and T. G. Aminov, Doklady Akad. Nuuk S.S.S.R., 1972, 206, 627. A. Bartecki and J. Maselko, Roczniki Chem., 1972,46, 543, (Chem. Abs., 1972,77, 118949~1. (a) A. Napoli, J. Znorg. Nuclear Chem., 1973,35, 3360; (b) B. R. Panchal and P. K. Bhattacharya, Indian J . Chem.. 1972, 10, 857.

52

Inorganic Chemistry of the Transition Elements

respectively. Complex formation between V" and 1,2-335aand 2,5-355bdihydroxybenzoic acids (H,L) has been investigated and VOL and VOLZcomplexes identified for both these acids, the latter being favoured at higher pH values. However, no evidence for any VL; - complexes could be obtained. 1:l and 1:2 complexes between V" and gallic acid have been characterized following reactions in MeOH; in 98 % H,SO, a 1 :3 complex is also formed.356 The reaction of perfluoropinacol (H,X) with aqueous VOSO,, followed by neutralization with KOH, affords K,[VOX,] whose electronic spectral and magnetic characteristics have been obtained.35 Polyglycol ethers R(OCH,CHJ,OH (HL1) (R = C6H13<&,~; n = 3-9) or (RCO,CH,),C[CH,(OCH,CH~,OH], (H2L2) (R = C,H9--C6H13; n = 25-29) react with VCl, to form VCl,L',xVCl, (x = 1-3), or (VC13),L2,yVC1, (y = lO-l6), respectively. Similar complexes have been observed with other large polyglycol ethers.I3 1 :1 and 1 :2 complexes of V" with xylenol and 3,5,7,2',4'-pentah y d r o ~ y f l a v o n ehave ~ ~ ~been ~ characterized. The magnetic properties of crystalline [VO(acac),] have been determined and shown to be more consistent with the Ballhausen and Gray d-orbital energy sequence than with other such schemes.359Hydrogen atom rearrangements in the mass spectra of [VO(acac),], [VO(Meacac),], and [VO(dbm),] have been studied using deuterium labelling and possible mechanisms for these reactions discussed.360E.s.r. studies of VOz+ P-diketonato-complexes in various solvents have been employed as a probe of the nature of the solutesolvent interactions in such systems. The results obtained have shown that isotropic e.s.r. spectra are not to be expected when either the ligands contain large organic substituents, and/or other bulky donor molecules are present.361

355

356 357 J58

359

360

361

S. Ya. Shnaiderman and G. N. Prokofeva. Zhwr. neorg. Khirn., 1972-17, 3124. N. V. Chernaya and S. Ya. Shnaiderman, Zhur. neorg. Khirn., 1973, 18, 126: S. Ya. Shnaiderman and A. M. Pleskonos, Ukrain. khim. Zhur., 1972,38, 1083, (Chem. Abs., 1973,78,48776~). C. I. Willis. J.C.S. Chrm. Cornm.. 1972. 944. ( a ) N . L. Babenko, A. 1. Busev, and 1. N. Chistyachenko, Zhur. neorg. Khirn.. 1972, 17, 1864: (b)N. V. Chernaya, V. G. Matyashov, and S. Ya. Shnaiderman, lzvest. V U . Z . , Khim. i khirn. Technol.. 1972, 15. 986 (Chern. Abs., 1972, 77, 144454~). A. K. Gregson and S. Mitra, J.C.S. Dalton, 1973, 1096. M. Y . Lacey, C. G. MacDonald, and J. S. Shannon, Austral. J . Chem., 1972,25. 2559. H. J. Stoklosa, H. L. Huffman. and J. R . Wasson. J . Inorg. Nurlear Chern.. 1973. 35,2587

53

The Early Transition Metals

The addition of substituted pyridines to [VO(acac)J has been studied, and cis- and trans-isomers identified by i.r. spectroscopy. This proposed structural isomerism has been confirmed by an X-ray diffraction study of [VO(acac),(pPhC,H,N)] which has the cis-configuration (29).362 A number of 0x0vanadium(1v) p-diketonato-complexes have been shown to be active catalysts for the epoxidation of c y c l o a l k a n e ~4-Benzoyl-3-methyl.~~~ 1-phenylpyrazolin5-one (30) forms 1 :1 and 1 :2 complexes with V 0 2 + , the stability constant of the latter being335b1.3 x lo1, l2 mol-2. Oxovanadium(1v) may be extracted from aqueous acidic media with the fluorinated 0-diketones (31).364 Ph

I

Ph

( 3 1) R n

= aromatic and =

heterocyclic nuclei

0- -15

(30)

The octahedral VIV p-diketonato-derivatives [VL,X,] (L = acac, X = C1; L = dpm, X = C1, Br, NCO, or NCS) and [VL,]Y (Y = FeCl, or SbC1,) have been prepared and characterized. The reactions between VCl, and L in anhydrous benzene or CH,Cl,-hexane solution afford [VL2C12] in good yield. Metathesis between [V(dpm),Cl,] and HBr, AgOCN, or NaSCN gives the corresponding [ v ( d p ~ ) ~ X ,derivative. ] The tris-p-diketonato-complexes may be obtained by the reaction of [VL2C1,] with anhydrous FeCl, or SbCl,. These V'" derivatives, which are notable for their lack of the V=O moiety, are intensely red in colour. The far-i.r, spectra of [V(dpm),X,] (X = C1 or Br) are phase-dependent, suggesting that there is a facile cis-trans equilibrium for these complexes, whereas the corresponding pseudohalides seem to adopt the cis-form exclusively. Complexes with Ligands containing Oxygen and other Donor Atoms. The e.s.r. spectra of liquid and frozen solutions of the oxovanadium(1v) monothio-pdiketonates [VO{CH(CSR')COR2}] (Rf,R2 = Me, CF,, Ph, 2-thienyl, or pnaphthyl) have shown that they exist as simple monomers in The formation constants of the 1 :1 complex between V 0 2 and thiodiglycolate354nand the 1 :1 and 1 :2 complexes between V 0 2 + and t h i o ~ a l i c y l a t e ~ ~ ~ ' have been determined as 1.4 x lo3 1mol-l, 3.8 x 10" 1 mol-', and 1.6 x lo9 l2 rnol-', respectively. The former ligand forms a less stable complex than diglycolate, although the latter forms more stable ones than salicylate. The stepwise formation constants for oxovanadium(1v)-rn-mercaptoacetamido+

362

363 364

36s 366

M. R. Caira, J. M. Haigh, and L. R. Nassimbeni, J . Inorg. Nuclear Chem., 1972, 34, 3171 C.-C. Su, J. W. Reed, and E. S. Gould, fnorg. Chem., 1973, 12, 337. M. L. Lucid, US.P., 3 700416 (Chem. Abs.. 1973,78, 74 896d) R. B. Von Dreele and R. C. Fay, J . Amer. Chem. SOC., 1972, 94, 7935. D Rehorek and P. Thomas, Z . Chem, 1973. 13. 22 (Chem. Abs., 1973,78, 1303198).

54

Inorganic Chemistry of the Transition Elements

phenol complexes have been reported as K , = 2.4 x lo6 1 mol-’ and K , = 7.0 105 1 moi-1.367 The first complete characterization of a naturally occurring vanadium compound amavadine has been achieved. This pale blue compound has been isolated from the fly Amanita muscaria, and its elemental analysis indicated the empirical formula Cl,H2,N2V0, ,,H,O. The molecular weight was determined as 415 and e.s.r. and i.r. spectroscopy confirmed that the vanadium is present as a V I V 4 group. Hydrolysis of amavadine in HC1 (6 mol 1-’) affords mainly L-alanine ;in NaOH (1 moll- l), sodium pyruvate and acetaldehyde are also formed. The reduction of the compound by Zn-MeC0,H produces a,a’-iminodipropionic acid and treatment with MeOH-H,SO, The nature of amavadine has been gives N-hydroxye,a’-iminodipropionate. confirmed by synthesis from N-hydroxyed-iminodipropionic acid and VOSO,

in H,O, the obtained complex (32) being identical with the naturally occurring derivative in chromatographic behaviour and e.s.r., i.r., and electronic spectra. The synthetic compound differs only in the chirality of the two optically active carbon centres, which are in the L-configuration for the natural product. However, the possibility cannot be excluded that the vanadium is fixed as a metal protein in A. muscaria, this complex being destroyed during the isolation procedure. Magnetic exchange interactions in oxovanadium(1v)-Schiff base complexes have been studied in some detail this year. The temperature dependence of the magnetic susceptibility of NN’-propylenebis(salicyla1diminato)oxovanadium(IV)has been determined and related to the known crystal structure of this compound. The absence of significant magnetic coupling between the metal centres suggests that they contain the unpaired electron in the 3 4 , However, 1:1 oxovanadium(1v) complexes with dibasic, terdentate Schiff bases generally involve an antiferromagnetic interaction, unless other ligands are present. The magnetic properties of a series of oxovanadium(1v)N-(hydroxyalkyl)salicylidinimines, which contain the ligands (33), have been determined. The room-temperature magnetic moments of the ethanol (n = 2) ( p = 0.891.41 BM) and propanol ( n = 3) (p = 1.34-1.58 BM) series, the considerable 367 368

S. N. Kakkas, N. S. Poonia, and P. V. Khadikar, J . lnorg. Nuclear Chem., 1973, 35. 3021. G. D. Simpsnn and G . 0. Carlisle. lnorg. Nuclecir Chern. Letters. 1973. 9, 815.

The Early TransitionMetals

55

decrease of these moments with temperature, and e.s.r., electronic, and i.r. spectral data are all consistent with the adoption of structure (34) by these complexes.369 A dimeric structure has also been suggested to explain the antiferromagnetic behaviour exhibited by the complexes VOL, where H,L = a Schiff base ligand derived from 2-hydroxy-1-naphthaldehydeand one of a number of substituted 2-aminophenols. The magnetic properties of the corresponding solvates VOL,S (S = H 2 0 or EtOH) obey the Curie-Weiss law.370

II

( 3 3 ) R' = H, Cl, Br, NO2, or OMe R 2 = H, NO2, or OMe n=2or3

(34)

0

Magnetic exchange interactions have also been identified in the oxovanadium2-hydroxy-1-naphthaldehyde and ethanolamine or p r o p a n ~ l a m i n e . ~ Such ~ ' complexes can accommodate two further donor atoms per metal and [VO(A)(L)] (A = bipy or phen; H2L = Schiff base from salicylaldehyde or 2-hydroxy-1-naphthaldehyde with glycine, alanine, anthranilic acid, or o-aminophenol) complexes have been shown to involve six-co-ordinate vanadium.372Similarly, VOL,B [H2L = 2-hydroxynaphthylideneamino-acid, B = H 2 0 , phen, or ( p ~; ) H2L ~ = 2-hydroxynaphthylidene-o-aminophenol, B = phen] have normal magnetic moments (p = 1.70-1.74 BM) at room temperature.373 The complex VOL (H2L = 6,ll-dimethyl-7,1O-diazahexadeca-6,1Odiene-2,4,13,15-tetrone) has been prepared from VO(OH),, heptane-2,4,6-trione, and en in MeOH. The structure (35)has been proposed for this compound, which reversibly adds py.374

(IV)complexes with the Schiff bases derived from

0

369

370

371

372 373 374

A. Sqamal, E. F. Carey, and L. J. Theriot, Inorg. Chem., 1973,12,245. G. 0. Carlisle, D. A. Crutchfield, and M. D. McKnight, J.C.S. Dalton, 1973. 1703. A. Syamal, Indian J . Chem., 1973, 11, 363. R. L. Dutta and G. P. Sen Gupta, J . Indian Chern. SOC., 1972,49,919. A. Syamal and L. 3. Theriot, J . Coord. Chem., 1973,2, 193. T. Yano,T. Ushijima, M. Sasaki, H. Kobayashi and K. Ueno, Bull. Chem. SOC. Japan, 1972,45, 2452.

56

Inorganic Chemistry of the Transition Elements

Several new 8-quinolinato-oxovanadium(1v) complexes have been prepared and characterized. AHCVOQ,] (A = morpholine, piperidine, or pyrrolidene, H Q = 8-hydroxyquinoline) appear to contain anions in which the metal is octahedrally co-ordinated, one of the 8-quinolinato-groups being unidentate. [VOQ2(QH)],2H,O, VOQ,, and VOQ,B [B = py, 4-Xpy (X = CN, Me, or NH,), 2-Mepy, 2,4-Me2py, py N-oxide, PhNH,, PhNHMe, or PhNHMe,] have also been obtained; the VOQ, molecules appear to have a trigonalbipyramidal geometry and the VOQ,B derivatives an octahedral one, in which the donor atom of B is trans to V=0.375 The temperature dependence of the magnetic moments of VOQ,,H,O and [VO(picolinate),],H,O have been investigated and the results discussed with respect to possible spin-spin interactions in these compounds.3s2 Complex formation between oxovanadium(1 v) and iminodiacetate and nitrilotriacetate ions has been investigated by pH titrations and the thermodynamic parameters for both of the 1: 1 complexes were determined.376In a similar manner the formation constants of the 1 : 1 and 1:2 V 0 2 diphenylamine-2,2'dicarboxylate complexes have been estimated as lo4 1 mol-' and 3.6 x lo3 1, mol- , respectively.243"VOCl, and VOSO, react with ethanolamine (HL) or triethanolamine(H,Q) in MeOH to afford VOL, or VO(HQ), respectively.377 Oxovanadium(1v) complexes of acylhydrazines such as [VO(SO),L,],H20 (L = acetyl-, benzoyl-, diacetyl-, or salicyloyl-hydrazine) have been prepared. Solutions of these compounds in alcohols are only weakly conducting, and i.r. spectra suggest the presence of co-ordinated acylhydrazines and bridging The formation of 1: 1, 1 :2, and 1 : 3 complexes between sulphate V 0 2 + and asparagine or g l ~ t a m i n e , , ~and ~ " 1 :1 and 1 :2 complexes with 3 ' - p y r i d y I f l ~ o r o n ehas ~ ~been ~ ~ established. 4-(2-Pyridylazo)resorcinol (H,L) and V 0 2 + give the complexes VO(HL)+ (Amax 560 nm) at pH 1-5 and VOL (Amax 550 nm) at pH 5-7. The extraction of oxovanadium(1v) species into polar organic solvents by this ligand has been studied.380 +

S-Donor and Se-donor Ligands. The xanthates of vanadium@), r(7c-C~)~V(S,COR)]+ (R = Me, Et, Pr', Bu, or C6Hll), have been prepared in aqueous media by the reaction of [(x-Cp),VCl,] and NaS,COR, and isolated as their BF, salts. The room temperature magnetic moments (p ca. 1.65 BM) have been determined as well as their i.r., electronic, and e.s.r. The absolute i.r. intensity of V=O bond stretching of [VO{S,CNEt,),] has been R. P. Henry, P. C. H. Mitchell, and J. E. Prue, lnorg. Chim. Acta, 1973, 7, 125. S. P. Singh and J. P. Tandon. J . prakt. Chem.. 1973.315 23 (Chem. A h s . 1973.78. 1 1 5 9 0 0 ~ ) 3 7 7 A. I. Astakhov and A. I. Kas'yanenko, Izuest. i!C!,Z. Khim. i khirn. Techno!., 1972,15, 1620 (Chern. Ahs.. 1973. 78. 66407e). j 7 * R C. Aggarwal and B. Prasad. Indian J . Chem. 1972. 10. 1182. "' (a) R. C. Tewari and M. N. Srivastava, Talanta, 1973.20, 133: ( h ) E. Asmus and J. dahny, Z . analyt. Chem., 1972,259,269 (Chem. Abs., 1972,77,56 147k). 3 8 0 (a) 0 . 1 . Karpova. V. V. Likachina and A. T. Pilipenko, Ukrain. khim. Zhur., 1973.39. 194 (Chem. Abs., 1973, 78, 141019k); Zhur. analif. Khim., 1973, 28, 86; (b) S. P. Mushran, 0. Prakash, and J. R. Verma. BUM.Chem. SOC.Japan. 1972.45 1709: (c) R. M. Pogranichnava. V. V. Nerubashchenko, and A. V. Tsevina, Zhur. analit. Khim.,1972, 27, 1845. 3 8 1 A. T. Casey and J. R . Thackeray. Austral. J . Chem.. 1972.25. 2085. 375 376

~

The Early Bansition Metals

57

obtained for CCl, and CS, solutions. As a result of this study, which included other oxovanadium(1v) compounds, the values of 2.0 x lo4 1 mol- and 1040 cm- have been suggested for absolute intensity and frequency, respectively, of V = O stretching in an essentially undisturbed V 0 2 + The oxovanadium(1v) complexes VOL, containing bidentate L (o-aminobenzenethiol, N-n-decyl-2-aminoethanethiol, or 2-aminoethanethiol) have been shown to contain molecules which have a square-pyramidal geometry. Molecules of VO(2-mercaptopyridine N-oxide),, however, probably have a pseudooctahedral structure with an N-oxide atom weakly co-ordinated in the sixth position.383 Several e.s.r. spectral studies of vanadiurq(1v) sulphur complexes have been reported. The e.s.r. spectra of magnetically-dilute samples of [VO(mnt),12 and [V(mnt), J 2 - (mnt = maleonitriledithiolene) ions in single crystals of diamagnetic hosts have been analysed and interpreted in terms of the electronic structure of these complexes as given by MO theory. The results indicate that in both ions the metal has more electron density than its formal oxidation state IV would imply, particularly in [V(rnnt),l2-. A reassignment of the ground state of this latter ion has been proposed, the electron being in the metal’s 3 4 , (Bu,N),[VO(S,C=C(CN),},] has also been studied by e x . spectroscopy, the results being consistent with a C,, structure.385 0x0vanadium(1v) complexes with Et,NCS, (dtc) and (EtO),PS, (dtp) have been studied using e.s.r. spectroscopy for solutions in toluene and py at 298 and 77 K, and the spectral parameters of the known VOL, (L = dtc or dtp) and P the new [VO(dtc)(dtp)] complexes obtained. These data, including superhyperfine splittings, suggest that dtp is a better ligand towards V 0 2 + than is d t ~ [VO(S,AsMeJ,] . ~ ~ ~ has been synthesized by treating a freshly prepared solution of VOCl, in MeOH with a warm solution of NaS,AsMe, in this solvent. The e.s.r. spectrum of this complex contains 27 lines, indicative of a 75As-superhyperfine intera~tion.~”The e.s.r. spectral parameters of oxovanadium-chelate complexes containing 0, N, or S-donor atoms have shown that the covalent nature of the metal-ligand a-bonds is a maximum for the VO(S), systems.388The effect of remote substituents on the metal-ligand bonding has been assessed for [VO(S,PR&,] (R = Et, Ph, OEt, or OC,H,,) molecules and the more electron-withdrawing substituents have been shown to enhance the covalent nature of the V-S bonds.389 [VO(S(Se)CNEt,),] has been prepared by treating VOSO, with NH,382 383 384

385 386

387

388

389

B. Folkesson and R . Larsson, Acta Chem. Scand., 1972,26, 4168. A. Hodge, K. Nordquest, and E. L. Blinn, Znorg. Chim Acta, 1972.6.491. N . M. Atherton and C. J. Winscom, Znorg. Chem., 1973,12, 383. R. Kirmse. W. Dietzsch, and E. Hoyer, Z. anorg. Chem., 1973,397, 198. B. S. Prabhananda. S. J. Shah, and B. Venkataraman. Indian J. Pure Appl. Phys., 1972. 10, 365 (Chem. Abs., 1972,77, 145938m). B. J. McCormick, J. L. Featherstone, H. J. Stoklosa, and J. R. Wasson, Znorg. Chem., 1973,12,692. G . M. Larin, V. V. Zelentsov, Yu. V. Rakitin, and M. E. Dyatkina, Zhur. neorg. Khim., 1972, 17, 2133. G. M. Larin, V. V. Zelentsov, Yu. V. Rakitin, and M. E. Dyatkina Zhur. neorg. Khim., 1972. 17, 21 36.

58

Inorganic Chemistry of the Transition Elements

(S(Se)CNEt,) in H,O-MeOH solution; the compound is unstable, but its e.s.r. spectrum has been recorded.390 N-Donor Ligands. The triplet-state X-band e.s.r. spectrum of the oxovanadium(1v)-chelateof tetrakis(aminomethy1)methane has been recorded for frozen aqueous-glycol solutions at 77 K. The spiro conformation of the methylene groups of this ligand ensure that the two metal centres in this dinuclear complex will have a non-parallel alignment of their g-tensor axes. An analysis of spectral data has afforded a value of 570(3) pm for the V 0 2 + - - - - V 0 2 + separation in these d i m e r ~V(NCS), .~~ in THF solution reacts with dry oxygenfree NH, at 20°C to give a precipitate of [V(NCS),NH2],4NH, which appears to have a polymeric structure with bridging amido-groups linking pseudooctahedral V'v-centres.391 (VO),[Fe(CN),] has been prepared by the redox reaction between Vv and [Fe(CN)6]3- in acidic media and the compound's magnetic and electronic spectral characteristics were determined.392

(36) R

=

H. Me. Et, o r Ph

1:2 Addition compounds between VOCl, and the 2-substituted benzimidazoles (36) have been prepared. 1.r. and electronic spectra suggest five coordination with the ligands co-ordinated via the unsaturated nitrogen atom.393 Transalkylation occurs when oxovanadium(Iv) octaethylporphyrin is heated with alumina, illite, or montmorillonite, which is an important result in terms of the natural synthesis of porphyrins and their h o m o l o g u e ~ Spectroscopic .~~~ studies have been made of the monomer-dimer equilibrium in aqueous media for the 1 :1 oxovanadium(1v)-tetrasulphophthalacyanine complex. The dimeric species may contain a V-0-V bridge, or the packing of two molecules with a staggered arrangement of the phthalocyanine rings may allow the overlap between their n-electron systems to provide the adhesion.395 Sb-Donor Ligands. The e.s.r. spectrum of the 1 : l complex formed between VOCl, and Bu,Sb in toluene has been reported. The behaviour of this ligand' contrasts with that of its phosphorus and arsenic analogues which form 1 :2 complexes under these conditions.396 Organornetallic Compounds. Attempts to isolate V(CH,CMe,), have not been successful. VCl, or VOCl, react with neopentyl Grignard or lithium reagents but no stable compound appears to be formed. The interaction of VCl, and 390 391 392

393 394 395

396

R. Kirmse, R. Heber, and E. Hoyer. Z . Chem., 1972,12, 226. H. Bohland, Z . Chem., 1972.14, 148. R. K . Prasad and K. K. Singh, lndian J. Chem., 1973, 11, 35. N. S. Biradar, S. Devale, and V. H. Kulkarni, Current Sci., 1973,42, 125. R . Bonnett, P. Brewer, K. Noro, and T. Noro, J.C.S. Chem. Comm., 1972, 562. R. D. Farina, D. J. Halko, and J. H. Swinehart, J . Phys. Chem., 1972,76, 2343 G. Henrici-Olive and S. Olive, J . Organometallic Chem., 1972,46, 101.

The Early Thansition Metals

59

LiCH,CMe, (1:4)in petrol at 160°C initially affords an intense green solution which, however, turns brown on warming to room temperature. E.s.r. spectral studies have characterized two S = 3 species in these solutions and these are presumed to be members of the V(CH,G~Me,),Cl,-, (n = 1 - 4 ) series.16sb Tetrakis(pentafluorophenyl)vanadium(Iv) has been isolated as its bis(diethy1 ether) adduct following the reaction between VC1, and LiC,F,(l: 4) in etherhexane solution at 170°C. The i.r. spectrum of this extremely moisturesensitive compound has been determined.397Further preparative routes to Table 3 Compounds containing uanadium-(Iv) and -(v)in oxide lattices 13.3

Li2C03-V205

LiV60, 5

c, AH

a

t.d., X

b

v40°99

r”J;
Na2Si03-V,O, or N a 2 C 0,-V20 systems

3.3]

,

NaN0,-V20, system at 276 “C ir., t.d.

Na6V15040

P- MgV30, Mg3V6015

MgO-VZO, BaO-V20, systems

Ba3V4013

MV20048.

5

(M= Mg or Zn)

1

i

MV206-V205 MV12O30 (M = Ca, Sr, Ba, or system Cd) BaV*O20.9 a- and fI-Fe,V,O, (x = 0.10,0.22, or 0.32) ( x = 0.30,0.40,

0.505, or 0.60)

B- AgxV, 0

St

d

l x

e

1

J

X

5

P-cuxv2

C

M

+ V 2 0 , at elevated temps.

e.s.r., p

f e.s.r., p

5

(x = 0.33 or 0.40)

,

NaUVO + , (0 d x < 0.3) NaUV3OIo Na3UV3011 Na4UV40

N a 2 0 - V 2 0 5 - U 0 3 system

t.d.

9

14

(a) V . L. Volkov, L. L. Surat, and A. A. Fotiev, Zhur. neorg. Khim., 1972,17, 1529. (6) A. A. Fotiev, E. A. Bukelov, N. Kh. Valikhanova, and V . P. Malyshev, Zhur. priklad Khim., 1972,45,2381, (Chem. Abs., 1973, 78, 76773k); G. A. Kolta, 1. F. Hewaidy, N. S. Felix, and N. N. Girgis, Thermochimica Acta, 1973, 6, 165. (c) B. V . Slobodin, M. V. Mokhosoev, and V. G. Penkova, Zhur. neorg. Khim., 1973, 18, 493. (d) M. Saux and J. Galy, Compt. rend,, 1973, 276,C, 81. (e) A. A. Fotiev, V. L. Volkov, and V. A. Makarov, Vysokotemp. Khim. Silikat. Okislov, Tr. Vses. Soveshch., 3rd, ed. E. K. Keler, ‘Nauka’ Leningrad, Otd., Leningrad, 1968, 93 (Chem. Zbs., 1972, 77, 80091h). (f)A. Polaczek, K. Dyrek, and E. Polaczkowa Bull. Acad. polon. Sci., S&. Sci. chim., 1972, 20, 705, 713 (Chem. Abs., 1972,77, 145582r. 145583r). (g) C. Dion, J. M. Leroy, and G. Tridot, Compt. rend.,1972.275. C. 37. 397

G. A. Razuvaev, V. N. Latyaeva, A. N. Lineva, and N. N. Spiridonova, J. Organometallic Chem., 1972. 46, C13.

60

Inorganic Chemistry of the Transition Elements

V(CH,Ph), have been examined in an attempt to minimize the reduction to lower oxidation states of vanadium which occurs when VCl, reacts with M(CH,Ph), (M = Zn or Mg) or PhCH,MgC1.398 The preparation of [(n-Cp),V(S,COR)] complexes381 is described on p. 56. X-Band e.s.r. spectra of magnetically dilute glasses containing [(nCp),VX,] (X = C1, NCS, OCN, CN, or o-C,H,) have been recorded at 77 and 290 K and analysed in detail. With the exception of the X = CN complex, the unpaired electron in these compounds is contained in an essentially nonbonding 3dZr-orbital; in [(7c-Cp),V(CN),] the unpaired electron is delocalized into the 2px ligand orbitals.399 Mixed-valence Compounds. The majority of these compounds involve vanadium-(Iv) and -(v) in oxide lattices and much of this work is summarized in Table 3. The solid-state reaction of LiVO,, ZnO, and VO, at 750 "C has been shown to form the spinel Li,~,ZnV,~,O, and the electrical and X-ray diffraction characteristics of this compound have been determined.," Several members of the V,O,-,F, (0.01 < x < 0.85)series have been prepared by hydrothermal reactions between V,O,, V,O,, and VF, in sealed Au tubes. The transition temperature between monoclinic and tetragonal structures decreases rapidly with increasing fluoride substitution into the V 2 0 4 lattice and the electrical properties of these phases have been determined.," The liquid sodium vanadates have been shown to exhibit n-type semiconduction properties at Na,O concentrations of <10mol :!, and ionic conduction properties at Na,O concentrations of >25 mol %. The former conduction mechanism involves electron (or polaron) movement between VIVand Vv-centres and the latter transport of Na' and 02-ions. Very similar effects are observed in the Na,O-V,O,-Fe,O, system, except that additional movement of electrons (or polarons) between Fe" and Fe'" centres is possible.402 The production of VIV centres by introducing MOO, into the V,O, lattice289 is described on p. 43, and the ternary phases (Mo,-,VJO,., (0 < x < 0.40) have been prepared and their X-ray diffraction patterns obtained.,', The enthalpies of formation of the sodium bronzes Na,V,O,(s) (0.2 < x < 0.33) from Na(s) and V,O,(s) have been determined by solution calorimetry. The partial molar enthalpy of solutions of Na(s) in V,O,(s) is constant over this range of composition, the enthalpies of formation ranging from -75.3 (x = 0.20) to - 120.5 (x = 0.33) kJ mol-'. Hence the P-phase of Na,V,O, is thermodynamically stable with respect to both oxidation and disproportionation.,', The electrical and magnetic properties of the oxyfluoride bronzes +

398

''' 400 401

402 403 404

G. A. Razuvaev, V. N. Latyaeva, A. N. Lineva, and V. V. Drobotenko. Doklody Akad. Nauk S.S.S.R., 1973, 208, 876. C. P. Stewart and A. L. Porte. J.C.S. Dalton, 1973, 722. B. Reuter and G. Colsmann, Z . anorg. Chem.. 1972, 394, 138. B. L. Chamberland, Materials Res. Bull. 1971, 6, 425, (Chem. Abs., 1972. 77, 80521v). R. C. Kerby and J. R. Wilson, Canad. J . Chem., 1973, SO, 2871,2877. T. Ekstrom and M. Nygren, Acta Chem. S c a d . , 1972,26, 1827. P. G. Dickens. M . Jewess, D. J. Nield. and J. C. W. Rose. J.C.S. Dalton. 1973. 30.

The Early Bansition Metals

61

a'-NaV,O, -xF, (0 < x < 1) have been investigated and shown to be consistent with a statistical distribution of the VIV centres in the phases of intermediate composition.405 [VO(OC,H4NH2),] has been converted by slow oxidation into [VOVO,(OC,H,NH,),] which may be further oxidized to [V0,(OC,H4NH2)].377 Complex formation in the system V'v-Vv-pyrocatechol-Pyramidon has been studied by e.s.r., electronic, and ix. spectra and 1 :1 : 1 :1 complex identified with I,,, of 560 and 328 nm.,06 Vanadium(v).--Halides and Oxyhalides. The vapour-phase Raman spectra of VOF, and VOC1, have been obtained and compared with the corresponding i.r. data. For the latter molecule this study has shown that the lowest lying fundamental (125 cm-') is an e mode. VOBr, did not prove sufficiently stable in the vapour phase to allow its spectrum to be recorded. The Raman spectra of liquid mixtures of VOCl, and VOBr, have shown that they contain approximately statistical quantities of VOC1,Br and VOClBr, molecules. The Raman data obtained at ca. 77 K for solid films of VOCl, and VOBr, suggest that the former only exists as one solid phase, which is not isomorphous with that of POCl,, but that two or three phases are formed by VOBr3.407 The XeF,-VF, system has been re-investigated and both 1:l and 2 : l addition compounds were identified, the m.p. of the former being re-assessed as system have been 38 f 1°C.408 Phase equilibria in the KF-V,O,-H,O examined and the compound V20,,3KF has been characterized by X-ray diffraction spectroscopy.409 A crystal structure determination of Cs[VOF,] has shown that the anions have a square-pyramidal structure with the VIV atom 32.6pm above the base of four fluorine atoms p T = 178.8pm) and 152.9pm away from the oxygen atom. These square pyramids are linked by cis-fluorine bridges, involving a long V-F bond of 231.2 pm ca. trans to V = O , to give an anionic chain s t r u ~ t u r e . ~M3V02F4 '~ (M = Na, K, or NH,) have been prepared by treating MVO, with MHF, and these salts characterized by conductometric, t.g.a., and ion-exchange studies. The passage of a concentrated aqueous solution of (NHJ,VO,F, over a cation-exchange resin in the Ni" form affords Ni,(V0,F,)2,xH20.41 ' The polymeric structure of the anions in the NaVO,F, and NH,VO,F, salts has been confirmed by i.r., Raman, and X-ray diffraction and the related salts (Ph,A)VOX, (A = P or As; X = F or C1) have been precipitated from HX solutions of Na,VO, by the addition of Ph,AC1.412b The unit cell parameters of the

405 406

407

408

409 410 411

412

A. Carpy, A. Casalot, M. Pouchard, J. Galy, and P. Hagenmuller, J . Solid State Chrm.. 1972,5.229. E. P. Klimenko and S. Ya. Shnaiderman, Zhur. neorg. Khim., 1972, 17,2442. R. J. H. Clark and P. D. Mitchell, J.C.S. Dalton, 1972, 2429. V. A. Legasov and A. S. Marinin, Zhur.fiz. Khim., 1972,46,2420. A. K. Sengupta and B. B. Bhaumik, Indian J . Chem., 1972,lO. 752. G . W. Bushnell and K. C. Moss, Canad. J . Chem., 1972.50,3700. A. K. Sengupta and B. B. Bhaumik, Z . anorg. Chem., 1972, 390, 31 1. (a) R. Mattes and H. Rieskamp, Z. Naturjorsch., 1972, 27b, 1424; (b) E. Ahlborn, E. Diemann, and A Miiller. Z anorg. Chem., 1972,394. 1

62

Inorganic Chemistry of the Transition Elements

Table 4

Vanadates and mixed oxide compounds containing vanadiurn(v) Source

Compound

Properties reported

st, chains of VO, tetrahedra with a V-0 = 163-182pm

LiVO,

Na2C03-V,O, system

NazV 1 2 0 3 1 NH,VO, Ca(VO3),,4H,O Ca2V,07,5H,0 Ca,WO,),,I0H2O Ca2V,0 ,,13H20

1

SrV,O, Sr2V207

Sr3V208 Sr4V209 Sr10V602.5

TWO, TWO, Pb4V209

pb8vZo

Ref:

13

1J

a- and p-VPO,

X

b

t.d.

C

i.r., X

d

SrO-V,O, system

e

+

T120, V,O, + H 2 0at 250°C t.d., X TlVO, at 300 "C

X

PbO-V20, melts v205-p,01,

system

f 9

st, isotypic with a- and

h

P-VSO5

NaV0,-Na,PO,-H,O system

+ Na,VO,

I

in aq.

BiV04

Bi(N03), solution

(NHd4V203(S04)4 (NH4)8V203(S04)6

(NH4)2S04 + v2°3(s04)2,2 H 2 0 in air at 200°C for 24 h t'd.'

k

Te2V209

TeO,-V,O,

1

system

j

t.d., X

st, isostructural series containing [VTeO,]E- rn chains

MVTeO (M = Na, K, Rb, or Ag) MVO, (M = Sc or Y)

st, zircon structure

n

ZrV,O,

ZrO, + V,O, (1 :1) at 650°C for 15 h in Pt crucible

0

Cs,V,Mo, -xO, (X = 0.125, 0.25, 0.3754.40, or

CsV0,-MOO, system at 350°C X

P

0.504.55) M3V208

(M = Co or Ni) NiO-V,O, system

st, isotypic with Mg3V208 X st, V 0 6 distorted octahedra

4

r

F

63

The Early nunsition Metals

Table 4 (contd.) Compound

Source

cu3v’208

CuO V 2 0 5at 30 kbar and 900°C

cu5v?.010

CuO

Properties reported

+

+ V20, in K2C0,

LiCuVO, CdV20, Cd2V207

Re$

st, similar to that of Mg3V208 st, VO, tetrahedra with V 4 = 172.3 Pm

t

.u

}

CdO-V205 system

Cd,V20* a- and P-CdV,O,

st

C ~ Z V ~ O H,O ,,, (Cd0H)4V40 0.5H20

(CdOH)4,V,07,2HzO a-Hg2V207

pH 2.2-12.8

HgO-V,O, ; low-temp. phase HgO

LaVO, MVO, (M = Y or Gd) MLnV507 (M = Na, Ln = Y ; (M = K, Ln = Sm)

X

system at

129

+

M203

V z 0 5 at 3 0 4 5 kbar

+ vZo5

MzC03

+ Ln,03

-t V,05

Y

x*distorted pyrochlore lattice

X,dimorphic

aa

e

bb

X

cc

LnVO, (Ln = Dy, Tb, Ho, or Yb)

st, refinement

ff

Ln8V201 7

X

99

(Ln = Er, Tm, or Yb)

(a) R. D. Shannon and C. Calvo, Canad. J. Chem., 1973, 51, 265. (b) G. A. Kolta, 1. F. Hewaidy, N. S. Felix, and N. N. Girgis, Thermochim. Acta, 1973,6, 165. (c) I. K. Bhatnagar, D. K. Chakrabarty, and A. B. Biswas, Indian J. Chem., 1972, 10, 1025; M. E. Brown and B. V. Stewart, ‘Proceedings of the 3rd International Conference on Thermal Analysis’, ed. H. G. B. Wiedemann, Basel, 1971,2, 313 (Chem. Abs., 1973, 78, 129065q); 1. H. Park, Daehan Hwahak Hwoejee, 1972, 16, 157 (Chem. Abs., 1972.77.96410~).(d) L. N. Kovgan and A. P Nakhodnova. Zhur neorq. Khim., 1973,lS. 398. (e) J. J. Brown, jun., J. Amer. Ceram. SOC.,1972, 55, 500. (f)M. Touboul and C. Cuche, Compt. rend., 1973, 276, C, 1191. (g) R. Von Hodenberg Ber. Deut. Keram. Gesellschaft, 1972,49, 243 (Chem. Abs., 1972, 77, 14484th). (h) B. Jordan and C. Calvo, Canad. J. Chem.. 1973,51, 2621 : R. Gopal and C. Calvo,

(contd.)

Inorganic Chemistry of the Transition Elements

64

vanadium(v) bromoapatites M,(VO,),Br pu blished.,

’

(M = Ca, Br, or Ba) have been

0-Donor Ligands. Table 4 summarizes much of the data concerning vanadates and mixed oxide compounds containing vanadium(v) which have been reported this year. Developments in the detection of vanadate ions have been reviewed.,’, The ground state of the [VO4I3- ion has been studied by X-ray photoelectron spectroscopy and extended basis SCF-MO calculation^.^' The Na,O-V,O, phase diagram has been re-investigated and the reactions of various sodium oxy-compounds with V 2 0 , which lead to the formation of sodium pyro-, ortho-, and meta-vanadates have been reported. X-Ray powder diffractometry has shown that these vanadates exist in two, four, and two modifications, respectively.416The synthesis of the new, thermally stable, and highly strontium-specific ion-exchange matrix, titanium(~ v )vanadate, has been achieved by mixing 0.5Msolutions of titanium(1v) chloride and sodium vanadate at pH 0-1 .Io2’ Solid-liquid phase equilibria for the ternary systems Na,O-V,O,M,O, (M = Cr or Fe) and Na,-V,O,-MgO have been studied by d.t.a. and X-ray diffraction methods3’ 413 414

415

416

417

E. J. Baran, Monatsh., 1972,103, 1684. R . Belcher, Pure Appl. Chem., 1972,31. 537. A. Calabrese and R. G. Hayes, J . Amer. Chem. SOC., 1973, 95. 2819; J. A. Connor, I. H. Hillier, V. R. Saunders, M. H. Wood, and M. Barber, Mol. Phys.. 1972,24497. M. G. Barker and A. J. Hooper, J.C.S. Dalton, 1973, 1513. R . C. Kerbv and J. R. Wilson. Canad. J . Chem.. 1973,51. 1032

J. Solid State Chem., 1Y72, 5, 431. (i) K. A. Abduragimova and P. F. Rza-Zade, Rid. Zhur. Khim.. 1971, Abs. 21B913 (Chem. Abs., 1972, 77, 93509aj. (1) I. M. Gottlieb and Ch. R. Rowe, ‘Proceedings of the 3rd International Conference on Thermal Analysis’, ed. H. G. B. Wiedemann. Basel. 1971. 2, 303 (Chem. Abs., 1973,78, 131 488y). (kj J. Tudo and G. Laplace, Bull., SOC. chim. France. 1972, 1329. (l) M. R. Marinov. V. S. Kozhukharov, and Yu. N. Pavlova, Doklady Bolg. Akad. Nauk, 1972, 25, 1355 (Chem. A h . , 1973,78, 63464k). (m) J. Galy, Nat Bur. Stand. (U.S.A.),Spec. Publ., No. 364. 1972, 29. (nj G. Lohmiiller, G . Schmidt, B. Deppisch, V. Gramlich, and C. Scheringer, Acta Cryst., 1973. B29. 141 : H. C. Schopper. W Urban. and H. Ebel. Solid State Comm.. 1972,11,955.(0)J. C. Pedregosa, E. J. Baran, and P. J. Aymonino, An. Asoc. quim. Argentina, 1972,60,397 (Chem. Abs., l973,78,21112p). ( p ) V. L. Volkov, G. A. Tikhonova, E. V. Tkachenko, and A. A. Fotiev, Zhur. neorg. Khim., 1972, 17. 2806. (4)E. E. Sauerbrei, R. Faggiani, and C. Calvo, Acta Cryst., 1973, B29, 2304. (r) C. Gianoglio and G . Ramondo. Rev. Int. Hautes. Temp. Refract.. 1973, 10, 27 (Chem. Abs.. 1973. 78. 141205d). (s) C. Calvo and D. Manolescu, Acta Crystl., 1973, B29, 1743; D. Lavaud and J. Galy, Bull. Soc.frunc. MinPral. Crist., 1972, 95, 134. (tj R. D. Shannon and C. Calvo, Canad. J . Chem., 1972, 50, 3944. (u) R. D Shannon and C. Calvo. Acta Cryst.. 1973, B29. 1338. (1)) H. Saji, J . Phys. SOC. Japan. 1972, 33, 671, (Chem. Abs., 1972, 77, 120552t). ( w ) J. C. Bouloux, G . Perez, and J. Galy, Bull. Soc. franc. MinPral. Crist., 1972, 95, 130. (xj V. L. Zolotavin, 1. Ya. Bezrukov, and V. P. Vodop’yanova, Zhur. neorg. Khim., 1972, 17, 1331. (y) M. Quarton, J. Angenanlt, and A. Rimsky. Acta Cryst., 1973. B29, 567. (zj A. W. Sleight, Materials Res. Bull., 1972, 7, 827, (Chem. Abs., 1972, 77, 93927k). (aa) R. C. Popp and B. Carroll, J. Inorg. Nuclear Chem., 1973, 35, 1153. (bb) Kh. S. Bagdasarov, V. S. Krylov, and V. I. Popov, Vysoko-temp. Khim. Silikat. Okislou, Tr. Vses. Soveshch, 3rd, ed. E. K. Keler, ‘Nauka’, . V. S. Chincholkar, J . Leningrad, Otd., Leningrad, 1968, 123 (Chem. Abs., 1972, 77, 8 1 6 4 0 ~ ) (cc) Inorg. Nuclear Chem., 1972,34,2973.(dd) A. P. Nakhodnova. T. D. Voloshina, and 1. V. Mokhosoeva, Zhur. neorg. Khim.. 1972. 17, 1282. (ee) S. S. Kiparisov, R. A. Belyaev, V. V. Bondarenko, and V. P. Vyskubov, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1973, 9, 68. (ff)H. Fuss and A. Kallel, J . Solid State Chem.. 1972, 5, 11. ( g g j H. Brusset, R. Mahe, and J. P. Laude, Bull. SOC. chim. France, 1973.495.

The Early Pansition Metals

65

The anions of ol-Zn,V,O, consist of a pair of VO, tetrahedra linked by a common oxygen atom which lies on a crystallographic two-fold axis. The terminal Vdistances range from 165.8 to 172.8pm, with the V-0-V interbond angle of 149.3" being the largest so far observed in divan ad ate^.^,, A refinement of the crystal structure of synthetic chervetite, Pb,V,O,, has shown that the [V,0,l4- anions have terminal V - 0 distances ranging from 166.5 to 172.0 pm, bridging V 4 bonds of length 181.2 and 182.1pm, and a V - - - V interbond angle of 122°.419Spectrophotometric studies of solution equilibria for metavanadate over the concentration range 2.5 x to 1.2 x mol l-', at pH 7-9 and 10-40 "C in 3.0M-NaC104, have shown that, under these conditions, metavanadate is probably a mixture of [V3O9I3and [V,0,,]4- ions, the upper limits of the formation constants of these ions being 10.8 0.5 x low6l2 mol-, and 73 f 7 x lo9 l3 mol-3, respectively.420 The kinetics of the dissociation of decavandate ions in basic solutions have been studied spectrophotometrically from 15 to 50°C, and were shown to be very slow compared with both the formation of this ion and its acid decomposition.42la The syntheses, thermal stabilities, and X-ray diffraction patterns of the cadmium decavanadates, Cd3Vl00,,,15H20, M,Cd,V,,O,,,mH,O, (M = K, Rb, or Cs), and M,CdV,,O,,,nH,O (M = Na or K) have been [PV,reported.421bAlkali salts of the heteropolyanions [PVW, 1040]4-, W ,04,] -, [HPV, W,O,,] 6 - , and [H3PV6W60,0]6- have been prepared,,, from solutions containing metavanadate, tungstate, and phosphoric acid. These anions have been characterized in solution by stationary-electrode voltammetry and shown to undergo one-, two-, four-, and six-electron reductions, respectively, the voltograms being sufficiently specific to allow identification of the anions in mixtures and to trace their reactions. The tungstovanadophosphoric acids H, +x[PVxW,, -x0,,],nH20 (x = 1 4 ) have been isolated423" and the wide-line 'H n.m.r. spectra of the anhydrous compounds were shown to be consistent with the adoption of the Keggin structure.423b Other anions in this series can probably be obtained, but those containing an even number of vanadium atoms have a greater stability than those with an odd number. Preparation of vanadium-containing heteropolyanions by the formation of etherates has been shown to give variable The formation and stabilities of the heteropolyacids H,[IPV,MO,O,~], H3[PV,Mo60,2],424" and H4[A~V2M010040]424b have been examined.

,

418

419

'"' 421

422 423

424

R. Gopal and C. Calvo, Canad. J . Chem., 1973,51, 1004. R D Shannon and C. Calvo. Canad. J Chem., 1973.51. 70. P. H. Rieger, Austral. J . Chem., 1973, 26, 1173. (a) J. B. Goddard and A. M. Gonas, lnory. Chem., 1973. 12, 574; (b) V. P. Vodop'yanova, I. Ya. Bezrukov. and V. L. Zolotavin, Zhur. neorg. Khim., 1972, 17, 2426. 2429. D. P. Smith and M. T. Pope, lnorg. Chem., 1973,12, 331. (a) N. A. Polotebnova, G. M. Shinik, and N. A. Dunaevskaya. Zhur. neorg. Khim.. 1973,18. 796: (b) V. F. Chuvaev, G. M. Shinik, N. A. Polotbenova and V. I. Spitsyn, Doklady Akad. Nauk S.S.S.R., 1972, 204, 1403. K V. Nenakhova A. A. Malevich. and I. A. Korobova. Ref Zhur. khim., 1971. Abs. 23620 (Chern. Abs. 1972,77, 131421a): ( b )N. A. Polotebnova, K. K. Radul, and G. M. Tkachuk, Zhur. Vsesoyuz Khim obshch. im D. I. Mendeleevy 1972, 17, 227 (Chem. Abs., 1972, 77, 55754~).

66

Inorganic Chemistry ofthe Transition Elements

The oxodiperoxovanadate complexes M[VO(OJ,L],nH,O (M = Na, K, or (M = K NH,; L = bipy or phen; n = 2-5) and M3[VO(OJ,C,0,],2H,0 or NHJ have been prepared in hydrogen peroxide solutions of metavanadate ions containing the corresponding bidentate ligand. In the presence of large excesses of the bidentate N-donor ligands L, the salts LH[V,O,(OJ4L,],6H,O are formed.425The crystal structure at 193 K of ammonium peroxo(pyridine2,6dicarboxylato)aquovanadate(v) hydrate, NH,[VO(O,)H,O(C,H,N(COO),],xH,O (x ca. 1.3) has been determined and shown to contain the

anions (37) in which the vanadium(v) atom is co-ordinated to seven donor atoms arranged in an approximately pentagonal-bipyramidal manner, the 0x0- and aquo-oxygens being on the axial sites.426 Complex formation between V 0 2 + and P,O;- ions in aqueous solution at pH 1 4 has been studied and stability constant data were calculated.427 (CF,CO),O reacts with V205 or NH,V03 to afford VO,(O,CCF,) or NH,[VO(O,CCF,),], respectively.428The final product of the oxidation of dimeric vanadium(1v) D- and DL-tartrato-complexes has been shown to be an orange solution containing a vanadium(v)-tartrato species which appears to have a structure resembling that of the decavanadate ion. The lack of such a species in the case of meso-tartrate is probably due to the inability of this ligand to form stable bridges between two metal centres.351 The complex formation between vanadium(v) and tartaric acid (H,L) in aqueous media at was pH 4-7 has been studied, and the formation of [(VO,),(H,L),I4demonstrated by potentiometry, spectrophotometry, and c r y o ~ c o p y . ~ ~ ~ The i.r. spectra of VO(OR), (R = Me, Et, Pr, Pri, Bu, Bu', or Am) have been reported, and V = O and V - 0 bond-stretching modes identified in the regions 1 0 1 2 4 6 0 and 662-4500 cm- re~pectively.~~'. VO(Bu"), is a selective catalyst for the conversion of cycloalkenes into the corresponding epoxyc y ~ l o a l k a n e s .The ~ ~ ~substituted alkoxides VO(OR)L, (L = acac, dbm, or 8-quinolinate) have been prepared by treating a metal vanadate with HL in ROH containing an organic acid.431 The polyglycol ethers (RCOCH,),C425 426

427 428 429

430

431

N. VuletiC and C. DjordjeviC, J.C.S. Dalton, 1973, 1137. R. E. Drew and F. W. B. Einstein, Znorg. Chem., 1973,12, 829. V. A. Leitsin, S. D. Grekov, T. P. Sirina, and B. S. Pritsker, Zhur. neorg. Khim., 1972, 17. 1325. P. V. Radheshurar, R. Dev, and G. H. Cady, J . lnorg. Nuclear Chem.. 1972,34, 3913. M. Cadiot, B. Viossat, and C. Volfovsky, Compt. rend., 1972,275, C, 1399. M. G. Voronkov, N. I. Shergina, and A. Lapsina, lzvest. Akad. Nauk S.S.S.R., Ser. khim., 1972,2812. A. V. Savitskii, S. Ya. Shachilova, R. Ya. Vlaskina, and V. M. Zapletnyak, U.S.S.R. P., 355179 (Chem. Abs.. 1973.78,72 3720.

The Early Ransition Metals

67

{ CH,(OCH,CH,),OH}, (H,X) (R = C,H,-€,H,, ; n = 25-29) react with VOC1, to afford (VOC1,),X,rnVOC1, (rn = 10-16). Similar reactions have also been characterized with other such polydentate ligands.' 3 3 The stability constants of the vanadium(v) complexes VO(OH)L, with L = benzoylacetone or thenoyltrifluoroacetone have been determined as 4.2 x 10,' and 8.2 x 1021 and 8.2 x lo', 1, mol-,, respectively.432aThe related complexes, VO(OR)L, (R = Et, Pr, Pri, or Bu), have also been characterized.432b N-Donor and Mixed N-donor and 0-donor Ligands. The preparation of the tris(trimethylsiloxy)vanadium(v) imine, [(Me,SiO),V=NSiMe,], has been achieved from NH,VO, and NH(SiMe,),(l :2). [(Me,SiO),V=NPr] has been synthesized in a similar manner using PrNH(SiMe,).433 The crystal and molecular structures of [VO(OPri)(8-quinolinate),] have been determined. The O=V(OPr') group has a cis-configuration with an 0 - V - 0 interbond angle of 101.9" and V - 0 bond lengths of 160.0 and 177.4 pm to the 0x0- and isopropoxo-ligands, respectively. The V-N bond trans to the 0x0-ligand is 231.7 pm, whereas that trans to the isopropoxo-group is 220.9 pm. These data thus provide a quantitative assessment of the relative static trans-effects of 0x0- and isopropoxo-ligands. The two oxygen atoms of the 8-quinolato-groups, at distances of 190.2 and 192.5 pm, complete the octahedral co-ordination about the metal.,,, The i.r. and electronic spectra of the related complexes, [VO(OR)L,] (R = H or Et and HL = 8-quinolinol; R = H and HL = 5,7-dichloro-8-quinolinol) and [V20,L,] (HL = 8-quinolinol) have been measured and it has been concluded that the bonding to the metal atom from the oxygen atoms of the OR and 8-quinolato-groups includes a significant ~ t - c o n t r i b u t i o n ,consistent ~~~ with the above bond-length data. Electronic and e.s.r. spectral studies have shown that, in aqueous and CHC1, solutions containing Vv,8-quinolinol, and p-phenetidine, oxidation of the latter to the corresponding quinone imine occurs.436 Solution structures and equilibria for vanadium(v) complexes formed with edta (H,L'),ethylenediamine NN'-diacetate, (H2L2),and NN'-dimethylethylenediamine NN'-diacetate (H,L3) have been studied and the corresponding [VO,L' J 3 - , [V0,L2]-, and [V0,L3]- complexes isolated as their Na' or K + salts. 1.r. spectral studies indicate that the anions contain cis-VO, groups and that, whereas the first two acids form a single isomeric anion, designated a-cis, the last forms both a-cis and p-cis isomers. The equilibrium between these two forms has been studied at various temperature^.,,^ A spectrophotometric study of the reactions of edta, diethylenetriaminepenta-acetic 432

433 434

435

436

437

(a) N. A. Krasnyanskaya, N. V. Mel'chakova. and V. M. Peshkova, Zhur. analit. Khim., 1972,27, 1620; (b) A. Doadrio, F. Lorenzo, and C. Molina, Anales de Quim., 1972, 68, 357 (Chem. A h . , 1972, 77, 169300~). F. Becker, J . Organometallic Chem., 1973,52, C9. W. R. Scheidt, Inorg. Chem., 1973,12,1758. R. P. Henry, P. C. H. Mitchell, and J. E. Prue, Inorg. Chim. Acta, 1973,7, 151. B. G. Zhelyazkova, and K. B. Yatsimirskii, Teor. i Eksp. Khim., 1972, 8. 249: Doklady Akad. Nauk S.S.S.R., 1972,203, 1129. L. W. Amos and D. T. Sawyer, lnorg. Chem., 1972. 1 1 , 2692.

68

Inorganic Chemistry of the Transition Elements

acid, and nitrilotriacetic acid with metavanadate has been made, and the stability constants of the 1 : 1 complexes with V O t have been calculated as ca. lo71 mol- from these data.438 4-(2-Pyridylazo)resorcinol (H,L) has been shown to form VO,HL and [VO,L]- in aqueous solutions containing V", and [VO,(HI,)NH,OH], [VO,(L)NH,OH]-, and [V0,(L)ONH,]2- for these media in the presence of NH,OH. The electronic spectra of these complexes have been reported.380n The i.r. spectra of [VO(OMe)L,] (HL = cupferron, 8-quinolinol, or cinnamoylphenylhydroxylamine) have been studied to provide evidence for alkoxide formation.439 The system NH,VO,-isonicotinic acid hydrazide has been studied spectrophotometrically in aqueous media and two complexes found with metal :ligand ratios of 1:1 and 1:2 and respective stability constants of 1.7 x lo3 1 mol-' and 8.3 x 10' 1, mol-2.440 New co-ordination complexes of oxovanadium(v) with the terdentate ONO-donor ligand derived from 2-hydroxynaphthylideneamino-acid (H,L), [VO(OMe)L]MeOH and [VO(OH)L],, have been prepared and shown to be non-electrolytes in solution.373VO(OEt), reacts with the Schiff bases (H,L) bis(salicy1idene)ethylenediamine and salicylidene-2-hydroxypropylamine to form the corresponding VO(0Et)L complexes, which have been characterized by i.r. spectro~copy.~~' Organometallic Compounds. PhVOCl, has been synthesized by the addition of VOCl, to a suspension of MPh, (M = Zn or Hg) in pentane at - 30 "C, the mixture being stirred for 6 h. PhVOCl, reacts with bipy in pentane at - 30 "C to afford the 1 :1 a d d u ~ t . ~ ~ ~ The reactions between V 2 0 5and cyclopentadienyl or indene in THF have been studied and tricyclopentadienyl- and tri-indenyl-vanadium(v) oxide, respectively, obtained and ~haracterized.~,~ 4 Niobium and Tantalum Introduction.-The m.p. of 99.7% pure niobium has been measured as 2469 & 9 0C.444 The crystal structure of p-tantalum appears to be isomorphous with that of p-uranium, and its X-ray powder diffraction pattern has been indexed in terms of a tetragonal unit The absorption spectra of niobium atoms isolated in Ar, Kr, and Xe matrices at 14 K have been recorded. The absorptions observed in the U.V. region correlate well with those expected from known gas-phase data, but this was not the case for the visible and i.r. spectral regions. Spectral features observed upon annealing an Ar matrix containing Nb 43n

439 440

44f 442 443 444

445

R. P. Tishchenko. N. 1. Pechurova, and V. I. Spitsyn, lzvest. Akad. Nauk S . S . S . R . ,Ser. khim., 1972,2396. A. T. Pilipenko, L. L. Shevchenko, and L. A. Zyuzya, Zhur. neorg. Khim., 1973.18, 130. S. Zommer, Roczniki Chem.. 1972.46, 805 (Chem. Abs., 1972,77, 144471s). K. L. Chawla. P. Prasher, and J. P. Tandon, J . Indian Chem. Soc., 1972,49, 553. K. H. Thiele, W. Schumann, S. Wagner, and W. Briiser, 2. anorg. Chem., 1972,390,280. S . Kapur, B. L. Kalsotra, and R. K. Multani, lndian J . Chem., 1972,10,947. B. Ya Berezin, M. M Kenisaran, and V. Y a Chekhovskoi Teplofiz.Vysok. Temp, 1972 10, 1214 (Chem Abs, 1973,74 101 1071). P. T. Moseley and C. J. Seabrook Acta Cryst, 1973. B29. 1170.

The Early Ransition Metals

69

of atoms were assigned to transitions within Nb, d i m e r ~ The . ~ ~spectrum ~ Nb6+ has been re-analysed and the ionization potential of this ion was estimated to be 118.9 f 0.7 eV.la7 The reference literature on niobium and tantalum has been indexed272and that on niobates and carbon compounds of niobium revised.447A survey of the organometallic chemistry of niobium and tantalum published during 1971 has been presented.273Notable developments in the chemistry of niobium and tantalum reported this year include the synthesis of the pentahydrido-complex [H,Ta(Me,PCHzCH,PMez),J,448 the preparation of [(n-Cp),Ta(H),SnMe, J via amine elimination between [(z-Cp),TaH,] and M ~ $ L ~ N M ~ and , , ~ ~the ' synthetic route into niobium(n1) chemistry via borohydride reduction of [(n-Cp),NbCl,] which, in the presence of PR, (R3 = Ph, or PhMe,), affords [(n-Cp),NbH(PR,)].450 Molecules of this type [(n-Cp),NbH(L)] (L = PMe,, CzH4, or CO) react with AlEt, to give the (n-Cp),Nb(L)HAlEt, adduct. SimiIarly, the dimer of niobocene and [(n-Cp),TaH,] give [(n-Cp)(n-C,H,) NbHAlEt,], and [(x-Cp),TaH,AlEt,], respectively, with A1Et,.451 Other new niobium compounds which have been characterized include the metal-metal bonded niobium(Ir1)dimers, Nb,X6(SC4H,), (X = C1, Br, or I),which have been obtained by the reduction of the corresponding NbX,(SC4H8), adduct with Na-Hg in benzene.452 Magnetic c.d. studies of [M&11,]"+(M = Nb or Ta; n = 2, 3, or 4) in solution at room temperature have provided the first unambiguous assignment of the electronic spectra of these clusters and a revised bonding scheme for them has been presented.45 An unusual reversible one-electron oxidation of the [(Me6C&M3X6]+ (M = Nb or Ta; x = a or Br) clusters has been described. Since this affords diamagnetic species, the process is considered to involve the conversion of [(Me6C6)6M6X12]2+ to [(Me6C6)6M6X12-J4+ in a manner directly analogous to the two-electron oxidation of the corresponding [(M6Cll,)C16]6 - ion.454 has been The stereochemistry of tetrakis (dipivaloylmethanato)niobium(~v) shown by X-ray analysis to be the first example of a Mpidentate), complex whose stereochemistry is based on an idealized square antiprism (38).455 The first lslTa pure n.q.r. spectra have been detected in Ta,X,, (X = Cl or Br) as part of a detailed n.q.r. study of such d i r n e r ~ . ~ ~ ~ 446

447

448 449 450 451

452

4s3 454

455 4s6

D. W. Green and D. M. Gruen, J. Chem Phys, 1972, 57, 4462. Gmelin's Handbook of Inorganic Chemistry, System No. 49, Niobium Pt B, Sect 4, Gmelins Institute, Verlag Chemie, WeinheilIs 1973. F.N. Tebbe, J . Amer. Chem SOC, 1973,%, 5823. D. H. Harris S. A. Keppie, and M.F.Lappert, J. C. S. Dalton, 1973, 1653. C. R. Lucas and M.L.H. Green, J.C.S. Chem Comm, 1972, 1005. F. N. Tebbe, J . Amer. Chem Soc, 1973,95, 5412. E. T. Maas,Jun. and R. E. McCarley, Inorg. Chem., 1973,12, 1096; E. T. Maas, jun., Diss. Abs.(B), 1972, 33, 1440. D. J. Robbins and A. J. Thomson, J.C.S. Dalton, 1972, 2350. R B. King D. M. Braitsch, and R.N. Kapoor, J.C.S. Chem Comm, 1972 1072. T. J. Pinnavaia, G. Podolsky, and P. W. Codding, J.C.S. Chem Comm, 1973, 242. (a) P. A. Edwards and R E McCarley, J.C.S. Chem Comm, 1972 845; (b) Inorg. Chem, 1973,12, 900; (c) P. A. Edwards Diss. Abs. ( 4 1973, 33, 3532.

70

Inorganic Chemistry of the Transition Elements

Carbonyl C O ~ ~ ~ ~ X ~ ~ . - [ H , T ~ ( M ~ ~ Preacts CH~C at H80 ~ "C P Min ~~)~] benzene solution under 1500 p.s.i. of CO to produce [HTa(CO),(Me,PCH,CH,PMe,),], which is a fluxional molecule at 90°C but a rigid one near 0°C.448 The photochemical replacement of carbonyl groups in [(n-Cp)Nb(CO),] by cyclopentadienyl ones gives [(n-cp)Nb(CO),(c,H6)], which may be thermally decomposed to [(n-Cp),Nb(CO)H] via CO evolution and hydrogen migration. The molecular structure of this latter compound has been determined.457The protonation of various [(n-Cp)Nb(CO),L] complexes by CF3C02Hor HCl in CH2C1, has been demonstrated, and their basicities were assessed relative to similar complexes of neighbouring metals.279b Binary Compounds and Related Systems.-Halides. The composition of niobium subchloridesprepared from Nb and NbC1, by chemical transport reactions has been studied. When the disproportionation temperature of NbCl, was maintained at 350"C, NbCl, a mixture of NbC1, with NbC13.13, NbCl,.,,, and NbC1, (2.75 < x 6 3.02) were obtained, at partial pressures of NbCl, of >4.0, 3.1-1.6, 1.2, and 1 . 0 4 . 6 atm., respectively. At a partial pressure of NbC1, of 0.06 atm., the products obtained by disproportionation at 350 and 400-700 "C were NbCI,.,, and Nbcl,,,,, respectively.The disproportionation behaviour of these halides and their X-ray diffraction characteristics have also been examined.458 Further studies of the vibrational spectra of NbF, and TaF, vapours have been reported and, in agreement with the results of earlier work, have shown that the probable structural unit in the gas phase is a tetramer similar to that of the solid state.,,' Thermodynamic functions of NbBr,, TaCl,, and TaBr, in the gaseous state have been calculated over the temperature range 298-1500 K.460 TaCl, has been shown to be an effective catalyst for the complete exchange of aromatic hydrogens between molecules such as perdeuteriobenzene and Oxides. The i.r. absorption spectra of Nb160 and Nb180 isolated in Ar matrices have been determined; peaks were observed at 964,968, and 971 cm-' for the former and 918,921, and 924 cm-' for the latter.462 The first stages of oxidation of niobium have been studied by electron 451 458

459 460 46 1 46 2

N. I. Kirilova, k I. Gusev, and Yu T.Struchkov, Zhur. strukt. Khim, 1972, 13,473. Y. Saeki, M. Yanai, and A. Sofue, Denki Kagaku, 1972,46,816,870 (Chem Abs, 1973,78,167940d. 168 020r). J. M. Springer, jun, Diss Abs. ( 4 1973, 33, 3862. A. S. Yushin, L. I. Osipova, and V. I. Slegina, Zhur. fiz.Khirn, 1973, 47, 278. J. L.Garnett, M. k Long R F. W. Vining and T. Mole, J.C.S. Chem Comm, 1972, 1172. D. W. Green. W. Korfmacher, and D. M. Gruen, J . Chem Phys, 1973, 58 404.

The Early Transition Metals

71

diffraction and shown to involve tetragonal Nb,O (8 2 x 2 6.5) as the first phase and tetragonal Nb60 as the second phase.463A detailed study of the initial stages in the oxidation of single crystals of high-purity tantalum has also been carried A sub-oxide of composition Nb40 is formed on decomposition of a solid solution of oxygen (1.5 atom "/d in niobium by annealing at 500-700"C.465 The oxides formed on the surface of niobium in uucuo at elevated temperatures have been shown to involve solid solutions, NbO, NbO,, and Nb,05.466 The non-stoicheiometric phase Ta02.08,which has a tetragonal rutile-like structure, has been formed at 1000-1 200°C under shockwave compression of Ta,05.467 A new partial phase diagram for the Nb-0 system, concentrating on the existence of the phases NbO,.,, and NbO2.47, has been constructed by measuring the partial pressures of 0, in equilibrium with mixtures of Nb205 and NbO,. Each of these non-stoicheiometricphases has a composition domain for single-phase existence which increases rapidly with temperature for Nb02.47, this phase being metastable at temperatures <970 0C.468A direct observation of the lattice defects in H-Nb,O, has been achieved by using highresolution electron microscopy. The metal-atom positions were identified and shown to be in both ordered and heavily disordered regions. The blocks in the structure are well ordered along the b-axis, but heavily disordered in the acplane; the sub-cell structure of ReO, is still perfectly retained. Four kinds of planar defect were revealed in the ordered region, some of which produce non-stoicheiometry.A new polymorph of Nb205,having the same structure as P-Nb9025,was found in one of these defect structures and several new phases of Nb,O, were observed in the heavily disordered region.469A general formula has been deduced for structures analogous to H-Nb205.470 The reduction and non-stoicheiometryof niobium pentoxide over the composition range NbO2.42 to NbO,.,o has been re-examined in order to correlate thermodynamic behaviour with structural modifications during reactions. Structurally, this range involves a progression from H-Nb20, through Nb2,O6, to NbI2O29, the structures being generated in coherently intergrown lamellae and domains.47 A class of crystalline substances has been recognized in which changes of chemical composition are accompanied neither by the formation of a step-wise succession of phases, nor by the formation of non-stoicheiometric or solid 463

464

465

466

467

468 469 470 471

Y. Monfort, A. Maisseu, G.Allais, A. Deschanvres and P. Delavignette, Phys. Status Solidus (A), 1973. 15, 129. K. R. Lawkss and D. J. Kampe, U.S. Nat. Tech. Inform Sero, A.D. Rep.. 1972. No. 745341 (Chem. Abs, 1973, 78, 75 272j). V. M. Dekanenko, V. V. Vavilova, and I. I. Kornilov, Izvest. Akad Nauk S.S.S.R, neorg. Materialy, 1972, 8, 849. Ya. S. Umanskii M. N. Ageev, F. Y a Levin, M. P. Ermakova, and E. E. Pavlov, Izoest. Akad. Nauk S.S.S.R, neorg Materialy, 1973, 9, 382. 0. N. Breusov, A. N. Dremin, V. N. Brobyshev, and S. V. Pershin, Zhur. neorg. Khim., 1973, 18, 295. J. F. Marucw, Compt. rend., 1972,275, C , 1391. S. Iijima, Acta Cryst., 1973 A29, 18. M. Shimazy Kobutsugaku Zasshi 1972, 10, 326, (Chem Abs, 1972, 77, 67 162n). K. M Nimmo and J. S. Anderson J.C.S. Dalton, 1972, 2328.

72

Inorganic Chemistry of the Transition Elements

solution phases with disordered defect structures. Instead every composition orders into a superlattice and the diffraction patterns invariably show only one set of superstructure lines which is, however, different at every composition. The consequences of such adaptive ordering have been discussed in relation to phases derived from LTa,O, and it has been shown that the observed complexities in the chemistry of a wider range of solid-state systems can be interpreted consistently on this basis.,’ The crystal structures of T-Nb205 and of the isostructural Nb,05-ZrO, (91.5-8.5 mole ‘A have been determined215 and numerous Nb,O,-rich phases with complicated compositions have been prepared and ~haracterized.~? Chalcogenides. The ternary phase diagram of the Nb-0-S system has been studied and the thermodynamic properties of niobium sulphides have been estimated.473Nb14S, has been obtained as small but well-formed single crystals in a polycrystalline sample containing mainly Nb, The crystal structure of the former compound has been determined: the co-ordination number of the metal atoms ranges between fourteen and sixteen and the sulphur atoms have a capped trigonal-prismatic co-ordination geometry, N b 4 = 244.8270.4 pm.274The vibrational spectra of NbS, NbS,, and NbS,X, (X = C1, Br, or I) have been recorded and interpreted in terms of their structural units.25 A review discussing the structural transitions in TaS,, NbSe,, and TaSe, lattices and the distortions of the Nb, -,S structure has been presented.,’, Layer intercalation compounds of NbS,, TaS,, NbSe,, and TaSe, with NH,, N,H,,nH,O ( n = 0 or l), NHMeNHR (R = H or Me), nitrogen heterocycles and their N-oxides have been prepared and the layer expansions of the host lattice determined in each case.,’ The structure of the Ti0.167NbS2phase has been determined and the titanium atoms shown to be statistically distributed over the free octahedral sites between the NbS6 regular prisms. The structure comprises chains of NbS,-TiS, units, having D,, and C,, symmetry, respectively, in which the NbS, and TiS, moieties alternately share a common face and a common edge.27A critical rein!erpretation of the data recently reported for EuNb,S4 has been presented and the ‘compound’ was shown in fact to be a mixture of Euo.167NbSand EuS, the former being an intercalation compound containing both Eu and Nb atoms in trigonal-prismatic NbTe, has been shown to have a layer structure which is derived from the Cd1,-structure by slight displacements of the cations.476 Compounds with Elements of Group r! with Silicon, and with Germanium. The i.r. absorption spectra of Nl3I4N and Nbl’N isolated in an Ar matrix have been recorded and absorptions characterized at 1002.5and 974 cm- respectively.462

’,

472 413 474 475

476

R. Gruehn, Nut. &r. Stand. (U.S.A.)Spec. Pub/. No. 364, 1972, 63. D. Hodouin, J . Less-Common Metals, 1973,30, 127. H. Y. Chen, R T. Tuenge, and H. F. Franzen, Znorg. Ch’em, 1973, 12 552. F. Jellinek, Materials Res. &l/, 1971, 6, 169, (Chem Abs, 1972, 77, 80 565r). J. Van Landuyt and S. Amelinckx. Proceedings of the 5th International Materials Symposium, ‘Structure and Properties of Materials and Technical Application of Electron Microscopy’, 1971, 1115 ( C h e m Abs, 1972, 77, 144765r).

The Early I).ansition Metals

73

The reaction of niobium with nitrogen at lO-,Torr and 1000°C has been shown to form Nb,N, on the surface of the Hexagonal E-TaN has been converted into a high-pressure form 0-TaN at 20-100 kbar and 800960°C.47 The crystal structure of Nb,P, has been determined and shown to consist of an array of interconnected Nb$ trigonal prisms with additional Nb atoms inserted between them.478 NbSiAs, NbGeAs, NbSiSb, NbGeSb, and TaSiAs have been prepared and shown to possess the tetragonal PbFCl structure. In the last-named of these compounds, each Ta atom is surrounded by a square antiprism of four Si atoms ( T a - S i = 267 pm) and four As atoms (Ta-As = 269 pm), with an additional As atom located above the As, face (Ta-As = 277 The crystal structures of NbSi,, NbGe,, and TaGe, have been refined48oa and the feasibilityof preparing compounds in the N b G e system by co-reduction of NbCl, and GeCl, has been Phase equilibria in the Ti-NbGe ternary system have been studied for the metal-rich regions.34 Hydrides. The thermodynamic characteristics of the Nb-H system have been investigated,,' and the crystal structure of P-NbH,, which has a face-centred orthorhombic lattice, has been determined.482The crystal structure of Ta,D has b e e n ~ e p o r t e d . ~ ~ ~ Compounds with Nb-Nb or Ta-Ta Bonds.-The new metal-metal bonded niobium(m)dimers, [Nb,X,(SC,H,),] (X = C1, Br, or I) have been prepared by the reduction of the corresponding [NbX,(SC,H,),] adducts with Na-Hg in benzene.These new compounds,which are diamagnetic and solublein non-polar solvents, have been characterized by 'H n.m.r., i.r., and electronic spectroscopy. The n.m.r. study showed that the tetrahydrothiophen molecules are present in two different chemical environments and it is suggested that the dimers consist of two octahedra sharing a common face which comprises two halogen atoms and a tetrahydrothiophen sulphur atom. The sulphur donor ligands may be replaced by halide ions, and [Nb2C18(SC4H,)]2- and [Nb2Cl9I3- have been isolated, the former apparently retaining the bridging sulphur ligand (Et4N)3[Nb,C19] was found to be paramagnetic, in contrast to the alkali-metal salts of [Nb2Br9I3- and [Nb219]3-.452 Magnetic c. d. studies of the [M6ClI2]"+ (M = Nb or Ta; n = 2, 3, or 4) clusters have shown that previously proposed bonding schemes for these ions 477 478 479

480

481 482

483

G. Brauer, E. Mohr-Rosenbaum, A. Neuhaus and A. Skokan, Monatsh, 1972,103,794. S. Anugul C. Pontchow, and S. Rundqvist, Acta Chem. Scand., 1973,27, 26. V. Johnson and W. Jeitschko, J. Solid State Chem., 1973, 6, 306, F. Hulliger, J. Less-Common Metals, 1973,30,397. (a) R. Kubiak, R. Horyn, H. Broda, and K. Lukaszewicz, &//. Acqd, polon. Sci, Skr. Sci. chim., 1972,20,423{Chem Abs, 197277,80 6860; (b)N. A. Valueva, I. V. Petrusevich, and L. A. Nisel'son, Izuest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972 8, 2083. J. A. Pryde and C. G. Titcomb, J. Phys. (C),1972,5, 1301. M. S. Rashid and T. E. Scott, J. Iess-Common Metals, 1973,30, 399. V. F. Petrunin and D. Ya Khvatinskaya, Izoest. Akad. Nauk Uzbek. S.S.R, Ser. Fiz-Mat. Nauk, 1972, 16, 74 (Chem Abs., 1972 77, 157 4022).

74

Inorganic Chemistry of the Transition Elements

give an incorrect ordering of one-electron energy levels. A revised bonding scheme, which includes spin-orbit coupling for the first time, has been proposed to account for the spectral details (M6X:2)X$,nH,0 (M = Nb or Ta; X' = Cl or Br; X2 = Cl, Br, or I) have been prepared from (M6XI2)X2,nH,Oby reactions with HCl, HBr, or NaI in H 2 0 or MeOH solutions. The thermal decomposition, X-ray diffraction and i.r. spectral characteristics of these compounds have been obtained.484The green-brown cations [(Me6C6)6M6x,2I2+(M = Nb or Ta;X = Cl or Br) are readily oxidized to the corresponding tetrapositive cations by oxidizing agents such as (NH4)2[Ce(N03)6], and these clusters have been isolated as their [BPh,]- or [PF6]The full account of the crystal structure determination of the dimer of niobocene has been p~blished.,~ This compound catalyses competitive exchange reactions between D, and aromatic compounds.486AlEt, reacts rapidly with [(7c-Cp)(7c-C5H4)NbHl2to afford [(7c-Cp)(x-C,H,)NbHA1Et3]2.4s' Niobium(iii) and Tantalum(iir).-The preparation and properties452 of the niobium(~rr) dimers [Nb,X,(SC,H,),] (X = C1, Br, or I) are described on p.73 Other developments in the chemistry of these oxidation states have been confined to 7c-cyclopentadienyl derivatives. The reduction of [(n-Cp),NbCl,] by NaBH, in THF affords green crystals of [(.n-Cp),NbBH,] ; treatment of this borohydride with the tertiary phosphines PR3 (R3 = Ph, or PMeJ gives the corresponding dark-red [(n-Cp),NbH(PR,)] complexes. The hydride r(7c-C~)~NbH(PPhMe,)] reacts smoothly with BuBr (1 11) to give green crystals of [(n-Cp),NbBr(PPhMe,)]. These hydrido-complexes all appear to be basic and may be protonated in dilute HCl.450 The molecules of [(x-Cp),NbH(L)] (L = CZH, CO, or PMe,) react readily with AlEt, to afford the corresponding [(n-Cp),Nb(L)HAlEt,] derivative and the structures of these molecules have been discussed in the light of 'H n.m.r. data.4s1A 7c-ally1 to o-ally1 rearrangement occurs when [(7c-Cp),Nb(.rc-allyl)] reacts with CS,, to afford the red-violet compound [(7c-Cp),(o-allyl)NbCS2]. This compound undergoes oxidative addition with alkyl halides4* Niobium(1vj and Tantalum(Iv).-The fine structure of the L,, X-ray absorption spectrum of niobium in Rb,NbC16 has been analysed and the charge on the niobium was suggested to be +2.1.488 M,TaOCl, (M = K, Rb, or Cs) have been prepared by treating M2TaC16 with Sb203at 180-580°C under an Ar atmosphere. These compounds have been characterized by chemical, thermal, and X-ray diffraction analyses and appear to be more stable than their niobium analogues.489 The chemistry of the halides and oxyhalides of niobium(1v) and tantalum(1v) 484

485

487 488 489

H. Schifer, B. Plautq and H. Plaut&Z. anorg. Chem, 1972, 392, 10. L. J. Guggenberger, Inorg. Chem, 1973, 12, 294. U. Klabunde and G. W. Parshall, J. Amer. Chem SOC, 197294, 9081. G. W. A. Fowles, L. S. Pu,and D. A. Rice, J . Organometallic Chem, 1973.54. C17. R L. Barinskii I. M. Kulikova, and N. P. Lipatova Zhur. strukt. Khim, 1972, 13, 1089. k I. Morozov and I. I. Leonova Zhur. neorg. Khim, 1972 17. 2677.

The Early nunsition Metals

75

and their co-ordination compounds has been re~iewed.''~NbCl, reacts with py and various substituted pyridines to form complexes of the type NbC1,,2L which have a trans-octahedral geometry in solution. The e.s.r. spectra of these complexes show variations in the hyperfine parameters which correlate with the nature of the ligand s u b s t i t u e n t ~ The . ~ ~ ~mixed-ligand complexes, [NbC1,(OR)bipy] (R = Me, Et, Pr, or Bu), have been synthesized by the controlled rec Fiction of the corresponding [NbCl,(OR),] complexes using Li(bipy) in ThF. These niobium(1v) complexes are paramagnetic (p = 1.4-1.6 BM) and their i.r. spectra are consistent with co-ordinated alkoxo- and bipyridylligand~.~"[NbX,L,] (X = NCS or NCSe; L = bipy or 4,4'-dimethyl-2,2'bipyridine) have been prepared by the reaction between K,[NbX6] and L under anhydrous conditions, and for [NbX,(bipy),] via reduction of K[Nb&]. The i.r. spectra of these complexes are consistent with the ambidentate ligands being N-bonded, and the metal atomsappear to be eight co-ordinate, [Nb(NCS),(py),] has also been prepared and this appears to have trans-octahedral geometry; however, its magnetic moment (p = 0.97 BM) is significantly lower than those of the [NbX,L,] complexes (p = 1.72-1.86).492 The niobium bronzes MNbO, and M,NbO, (M = Ca, Sr, or Ba) have been prepared by heating MO and NbO, in vacuo, the reactions being monitored by X-ray diffraction techniques. These bronzes are paramagnetic, possess semiconductor properties, and are readily oxidized in air to MO and Nb,05.493 FeNbO, and Fe,NbO, with ilmenite and pseudobrookite structures, respectively, have been prepared by the reactions of NbO, with FeO and Fe,O,, respectively,at 1000-1 100"C in vacuo.The lattice parameters of the compounds have been determined by X-ray diffraction. These compounds are stable to aerobic oxidation up to 500 "C but at higher temperatures they react with oxygen to give FeNb0,.494 Compounds of the perovskite system Ba(Ce, -xTaJO, (0 < x < 0.5) have been prepared in single crystal form. At low temperatures the ion pairs Ce"-Ta" exist in octahedral sites ;however, on warming to 7% 750K the increases in resistivity and magnetic moment which occur would appear to indicate a change to Ce"'-Ta' ion Tetrakis(dipivaloylmethanato)niobium(Iv), [Nb{(Bu'CO),CH},] has been prepared by treating NbC1, with dipivaloylmethanein MeCN containing Et,N. X-Ray crystallographic studies have shown that this compound is the first example of an M(bidentate), complex whose stereochemistry is based on an idealized D , square antiprism (38). In the absence of oxygen and moisture, [Nb{(Bu'CO),CH),] affords stable, very weakly conducting solutions in CH,Cl, which contain the monomer.455 490

491 492

493

494

495

D. P. Johnson,J. Wilinski and R D. Bereman, J. Inorg. Nuclear Chern, 1973,35, 2365. N. Vuletik and C. Djordevik J.C.S. Dalton, 1973, 550. J. N. Smith and T. M. Browq Inorg. Chern, 1972 11, 2697; J. N. Smith, Diss Abs. (B), 197233, 1049. E. G. Vovkotrub, Y u N. Makurin, E I. Krylov, and G. G. Kasimov, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972 8, 2217. E. I. Krylov, G. G. Kasimov, and E G. Vovkotrub, Zhur. neorg. Khirn, 1973, 18, 548. T. Nakamura, and T. Sata f i l l Tokyo Inst. Technol, 1972 149 (Chern Abs, 1973,78, 8819~).

76

Inorganic Chemistry of the TransitionElements

l'he 'H and 13C n.m.r. spectra of [Nb(S,CNPr,),] have been obtained as part of a general study of ligand inequivalencein eight-co-ordinatec0rnp1exes.l~~ NbC1, reacts with difluorodithiophosphinic acid, F,PS,H, to give [Cl,Nb(S,PF,),]. The compound (pyH),[Nb3S3C1, J,2py is slowly deposited from py solutions of [NbC13(S,PF,),] as paramagnetic (p = 2.2 BM) green crystals; [Nb,Cl,(S,PF,),] may be obtained in low yield by heating NbC13(SzPF2),.'45 Tl,Pt,TaS, has been prepared by heating the binary sulphides for 2-4 days at 400-600"C in the absence of air.255 X-Band e.s.r.spectra of magnetically dilute glasses containing [(7t-Cp),NbX2] (X = C1, NCS, OCN, CN, or 0-C5H3have been recorded at 77 and 290 K and analysed in detail. With the exception of the [(n-Cp),Nb(CN),] complex, where the unpaired electron is delocalized into the ligand p-orbitals, the unpaired electron is in the 4dZ2orbital which is essentially non-bonding. The e.s.r. spectra of several redistribution complexes, [(n-Cp),NbClY] (Y = NCS, CN, or o-C5H5),were also detected in this ~ t u d y . ~ " Niobium(v) and Tantalum(v).-Halides and Oxyhalides. Phases between N b 2 0 5 and Nb30,F have been studied by heating these components for 4--90h at 1200--1270°C in sealed Pt tubes; the phases Nb(O,F), (n = 2.510 and 2.523) were ~haracterized.,~~" Unit cell parameters have been reported for the phases NaTaO,F,, Na,Ta,O,F, NaTa,O,F,, Na2Ta6015F2, NaTa,O,,F, Na,Ta,O,F, Na,Ta,0,,F9, and Na,TaO,+,F,-, (x = 0 . 1 3 4 . 1 7 ; 0.95).496b Kinetics studies of the reactions of Nb205,or Ta205,with HF or F, have been carried out and the reactions of the latter oxide shown to be more complex than those of the former, mixtures of TaF,, Ta,O,F, and Ta0,F being produced. The reactions between T a 2 0 5or Ta0,F and F, or NH,F,HF have been studied in some Formation constants of niobium(v) fluoride complexes have been obtained at 25°C for aqueous solutions containing K,[NbOF,], NaF, NaClO, and HClO, by using a fluoride-selectiveelectrode to monitor the equilibrium concentrations of fluoride. At high acidities, i.e. [H'] :[NbV] > 175, NbF;-" (7 6 n 6 9) ions were characterized, as were the rNbOF,']3-" ( 2 6 n 6 9 ions at lower acidities.49893Nband 19Fn.m.r. studies of niobium(v) 0x0- and peroxo-fluoro-complexes,formed in aqueous media, contain [NbOF,have been reported. Aqueous solutions of (NH,),[Nb,O,F,] (H,O)]- ions which react with HF or H,O, to afford [NbOF,]'or [NbO,F,];respectively. This latter anion is also present in 60% H , 0 2 solutions of (NH,),[NbOF,] and (NH,),[NbOF,]. The addition of NH, to a solution of (NH,),[NbOF,] in 60% H,O, produces some [Nb(O,),F,I2-

496

497

JyLI

(a) R. Gruhn 2. anorg. Chem, 1973,395, 181; (b) J. P. Chaminade, M. Pouchard and P. Hagenmuller, Rev. chim Mineral&, 1972, 9, 381. E. G. Rakov, D. S. Kopchikhin, B. N. Sudarikov, and B. V. Gromov, Zhur. neorg. Khim, 1973, 18 579; V. D. Bratishko, E. G. Rakov, B. N.Sudarikov. B. V. Gromov, and E. Ya. Sklyakhter. rhid.. p 712. J. E. Land and C. V. Osborne, J . Less-Common Metals, 1972, 29, 147.

The Early 'I).ansitionMetals

77

ions.499aNiobium(v) and tantalum(v) peroxofluoro-complexes formed in 20 % H2S04 have been identified and stability constant data determined.499b The crystal structure of LiTaO,F, has been solved by X-ray diffraction and shown to contain infinite Re0,-type blocks, three unit cells thick, stacked perpendicular to the c-axis and displaced along the [1101direciton with respect to each other. These blocks are connected together by Li' atoms which have a square-pyramidal c o n f i g u r a t i ~ n . ~ ~ ~ The reaction of K[TaCI,] with oxygen at 200--900"C has been studied by t.g.a., i.r., absorption, and X-ray diffraction methods and the compounds K[TaOCl,], K[TaO,Cl,], TaO,Cl,KCl, and Ta,O,,KCl identified at 300550, 550400,600-700, and 700--800"C, respe~tively.~~' The salts M[Ta02Cl,(H,O)] (M = K, Rb, Cs, or NHJ have been prepared by treating TaCl, with MCl in saturated HC1 solutions. The anhydrous compounds have been obtained by heating these monohydrates in an Ar or HC1 atmosphere at 105"C, and shown to contain i.r. absorptions in the 875-830 cm-' region which appear to indicate the presence of Ta=O--- -Ta=O----- chains.502 Since fluoro-bridges have been identified in both NbV- and Tav-fluoride systems, the possibility of preparing discrete fluoroanions containing both these metals is feasible. This has been achieved by mixing solutions of MIF, (M' = Nb or Ta) and (Bu,N)[M2F,] (M2 = Ta, Nb, or Sb) in either SO, or CH,Cl,. The mixed-metal anions [M1M2F,'3- were characterized by their 19F n.m.r. spectra in these media.,',= Similarly, NbF, and TaF, react with [MoF,] - to afford [MoNbF,,]- and [MoTaF, '1,- respectively.MoF, in SO2, SO,Cl,, or CH,C12 reacts rapidly with the solvent in the presence of NbF, or TaF, to give a variety of The complete details of the crystal structure of NbF,,SbF, have now been published504 and the Raman spectra of XeF[Nb,F,,] and XeF[Ta2Fll] have been The phase diagram of the TaF,-UF, system has been constructed.506 The fine structure of L,,, X-ray absorption spectra of niobium in K,[NbPF,], (Et,N)[NbF,], and Rb,[NbOCl,] has been interpreted and the charges on the niobium atoms in these salts were assessed as + 2.6, + 2.8, and 2.2, respectively.This study has also showed that the oxyanions [NbOX,]'- (X = F or C1) in the above salts have C,, symmetry, their d-orbital energy sequences being e < b, < a, < Halogen and metal n.q.r. transitions have been determined in the M2XI0(M = 93Nbor 181Ta;X = ,'Cl, "Br, or '271) dimers; the ls'Ta resonances are the first pure quadrupole transitions detected for this nucleus. The metal resonances indicate that the co-ordination about the metal

+

499

500

501 502

503 504

(a) Y u A. Buslaev, E. G. Il'in, V. D. Kopanev, and V. P. Tarasov, Zhur. strukt. Khim., 1972, 13, 930; (b) G. N. Latysh, k S. Chernyak, and T. E Serebrennikova, Zhur. neorg. Khirn., 1973, 18, 1014. M. Vlasse, J. P. Chaminade, and M. Pouchard Materials Res. aCU, 1973, 8, 117 (Chem Abs., 78, 89 692h). T. I. Beresneva. G. P. Gosteva, and A. N. Ketov, Zhur. neorg. Khim, 1973, 18, 134. A. I. Morozov and I. I. Leonova, Zhur. neorg. Khirn, 1972,17,2128. (a) S. Brownstein, Inorg. Chem, 1973, 12, 584; (b) S. Brownstein, Canad. J. Chem, 1973,51, 2530. A J. Edwards, J.C.S. Dalton, 1972, 2325. R. J. Gillespie and B. Landa Inorg. Chem, 1973, 12. 1383.

78

Inorganic Chemistry of the Pansition Elements

atom becomes more nearly octahedral, C1 < Br < I. The positive temperature coefficients associated with the terminal halogen atom resonances are indicative of metal-halogen x-bonding, which also causes these resonances to be at frequencies lower than those of the bridging halogen atom ones.456The seven hexahaloniobate(v) anions [NbCl,Br, -,,I - (n = 0-6) have been prepare& in MeCN solution and their 93Nbn.m.r. spectra determined. These data show that the [NbCl,Br,],- [NbCl,Br,],- and [NbC14Br2]- ions exist exclusively as the cis-,fuc-, and cis-isomers, respectively, in solution. A similar study of the six pentahaloniobium(v)-acetonitrile adducts [NbCl,Br, - ,MeCNJ (n = 0-5), prepared in MeCN or CH,Cl, solution, has shown that only seven of the possible twelve geometric isomers are obtained. In this study, the 'pairwise additivity' model for predicting chemical shifts has been extended to six-co-ordinate complexes, where it constitutes a powerful technique for identifying specific isomers in solution. Chlorine substitution was found to cause an upfield shift of the ',Nb resonance relative to bromine substitution.507 Halide-transfer reactions between Bu'Cl and PC12X (X = C1 or Me) with NbC1, or TaC1, have been shown to form the corresponding (Bu'XPC1~[MC16](M = Nb or Ta) salts, the vibrational spectra of which have been re~orded.~" Phase diagrams of the ICl-NbCl, and ICl-TaC1, systems have been published and the compound TaCl,,ICl (m.p. 102"C) identified in the latter ~ystem."~ 0-Donor Ligands. Table 5 summarizes many of the data reported on niobates and tantalates and mixed oxides containing niobium(v)or tantalum(v)published this year. The structures and vibrational spectroscopic properties of NaNbO, and related compounds have been investigated in some considerable detail. The lattice parameters of NaNbO, at temperatures up to 800°C have been determined with a high precision, and six distinct phases were identified."'" NaNbO, undergoes an antiferromagnetic-ferroelectric transition at temperatures below - 110°C.The lower temperature phase is isostructural with LiNb03 and, in the higher temperature phase, the NbO, octahedra remain nearly regular but are tilted about the three-fold axis with the Nbv atoms being displaced from the centre of the octahedra in a sense parallel to this axis.' l o b The mixed oxides LiNbO,, M N b O , and MTaO, (M = Na, K, or Ag) have been prepared by heating Nb205 or Ta,O, with MN03, M2C03, or M,SO, and crystalline transitions in them were detected from -150 to 1500°C by d.t.a. Their i.r. spectra have been recorded at - 120"C and at room temperature and discussed in relation to their crystal s t r u c t ~ r e s . ~Raman and electronic spectra of cubic

''

506

507 508 509

510

511

V K Ezhov, Zhur. neorq. Khim, 1972 17. 2043 R. G. Kidd and H. G. Spinney, fnorg. Chem, 1973, 12, 1967. J. I. Bullock, F. W. Parretf and N. J. Taylor, J.C.S. Dalton, 1973, 522. V. V. Safonov, E. A. Abramova, and B. G. Korshunov, Zhur. neorg. Khim, 1973, 18. 568. (a) A. M. Glazer and H. D. Megaw, Acta Cryst, 1973, ,429,489; M. Ahtee. A. M. Glazer, and H. D. Megaw, Phil. M a g , 1972, 26. 995. (b)C. N. W. Darlington and H. D. Megaw, Acta Cryst., 1973.

B29,21 7 1 . C. Rocchiccili-Deltcheff and C. Wadier, Spectrochim. Acta, 1973, 2 9 4 93; Q. D. Nguyen, E. Hussen, and Y. Repelin, Compt. rend.. 1972 275, C,609.

The Early nunsition Metals

79

Na3Nb04have been recorded and interpreted on the basis of a rock salt lattice containing a disordered distribution of Na' and Nbv atoms among the cation sites.512A corrected atomic position parameter for Ba3Si4Nb6026 has been given., l 3 Partially oxidized tin(@niobate and tantalate pyrochlores have been shown by Mossbauer 9Sn spectroscopy to be homogenous cubic phases containing tin(1r) and tin(rv) MTaO, (M = Ti, V, Cr, or Fe) have been prepared from the corresponding oxides by ceramic techniques and X-ray and neutron diffraction, magnetic and Mossbauer measurements have indicated that the metal atoms are distributed statistically over the metal sites of the rutile struct ~ r eThe . ~ compounds ~ M~,M~.,Te,O,(MI" = Sc, Cr, Fe, Rh, Ga, In, or Bi; MV = Nb or Ta) have been shown to be isostructural with TiTe308 by X-ray diffraction spectro~copy.~'~ The substitution of K' and Tiw atoms by Nbv or Tav (M) in KTi2(POJ3 leads to the formation of the isotypic compounds MTi(POJ,.l10 The crystal structure of the mineral nenadkevichite, Na3.761.2oSi8O24,H20, has been deterKO.24Cao.11Mn0.03(Nb2.7 1.1d02. 8 ,(OH) mined and shown to contain square rings of Si4Ol2 units joined together by Nb06 octahedra. The large cavities in this structure accommodate Na' atoms in two partially occupied sites and H 2 0 molecules in two fully occupied ones. Other minerals in this series contain progressively more Tiw for NbV.lo7The superstructure of the Nb20,-ZrO, and Ta,O,-ZrO, systems have been described and shown to have a Nb205:Zr02 ratio which varies from 2 :9 to 2 :15.214 The structure and the intergrowth of polymorphs of Zr02,12Nb20, have been investigated.215 A phase diagram has been given for the LiNb0,-KMb03 system based on X-ray diffraction data. The system forms the bronze Li4K6Nb12030and the ferroelectric Li,K6Nbl 2030 compounds but no solid solution^.^'^ The crystal structures of RbNb30, and Rb3Nb540146have been determined. The former material is similar to the hexagonal tungsten-bronzes.The latter has an unusual framework of Nb06 octahedral and Nb07 pentagonal-bipyramidal groups which together form four-, five-, six-, and seven-sidedtunnels extendingthroughout the structure; the Rb' atoms partially fill the six-sided tunnels.517The (M = Nb or Ta; 0 < x < 0.40) have been studied by systems (M,Mol -J02.80 d.t.a. and X-ray powder diffraction spectroscopy at room temperature for samples quenched from 600-900°C. Stable ternary phases with the Mo,O,, structure are apparently formed at > 600 "Cfor N b contents of x ca. 0.09 and x = 0.40 and Ta content of x ca. 0.07.5'8 New non-stoicheiometric phases M:(M'O), M'U, (Mz = Sr, Pb, or Bi; M' = Nb or Ta), having the tetragonal '12

513 514 515

'lh

'18

G Blasse and G. P. M. Van den Heuvel, Materials Res. all.,197Z 7,1041, (Chem A h . , 1972,77, 158 266r). J. Shannon and L. Katz Acta Cryst, 1972, B28 3438. D. J. Stewart, 0. Knop, R E. Meads, and W. G. Parker, Canad. J. Chern., 1973.51, 1041. J. Galy, Nat. Bur. Stand. (U.S.A.), Spec. Publ. No. 364, 1972,29 I. G. Ismailzade, V. I. Nesterenko, and E k Il'yasov, Kristallografiya; 1973, 18, 185. B. M. Gatehouse, D. J. Lloyd, and B. K. Miskin, Nat. f i r . Stand. (U.S.A.)Spec. Publ. No. 364,1972, 15. T. Ekstrom and M. Nygren, Acta Chem Scand, 1972, 26, 1836.

Inorganic Chemistry of the TransitionElements

80

Table 5 Niobates, tantalates, and mixed oxide compoundr containing niobium(v) or tantalum(v)

Na2Ta401

1

Na2Ta802

1

Properties reported

Source

Compound

LiNbO, Li,Nb04 Li,Nb80,, u- and P-LiTa,O,

Li,O-Nb,05 system

X

Li,O-Ta,O, system

X X

K,Ta5O1,SH,O

Mg0.667Nb

Nb-rich part of MgO-Nb,05 system

33O29

1 1.3

CaNb,O, Ca2Nb Zo 7 M,NaTa5015 ( M = Sr or Ba) M2NaNb5(1

-x,Ta5x0

CaO-Nb205 system

, ,

Pb5Nb4015

M 3 Nb(S04) 4 ( M = NaorK)

d

X X st ; NbO, octahedra

f' 9

X ;W-bronze structure h

1

CaloNb,Si,O,, Sn, Nb 0, Sn,Ta,O, PbNb 0, PbNb40 Pb,Nb,07

X neutron diffraction; isomorphous with BaTiO,

15

(M = Sr or Ba; x = 0-1) A1NbO4 A1Nb11029 A1,0,-Nb,O, system AlTaO, A1,0,-Ta,05 system GaNbO,AH,O Ga(NO,), + corresponding K Ga(Nb03),,9H,0 Ga,(Nb6Ol9),,30.5H2O niobate in aq. sol. InNbO, InTaO, M,TlNb,O (M2 = Sr,, CaBa, or SrBa)

CuNb,O,

ReJ

CaO-Nb,O,-SiO, SnO + Nb205 SnO + Ta,05

Z

X, isostructural with wolframite p,X, W-bronze structures

system

PbO-Nb,O, system

1 g

X, pyrochlore lattice st, NbO, octahedra

m

n

X

H,SO, + N b 2 0 5+ M2S04 X at 250 "C RbNb0,-TeO, X, pyrochlore KTa0,-W 0, systems lattice Fe,O, + TiO, + Ta,05 at 1 150-1 250°C under pressure e, AH

Y

r S

The Early Transition Metals

81

Table 5 (cont.) Source

Compound

Properties reported

Ref.

a-and P-ZnNb,O, Zn@Nb,O,

Zn3Nb208

system

X

0,t

X

U

st, similar to that of LiNb60,,F

2)

X

W

i.r., X X, pyrochlore lattice

X

t.d., X

Y

m.p. 2060°C m.p. 1800°C

7

Zn2Nb34087

NbzO.j-HfO,, Ta,O ,-Hf02 systems

17

Nb2Hf60

TaZHf60

17

Nb2W08 NaNb0,-M 0, NaTa0,-MO,, systems

NaNbMO, NaTaMO, (M=MoorW) Ag2Ta802 1

Ag,SO,-Ta,O, system at 1250°C CdO + Nb,O, CdO Ta,O,

,

Cd Nb 0 Cd,Ta,O,

+

M(N03),-KNbO,-H,O M(NO3) 3-K3 NO,-H, 0, systems Y 0,-Ta, 0, system at 1200-1450°C

M (NbOJ3,mH,O MNbO,,nH,O ( M = ScorY) Y(TaO3)3 YTaO, KBa ,ZrNbg 0 LiLaNb,O, Li3La,Zr2Nb803, LiNa,Ba,LaNb,oO,o Na3Ba, MNb, 0030 (M = Y, La, ELI, Gd,

,

,

or DY)

LaTaO, MZr LaTaO, ( M = Ca, Sr, Ba, Cd, or Pb) MTiNdNbO, M TiNdTaO (M = Cd or Pb) NdNbO, Nd,NbO, MTiNbO, (M = Ce, Pr, or Nd) Lnx(M3xW1

- 3J03

(Ln = lanthanrde; M = Nb or Ta; x = 0.04-4.33) EuTa,O, Eu, - ,,,,(TaO),Ta03 (X = 0 4 . 1 3 3 ) Eu,Nb, 0 Eu2Nb6018

Eu2Nb10028 Eu6Nb2014

,

mixed oxide systems

I

mixed oxide systems

n

X,complex structures of low symmetry aa related to W-bronzes

X, pyrochlore structure

bb

X

a

X

cc

X,non-stoicheiometric perovskites

dd

Eu,O, + Eu Ta,O, under Ar at 1350°C

X, W-bronze structures

ee

Euz03-Nb205system

X

ff

J

Nd 03-Nb2 0,system coppt. of hydroxides heated at 1 150 "C Ln,O,-M,O,-WO, system

+

82

Inorganic Chemistry of the Transition Elements

Table 5 (cont.) Compound

Source

MTaO, ( M = La, Sm, Gd, Ho, or Yb) M 3Nb07 M2Nbl2033 (M = La-Nd) M NbO, MNb309 ( M = La-Nd, Sm, Gd, Dy, or Yb) MTaO, MTa,O, 2Ta12033

I

Properties reported

i.r.

I

M20,-Nb, 0 systems

(M = lanthanide--Pm, M,O,-Ta,O, system Yb) M ,Ta07 ( M = lanthanide-Pm, Er, or Yb) YbTaO, M,O,-Nb,O, systems M,Nb07 (M = La-Dy) MLnNb,O, M2C03 Ln,O, MLnTa, 0, Nb,O,, or T a 2 0 5 (M = Li, Na, or K ; Ln = Y,La, Nd, Sm. Gd, or Dy)

+

+

Re& 99

1

i

X

hh

X

ii

(a) V. A. Dyakov, V. V. Zubenko, and L. N. Rashkovitch, Eksp. Issled. Mineraloobrazou. Sukhikh, Okisnykh. Silikat. Sist., e d V. V. Lapin, ‘Nauka’ Moscow, U.S.S.R, 1972, 69. (b) M. Pouchard and J. P. Chaminade, Compt. rend, 1972 274, C, 1739. (c) Ref. 4966. (4P. V. Dyunov, V. G. Chuklantsev, and A. N. Zelikman, Zhur. neorg. Khim, 197717, 1341. (e) A. W. Hewat, K D. Rouse, and G. Zaccai, Ferroelectrics, 1972 4, 153 (Chem Abs, l973,78,34792k). ( f j R.Norrin, C. G. Arbin, and B. Nolander, Acta Chem Scand, 1972, 26,3389. (g) A. Carpy, P. Amestoy, and J. Galy, Compt. rend., 1972, 275, C, 833; A. Jongejan and A. L. Wilkins J. Less-Common Metals 1972, 29, 349. (h) J. P. Chaminade, A. Perroq J. Ravez, and P. Hagenmuller, Bull. SOC.chim France, 1972 3751. (4 N A. Godina, E. P. Savchenko, T. 1. Panova E. N. Isupova and E. K Keler, Vysokotemp. Khim Silikat. Okisloii. Tr Kws. Soueshch., 3rd., ed. E. K. Keler, ‘Nauka’ Leningrad, Otd. Leningrad, U.S.S.R. 1968, 176. c/) A. P. Kvashenko and S. P. Rozhenko, Ukrain khim Zhur, 1972, 38, 720 (Chem. Abs, 1972, 77, 121 572m). (k) J. Liebertz, Acta Cryst, 1972 B28. 3100. (0 J. Ravez J. Grannec, J. Portier, and P. Hagenmuller, Compt. rend., 1973, 276, C, 77. (m) F. Brisse, D. J. Stewart, V. Seidl, and 0. Knop, Canad. J. Chem., 1972, 50, 3648. (n) Ph. Labbe, M. Frey, and G. Allaiq Acta Cryst, 1973, B29, 2204. (0)H. Brusset, R. Mahe, and Vu Hoang Kyi, Materials Res. Bull. 1972, 7, 1061; Compt. rend, 1972, 275, C, 327. (p) M. I. Andreeva, E. A Podozerskaya, T. A. Kobycheva, and V. Ya Kuznetsov, Zhur. neorg. Khim., 1973, 18, 549. (9) B. Darrief M. Rat, J. Galy, and P. Hagenmuller, Materials Res. &[I, 1971, 6, 1305 (Chem. Abs., 1972,77, 80530a). (r)E. I. Krylov, F. A. Rozhdestvenskii, and V. A. Zavol’skii, U.S.S.R. P., 340 622 (Chem Abs, 1973,7860442). (s) A. A. Slobodyanyuk, Yu D. Tret’yakov,and A. F. Bessonov, Izuest. V U. Z., Tsvet. Met., 1972, 15, 18 (Chem Abs, 1972, 77, 131 549y). (t) R R. Dayal, J. k s s Common Metals 1972, 29, 1. (u) F. L Chan and G. G. Johnson, jun, Deiielop. Appl. Spectroscopy, 1972, 10, 307 (Chem Ah., 1973, 78. 141 335k). (v) M. Lundberg Acta Chem Scand, 1972, 26, 2932. (w) 0. B. Thakre and V. S. Chincholkar, Curr. Sci, 1972, 41, 735. (x) G. D. Yanson, Eksp. Issled. Mineraloobrazoti Sukhikh. Okisnykh. Silikat. Sist, e d V. V. Lapin, ‘Nauka’ Moscow, U.S.S.R, 1972, 74 (Chem. Abs., 1973, 78, 66325b). (y) A. M.Golub, R. V. Maksakova, and S. P. Rozhenko. Zhur. neorg. Khim., 1972,17,1808; A. M. Golub, R. V. Maksakova, S.P. Rozhenko, and V. S.Savoshchenko, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972, 8, 1954. (z) I. A. Bondar, k I. Kalinen, and L. N. Koroleva Izi-est. Akad. Nauk S.S.S.R., neorg. Materialy, 1972. 8, 1873. (aa) M, Kestigian and W. R.

The Early Pansition Metals

83

tungsten-bronze structure, have been isolated and the effect of the insertions of the M2 elements into the oxide lattice has been discussed.519The upper limits of the ionic charges possessed by the ions in W 4 N b 2 6 0 7 7 have been assessed as + 1, + 1.2, -0.8 (all +0.5), respectively, by high precision electron diffraction measurements for low sin0/h values.52oThe results of MO calculations of niobate(v) octahedra in edge-sharing dimers have been rep~rted.~,' The lattice parameters of the tetrakis(peroxo)niobium(v) salts M3[Nb(02)4] (M = K, Rb, Cs, or NHJ have been determined. These compounds are not isomorphous with Li3[Nb(0,),].522 The corresponding salts of the peroxooxalato-complexes M [Nb(0,) 3( C, O,)] and M [Nb(0,) (, C2O,),] have also been synthesized and their i.r. spectra and thermal decompositions The identification of some niobium(v) peroxofluoro-complexes4gg is mentioned on p. 76. The thermodynamic characteristics have been given for the formation of [TaO(S0,),,H,0,]3 - complexes in solutions containing 6 4 - 9 5 wt. % of H2S04.524An e.s.r. study has revealed that large number of Nbv-O, complexes exist in aqueous acidic media; these spectra have a hyperfine structure due to the interaction between the unpaired electron of the 0;ion and the 93Nb nucleus.525 The crystal structure of Cs~NbO(C20,),(H,0),],2H,0has been determined and the metal atoms were shown to have the pentagonal-bipyramidalco-ordination (39). The apices of the bipyramid are occupied by the 0x0- and one of the aquo-ligands, with N b - 4 bonds lengths of 169.1(5)and 232.8(4) pm, respectively. The average of the N b 4 bond lengths in the equatorial plane is 212.5 pm.526The relative thermal stabilities of several niobium(v) oxalato(a) A Deschanvres G. Desgardin, and B. Raveau, Materials Res. Lid/- 1972 7, 921 (Chem. Abs., 1972,77,131 714y). ( b ) L. LeParmentier, Rev. chim. Mineral&, 1972,9,519. 52D J. G. Allpress E A. Hewat, A. F. Moodie, and J. V. Sanders Acta Cryst, 1972, A28, 528; G. R Anstis D. F. Lynch, A. F. Moodie, and M. A. O'Keefe, ibid, 1973, A29, 138. s 2 1 N. R. Windgassen, J. Inorg. Nuclear Chem, 1973,35, 300. 5 2 2 R N. Shchelokov,E. N. Traggeim, M. B. Varfolomeev, M. A. Michnik, and S.V. Morozova, Zhur. neorg. Khim.,197717, 2439. 523 R. N. Shchelokov, E. N. Traggeim, M. A. Michnik, and K. I. Petrov, Zhur. neorg. Khim., 1972, 17, 2433. 5 2 4 V. P. Vasil'ev and G. A. Zaitseva, Zhur. neorg. Khim, 1973, 18, 139. 5 2 5 A. A. Merkulov, V. M. Berdinkov, Yu. V. Gatilov, and N. M. Bazhin, Zhur. neorg. Khim., 197717, 3253. 5 2 6 B. KojiC-ProdiC. R. Liminga, and S. ScavniEar, Acta Cryst, 1973, B29, 864. 519

Bekebrede, Materials Res. hl171973,8, 319 (Chern Abs, 1973,74 116084~);I-€ Iwasaki ibid, 1971, 6, 251 (Chem Abs, 1977 77, 80576~).(bb) L N. Aver'yanova, V. M. Ezhov, and D. V. Balashov. Zhur. neorg. Khim, 1972, 17, 2842; I. N. Belyaev, L. N. Aver'yanova and V. M. Ezhov, ibid, 1973, 18. 1141. (cc) A. K. Borisov, E. I. Krylov, and F. A. Rozhdestvenskii, Ref. Zhur. khim., 1971, Abs. 21B643, (Chem Abs, 1972 77, 963192). (dd) A. Deschanvres G. Desgardin and B. Raveau J. Inorg. Nuclear Chem.. 1973, 35, 2287: G. Desgardin and B. Raveau, J. Inor?. Nuclear Chem, 1973, 35, 2295. (ee) G. Desgardin, J. P. Fayolle, and B. Raveau, Compt. rend., 1973,276, C, 1101. ( j j )S.S.Kiparisov, R.A. Belyaev, V. V. Bondarenko, and V. P. Vyskubov, lzvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1973, 9, 68. (gg) K. I. Petrov, V. N. Gundobin, V. V. Kravchenko, and S. S. Plotkin, Zhur. neorg. Khim., 1973, 18, 833. (hh) G. Tilloca, M. Perez y Jonba, J. P. Traverse, and J. Coutures Colloq. Int. Cent. Nat. Rech. Sci, 1972, 369 (Chem Abs, 1973, 78, 165378~).(ii) V. S. Chincholkar, J . Inorg. Nuclear Chem., 1972,34,2973.

84

Inorganic Chemistry of the Transition Elements

H** (39)

complexes have been assesseds2' and a 1 :1:1 complex between Nbv, C202-, and lumogallon has been identified by i.r. spectroscopy.528 The formation of the adducts NbCls,0PX3 (X = Cl or Br) has been observed in CHC1, solution by 31Pn.m.r. spectroscopy and the enthalpy and entropy of activation for the exchange reaction between bulk and co-ordinated POC1, determined as 71 _+ 12 kJ mol-1 and 75 & 42 e.u., respectively. The comparative stabilities of the adducts NbCl,,OPR, (R = Cl, Br, OMe, or NMe3 have also been assessed.5'') TaCl,,OPCl, dissociatesinto its constituent molecules at ca. 400°C, the enthalpy and entropy changes for this process being 71 & 4 kJ A study of the preparation, electronic mol-' and 96 f 4 e.u, re~pectively.~~' spectra, and stabilities of 1:1 and 1 :2 complexes between HMPA and MX, (M = N b or Ta; X = F, Cl, or Br) has been rep~rted.'~' The average M--O bond energies in the two series of penta-alkoxides Nb2(OR),, and Ta,(OR),, (R = Me, Et,or Pr) have been determined by combustion calorimetryas418 f 12 and438 k 12kJmol- re~pectively.'~~ Intramolecular exchange processes in such molecules (R = Me, Et, or Bu3 have been studied by 'H n.m.r. spectroscopy. The activation energy for the scrambling of terminal and bridging alkoxo-groupswas found to be fairly constant (42-50 kJ mol- '), but the free energy of activation for this process increases with the ligand bulk. Terminal site scrambling occurs at a faster rate than terminal-bridging scrambling in these molecules.533The 70 eV mass spectra of the molecules Nb,(OEt),ClI0-, (n = 2 or 6-10) have been recorded.534C 0 2 (1 atm) reacts smoothly with Nb,(OEt),' at 30°C to give a mixture of partially carboxylatedproducts. 127 [M(NCS),(OR),(bipy)], (M = Nb or Ta; R = Me or Et) have been prepared by dissolving [M(OR),Cl,] in ROH, adding dry bipy, and heating to ca. 40°C before adding a solution of KCNS in ROH. Molecular weight determinations for benzene solutions confirmed the dimeric nature of these complexes and i.r. and 'H n.m.r. spectral evidence suggests that they have the structure (40), in

52i

52R

529 530

531 532

533 534

N. Brnicevic and Z Despotovic, Proceedings of the 3rd International Symposium on Thermal Analysis 1971, 2 705 (Chem A h . . 1973. 78. 131 583a). A. T. I'ikpenko, A. 1. Zhebentyaev, and A. I. Volkova, Ukrain khim. Lhur., IV72,38,1165 (Chem. Abs., 1973,74 51889q). J. C. Bunzli and k Merback, Helv. Chim Acta, 1972,55, 2867. k M. German, A V. Suvorov, V. k Titov, and V. I. Trusov, Zhur. neorg. Khim, 1972 17, 3101. J. Masaguer and J. Sordo, Acta Cient. Compostelanq 1971,8,115 (Chem A h , 197277,172046a). V. I. Tel'noi I. B. Rabinovich B. I. Kozyrkin, B. k Salamatin, and K. V. Kir'yanov, Doklady Akad. Nauk S.S.S.R., 1972 205, 364. C. E. Holloway, J . Coord. Chem, 19721, 253. H Preiss Z. anorg. Chem.. 1972, 389, 293.

The Early Transition Metals

85

R

R

(40)M

=

Nb or Ta

N

=

bipy

N

which the metal atoms are eight c o - ~ r d i n a t e . ~ The ~ , complex [NbOL,] - (HL = pyrocatechol) has been identified in solvent extraction studies536"and 1:1 and 2 :1 complexes between Tav and xylenol orange have been characterized by electronic spectroscopy.536b S-Donor and Se-donor Ligands. o-Mercaptophenol (H,L) reacts with NbCl, or TaC1, to give the corresponding H[ML,] complexes which have been characterized by i.r. and electronic spectroscopy.' 79a Difluorodithiophosphonicacid F,PS,H, reacts with NbC1, and TaCl, to give the corresponding [Cl,M(S,PF,),] complex, the i.r. and Raman spectra of which are consistent with seven-co-ordinategeometries. Pyridine reacts with [Cl,Nb(S,PF,),] to release SPF, and form a py-chlorothioniobium(v) complex; with Cl,Ta(S,PF,), it forms an adduct. The formation of the (pyH)4[Nb3S,C11,] and [Nb,Cl,(S,PF,),] compounds from [Cl,Nb(S,PF,),] is described on p. 76.145 A 4 :1 pyrrolidenedithiocarbamato-niobium(v) complex has been characterized spectrophotometrically.537Compounds of the type Cu,MS,Se, -, (M = N b or Ta; x = 0 4 ) have been prepared by heating stoicheiometric amounts of these elements for fourteen days at 550°C in an evacuated quartz tube. X-Ray diffraction studies have shown that the unit cell parameters of these compounds increase linearly with their selenium content.538 N-Donor and Mixed N-donor and 0-Donor Ligands. Ligand exchange reactions between NbCl,,R'CN complexes and R'CN [R1,R2= Me,XCH, (X = F, Cl, Br, or I), or But] have been studied by 'H n.m.r. spectroscopyand these reactions shown to occur via a slow dissociative cleavage of the Nb-NCR1 bond. There is thus a linear correlation between AGt for such a process and the free enthalpy of formation of NbCl,,R1CN.539The complexesTaX,L (X = NCS or NCSe; L = bipy or 4,4'-dimethyl2,2'-bipyridyl) have been characterizedfollowing the reactions between K[TaX6] and the ligand L under anhydrous conditions. Their i.r. spectra indicate that the ambidentate ligands are N-bonded and the bipy compounds behave as 1:1 electrolytes in MeCN and ClCH,CH,Cl. Ta(NCS),,py has also been prepared. NbC1, and TaC1, react with MeNCS 535

536

537

538 539

N. VuletiC and C DjordjeviC, J.C.S. Dalton, 1972, 2322 I. Lobanov, 0. D. Savrova, and I. M. Gibalq Zhur. neorg. Khim, 1973, 18 408: (b)T. N. Nazarchuk and V. I. Kornilova, Ukrain khim Zhur, 197238 705 (Chem Abs, 197277,118 922v). K. A. Uvarova Yu. I. Usatenkq and Zh G. Klopova, Zauod Lab., 1972, 38, 1431 (Chem Abs., 1973, 78, 154 507t). k Miiller and W. Sieverf Z . Naturforsch., 1972, B27, 722. A. Merbach and J. C Biinzli, H e h . Chirn. Acta, 1972,55, 1903.

(a) F.

86

Inorganic Chemistry of the Dansition Elements

and MeSCN to give the corresponding N-bonded MCl,,NCSMe add~ct.,~' The new octaethylporphyrin (H,L) complexes NbF,L, TaF,L, NbOFL, and (NbOL),O have been synthesized, and characterized by magnetic and spectral techniques.540 Niobium(v) forms a 1 :2 complex with salicylhydroxamic acid in aqueous ~ ' extracHCl which has a formation constant of ca. 2.5 x lo4 1' r n ~ l - ' . ~The tion of niobium(v) with N-phenylacetylhydroxamic acid (A) in benzene and CHCl, has been studied in the presence of pyrocatechol (B) or thiocyanate and a Nb :A :B complex of stoicheiometry 1 :2 :2 and a Nb :I :NCS one of stoicheiometry 1 :2 :3 have been identified.542 Organometallic Complexes. The reactions between NbCl, or TaCl, and ZnMe, have been studied in detail. NbCl, and ZnMe, (1 :1.1) react in n-pentane to give Me2NbC1,, provided that at least 12 h is allowed for the reaction. Shorter reaction times result in contamination with MeNbC1,. Me,NbCl, has been isolated pure; however, MeNbC1, has not, since attempts to make the latter using NbCl, and ZnMe, (2:l) still afforded solutions containing some Me,NbCl, and, for short reaction times, some Me,NbCl,. 'H N.m.r. spectra of TaCl, and ZnMe, mixtures show that they involve equilibria in which MeTaC1, and Me,TaCl, participate. A large number of adducts of these methylchloro-derivatives have been prepared with a variety of uni- and bi-dentate 0-, N-, S-, and P-donor ligands including, for example, the MeNbCl,,L (L = lP-dioxan or 1,2-diphenylthioethane)derivatives, and characterized by i.r. and 'H n.m.r. spectroscopy. These data suggest that most of these adducts contain six-co-ordinate metal atoms, although seven co-ordination seems probable for complexes involving certain bidentate ligands.543 This latter prediction has been confirmed by X-ray diffraction studies for [Me,TaCl,(bipy)]. This molecule has distorted capped trigonal-prismatic geometry with a chlorine atom capping a face consisting of one chlorine atom, two nitrogen atoms, and a methyl group. The geometry adopted by this complex has been rationalized by considering ligand-ligand repulsions and the constraints imposed by the bipyridyl ligand.,,, The full account of the reactions of NbCl, and TaCl, with trimethylsilylmethyl- and neopentyl-Grignard and -lithium reagents has been published and the isolation and characterization of [(Me,SiCH,),M(CSiMe,),M(CH,SiMe,),] (M = Nb or Ta) and R,TaCl, (R = Me,CCH, or Me,SiCHJ have been described in detail. 165b MeNC inserts into M - 4 bonds of both NbCl, and TaCl, to give the corresponding pale-brown [MCl,{ C(Cl)=NMe}(CNMe)] products which appear to be dimeric in MeCN. These complexes have a strong i.r. absorption in the range 2286-2271 cm-' characteristic of the v(N+ stretch of the coordinated MeNC group which, in the niobium derivative, may be displaced by 540 541 542 543 544

J. W. Buchler and K. Rohbock, Inorg. Nuclear Chem Letters, 1972 8, 1073. F. I. Lobanov, V. S. Voskov, I. M. Gibalo, and V. F. Kamenev, Zhur. neorg. Khim, 1972, 17,2683. I. M. Gibalo, V. S. Voskov, V. F. Kamenev, and F. I. Lobanov, Zhur. analit. Khim, 1972 27,2405. G. W. A Fowleq D. k Rice, and J. D. Wikinq J.C.S. Dalton, 1972 2313; 1973, 961. M. G. B. Drew and J. D. Wilkins J.C.S. Dalton, 1973, 1830.

The Early Transition Metals

87

PPh,. 1.r. bands in the 1700-1600 cm-I region have been assigned to v(C=N) stretching frequencies of the C(Cl)=NMe group which, in the niobium derivative, is protonated at the nitrogen by HCl. [NbCl,(C(Cl)=NMe)CNMeJ reacts further with MeNC to afford [NbCl,(C(Cl)=NMe),CNMe] which may also be made directly from NbC1, and MeNC in the ratio 1 :3.545 [(n-Cp),(~-allyl)Nb(CS,)] undergoes oxidative addition with alkyl iodides and bromides (RX) to afford the corresponding [(n-Cp),(o-allyl)NbX{C(S)SR]] derivative. Compounds of this type are remarkably thermally stable in the solid [n-Cp),MH,] state and may be heated to cu. 100°C without decomp~sition.~~’ (M = Nb or Ta) and [(n-MeC,H,)TaH,] catalyse the exchange reactions between D, and aromatic compounds; however, the tantalum compounds are far less effective in this respect than are [(n-Cp),NbH,] and n i o b o ~ e n e . , ~ ~ Amine elimination between Me,SnNMe, and (n-Cp),TaH, affords [(n-Cp),Ta(H),SnMe,], one of only a few compounds known to contain a Ta-Sn bond.449 [(n-Cp),TaH,] reacts with AlEt, to afford (n-Cp),Ta(H),AlEt, which probably contains a Ta-----H-.----Alinteraction. The analogous GaEt, adduct has also been prepared and weaker adducts have been identified with Et,Zn and Et,Cd. The corresponding [(n-Cp),NbH,] adducts have been detected by ‘H n.m.r. spectroscopy at - 20 to - 50°C; however, at room temperature they evolve ethane to produce (n-Cp),Nb(H),AIEt,, {(x-Cp),NbH,),Zn, and related compounds. (n-Cp),M(H),Hf(CH,Ph), (M = Nb or Ta) have also been characterized; however, they readily eliminate toluene.45 5 Chromium

Introduction.-Reviews have been published concerning the organometallic chemistry of chromium reported during 1971546 and the preparation and properties of chromium-(rv), -(v), and -(w) oxides and halides.547 There have been several interesting developments in the chemistry of chromium during this past year. Tetranitrosylchromium has been synthesized independently by two groups of workers using slightlydifferent conditions ; an excess of NO reacts with Cr(CO), dissolved in a hydrocarbon solvent. Cr(NO), appears to be a simple tetrahedral molecule. 548 The first dinitrogen complexes of chromium, [(n-arene)Cr(CO),N,] (arene = benzene or hexamethylbenzene) and [((n-arene)Cr(CO),) ,N,] (arene = mesitylene or hexamethylbenzene) have been isolated and characterized. In the latter molecules the dinitrogen appears to bridge between the two chromium atoms.549 (Cr(CO)5)2N2H,has been prepared by oxidizing (Cr(C0)5}2N2H4;the structure (41) was proposed for this compound on the basis of its lH n.m.r. and 545 546 541

548

5 49

B. Crociani and R L. Richards, J.C.S. Chem Comm, 1973, 127. D. J. Darensbourg, J. Organometallic Chem., 1972,45, 257. C Rosenblum and S. L.Holt, ‘Transition Metal Chemistry’,ed. R. L. Carlin, Marcel Dekker, Inc., New York, 1972, Vol. 7, p. 88. (a) B. I. Swanson and S. K. Satija, J.C.S. Chem Comm, 1973,40; (b) M. Herberhold and A. Razavi Angew Chem Internat. Edn, 197211, 1092. D. Sellmann and G. Maisel Z.Naturforsch, 197227b. 465, 718.

88

Inorganic Chemistry of the Transition Elements

i.r. ~ p e c t r a . ” ~The novel biscarbene complex c ~ ~ - [ ( M ~ , P ( O E ~ ) C ) , C ~ ( C O ) ~ J has been prepared and characterizedss1 and the first examples of a new class of compound, having a transition-metal-carbon triple bond, XM(CO),CR (M = Cr, Mo, or W ; X = Cl, Br, or I; R = Me or Ph) have been synthesized by treating BX, with the corresponding carbenes (OC),MC(OMe)R.’ 5 2 The compounds HM’M2(CO)lo(M’ = Cr, Mo, or W ; M2 = Mn or Re) have been synthesized and are the first examples of compounds in which transition-metal atoms of a different periodic group are bridged by a hydrogen atom alone.553 Cr(CNPh), reacts with I, (2 :1) in CH,Cl, to afford the novel [Cr(CNPh),] +, which has been isolated as its BPh, The e.s.r. spectrum of the Cr’ ion in a crystal field of cubic symmetry has been observed in MgO crystals following doping and y-ray irradiation at 77 K.554bThe direct synthesis of a new class of a-bonded organochromium(II1) complexes containing [(aryl),Cr(bipy),]+ ions has been achieved by oxidation of the corresponding organochromium(1r) compounds. In contrast to all other known o-bonded organochromium(1xr) derivatives, these are inert towards both air and water.’” The reduction of Cr0:in the presence of perfluoropinacol leads to the formation of [CrO{(CF,)2C(0)C(O)(CF,),),1- ions which have been isolated as their K + ,Cs’, or Et4Nf salts. These compounds are remarkably stable chromium(v)

derivative^.^' Carbonyl Complexes.-This section is considerably shorter than in previous years, the data reported being selected for general interest rather to provide a comprehensive survey of the literature. For this the reader should consult the Organometallic Specialist Periodical Report* The Raman intensities of terminal carbonyl stretching vibrations have been calculated for M(CO), (M = Cr, Mo, or W) and (x-arene)Cr(CO),-type molecules using Wolkenstein’s polarizability approach, and general intensity formulae were obtained. This model is particularly instructive in certain respects, for example, it allows an understanding of why the totally symmetric modes of these systems frequently give rise to only a weak Raman effect.556

D. Sellmann, A. Brandl and R Endell, J . Organometallic Chem, 1973,49, C22. E. 0. Fischer, F. R Kreissl C. G. Kreiter, and E W. Meineke, Chem Ber, 1972, la,2558. 5 5 2 E. 0. Fischer, G. Kreis C. G. Kreiter, J. Miiller, G. Huttner, and H. Lorenz Angew. Chem. Internat. Edn, 1973, 12, 564. 5 5 3 A. S. Foust, W. A. G. Graham and R. P. Stewartjun., J . Orgarlometallic Chern., 1973. 54, C22. 5 5 4 (a) P. Gans and S. M. E. Haque, Chern. and Ind., 1972,978; (b)G. Rius and A. Herve, Solid State Comm., 1972 11, 795 5 5 5 R. P. A. Sneeden and H. H. Zeiss J . Organometallic Chem., 1973, 47. 125. 5 5 6 S. F. A. Kettle, I. Paul and P. J. Stamper, J.C.S. Dalton. 1972, 2413. * ‘Organometallic Chemistry’, ed. E. W. Abel and F. G. A. Stone, (Specialist Periodical Reports), The Chemical Society, London, 1973, vol. 2, 1974, vol. 3. 550 551

89

The Early TransitionMetals

The products of flash photolysis of Cr(CO), have been re-examined using apparatus with a higher time resolution and more extensively purified solvent than in previous studies. A species was shown to be formed within 50 ns of the excitation of Cr(CO), which has a broad absorption at 503 f 5 nm, a lifetime of > 200 ps, and is believed to be Cr(CO),. The species is the precursor of two other species, previously thought to be the D3h and C,, forms of Cr(CO),, but now known to arise from reaction with impurities. The structure of Cr(CO), is not presently known.557Co-condensation at 20 K of sodium atoms and Cr(CO), diluted in argon leads to the formation of [Cr(CO),]-, the i.r. spectrum of which is consistent with a C,, structure.558 [HReCr(CO),o] has been synthesized by stirring a slurry of Et,N[ReCr(CO),,] in n-pentane over 8 5 % phosphoric acid for two days, before cooling to - 78 "C and fractionally subliming the solid obtained. X-Ray crystallographic studies have shown that these p-hydrido-anions have the eclipsed structure (42) with a R e - C r separation of 34331) pm.553Protonation 0 C

0 C

I /co I/co

OC- Re- H -Cr -CO

of [(C,H,)Cr(CO)&] complexes by CF3CO2H or HCl in CH,C12 has been established, and their relative basicities have been compared with similar complexes of neighbouring metal atoms.' 7 9 b Measured core-binding energies and calculated charge distributions in CO, Cr(CO),, and Cr(CO),NH, have shown that the o-framework of the CO ligand, which is drastically altered in the formation of Cr(CO),, remains essentially unaffected on substitution of NH, for CO. The formal charge distribution on Cr is also essentially unchanged by this substitution.559A new synthetic approach to the formation of substituted metal carbonyl anions of the type [M(CO),X]- (M = Cr, Mo, or W ; X = Cl, I, CN, NCS, C=CPh, or SR)consists of treating [M,(CO),o]2- in CH,Cl, at room temperature with either AgX or HgX,. 6o The halogenopentacarbonylmetallate anions of Cr, Mo, or W (M) react with ligands (L) in the presence of a Lewis acid such as Et,OBF, or AgNO,, to afford M(CO),L in high yield under mild conditions. This specific synthetic route has wide applicability and with potentially ss7 5s8 5s9

'''

J. N. Kelly, H. Hermann, and E K. von GustorE J.C.S. Chem Comm., 1973, 105. P. A. Breeze and J. J. Turner, J . Organometallic Chem., 1972, 44, C7. M. Barber, J. A. Connor, I. H. Hillier, and W. N. E. Meredith J . Electron Spectrosc. Refat. Phenomena, 1972 1. 110. W. J. Schlientz and J. K. Ruff, Znorg. Chem., 1972,11,2265; Syn. Znorg. Metal-Org. Chem., 1971, 1, 215.

Inorganic Chemistry of the i9ansition Elements

90 bidentate

ligands provides a

convenient synthesis of mono-hapto(n = 1 or 3, R = Ph; n = 2, R = Me or Ph) and [Cr(CO),PPh,(CH,),AsPh,~ have been synthesized in this manner and the mechanism of chelate-ring formation, to form the corresponding Cr(CO),L complexes, has been studied. These reactions follow first-order kinetics, as required for an intramolecular process, and the large variation in the positive entropy of activation suggests a concerted process in the transition state.561b The reactions of APh, (A = P or As) with [(n-arene)M(CO),] (M = Cr, Mo, or W) to yield [M(CO),(APh,),] have been re-examined and anomalies in earlier literature resolved by the isolation of two solid-state forms of each complex and a study of their decomposition products.562Convenient large-scale syntheses of the phosphine complexes [Cr(CO),PH,], cis-[M(CO),(PH,),J, andfac-[M(CO),(PH,),J (M = Cr, Mo, or W) have been developed and the crystal structures of these three chromium compounds have been determined.563 The Cr-P bond lengths in these compounds, 235-236 pm, are intermediate between those of 230.9 and 242.2 pm in [(OC),CrP(OPh),] and [(OC),CrPPh,], respectively, and the lengths of the Cr-P bonds in all these compounds ) stretching mode ; correlate well with the value of the corresponding v ( C ~ 0 (E) the weaker the base, the higher the stretching frequency, and the shorter the ~~ Cr-P bond, as expected from a synergic Cr-PR, i n t e r a ~ t i o n . ’Cr(CO), reacts with the triaryl phosphines PR, (R = Ph, m- or p-MeC,H,) at high temperatures to give both [Cr(CO),L] and [Cr(CO),L], complexes ;however, only the latter have been isolated in a pure state. Their i.r., ‘H n.m.r., and mass spectral data suggest the novel bridged structure (43).565 cis-[ Mn(CO), (triphos)Br] reacts with [Cr(CO),THF] in THF over 12 h to yield two orange products which have been separated by t.l.c., both compounds analysing for [Br(OC),Mn(triphos)Cr(CO),]. X-Ray crystallography has shown that one of these isomers contains molecules with the structure (44)the other isomer probably containing the bromine atom trans to a phosphorus in the manganese moiety.,,, The crystal structures of four compounds of the type Me,XCHR- CF,XMe,. M(CO), (M = Cr or Mo; X = P or As; R = H or Co have been redetermined, and two previously reported crystal structures of this type re-interpreted. In all of these cases, the crystals contain disordered arrangements of molecules with normal geometries and dimensions, but each crystal contains two molecular configurations the ratio of which varies from 1 :1 to ca. 6 : 1. Thus, the previous interpretation of such X-ray data, involving a single

derivative^.'^'" [Cr(CO),PR,(CH,),PR,]

562

563

564

565

566

(a) J. A. Connor, E. M. Jones, and G. K. McEwen, J . Organometallic Chem., 197243, 357; (b) J. A. Connor, J. P. Day, E. M. Jones, and G. K. McEwen. J.C.S. Dalton, 1973, 347. J. A. Bowden, R. Colton, and C. J. Commons, Austral. J . Chem, 1973, 26. 655. L. J. Guggenberger, U. Klabunde, and R k Schun, Inorg. Chem., 1973, 12, 1143: G.Huttner and S. Schelle, J. Organometallic Chem, 1973. 47, 383. H. J. Plastas, J. M. Stewart, and S. 0.Grim, Inorg. Chem., 1973,12, 265. J. A. Bowden and R. Colton, Austral. J . Chem, 1973, 26, 43. M. L. Schneider, N. J. Coville, and I. S. Butler. J.C.S. Chem. Comm, 1972 799.

The Early Pansition Afetals

91

molecular geometry containing unusual dimensions of the chelate, is now seen to be erroneous.567 [(n-Me,C,)Cr(CO),], has been shown by X-ray crystallography to have the unbridged dinuclear structure (45)with a C r 4 r bond length 227.6 pm. The 18-electron rule implies that this is a triple bond.568(Me,Si),CHLi and SnCl, react in ether at 0°C to give Sn(CH(SiMe,),], which behaves chemically as a singlet 'stannylene', yielding complexes such as [((Me,Si),CH},SnM(CO),] (M = Cr or Mo) with u.v.-irradiated solutions of M(CO)6.569The crystal and molecular structures of [py(B~?~SnCr(C0),]have been determined by R2 p

p

y Cr (CO),

co oc I ,co h

co oc\

n

'I

\

Ph2P, C-CO%h , c H 2 - c H * \ p d / H 2 l H2

Br (43) R'

=

1 /""

Cr

\co

co

Ph, m- or p-MeC,H,

R2 = H,m- or p-Me X-ray crystallography and the data show that the complex is nut a stannylene derivative, rather the py ligand allows the tin atom to achieve a co-ordination number of four and a valence-shell octet of electrons. 70 A general synthesis of transition-metal-carbene complexeshas been described which involves the displacement of a CO, olefin, tertiary phosphine, or halide ligand from a suitable precursor by a nucleophilic carbene fragment derived from an electron-rich olefin. Thus, cis-[(OC),CrL,] has been prepared by photolysis of cr(co)6 with L, (49 in THF for 8 h at 20 0C.571The kinetics and mechanism of LiMe attack on M(CO), (M = Cr, Mo, or W) have been studied and the data obtained suggest that these reactions may involve direct attack by LiMe at a carbonyl carbon atom.572A new reaction sequence has been described where the metal complex (47) of one class of carbene is converted into another (48). These latter compounds are a new type of carbene complex 73 The novel biscarbene complexes stabilized by 6n-electron del~calization.~ C~~-[(M~,P(OE~)C],M(CO)~] (M = Cr or W) have been prepared in 1.5% yield by treating M(CO), with LiPMe, in Et,O at - 78 "C followed by treatment with Et,OBF, in CH2C12.551[(Oc),CrC(OMe)Ph] reacts with 1,4567

568

569

570

''' 572

573

I. W. Nowell and J. Trotter, J.C.S. Dalton, 1972,2378; I. W. Nowell, S. Rettig, and J. Trotter, ibid., p. 2381. J. Potenza, P. Giordano, D. Mastropaolo, A. Efraty. and R. B. King J.C.S. Chem Comm., 1972, 1333. P. J. Davidson and M. F. Lappert J.C.S. Chem. Comm, 1973, 317. M. D. Brice and F. A. Cotton, J. Amer. Chem SOC.,1973, 95, 4529. B. Cetinkaya P. DixneuE and M. F. Lappert J.C.S. Chem Comm, 1973, 206. G. R. Dobson and J. R. Paxson J. Amer. Chem SOC.,1973,95, 5925. C. W. Rees and E. Von Angerer. J.C.S. Chem. Comm.. 1972 420.

Inorganic Chemistry of the Transition Elements

92

Me Me *Me

..-.'

Me

Me

Me

diazabicyclo[2,2,2]octane to afford the yellow diamagnetic compound (49), a nitrogen ylide complex.574The compounds [(OC),MC(OMe)R] (M = Cr, Mo, or W ; R = Me or Ph) react with BX, (X = Cl, Br, or I) in alkanes to afford the yellow or colourless, diamagnetic, thermally unstable compounds [XM(CO),CR]. Dipole moment, mass, 'H and 13C n.m.r., and i.r. spectral studies all lead to the formulation of these compounds as trans-[XM(CO),CR] carbynes. These conclusions have been confirmed by X-ray crystallography for the [IW(CO),CPh] derivative, the length of the metal-carbon triple bond being 188(10) pm.552 Me2

Me2

Me2

Me2

(46)

t

OMe, OEt. Ph NHEt, or M = Cr or Mo

R

Ph

=

0

(47)

Organometallic n-Complexes.-As explained (p. 88) only a selection of the material reported this year is presented. The vibrational spectrum of [(OC),Cr(bicyclo[2,2,l]heptadiene)] has been reported and the metal-olefin bond stretching mode was identified at ca. 250 cm- ', the lowest known frequency for such vibration^^'^. A series of ten maleic anhydride complexes of the type (50) has been prepared by photochemical substitution reactions from the 574 575

F. R. Kreissl, E. 0.Fischer, and C. G. Kreiter, Angew. Chem. Internat. Edn., 1973,12,563. D. M. Adams and W. S. Fernando, Inorg. Chim. Acta. 1973,7,277.

93

The Early TransitionMetals

(OC)5Cr-C

YMe I

/CH2-CH2 - N-CH,-CH,--N

Ph

'CH2-cHi

\

/

corresponding [(n-arene)Cr(CO),] complexes. A comparison of the i.r. and 'H n.m.r. data for both series has indicated that n-bonded maleic anhydride is a more powerful electron-withdrawing ligand than CO in such complexes.576 The details of the distortion of the benzene ring fi.1 [(C6H6)Cr(CO),] have been established by X-ray and neutron diffraction studies at 78 K. In comparison with the C--C bond in benzene (139.8pm) the three C--C bonds which project on to the C r 4 O bonds are lengthened by some 2 pm, and the

\I

0 (50)

other three are essentially unaltered. Thus, if the Cr-ring bonding occurs preferentially to these longer bonds, the co-ordination about the chromium should be considered as trigonal prismatic. The neutron diffraction results show that the hydrogen atoms are displaced towards the metal by 2.13.8 pm.577 A review of the n-cyclopentadienyl complexes of chromium, molybdenum, and tungsten has been published.5 7 8 Co-condensation of atomic chromium vapour with organic substrates at -196°C at pressures below 10-4Torr affords a route to a variety of bis(arene)chromium compounds, including those in which the arene contains highly electronegative sub~tituents.'~~ Under these conditions chromium atoms will trimerize acetylene to afford benzene, isomerize but-1-ene to a mixture of but-2-enes, and form complexes with buta-1,3-diene and p r ~ p e n e . ' The ~ ~ ~2p- and 3s-binding energies of chromiumin [ C T ( C ~ H ~ ) ~ [Cr(C,H,) ] ~ + , (C7H7)]"+(n = 0 or l),and [Cr(CSHS)(C,H6)] n-complexes have been determined, and a comparison with the 576 577

s78 579

M. Herberhold and C. R Jablonski, Inorg. Chim A c t 6 1973, 7, 241. B. Rees and P. Coppens, J . Organometallic Chem., 1972,42, C102. K. W. Barnett and D. W. Slocum J . Organometallic Chem., 1972,44, 1 . (a) R. Middleton, J. R Hull, S. R Simpson, C. H. Tomlinson, and P. L. Timms J.C.S.Dalton, 1973 120; (b) P. S. Skell, D. L. Williams-Smith and M. J. McGlinchey, J . Arner. Chem SOC.,1973, 95, 3337.

94

Inorganic Chemistry of the nunsition Elements

corresponding values for the metal indicates that chromium possesses a small positive charge in all of these complexes.58o Trifluorophosphino-complexes.-Improved syntheses of M(PF, ), (M = Cr, Mo, or W) have been described. One method involves the photochemically induced substitution of the CO groups in [M(CO),(PF,),] by PF, under moderate pressure. A full analysis of the mass spectrometric fragmentation patterns of these M(PF3), complexes has been presented and i.r. and Raman data have been obtained. Normal-co-ordinate analyses show that, in all cases, the vibrational mode in which M-P bond-stretching is predominant involves a significant contribution from P-F bond-stretching. '" [Cr(n-allyl),] in ether at 20°C reacts with PF, at 30-40 atm to give [(x-allyl),CrPF,] and then Cr(PF,),, which may be obtained directly from these reagents at 50°C and 250 atm pressure of PF,.s82 Stable [(n-arene)Cr(PF,),] (arene = benzene, hexafluorobenzene, cumene, or mesitylene) complexes have been made by the co-condensation of the vapours of Cr, PF,, and the arene.s79a Dinitrogen Complexes-The first report of the preparation and isolation of dinitrogen complexes of chromium has been published. [(7c-C&)Cr(C0)2(n-cyclopentene)] in benzene reacts with an excess of N2H4 at 10°C to give [(n-C,H,)Cr(CO),(N,H,)], which may be oxidized in THF in the presence of Cun at -10°C to yield [(n-C,H,)Cr(CO),N,]. This complex may also be prepared by decomposing the hydrazine complex in vacuo at 20"C, or by injecting N, into a solution of [(n-C,H,)Cr(CO),(n-cyclopentene)] in benzene. [(n-C,Me,)Cr(CO),N,] has been prepared by U.V. irradiation of a solution of [(n-C6Me6)Cr(CO),] in N,-saturated THF. The ability of these chromium systems to fix dinitrogen would appear to increase with increasing electron density in the arene ring. The [((n-arene)Cr(CO),} ,N2] (arene = mesitylene or hexamethylbenzene) complexes have also been prepared by U.V.irradiation of THF solutions containing [(n-arene)Cr(CO),] under a N, atmosphere. The 'H n.m.r. and i.r. spectra of these complexes are consistent with a structure in which the dinitrogen bridges between the two chromium atoms.549 Nitrosyl Cornplexe~-Cr(NO)~ is formed when a slow stream of NO is drawn through an irradiated solution of Cr(CO), in a hydrocarbon solvent. The compound has been characterized by i.r., Raman, and mass spectral studies and shown to be a simple molecular species. The occurrence of only one v ( N - 0 ) stretching mode (1716cm-l) in the i.r. and the occurrence of two such modes (at 1777 and 1694 cm- ') in the Raman are consistent with & molecular symmetry. The compound is a diamagnetic, red-black solid, soluble in non-polar solvents, decomposing in imuo to NO and chromium The crystal and molecular structures of [(n-Cp),Cr,(NO),NH,] have been determined by X-ray crystallography. The two chromium atoms are linked by a C r 4 r bond of length 265 pm, a bridging nitrosyl, and a bridging amido580 581

582

H. Binder and Ch. Elschenbroich, Angew. Chem. Internat. Edn., 1973,12,659. K. M. Lee and R. E. Hester, J . OrganornetalIic Chem, 1973. 57, 169. Th. Kruck. H. L. Diedershagen and A. Engelmann Z. anorg. Chem., 1973, 397. 31

The Early TransitionMetals

95

group. Each chromium is bonded to a terminal nitrosyl group and a n-cyclopentadienyl ring.583 Photolysis of [(n-Cp)Cr(CO),NO] in cyclo-octene solution results in the formation of the [(x-Cp)Cr(CO)(NO)(C,H,,)] olefincomplex which yields the derivatives [(x-Cp)Cr(CO)(NO)L] [L = C2H4, C,H,, C,(CO,Me),, C,H,O,, C7H10, or C,,H,] on displacement of the olefin by the various unidentate n-bonded ligands L. The n.m.r. spectrum of the acetylene complex is temperature-independent above room temperature, consistent with the rotation of this group.,,, Each of the complexes [(xC,Me,-,H,)Cr(CO),L] (n = 0-3; L = co or PPh,) reacts with NOPF, in MeOH-toluene solution to give the corresponding [(n-C,Me, -nHn)Cr(CO)(NO)L]PF, salt. The cations are converted by hydride ions into the neutral cyclohexadienyl derivatives [(n-c, Me, -,H,+ 1)Cr(CO),N0].585 [(nCp)Cr(NO),Cl] reacts with C4F,Ag perfluoro-1-methylpropylene silver, to afford the volatile green compound [(n-Cp)Cr(NO),C,F7].586 1.r. spectroscopic evidence has been presented for the co-ordination of a nitrosyl oxygen atom of [(n-Cp)Cr(NO),Cl] and [(n-Cp)Cr(CO),NO] to Lewis acids such as (MeC,H,),Sm or (Cp),Yb. Such co-ordination results in a lowering of the v ( N - 0 ) stretching frequency by ca. 30 cm- The nature of the donor atom of [(n-Cp)Cr(CO),NO] shows that the oxygen atom of the NO group is a better Lewis base than those of the CO groups in this A direct, quantitative, and convenient method for the preparation of [Cr(H20),N0]2+ has been achieved by the slow, dropwise addition of an aqueous solution of Crn (10 ml, 0.5 moll-') to a stirred solution of HClO, (200 ml, 0.1 moll-,) which was continuously saturated with NO. This reaction is rapid and produces only [Cr(H,0),N0]2+, provided that NO is in excess. This study also confirmedthe previously reported d-d spectrum of this ion.5 8 8 Several e.s.r. studies of chromium nitrosyl complexes containing a variety of other ligands have been reported.589 The i.r.-polarized spectra of K, [Cr(CN),N0],2H2O have been determined and the results strongly support the suggestion that the orientation of the anions is disordered. The salts K,[M(CN),NO] (M = Cr or Mo) appear to be isomorphous and the assignment of the vibrational modes in these590and related compounds has been discussed.'* '* Binary Compounds and Related Systems.-Halides. A new method for the preparation of CrCl, by chemical transport via CrC1,,2A1Cl3 has been reported.

'.

5M3

584 585 586 587 588

589

590

L. Chan, Diss. Abs. (9,1972, 33, 98. M. Heberhold and H. Alt J . Organometallic Chem, 1972 42, 407,413. D. E. Ball and N. G. Connolly, J . Organometallic Chem., 1973, 55, C24. R. B. King and W. C. Zipperer. Inorg. Chem, 1972 11. 2119. A. C. Crease and P. Legzdins, J.C.S. Dalton, 1973, 1501. J. N. Armor and M. Buchbinder, Inorg. Chem 1973, 12, 1086. N. S. Garif'yanov, A. D. Troitskaya, A. I. Razumov, I. V. Ovchinnikov, P. A. Gurevich and 0.I. Kondrat'eva, Zhur. neorg. Khim, 197217, 1346; S. A. Luchkina and T. P. Tokareva ibid.. p. 2456; E. V. Semenov, P. M. Solozhenkin, N. 1. Zemlyanskii 0.N. Grishina, and Ya I. Mel'nik Doklady Akad. Nauk Tadzh. S.S.R, 1972, 15, 37 (Chem Abs, 1972,77, 120 55311);P. M. Solozhenkin, E. V. Semenov, G. P. Rudzit and M. D. Gertner. ibid., p. 22 (Chem Abs., 1973, 78 102 632k). L. Tosi, J . Chim phys, 197269, 1052.

96

Inorganic Chemistry of the Transition Elements

When a CrC1,-Cr mixture is heated in an atmosphere of Al,Cl, at 620 K in a high vacuum, CrC1, is deposited in the 520 K temperature zone.591 The Cr-I system has been examined in detail and CrI, (m.p. 867 "C)and CrI, (m.p. 857 " C ) were characterized by their X-ray diffraction patterns and eutectics identified at 831 "C (69 at. % I) and 113°C (ca. 100 at. % I).592aThe structure of CrI, contains layers of elongated CrI, octahedra in which four Cr-I bonds are of length 273 pm and two of length 323 ~ m . " ~X-Ray * photoelectron spectra of CrX, (X = F, Cl, or Br) have been reported and the metal 2p- and 3s-orbital ionization potentials determined. 5 9 Oxides. The structures and properties of chromium oxides have been reviewed. The standard heat and entropy of formation of CrO have been determined as -306 kJ mol-' and 47 ex., respectively.594The evolution of the structure of a-Cr203from Cr(OH), has been followed using a variety of physical techniques. The material obtained by drying in air at 25°C contains crystalline Cr(OH),; at and above a drying temperature of 60°C, the gel passes through many amorphous phases ; crystallization of corundum occurs at 390 "C. All the amorphous phases contain regions of short-range order, the atomic arrangement of which is similar to that in HCr0,.595 Orthorhombic HCrO, has been synthesized from CrO, hydrothermally under a reducing atmosphere, and the mechanism of conversion discussed in terms of the crystal structures of these materials.596 The positions of the Cr" atoms in ruby containing 5.2 mol % of Cr,O, have been re-determined in a single-crystal X-ray diffraction study; these atoms are disordered in the cation site of the corundum lattice and displaced some 3 pm toward the nearest cation along c . ' ~ ' The Raman spectrum of single crystals of CrO, has been studied from 77 to 500K and seen to be similar to that of r ~ t i l e . ~The ~ * electron affinities of CrO, and HCrO, have been estimated at 390 and 229 kJ mol- ', respectively, by studying electron attachment and compound formation in H2-02-N2 flames.599X-Ray photoelectron spectra have been reported for several oxygen-containing compounds of chromium, including Cr,O, and CrO,, and the ionization energy of the metal's 2p-electrons was shown to be some 2-3 eV lower in Cr" compounds than in CrV' compounds.600 Chalcogenides. A review has been published in which the disorder of CrS and the order-disorder transitions in Cr,S and AgCrSe, are discussed.293 The metal 2p- and 3s-orbital ionization potentials in Cr,S, have been deter-

'

5y1 592

593 5y4 595 596

597

598 599

6oo

K. Lascelles, R. A. J. Shelton, and H. Schaefer, J . Less-Common Metals, 1972,29, 109 (a) L. Guen, M. Alleaume, R. E. Eholie, and J. Flahaut, Compt. rend, 1972 275, C, 1 1 1 ; (6) F. Besrest and S. Jaulmes Acta Cryst, 1973, B29, 1560. J. C. Carver, G. K. Schweitzer, and T. A. Carlson, J . Chem Phys, 1972, 57, 973. N. I. Shirokov, lzvest. Akad. Nauk S.S.S.R, Metal., 1973, 102 (Chem. A h . , 1973, 78, 165068b). P. Ratnasamy and A. J. Leonard J . Phys. Chem., 1972, 76. 1838. Y. Shibasaki, Materials Res. &111., 1972, 7, 1125 (Chem. A h . , 1973, 78. 10937k). J. W. McCauley and G. V. Gibbs Z. Krist. Kristallgeom, 1972, 135, 453 (Chem A h . , 1973, 78, 8889~). R. Srivastava and L. L. Chase, Solid State Comm, 1972, 11. 349. W. J. Miller, J. Chem. Phys., 1972, 57, 2354. G. C. Allen M. T. Curtis A. J. Hooper,and P. M. Tucker. J.C.S. Dalton, 1973, 1675.

The Early Transition Metals

97

mined by X-ray photoelectron spectroscopy.593The mixed-cation disulphides Tio,9zCro.09Sz and Ti0.70Cr0.32S2 have been prepared by grinding a mixture of TiS,, Cr, and S, before heating for one week at 950°C.26 La,Cr,S,, and LnCrSe, (Ln = La, Ce, Pr, or Nd) have been prepared and their structures and magnetic properties investigated.60 Compounds with Elements of Group I.: The existing thermodynamic data for the Cr-N system have been analysed,a partial phase diagram has been presented, and the heats of formation of Cr,N and CrN have been assessed as - 133 +4 and - 119 + 6 kJ mol- respectively.602The nitrides MCr,N (M = Rh, Pd, Pt, Ir, or Sn), which have the perovskite lattice, have been prepared by the solidstate reaction of Cr, CrN, and the corresponding metal at ca. 700°C in an evacuated SiO, ampoule. PtCrNo.7 has also been prepared.603 A single-crystal structure refinement of Cr,P has shown that the compound crystallizes with the Fe,P-type structure.604 CrP, and CrAsz have been prepared from their constituent elements under 65 kbar pressure at temperatures between lo00 and 1200°C. CrP, has the OsGe,-type structure, in which each metal atom is co-ordinated to eight phosphorus atoms (Cr-P = 241 pm), sic of these forming a trigonal prism and the other two capping rectangular faces. CrAs, is isostructural. Two families of transition-metal dipnictides have been distinguished, one of which includes CrP, and has the high co-ordination numbers characteristic of metallic structure, and the other, which includes NiAs,, has lower co-ordination numbers and semi-conductor properties.605 Carbides and Silicides. The free energies of formation of Cr,C2, Cr7C3, and CrZ3C6have been estimated as -450+5, -195k2, and -9252kJmol-’ respectively,606and the crystal structure of the latter compound has been reported.607The Mo-Cr-C phase diagram has been constructed on the basis of the available free energy data and shown to be in good agreement with that determined experimentally.608 The thermodynamic characteristics of the chromium silicides Cr,Si, Cr,Si,, CrSi, and CrSi, have been determined electrochemically.609

’,

Brides and Gallides. Cr3NiB6 and Cr2Ni,B6 have been identified in the Cr--Ni--B system and shown to possess the V,B,- and V5B6-typestructures, respectively.610The ternary borides Cr3RezBs,C T R ~ ~ Band ~ _(Cr, ~ ,Mo),BZ 601

602

‘03

604

605

606

607 608

609

610

G. Collin H. D. Nguyen. 0. Gorochov, M. Guittard P. Larciellc and J. Flahauf Nat. &r. Stand. (U.S.A.)Spec. Publ. No. 364, 1972, 645. J. P. DeLuca and J. M. Leitnaker, J . Amer. Ceram. SOC., 1973, 56, 126. M. Nardin. G. Lorthioir, M. Barberon, R. Madar, E. Frucharf and R. Fruchart, Compt. rend., 1972 274, C, 2168. M. Ourusy H. Jawad T. Lundstrom and R. Rundqvisf Phys. Ser.. 1972,6, 67 (Chern Abs, 1973, 78, 49 274s). W. Jeitschko and P. C. Donohue, Acra Cryst., 1973, B29, 783. A. D. Kulkarni and W. L. Worrell, Met. Trans, 1972, 3. 2363. A. L. Bowman, G. P. Arnold E. K Storms, and N. G. Nereson, Acta Cryst.,1972, B28, 3102. Y. A. Chang and D. Naujock, Met. Trans, 1972,3, 1693. V. N. Eremenko. G. M. Lukashenko, V. R. Sidorko, and A. M. Khar’kova, Porosh. Met.. 1972, 12 61 (Chem. Abs, 1972,77, 119012k). M. V. Chepiga, V. P. Krivutskii and Yu V. Kuz’ma, lzvest. Akad. Nauk S.S.S.R.,neorg. Materialy, 1972 8, 1059.

98

Inorganic Chemistry of the Ransition Elements

’’

have been characterized in X-ray diffraction studies6 and the crystal structure of Cr,CeB, has been determined.,12 The phase diagram of the Cr-Ga system has been studied and the four intermetallic compounds Cr,Ga (m.p. 1620”Q CrGa, Cr,Ga6 (m.p. 775”C), and CrGa (m.p. 700°C) were Hydrides. The standard enthalpy and free energy of formation of CrH have been calculated as - 13.7+_ 0.5 and - 17.4& 0.3 kJ mol- of H,, by measuring the equilibrium pressure of hydrogen above the compound at 150°C.614 Chromium(ri).-Halides. The preparation of halogen complexesof chromium(r1) in anhydrous acetic acid has been re~iewed.~” New M,CrF, (M = K, Rb, or Cs) phases have been characterized and shown to be isostructural with KO.,,W0,.616The single-crystal structures of CsCrC1, and CsCrBr, have been reported and the compounds shown to be isostructural. Their main structural feature is a linear array of face-sharing CrX, octahedra in which there is no evidence of a static Jahn-Teller distortion. The Crn atoms are located on sites whose symmetry is required to be no lower than C , , thus the degeneracy of the e, orbitals is not removed by the crystal field. Each compound contains two sets of three Cr-X bonds, with lengths of 241.9 and 261.8 pm, and 257.4 and 278.0 pm, respectively, and also exhibits a large component of the halogen atoms’ anisotropic motion parallel to the anion-chain axis. Since the El, vibrational mode of the chain involves displacement of the halogen atoms in this sense, and is Jahn-Teller active, this could explain both the anisotropic motion of the halogen atoms and apparent absence of static Jahn-Teller distortions. The optical spectra of these compounds have also been reported.617 The complexes (pyH),[CrCl,(H,O),J and M,[CrBr,(H,O),] (M = Rb, Cs, NH,, or pyH) and their anhydrous analogues offer a neat illustration that the type of magnetic interaction in solids can be influenced by effects such as the nature of the cation and/or the presence of other ligands. The hydrated compounds are all normal, paramagnetic, high-spin chromium(I1) complexes, but the corresponding anhydrous materials are all antiferromagnetic, with the exception of Cs,CrBr, which is ferromagnetic.61 0-Donor Ligands. Magnetic and e.s.r. studies of MOO, olefm polymerization catalysts containing CrO, and supported on SO,, have shown that the active species contains Cr’ and Mow acting in concert.619Cr,SiO, has been prepared by treating chromium metal with SiO, and C r 2 0 3at elevated temperatures

’

611

612 6” 614

l5

616

‘17

618 ‘19

V. S. Telegus Ref: Zhur. khim., 1971, Abs. 19B816 (Chem Abs, 1972.77, 93 797t). Yu. B. Kuz’ma and S. I. Svarichevskaya Kristallografiva 1972. 17. 939. J. D. Bornand and P. Feschotte, J . Less-Common Metals, 1972,29, 81. B. Baranowski and K Bojarski, Roczniki Chem, 1972 46, 1403 (Chern Abs., 1972,77, 144 669n). H. D. Hardt M. Fleischer, and G. Streit ‘Proceeding of the 3rd International Co-ordination Chemistry Symposium’, e d M. T. Beck, Akad. Kiado, Budapest. Hung., 1970, Vol. 1, p. 165 (Chem. Abs, 1973, 78, 105 422j). D. Dumora J. Ravez and P. Hagenmuller. J . Solid State Chem.. 1972 5. 35. G . L. McPherson, T. J. Kistenamcher, J. B. Folkers, and G. D. Stucky, J . Chem. Phys., 1972,57, 3771: T.-I. Li and G. D. Stucky, Acta Cryst., 1973, 1329, 1529. L. F. Larkworthy and A. Yavari, J.C.S. Chem Comm, 1973, 632. G. Henrici-Olive and S. Olivi: Angew. Chem Internat. Edn.. 1973. 12 754.

The Early Transition Metals

99

and the lattice parameters of this compound were determined; Cr" has been doped into Mg,SiO, with the olivine-type structure, and the optical absorption spectra of Cr" in these two lattices indicate considerable structural differences between them.620 Chromium(I1) succinate dihydrate, [Cr(C,H,O,)H20'J2,2H20,has been prepared and its i.r. spectrum recorded and X-ray diffraction studies have shown that it is isostructural with the analogous copper(I1) compound.621The crystal structure of the carbonato-complex Mg2[Cr(CO3),H,0],,4H,O has been determined; the Cr-Cr distance is 222 pm. Unlike the succinate, this chromium(I1) carbonato-complex is stable in air.622 N-Donor Ligands. The 'H n.m.r. spectra of the outer-sphere reducing agents [CrLJ2+ (L = o-phenanthroline or a Me or Et substituted derivative) have been investigated in an attempt to elucidate the relationship between the electronic structure of these complexes and their mechanism of electron transfer. This study has shown that they contain extensive metal-ligand nbonding and, as a consequence, there is highly localized electron spin-density at the C-4 and C-7 atoms of the ligands (51); thus, in some electron-transfer

(51)

R

=

Me or Et

reactions, interactions with solvent molecules such as H 2 0 or MeOH occur specifically at these carbon atoms, and probably involve h y d r o g e n - b ~ n d i n g . ~ ~ ~ Various voltammetric techniques have been used to determine the redox potentials of Cr"'/Cr' and Cr"/Cr' couples complexed with a number of substituted phenanthrolines and related ligands. The electrode potentials for reduction of Cr'" and Cr" were found to depend directly on the electronacceptor properties of the ligand. Both of these types of reduction are reversible.624The electrochemical reduction of [Cr(bipy),Cl,] proceeds in a one-electron step and is followed by fast ligand disproportionation and water substitution which produce an equimolar mixture of [Cr(bipy),12 and [Cr(bipy)(H20),12+. When the reduction is performed in the presence of one equivalent of free bipy, [Cr(bipy),]'+ is the sole A series of chromium(r~) complexes containing quadridentate macrocyclic N-donor ligands has been prepared and shown to contain high-spin Cr" centres (p ca. 4.90 BM).626 The one-electron polarographic reduction of octaethylpor+

+

620

B. E. Scheetz and W. B. White, Contrib. Mineral Petrology, 1972. 37, 221 (Chem. Abs., 1973, 78,

66 334d). P Sharrock T. Theophanides, and E Brisse. Canad. J . Chem., 1973, 51, 2963. 6 2 2 R. Ouahes, Y. Maouche, M. C. Perucaud and P. Herpin, Compt. rend., 1973. 276, C, 281. 623 G. N. LaMar and G. R. Van Hecke, J . Amer. Chem SOC.,1972,94,9042 9049; G. N. La Mar, ibid.. p. 9055; G. N. La Mar and G. R. Van Hecke, Inorg. Chem., 1973, 12, 1767. 6 2 4 M. C. Hughes, Diss. Abs. (4, 1972. 32 5672. 6 2 5 D.M. Soignet and L. G. Hargis, Inorg. Chem., 1973.12, 877. 6 2 h C R Sperati Diss Abs. (4, 1972 32 6282.

621

100

Inorganic Chemistry of the Transition Elements

phinatochromium(n1)hydroxide observed at E , = - 1.14 V has been attributed to reduction of the metal, further reduction at -1.35 V appears to involve reduction of the m a c r o ~ y c l i cThe . ~ ~violet ~ pyrophoric compound CrL2,2THF (HL = imidazole) has been prepared by refluxing CrBr2,2THF with LiL in THF.628By mixing hydrazine with slightly acidified solutions of the appropriate chromium(I1) salts the derivatives [Cr(N,H,),X,],nH,O (X, = Cl,, Br,, 12, or SO,) have been prepared.629 Orgnnometallic Compounds. Diphenylmethylchromium diphenyl, [(Ph,CH)CrPh,], reacts with bipy to afford [Ph,Cr(bipy),], and with LiPh in THF to form Li,CrPh4,4THF. This latter compound reacts with bipy to yield [Li2CrPh4(bipy)],2THF. The p values of these arylchromium(I1) derivatives are 3.2, 4.7, and 3.7 BM re~pectively.~~’ The e.s.r. spectrum of chromocene has been determined and the g1 and gI1 values were found to be 1.97 and 2.49, re~pectively.~ Chromium(III).-Papers concerned with the kinetics and mechanisms of chromium(@ complexes are reviewed in the Inorganic Reaction Mechanisms Specialist Periodical Report.” Reviews of the absorption and emission spectra chromium(1n) complexes are reviewed in the Inorganic Reaction Mechanisms A model based on the antibonding properties of excited electronic states has been developed which correctly predicts the types of photoreaction and relative quantum yields of chromium(II1) and other transition-metal complexes.633 Optically Active Complexes. The c.d spectra of nineteen optically active chromium(II1) complexes have been recorded in both the spin-allowed and spin-forbidden d d transition regions, and discussed in The rotatory strengths of the d d transitions of trigonally distorted six-co-ordinate complexes of chromium(II1) with N- and 0-donor atoms have been calculated using a MO model. The results obtained suggest that neither the Piper nor the Liehr MO model provides adequate representations of the source of d d optical activity in such systems.635 Partial photoresolution of [Cr(acac),] in several organic solvents has been

”’ K. Kadish, D. G. Davis, and J. H. Fuhrhop, Angew. Chem. Internat. Edn.. 1972, 11, 1014. 628

629 630

631

633 634

635

D. Tille, Z. anorg. Chem., 1972,390, 234. R. Y a Aliev, Zhur. obshchei Khim, 1972, 42 2370. W. Siedel, K. Fischer, and K. Schmiedeknecht Z.nnnrg Chenl. 1972. 390. 273. R. Krieger and J. Voitlander, Z . Naturforsch, 1972,27a, 1082. P. D. Fleischauer, A. W. Adamson, and G. Sartori, Progr. Inorg. Chem., 1972, 17, 1 ; A. D. Kirk iMol. Photochem, 1973, 5, 127. J. I. Zink, J . Amer. Chem SOC, 1972, 94, 8039. S. Kaizaki J. Hidaka, and Y. Shimura, Znorg. Chem, 1973,12, 142. R W. Strickland and F. S. Richardson. Inorq. Chem., 1973. 12 1025.

* ‘Inorganic Reaction Mechanisms’, e d J. Burgess (Specialist Periodical Reports), The Chemical Society, London, 1972, Vol. 2, p. 140.

The Early Transition Metals

101

achieved using circularly polarized light of wavelength 456.1 nm.6360 [Cr(C,O,)(phen),] +,[Cr(C,O,),(phen)] -, and [Cr(bipy),13+ have similarly been partially resolved using light of wavelengths 496.5 and 514.5 nm from an argon laser.636bComplete resolution of racemic [Cr(en),] 3 + has been achieved by electrophoresis in an electrolyte of sodium d-tartrate and AlC13. The data obtained indicate that the enantiomeric separation was accomplished by some aluminium d-tartrato-complexanion.6 Tris-(1,2-~yclopentanediamine)chromium(II1) has been re-investigated and its optical activity studied ; contrary to previous reports, it is Chromium(m)complexes with mixed ethylenediamine trimethylenediamine chelates, [Cr(en), - ,(tn),] (n = 0-3) have been prepared and resolved with nitro-( +)D-camphor. The c.d. spectra of these complexes have been recorded in the region 606-230 nm.6380Racemic cis-[Cr(en),(NCS),]NCS has been resolved using potassium antimonyl-(+)tartrate and also with ammonium a-bromo-(+)=camphor sulphonate. The c.d. spectra of these diastereoisomers are sufficiently similar to those of the corresponding cobalt(n1) complexes to allow the absolute configurations to be Nine new optically active chromium(Ir1) complexes [L,Cr(OH),CrLJ4+ [L = (bipy), or (bipy)(phen)], {Cr(C,OJ (bipy)(phen)]+ and [CrL,(en),-,](3-")+ (L = acac, 3-C1- or 3-Br-acac; n = 1 or 2) have been prepared and resolved. The diastereoisomers were characterized by i.r., electronic, and c.d: spectra and their absolute configurations determined.639 The optically active tris-{( +)-N-a-methylbenzy1dithiocarbamato)chromium(rI1) complexes have been prepared by warming an aqueous solution of CrCl, and the ligand to 60°C for 2 h. The 0.r.d. curves of their sodium salts in aqueous solution and of their ammonium salts in organic media have been recorded and Cotton effects identified.640 Halide and Oxyhalide Complexes. The preparation of halogen complexes of chromium(II1) in anhydrous acetic acid has been reviewed.61s Tungsten-bronze-typephases M,(LiO~5,Cr0.5,W1 -J03 - 3xF3x (M = Li, Na, K, Rb, or Cs; 0.5 < x < 0.7) have been characterized by X-ray diffraction studies in the corresponding M,LiCrF,-WO, systems.641 Semiempirical MO calculations on [CrF6I3- using a new parameter-free method have been published, and the calculated values of the ligand-field splitting, the superhyperfine constants, and the spin densities were shown to be in excellent agreement with the experimental data.44 The crystal structure of CaCrF, has been determined by X-ray diffraction studies. These crystals contain zig-zag chains formed by CrF, octahedra sharing corners,and the Can atoms 636

637

638

639 640 h41

(a) K.L.Stevenson, J. Amer. Chem SOC,1972946652;(6)N. A P. Kane-Maguire and C H. Langford Canad. J C h m . . 1972 50. 3381. (a) H. Yoneda and T. Miura, Bull. Chem. SOC.Japan, 1972,45,2126; (6)H. Toftlund and E. Pederson, Acta Chem. Scand., 1972,26,4019. (a) M. Rancke-Madsen and F. Woldbye, Acta Chem Scand, 1972 26, 3405; (b) D. A. House. J . Iriorg. Nuclear Chem, 1973, 35, 3103. S. Kaizaki J. Hidaka, and Y. Shimura, Znorg. Chem, 1973.12 135. D.H. Brown and D. Venkappayya, J . Znorg. Nuclear Chem., 1973.35, 2108. A. Vedrine J. P. Besse, and M. Capestan. J. Inorg. Nuclear Chem, 1972, 34, 2771.

102

Inorganic Chemistry of the Transition Elements

are located in pentagonal-bipyramidal sites between four neighbouring chains. The compounds MiNaCrF, (M'= K or Rb) and M:KF, (M2 = Rb or Cs) have been prepared by the reaction of the corresponding alkali-metal fluorides with CrF, in a sealed Ag tube at 450-520°C under argon. X-Ray diffraction studies have confirmedthat each of these compounds has a perovskite The compounds CaMF, (M = Al, Ga, Ti, V, Cr, or Co) constitute an isostructural series.643The preparation, X-ray diffraction,and magnetic properties of the modified pyrochlores MMnCrF, (M = Rb, Cs, or TI) and the tetragonal KMnCrF, have been reported.644 E.s.r. studies of Cr'"-doped K,SbF, have characterized five different sites for the guest ions. Although the predominant sites involve octahedral co-ordination of Cr"', a site is present in low concentration which perhaps can be associated with a five-co-ordinate species.645 However, e.s.r. studies have shown that, when CrIn substitutes in K,SbCl,, it does go into a site of C,, five-co-ordinate symmetry and calculations support the assignment of the magnetic species as [CrC1,]2-.331 The i.r. and Raman spectra of [Cr,C1J3- ions in a variety of salts have been determined and a normal-co-ordinate analysis of Cs, [Cr,Cl,] gives excellent agreement between the calculated and experimental data.646 A number of new chromium(n1) halide complexes with N-heterocyclics have been prepared by thermal decomposition techniques involving the loss of volatile ligand from parent complexes.Thus, [Cr,C16L4] (L = py, 3- or 4-Mepy, or L, = bipy) have been prepared in this way from complexes such as CrCl,L, or pyH[ CrCl,(bipy)], and their i.r. and electronic spectral properties are consistent with two octahedral chromium(II1) centres bridged by two chloride A convenient route to the formation of [CT(NH,)~X,]+ and [Cr(en),X,]+ complexes has been described and the new species [Cr(NH,),FCl) + and [Cr(en),FBr] have been prepared and characterized.647b 0-Donor Ligands. Table 6 summarizes many of the data reported this year concerning mixed-oxide compounds containing chromium(II1). The X-ray photoelectron spectra of Cr203, MCrO, (M = Li, Na, or Cu) and some chromium(v1)compounds have been reported, and the ionization potentials of the metals' 2p-electrons were shown to depend primarily on the oxidation state of the metal ;however, small perturbations due to the Madelung potential were also identified.," The enthalpies of formation, at 1273 K, of the chromites MCr20, (M = Mg N i C y Zn, or Cd) from the corresponding oxides have been determined by oxide-melt solution calorimetry as -46.5, -5.4, + 10.5, +

h42

643

644

h45 646

647

G. Siebert and R. Hoppe. Z. anory. Chrm.. 1972 391. 117. D. Dumora, R. Von der Miihl and J. Rave6 Materials Res. & I / , 1971,6,561 (Chem. Abs.. 1972 77. 80 720n). E. Banks 0. Berkooz and J. A. De Luca Materials Res. Wtll, 1971. 6. 659 (Chem. Abs.. 1972,77, 80571q). J C Hempel D. Klassen. W. E. Hatfield and H. H. Dearman. J . Chem. Phys., 1973,58, 1487. R.J. Ziegler and W. M. Risen. jun., Inorg. Chem., 1972 11, 2796. (a) D. H. Brown and R. T. Richardson, J. fnorg. Nuclear Chem, 1973, 35, 755; (b) G. Wirth C. Bifano, R. T. Walters and R. G. Linck Inorg. Chem., 1973, 12 1955.

The Early TransitionMetals

103

Table 6 Mixed-oxide compounds containing chromium(111) Compound Cr,Ge03

Tl,Cr(SO4)3 Li MCr408 ( M = Ga, In, or Fe) BaCrTi(PO,), KMCrAPOJ, (M = Sr or Ba) Cr(H2As04),,H20 (Ti02)xCr2 3(so3)Y (X = 0.1-0.8), y = 1.3-1.4) CrFeTi,O, NiCr,Mn, -xO, (0 d x < 2) CrTaO,

crO.

S

0. STe 3O8

(M = Nb or Ta) NaCr(MOO,), Na16Cr2(Mo04)1 1 Sr,Cr2W09

Source Cr203 + GeO, at 1100°C Tl,SO, + Cr,(SO,), in sealed ampoules in uacuo at 450°C for 24 h Li,CO, + M 2 0 3 + Cr203 (1 :1 :2) BaCO, + TiO, + Cr203 + (NH&HP04 (2 :2 :1 :6) K2C03 + MCO, Cr203 +(NH,),HPO, (1:2: 2: 6 )

+

Ti0,-Cr, 0,-SO3-H20 system in 80% H2S04

Cr, 0,-Ta2 0 system

Cr,O,-M,O,-TeO, system Na,MoO, + Cr203(1 :1) Na,MoO, + Cr,O, (8 :1) Sr,W06 Cr203 at 1200"C Ag,SO, Cr2(S04), at 450°C for 2 days La20, + Cr203(1 : 1) at 1100°C for 10h

X

b

i.r. ; ordered spinels

C

X

d

X

e

X

f

st ; isostructural with Cr2Ti20,

9

X ; spinel lattice

h

p, neutron diffn., X ;rutile lattice with cation disorder X ; isostructural with TiTeJO,

j

i.r., X

k

+

+

LaCrO,

Properties reported R eJ: a d, i.r., X

1

1

X

m

e.d.,X ; structural n transitions identified

(a) G. Odent and F. Annabi Compt. rend, 1972,275, C, 1275. (b) R Perref a t l L Sac franc. MinPral. Crist, 1972, 95,159. (c) P. Tarte and J. Preudhomme, Spectrochim Act4 1973,29A, 1301. (4R Masse, atll SOC.frang. MinkraL Crist, 1972, 95, 405. (e) M. Ronis and F.DYvoire, h l l SOC.chim France, 1972, 2581. Ref. 112 (g) I. E Grey and W. G. Mumme, J. Solid State Chem, 1972,s 168. (h) N. Renaulf N. Bafier, and M. Huber, J. Solid State Chem, 1972, 5, 250. (3 Ref 49. (J Ref. 515. (k) J. Bernard and M. H. Nguyen, Compt. rend, 1973, 276. C. 13. (0 D. Harari and P. Poix, Compt. rend, 1973.276. C. 265. ( m ) Ref. 3146. (n) N. Terao, Compt. rend.. 1973,276. C, 5, 125: J. P. Traverse and R. Berjoan, ibid., p. 1167.

(a

-63.2, and -42.3 kJ mol-l, respectively, and compared with other thermodynamic quantities already reported for these and related ~ h r o m i t e s . ~ ~ * Two types of chromium(rI1) phosphate ion-exchanger have been prepared, one having a low, and the other a high, affinity for highly charged cations. Distribution coefficients and their temperature dependences were measured b48

F. Muller and 0.J. Kleppa J . lnorg. Nuclear Chem.. 1973.35. 2673.

104

Inorganic Chemistry of the Transition Elements

for a wide range of cations on these exchangers, and the pH titration curve? showed that they are polyfunctional for Na' and Cs' but monofunctional for ~ ~.6490 1 The 1 ion-exchange characteristics of five insoluble chromium(rI1) compounds, the hydroxide, arsenate, antimonate, molybdate, and tungstate, have been compared, and the arsenate was shown to have the highest ionexchange capacity.649bThe thermal decomposition of CrH,P,O has been shown to lead to Cr(PO,),, which contains the anions in infinite chains, or Cr,(P,O, 2)3, which contains the cyclic anions, depending on the conditions employed; however, the final product of heating to 1330°C is Cr4(P207)3.650 Nitrato-ligands in chromium(1n) ammino-complexes have been shown to accelerate strongly the aquation of the NH,-ligands in the cis-position. This observation affords an explanation of several apparent anomalies in the co-ordination chemistry of chromium(II1) involving other groups such as carboxylate, sulphate, and nitrite, which are also able to chelate two cisposition^.^ '' Four new nitrito-chromium(n1) complexes have been prepared and their electronic spectral characteristics determined ; the complexes are cis- and trans-[Cr(NH,),(OH,)ONO)Cl, and cis- and trans-[Cr(NH,),(NCS)(ON0)]C10,.652 A 1 :2 chromium(II1) sulphito-complex with a stability constant of 3.3 x 10"12 mol-', has been characterized spectrophotometrically in aqueous solutions at pH 3.8.653 The oxalato-complexes [Cr(NH,),-,(H20),C204]+ ( n = 1 or 2) have been identified spectrophotometrically during the aquation of [Cr(NH3),C204] + , 6 5 4 The thermal decomposition of chromium(rr1) oxalato-complexes has been shown to proceed tiia electron transfer and C--O bond fission, to afford CO, and a smaller quantity of CO., l 7 The stability constants of some chromium(Ix1) formato-complexes have been determined,6 and the blue succinato-complex Cr(C,H,O,)OH,H,O has been characterized following aerobic oxidation of chromium(I1) succinate dihydrate.62' Heterogeneous equilibria in aqueous systems of urea and various CrX, (X = C1, NO,, or $0,) hydrates have been investigated and the conditions for forming salts containing the rCr(OC(NH,),)6]3+ ion defined.656 The preparation and electronic spectra of the complexes [Cr(HMPA),(NO,),] and [Cr(NIPA),(NO,),] (NIPA = nonamethylimidophosphoramide) have been and the new DMSO complexes cis- and trans-[(Cr(H,O),(DMSO)I]+ and rCr(H,O),(DMSO),I]Z have been reported and their d-d

''

+

649

650 b51

652 653

654 655

656 657

(a)T. Akiyama and I. Tomita, 1.Inorg. Nuclear Chem, 1973,35,2971;(6) M. Qureshi R. Kumar. and H. S. Rathore. Talanta. 1972, 19. 1377. P. Remy and A. Boulle, Bull. SOC.chim. France, 1972,2213. G. Guastalla and T. W. Swaddle. J.C.S. Chem. Comm.. 1973. 61. T. C. Matts, P. Moore, D. M. W. Ogilvie, and N. Winterton, J.C.S.Dalton, 1973. 992. V. A. Konev and A. 0. Brandt. Zhur. neorg. Khim., 1972, 17. 3127. M. B. Davies J. W. Lethbridge, and M. S. Mirrlees J. Inorg. Nuclear Chem.. 1973, 35, 3354. P. H. Tedesco, V. B. De Rumi, and J. A. Gonzalez-Quintana, J. Inorg. Nuclear Chem., 1973, 35,

285. V. A. Tatarinov. Ref: Zhur. khim.. 1971. Abs. 15V62 (Chem A h . . 1972 77, 66 865g). M. W. G. De Bolster. F. J. Wiegerink and W. L. Groenveld J. Inorg. Nuclear Chem.. 1973. 35, 89.

105

The Early Transition Metals

electronic spectra determined.658 [CrLi](N03)3659and [CrL:]660 (L1 = 2,6butidine N-oxide and L2 = 2-picolinic acid N-oxide) have been synthesized and their electronic spectra reported. The parameters that affect the retention behaviour of volatile metal pdiketonato-complexes in various g.1.c. systems have been investigated in some considerable detail. The vapour pressures and heats of vapourization have been determined for tris(hexafluoroacety1acetonato)-and tris(heptafluor0dimethy1octanedionato)-chromium(m), Cr(hfa), and Cr(fod),, respectively, and those of the corresponding tris-derivatives of other metals. These results show that the hfa chelates are more volatile than the fod ones, the latter exhibiting a similar volatility to tris(trifluoroacety1acetonato)(tfa) complexes. G.1.c. retention data over a range of temperatures have been measured for Cr(hfa),, Cr(tfa),, and several other such chelates in three liquid phases and, together with other solution-phase data, have been used to show that the behaviour of these complexes in the liquid phase is determined solely by nonspecific van der Waals-type forces.66la The electrophilic substitution reactions of fluorinated pdiketonato-chromium(II1)complexes have been studied under controlled conditions and the results obtained were shown to support the quasi-aromatic character of the six-membered chelate ring.6 l b Seven new tris(p-diketonato)chromium(nI) complexes have been prepared and characterized by magnetic, i.r., and electronic spectral studies.662 In acidic aqueous ethylene glycol (G), chromium(rr~)forms two different monoglycol complexes, [Cr(H,O),G] and [Cr(H,O),GI3 +,in which the glycol functions as a unidentate and a bidentate ligand, respectively. Both of these species have an appreciable stability but, in contrast to ethylenediamine, the unidentate has the greater relative stability. Species containing two or more co-ordinated ethylene glycol molecules have not been isolated ; however, spectral evidence was obtained for them in solutions with high glycol conc e n t r a t i o n ~ .Chromium(II1) ~~~ forms complexes with methylthymol blue (H,L) and equilibria have been established for Cr(H3L) and [Cr2H3LI3+ formation.664The reaction between the complexes [Cr(R10H),]3+ (R1 = Me, Et, or C5H11; m = 6-9) and RiN (R2 = Me or Et) affords mixed aminoalkoxide complex anions with trialkylammonium cations.66 Polymeric Complexes containing Bridging Oxygen Atoms. The redetermined crystal structure of [(H3N),CrOCr(NH3),]Cl,,H20 is in agreement with the earlier report (Vol. 1, p. 58), the cation possessing ca. D, symmetry with a linear +

658 659

660 661

662

6h3 664 665

D. B. Vanderheim and E. L.King, J . Amer. Chem SOC, 1973,95, 3860. N. M. Karayannis C. M. Mikulski, L. L Pytlewski and M. M. Labes J. Inorg. Nuclear Chem., 1972, 34, 3139. T. J. Delia, M. A. Little, and D. X. West, J. Inorg. Nuclear Chem, 1973,35, 1400. (a) W. R Wolt R E. Sievers and G. H. Brown, Inorg. Chem., 1972,11, 1995; (6) K. C. Joshi and V N Pathak. J . C S Pcrkin I. 1973. 57 A D Taneja K. P. Srivastava and N.K. Agarwal, J . Inorg. Nuclear Chem, 1972, 34, 3573. H. B. Klonjs and E. L. King Inorg. Chem, 1972 11, 2933. E. Chiacchierini, V. Petrone, k L Magri and F. Balestrieri, Gazzetta, 1972, 102, 911. M. W. G. De Bolster and W. L.Groenveld J Inorg Nuclear Chem, 1973.35. 2106.

106

Inorganic Chemistry of the Transition Elements

Cr--O--Cr arrangement. The C r - 0 distances of 180 pm are slightly shorter than those previously obtained and extensive x-bonding between these atoms is again implied. Single-crystal polarized spectra have been recorded for this compound in the visible and U.V. regions.666 The structure of [(H,N),Cr(OH)Cr(NH3)5]C15,H,0 has been redetermined and the Cr--O--Cr interbond angle refined to a value of 166 & 1’. The temperature variation in the magnetic susceptibility has also been determined,667aand further detailed spectroscopic and magnetic studies of this compound in slightly different crystalline environments have resolved previous differences in the interpretation of such data.6676 The complex C~S-[F(H,N),C~(OH)C~(NH,)~]~+ has been prepared and its d-d spectrum recorded.668Irradiation of ~~~~s-[(H,O)(H,N),C~(OH)C~(NH,)~] and ~~U~S-[C~(H~N),C~(OH))C~(NH~)~]~+ at their d-d absorption energies leads to the formation of cis-[(H,O) (H3N),Cr(OH)Cr(NH3) 5 ] in each case. A second dinuclear complex is produced by ammonia photoaquation; however, its nature has not been established. These photoreactions are qualitatively different from thermal paths which involve cleavage of the hydroxo-bridge, but they do parallel the photoreactions found in analogous mononuclear +

’+

The crystal and molecular structure of di-p-hydroxo-tetraglycinatodichromium(m), [(gly),Cr(OH),Cr(gly),] has been determined. The structure consists of well-separated dimeric pairs of octahedrally co-ordinated chromium atoms, each complexed to two glycinato NO-ligands and linked by two hydroxobridges. The whole hmplex has a centre of symmetry and therefore the Cr0,Cr unit is strictly planar with Cr---Cr and 0---0 separations of 297.4(2) and 257.5(6) pm, respectively, the C r - 0 bonds being 196.7(4)pm in length. The magnetic properties of this complex are similar to those of copper(I1) dimers with such a bridging geometry.670A similar structure has also been identified for the cations in [(phen),Cr(OH),Cr(phen), JCl,,H,O (52)?” The cationic complexes of basic chromium(Ir1) sulphate have been separated by ion-exchange chromatography and the cations in two of them have been identified as (53) and (54). The kinetics of isotopic sulphato-substitution of these complexes have been measured and a mechanism for the exchange was proposed.67 2 A dinuclear chromium(Ir1) anion containing a bridging palmitatogroup has been characterized following the reaction of Cr(N03)3,6H,0 with palmatic acid (1 :3) in a polar organic solvent.673 666

b67

669 670

671 672

673

A. Urushiyama, Bull. Chem. SOC.Japan, 1 9 7 2 , 6 2 4 0 4 . (a) J. T. Veal D. Y.Jeter, J. C. Hempel, R P. Eckberg W. E Hatfield, and D. J. Hodgson, Chem. Phys. Letters, 1973,18, 140; ( b ) J. Ferguson and H. U. Giidel, Austral. J . Chem., 1972, 26, 505; J. Ferguson, H. U. Giidel, and M. Puza, ibid, p. 513. H. N. P. Chung and S. R Davis, J. Inorg. Nuclear Chem., 1973, 35, 2849. P.Riccien and E. Zinato, Inorg. Chim Acta, 1973,7, 117. J. T. Veal, W. E. Hatfield, D. Y. Jeter, J. C. Hempel, and D. J. Hodgson, Inorg. Chem., 1973, 12, 342; J. Coord. Chem, 1972, 2, 1 . J. T. Veal, W. E.Hatfield, and D. J. Hodgson, Acta Cryst., 1973, B29, 12. S. Indubala and D. Ramaswamy, J. Inorg. Nuclear Chem., 1973, 35,2055. E.D. Temyakov, and N. N. Pavlov, Nauch. Tr. Mosk. Tekhnol. Inst. Legk Prom, 1972 202 (Chem. Abs., 1973, 78. 135 579b).

The Early nunsition Metals

107

rN H N r

T

I ,N Cr

N,Ar,O,

-

N N = 1,lO-phenanthroline Cr-N

=

t

205.2(6)pm

2+

'S'

(53)

(54)

A spectroscopic study of [Cr30(0Ac)6(H,0),]Cl,6H20 at low temperatures has confirmed the presence of two sets of inequivalent trimeric The e.s.r. spectra of mixed Crl*'-FeIn acetates of general formula rM ,O(OAc),(H, 0) ,] NO AcOH have been determined at temperatures down to 4.2 K and the exchange integrals shown to be in the sequence J ( C r 4 r ) < J(Cr-Fe) < J(Fe-Fe).674b A trimeric chromium(II1) complex, probably containing bridging hydroxo-groups, has been isolated with the ligand 8-amino-7-hydroxy-4-methylcoumarin. 67 Further studies of the magnetic properties of Pfeiffer's cation [Cr4(0H),(en),J6+, as its sulphate and azi& salts, have been published.676 The alkali-metal and guanidinium salts of the heteropoly-anion [CrZnW, 1040Hz]7- have been isolated following substitution of Cr'" for the octahedrally co-ordinated Zn" in [Zn,W, 1O40H2]*-.344 The addition of alkali to solutions of [Cr(H20)6]3+ initially causes simple deprotonation followed by precipitation of [Cr(OT$,(H,O),], which may be obtained in a crystalline form by precipitation at low temperatures. The structure of [Cr(OH),(H,O),] is of the inverse bayerite-type with the metal atoms in one-third of the octahedral sites, and the structure consists of hydrogenbonded layers of [Cr(OH),(OH,),], units in which the octahedral units are also linked by hydrogen bonds. Elimination of water from [Cr(OH),(H,O),] occurs readily to form a well-ordered structure in which the metal centres are connected by p-hydr~xo-bridges.~~

,,

b74

675 676

677

Ferguson and H. U. Gudel, Chem. P h y s Letters, 1972, 17, 547; (b) Yu. V. Yablokov, V. A. Gaponenko, M. V. Eremin, V. V. Zelentsov, and T. k Zhemchuzhnikova, Zhur. eksp. teor. Fiz., Pis'mau, 1973, 17, 207 (Chem Abs, 1973, 78, 130309d). M. P. Teotia, D. K Rastogi, and W. U. Malik J . Inorg. Nuclem Chem, 1973,35, 3015. T. Iwashita, T. Idogaki and N. Uryu, Kyushu Daigaku Koguku Shuho, 1970,43,744 (Chem Abs., 1972, 77, 67 8122); 1972,45, 305 (Chem Abs, 1972,77, 1324660. U. von Meyenburg 0. Sirokf, and G. Schwarzenbach, Helu. Chim. Act@ 1973, 56, 1099; R. Giovanoli W. Stadelmann, and W. Feitnecht ibid, p. 839; R. Giovanoli W. Stadelmann, and H. Gamsjaeger, Chimia, 1973, 27, 170. (a) J.

Inorganic Chemistry of the Transition Elements

108

Complexes with S-donor, Se-donor, or Te-donor Ligands. Several mixed-metal sulphides, selenides, and tellurides containing chromium(II1) have been prepared and these are detailed in Table 7. The ions [(H20),CrSCH2CH2NH3] and [(H20),CrSC6H,NH,] have been prepared via the chromium(I1) reduction of the NS(2-mercaptoethylamine) (ethylenediamine)cobalt(nr) ion and p-aminophenyldisulphide, respectively, and the U.V.and visible absorption spectra of these chromium(II1) complexes have been recorded.678 The preparation of some optically active tris(dithiocarbamato)chromium(rIx) complexes640 is described on p. 101. The synthesis of the first dithioacetylacetonato-complex of a Group VI transition metal (55) has been achieved by the reduction of the 3,5-dimethyl-1,2-dithioliniumcation with chromium(I1). This dark-green compound consists of discrete molecules which undergo a +

+

Table 7 Mixed metal sulphides, selenides, and tellurides containing chrorniurn(1rr) Compound

SnCr,S, In(Ni,Cr)S, FeCr,Se, ZnCrzSe, MCr,X, (M = Cu, X = S or Se; M = Cd, X = S, Se, or Te; M = Hg, X = Se) CuCr Se, Br CuCr,Te,I LaCrS, Ln,CrBe,S,, (Ln = Y, La-Nd, Sm, Gd, Dy, or Er)

,

Comments and reported properties

P?x p, X ; spinel lattice

Re? a b

X ; NiAs-structure X ; spinel lattice

c

X ; spinel lattice

c, d

e, p, X ; spinel lattice

e

X

f

X

9

(a) A. W. Sleight and C. G. Frederick, Materials Res. &11,1973,8,105 (Chem Abs, 1973,78,89 685h). (6) W. Schlein, Bol. SOC.Chil Quim, 1972, 19, 10 (Chem Abs. 1973, 7 4 118615t). (c) N. I. Murashko, V. A. Obolonchik, and Y u M Goryachev,Izvest. Akad Nauk S.S.S.R.,neorg. Materialy, 1972,8, 1669. (dj Y u D. Tret’yakov, I. V. Gordeev, V. k Alferov, and Y u G. Saksonov, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972 8, 2215; Y. Wad& Seramikkusu, 1972, 7, 587 (Chem A h , 1972, 77, 157948~). (e)M.Robbinq US.P, 3 676 082 (Chem Abs, 1972,77,120 0493.(f)T.Takahashi T. Oka, 0.Yamada, and K. Ametani Materials Res. h l l , 1971, 6, 173 (Chem Abs, 1972 77, 80743~).(g) Ref. 64.

reversible one-electron reduction at - 0.47 V us. AgCl/Ag ; at - 1.26V us. AgCl/Ag a multi-electron reduction occurs, presumably with the gross degradation of the complex.679 [Cr{ S,P(OEt),),] crystallizes in two different modifications, one of which is isomorphous with the corresponding vanadium complex. The structure of the other has been determined and the only difference 678

b79

L. E. Asher and E. Deutsch, Inorg. Chem., 1972,11,2927; 1973,12,1774. G. A. Heath R L. Martin and A. F. Masters Austral. J . Chem., 1972, 25, 2547.

109

The Early Transition Metals

(5 5)

between the two modifications is in the packing of the molecular units.680 The reaction of difluorodithiophosphinic acid, F,PS,H, with CrO,Cl, has been shown to be an alternative route to [Cr(S,PF,),J.68’ The i.r. spectrum of [Cr(S,CPh),] has been determined, as part of a study of dithiobenzoatocomplexes, and the metal-sulphur stretching frequencies were identified at 370 and 354 cm- 1.682 The magnetic susceptibility of [Cr(S,CNEt,),] from room temperature to 4 K indicates that the magnetic moment (3.80-3.54 BM) remains essentially independent of temperature; however, between 4 and 2.5 K there is a very large decrease in the moment which may be due to a very weak exchange interaction between molecules or to a very small zero-field ~plitting.,~ Magnetic, electronic, and e.s.r. spectral studies have been reported for [Cr(S,PR,),] complexes and shown to be consistent with the presence of CrS, c h r o m o p h ~ r e s K(S,AsPh& .~~~~ reacts with CrCl, in alcohol to yield [Cr(S,AsPh,), J ; its characterization by i.r. and electronic spectroscopy and its magnetic properties were reported.322 [Cr(Se,COEt),] has been prepared by adding a large excess of solid chromium(II1) alum to a solution of K(Se,COEt) in H,O and gently warming the resultant solution before extracting with CHCl,. This green-brown compound dissolves in organic solvents as the monomeric species, the electronic spectra of which are consistent with an octahedral CrSe, N-Donor Ligands. CrF, reacts with gaseous N, at 650°C to afford chromium(1n) nitride fluoride, Cr,NF,. The room temperature magnetic moment of this compound, 3.92BM, indicates that it does not involve any strong antiferromagnetic coupling between the metal Several new isocyanide complexes of chromium(n1) have been prepared by the electrochemical reduction of heavy-metal adducts of chromium(rI1) aquocyano-complexes, and characterized by their visible spectra.686The chromium 2p- and 3s-orbital ionization potentials in K,[Cr(NCS),] have been r e p ~ r t e d , ”and ~ the lattice parameters for this anion in the salt with diaquotris(nicotinic acid)holmium(III) determined.,*’“ The absorption spectra of the

680

682

683

685 686

H. Schousboe-Jensen, F. Vincents, and R. Groenbaek-Hazell, Acta Chem. Scund., 1972,26,1375. R G. Cavell and A. R Sanger, Inorg. Chem., 1972, 11, 201 1 . M. Maltese, J.C.S. Dalton, 1972, 2664. (a)B. N. Figgis and G. E Toogood, J.C.S. Dalton, 1972,2177; (b)R N. Mukherjee and M. D. Zingde, J . Inorg. Nuclea Chem., 1973, 35, 696. C. Cauletti and E. Cervone, J. Inorg. Nuclem Chem, 1973,35, 593. A. D. Westland, J. Inorg. Nuclear Chem, 1973, 35, 451. S. N. Frank and F. C. Anson, Inorg. Chem, 1972 11. 2938.

110

Inorganic Chemistry of the Transition Elements

complexes Cr(NCS)i-'(n = 1-6) have been obtained in Bu,PO, Accurate spectral and kinetic measurements have shown that, contrary to an earlier interpretation, the photoaquation product of [Cr(NH,),NCS)' consists of at least 95 % c~s-[C~(NH,),(OH,)(NCS)]~+.~~~ The photoaquation of trans-[Cr(en),(NCS)ClJ occurs in three distinct reactions which form [Cr(en)(enH)(0H,)( N CS)C1] +,[Cr(en)(, NCS)(0H,)I ,and [Cr(en) (0H ,)C1I2 . 6 8 9 Other isothiocyanato-complexes of chromium(II1) reported include [CrL,(NCS),] (L = Ph,PO, DMF, quinoline, and 4-Mepy), [Cr(en),(NCS),], and [Cr2(phen),(NCS)6], all of which behave as 1 :1 electrolytes in solution.690 Also reported are C~~-[C~(NH,),(H,O)NCS]~ +,668 [Cr(H,O),(CN)(NCS)]-,691and the salts [Ag(NH,R),] [Cr(NCS),(aniline),] (R = H, Me, or Et) whose i.r. spectra and magnetic susceptibilities have been determined.692 The electronic spectrum, magnetic susceptibility, and e.s.r. spectrum of [Cr(N(SiMe,),} J have been determined and interpreted using a crystal-field = C1 or model for D , , ~ymmetry.~'Irradiation of [Cr(NH,),][ZnCl,](X NO,) and [Cr(NH3)6])33 (X = Cl, Br, I, or NO& at 366, 404, and 436nm results in their partial conversion into the corresponding [Cr(NH,),X]2 + complex via energy transfer in the solid state.693By mixing N2H4 with slightly acidified solutions of the appropriate chromium(rI1) salt, the complexes [Cr(N,H,),Cl,], 2 H 2 0 and [Cr(N,H,),(OAc),],H,O have been prepared.629 The stability constants of the outer-sphere complexes formed by [Cr(en),13 and several oxyanions have been determined and in general found to be less than those for the formation of the analogous [Co(en),13+ complexes.694Two of the propane-l,3-diamino-ringsin [Cr(pn),] [Ni(CN),],2H20 have the expected chair conformation, but the third adopts the conformationally less stable skew-boat conformation.695 The azidoaquo-complexes [Cr(HnL1)(HzO)n+1N,]nf2(n = 1, 2, or 3, L1 = trieth~lenetetrarnine),~'~" and the aquo-complexes [Cr(H,L2)(H,0),+ ( n = 0-4, L2 = tetraethylenepentamine),696bhave been characterized during the stepwise aquation of cis-a[CrL1(N,),]Br and a-[CrL2C1]C1,, respectively. A detailed study of the photoand trans-[Cr(2,3,2chemical reactions of cis- and trans-[Cr(cyclam)C1,] tet)Cl,] + (cyclam is 1,4,8,11-tetra-azacyclotetradecane and 2,3,2-tet is 1,4,8,11+

+

+

,

+

+

+

687

688 689 690

691 692

693 694

695 696

(a) J. Kay, J. W. Moore, and M. D. Glick, Znorg. Chem., 1972, 11, 2818, (b) G. P. Tikhonov, A. I.

Sukhanovskaya, I. V. Sinitsina, E. A Solov'ev, and E A. Bozhevol'nov, Zhur. analit. Khim, 1972, 27, 2191. E. Zinato and P. Riccieri, Inorg. Chem, 1973, 12, 1451. M. T. Gandolfi, M. F. Manfrin, L. Moggi and V.Balzani J. Amer. Chem Soc.. 1972,94, 7152. S. J. Patel, Bol. SOC.Chilinu Quim, 1971, 17, 61 (Chem Abs., 1972, 77, 83 056m). A. A Schilt and W. B. Schaap Inorg. Chem, 1973, 12 1424. P. V. Mathur and L. N. Srivastava, .I. Inorg. Nuclem Chem, 1973, 35, 21 12. C. D. Flint P. Greenough, and A. P. Matthews, J.C.S. Dalton, 1973, 368. I. E. Umova B. I. Lobov, Yu I. Rutkovskii, and V. E. Mironov, Zhur. neorg. Khim., 1973. 18, 836. F. A Jurnak and K. N. Raymond, Inorg. Chem, 1972, 11, 3149. (a) S. C. Tang R. L. Wilder, R K. Kurimoto, and C. S. Garner, Syn. Inorg. Metal-Org. Chem., 1971. 1. 207; (b) J. Ranney and C. S. Garner, ibid, p. 179.

111

T h e Early 'T).ansitionMetals

tetraazaundecane) has been The new complex of octaethylporphine (H,L), [Cr(OPh)(HOPh)L], has been isolated and ~haracterized.~~" A series of chromium(m) complexes containing N-donor macrocyclic ligands has been prepared by halogen oxidation of the chromium(Ir1) analogues.626 The bright-red compound Li,[CrL6],THF (LH = imidazole) has been prepared by refluxing LiL with CrC1,,3THF in THF.628The electronic structure of the [Cr(bipy)]"+ ( n = 3 to -1) complexes have been investigated in some detail and the general conclusion reached that reduction from the chromium(Ir1) complexes involves the addition of electrons to orbitals which are essentially localized on the ligand~.~' The reaction of e; with [Cr(bipy),13+ and [Coproduces a transient intermediate with an intense absorption at (bipy),], 300 nm. This one-electron reduction appears to proceed via the addition of an electron to an orbital of the ligand, although the decay of the intermediate appears to involve the transfer of the added electron to the metal centre.698 The one-electron reductions of [Cr(bi~y)~], and [Cr(phen),13*+ have also been investigated electrochemically. In aqueous solution both complexes undergo this reduction at -0.50 V (us. SCE) followed by a series of reactions which converts all the unreduced [Cr(NN),I3+ complex ( N N = bipy or phen) into the corresponding [Cr(NN),(H2O)J3 one. Both these diaquo-complexes can be reduced to the analogous chromium(I1) complexes at -0.72 V (us. SCE).699 Mixed N-donor and Other Donor Atom Ligands. CrC1, reacts with diethyl 6-methylpyridine-2-phosphonateat elevated temperatures to form tris(ethoxy6-methylpyridine-2-phosphonato)chromium(111). Spectral data suggest that the ligands act as bidentate NO-chelates to give monomeric complexes which have a distorted octahedral geometry.73The dinuclear complex of pyrazine N-oxide (L), [L,(EtOH)CrL,Cr(EtO13)L3]6+, has been isolated as its perchlorate salt following the reaction between Cr(ClO,), and L (1 :3) in ethanokthylformate (3 :2) solution at 50°C. The above formulation, containing uni-(0), bi-(Olv>,and bridging (ON) pyrazine N-oxide groups, has been suggested from i.r. and electronic spectral studies. There is, however, no appreciable coupling between the metal atoms in the dimeric unit as p = 3.75BM per Cr"1.700The 8-(2'carboxypheny1)aminoquinolines (59(L) form complexes with chromium(II1) in which they function as terdentate dibasic ligands to give distorted octadehral [CrL2] - complexes which can exist in three isomeric forms. This isomerism is consistent with the co-ordination of the central nitrogen atom and thus the ligands in the complex will be bent."' Some new complexes of chromium(n1) with dibasic quadridentate Schiff bases (H,L) have been reported. These bases were prepared by the condensation of salicylaldehyde, 3-~arboxysalicylaldehyde, or o-hydroxyacetophenone with +

+

+

697

698 699

700 701

C. Kutal and A. W. Adamson, Inorg. Chem, 1973, 12 1990. h4 Z. Hoffman and M. Simic, J.C.S. Dalton. 1973, 640. D. M. Soignet and L. G. Hargis Inorg.Chem., 1972, 11, 2349, 2921. A. N. Speca, N. M. Karayannis and L. L. Pytlewski J. Inorg. Nuclear Chem., 1973, 35, 3113. E. Steiner and G. Schetty, Helv. Chim Acta, 1973, 56, 368.

112

Inorganic Chemistry of the Transition Elements

R2

R2 = H. R' = Me. RZ = H R ' = H. R 2 = CMe,, R ' = Br, R 2

(56) R'

=

=

H

en, 1,3diaminopropan-2-01, or o-phenylenediamine, and the complexes obtained include the 1 :1 electrolytes [CrLX,]Y (X = H,O, NH,, or py ; Y = C1, Br, I, or OAc) and the neutral [CrL(py)Cl] compounds.702 Spectral and magnetic studies have been reported for the complexes [Cr,L:X,] [HL' = 8-amino-7-hydroxy-4-methylcoumarin (57); X = OH or CN] and [CrL2(0H)(OH,)] [HL2 = 3,3'-diamino-4,4-dihydroxydiphenylsulphone(58)]. The former appear to be composed of trimeric clusters containing bridging hydroxoor cyano-gro~ps.~' The reaction of chromium(n1) with an excess of NH2C2H,0H affords [Cr(NH,CH,CH,O),] initially, which is converted into a dimeric species on standing. 703 Several chromium(m) amino-acid complexes have been prepared Me

Hoq H2NrY 0

s4

*ZN

NH2

HO

(57)

'-.

+i

(58)

by treating CrCl, with the corresponding amino-acid, and their c.d. spectra have been reported. These complexes were of the type [CrA:],O.SH,O (HA1 = L-alanine), [CrA$(OH,),]Cl (HA' = L-alanine,L-phenylalanine, or L-citrulline), ~ ' ~ comor [CrA~(OH)(OH2)],2H,O(HA' = L-phenylalanine or ~ - s e r i n e ) . The plexes formed by treating chromium(m) nitrilotriacetate, [Cr(N(CH,CO,), >], with D M F or one of a variety of amines, have been characterized by i.r. spectrocopy.^^^ Several chromium(II1) complexes of nitrilotriacetic, iminodiacetic, propyliminodiacetic, and 2-picolyliminodiacetic acids in aqueous media have been characterized and some potentiometric and polarographic data reported 702 703 '04

705

K. Day, R. L. De, and K. C. Ray, Indian J . Chem, 1972, 10, 864. E. G. Timofeeva and V. Ya Tkacheva, Zhur. neorg. Khim., 1972, 17, 1935. P. Vieles and A. Bonniol, J. C h i m phys, 1973,70, 348. M. G. Voronkov and S. V. Mikhailov, K h i m geterotsikl. Soedinenii 1972, 1174 ( C h e m Abs., 1973, 78. 1 1 004r).

The Early Transition Metals

113

for them.706The nature of the complexes formed between chromium(II1) and a variety of aminopolycarboxylic acids has been studied using i.r. and ion-exchange technique^.^ Na[Cr( CH, { CH,N( CH,CO,),) ,)I has been converted into the corresponding hydrogen salt by cation e~change.~"Several chromium(r~r) complexes with dl-propylenediaminetetraceticacid (H,L) have been prepared, including Na[ CrL],2H 0, Na, [CrL(OH)],2SH 0, and [Cr( HL)(OH,)],H 2 0 . 7 0 9Acid dissociation constants for a chromium(II1) complex of N-(2hydroxyethy1)-ethylenediamine-NN""-triacetic acid (H,TOH) have been determined by potentiometric titration. The removal of the first three hydrogen ions gives rise to [Cr(TOH)H,O], [Cr(TOH)OH]-, and [Cr(TO)(0H)l2and at pH > 13.1 de-chelation of the ligand from the metal ion occurs to give [Cr(TO)(OH),I3 - and [Cr(TO)(OH)3]4- .' l o Acetatobis-(3,3',5,5'-tetramethyldipyrromethanato)chromium(In) has been prepared in MeOH under N,, and was shown to have an octahedral geometry about the metal, the acetato-group being bidentate.711

,

,

N-Mercaptoacetamidophenol(59)complexes with chromium(m) to afford a 1.1 complex with a stability constant of 5.4 x lo6 1 mol-1.367The chromium(111) complex of 3,4,5-pyridazinetrithiol (H,L) (60), CrL, has been prepared by adding an ethanolic solution of the ligand to a solution of CrCl, in EtOH and warming for 2 h. The magnetic moment of this complex (p = 0.7 BM) is surprisingly low and although spectroscopic studies have been undertaken, little structural information is presently available.712 Table 8 summarizes data reported for other chromium(II1) complexes containing a variety of donor ligands. P-Donor Ligands. [C1,Cr,PMe,PMe,,CrC13] has been isolated following the reaction between CrCl, and Me,PPMe, in MeCN, THF, or benzene, and its i.r. and electronic spectra and magnetic properties were determined.75 Cyano-complexes. The crystal structure of Cd,[Cr(CN),],, nH,O is closely related to that of Prussian Blue and contains Cr(CN), groups carbon-bonded 706

707

'08 '09

711

'l'

e

P. Souchay, P. Gouzerh, and A. Richard, Colloq. Internat. Centre Nat. Rech. Sci. (Paris), 1970 No. 191 289 (Chem. Abs., 1972, 77, 131 392s). J. Shankar and G. M. Phatak, Indian J . Chem.. 1972, 10, 861. J. Chung and Y. Kwak Dachan, Hwahak Hwoejee, 1973. 17, 141 (Chem. Ahs.. 1973,78, 1543762). J. M. Suarez Cardeso and S. G. Gonzales, Anales Real SOC. espaii, Fis Quim., 1972,68,1227 (Chem. Abs.. 1973, 78, 91 971s). R. K. Wharton and A. G. Sykes J.C.S. Dalton. 1972. 2404. Y. Murakami, Y. Matsuda, and K. Iiyama, Chem. Letters, 1972,1069. J. S. Dwivedi and U. Agarwala J . lnnrg. Nuclear Chem.. 1973, 35. 2229.

Inorganic Chemistry of the Transition Elements

114

Table 8 Chromiurn(II1)complexes containing a variety of ligands Complex C~S-[C~(NH~),(OH,)F]~

A,

+

I

trans-[Cr(tmd),X,] (X = C1 or Br) truns-[Cr(tmd),(OH) (OH,)] tran~-[Cr(tmd),(OH,)X]~ (X = C1 or Br) cis- and tr~ns-[Cr(tmd),(OH,)~] [Cdtmd) (OH2)J3+ cis- and trans-[Cr(en) (tmd) (OH2),I3+ (tmd = 1,3-diaminepropane) +

+

+

+

Comments and reported properties 375(21) 512(41) nm

cations isolated as C1-, Br-, or ClO, salts, electronic spectra recorded

A, 393(62) 524(62) nm rCden) (c204) (OH,),] -k ,A 405(50) 544(42) nm [Cr(enH) (c204) (OHJ312+ [CrLX,]Cl (X = H 2 0 or RNH, ; R = H, Me, Pr, or Bu) i.r. and electronic spectra K[CrLX,] (X = CN, NCS, or NO,) [HL = NN'-ethylenebis(acetylacetoneimine)] [CrL(OH)n(OH2)3- n]" -(H3L = nitriloacetic acid, n = 0-3) cis-[Cr(2-picoly1amine)X) (X = H,O, n = 3 ;X = F, C1. or Br, n rCr(3-picoline)(H20)J3 +

=

solvent extraction studied e, X and partial structural 1) assignment ,A 400(22) 558(19) nm

Re$ U

b

C

d

e

f 9

(a) Ref. 668. (b) M. C. Couldwell and D. k House, Inorg. Chem., 1972, 11, 2024; M. C. Couldwell, D. A. House, and H. K. J. Powell ibid., 1973, 12, 627. (c) 0. Nor, J. W. Lethbridge, and A. G. Sykes, J.C.S. Dalton, 1973, 1758. ( d ) K. Yamanouchi and S. Yamada, Bull. Chem. Soc. Japan, 1972, 45, 2140. (e) H. M. N. H. Irving and R H. Al-Jarah Analyt. Chim Actu, 1972 60, 345. (A K. Michelson, Acta Chem Scand, 1972, 26, 1517. (g) M. Orthanovic and M. Avdagic, Inorg. Chem., 1973, 12, 492.

to chromium(rr1): one-third of these groups are absent, giving the cadmium atoms co-ordination spheres of average composition CdN402.713The chromium 2p- and 3s-ionization potentials in K,[Cr(CN),] have been determined by X-ray photoelectron spectroscopy.593The 5 K luminescence spectrum of [CI-(CN),]~- diluted in K,[Co(CN),] has enabled the i.r. and Raman inactive T2,,C r 4 - N and C - 4 r - C bending modes to be located at 360 and 86 + 96 cm- respectively, the latter being coupled with lattice vibrations.714 The photolysis of [Cr(CN),13- has been studied in DMF solution, where [Cr(CN),DMFI2- is the first reaction product, and in H,O containing sensitizing agents. The results of both studies agree that the photoactive state is not the 2Eg one but is probably the 4T,g one.715The reactions of [Cr(H,O),CN]2+,~i~-[Cr(H20)4(CN)2]+, andfuc-[Cr(H,O),(CN),] with Hgn and Ag' to form dinuclear and trinuclear adducts have been investigated and equilibrium

713 '14

'I5

H. U. Giidel, Acta Chem. Scand, 1972, 26, 2169. C. D. Flint and P. Greenough J.C.S. Chem Cornm, 1973, 489. H. F. Wasgestian, J . Phys. Chem, 1972,76, 1947; N. Sabbatini and V. Balzani J. Amer. Chem SOC., 1972.94. 7587.

The Early Transition Metals

115

constants for the formation of these complexes determined [Cr(H2O),CNl2 affords [Cr(H,O),(CN)(NCS)]- [h ,,,503(46) and 403(50) nm] in the presence of NCS-.691 [Cr,L,(CN),] [HL = 8-amino-7-hydroxy-4-methylcoumarin (531 has been prepared and its i.r. spectrum shown to indicate bridging +

cyano- group^.^ Organometallic Compounds. Organocobaloximes react with Cr"(aq) to afford [(H2O)CrRl2+(R = Et, Pr, P8 neopentyl, or 2-octyl) and the first three of these complexes have been purified by ion-exchange technique^.^' The complexes [(aryl),Cr(bipy),]+ (aryl = 2-, 3-, or 4-MeOC,H4, or Ph) constitute a new class of o-bonded organochromium compounds which are remarkably inert to both air and water, presumably owing to the stabilizing effect of heterocyclic l i g a n d ~Crystal . ~ ~ ~ structure analyses for the phenyl and 2methoxyphenyl derivatives have confirmed the presence of two cis--bonded aryl groups with Cr--C bond lengths of 208.7(4) and 2 10.1(1.2)pm, respectively, implying that this bond length is insensitive to the nature of the substituents on the aryl ring.717 Essentially the same value of the C r 4 bond length C210.7 (1.2) pm] has been identified in ~is-[(Me,SiCH,),Cr(bipy)~]I.~'~ Although the stabilizing effect of nitrogen heterocyclic ligands on 0-bonded organochromium(m) derivatives does extent to [EtCrCl,(py),], the addition of AlPr, to a solution of this compound in THF at room temperature results in the rapid evolution of ethane.163 (Dipheny1methyl)chromium dichloride, [(Ph,CH)CrCl,], has been isolated as its bis-THF adduct following the reaction of CrCl, with (Ph2CH)Li,2dioxan in THF at - 50°C. This compound is thermally stable to ca. 110°Cbut reacts with ligands to afford Ph,CHCHPh, and 2CrCl,,L, (L = py, bipy, or MeOCH,CH,0Me).7 l 9 LiPh reacts with (Ph2CH)CrC1,,2THF to yield (Ph,CH)CrPh,.630 Ph2Cr,3THF may be converted into its phosphine adducts Ph3Cr,2PR,Ph (R = Et or Bu) by mixing with PR,Ph and removing the THF under reduced pressure, followed by recrystallization from hexane at - 70°C.720 The crystal structure of Na2CrPh,,3Et,O,THF has been determined and the anion shown to have a distorted trigonal-pyramidal configuration with five phenyl ligands o-bonded to the chromium(II1). As expected the axial C r - C bond lengths, 212(7) and 222(7)pm, are longer than those in theequatorial plane, which average 203 pm in length.721 Crystals of Li[(7c-Cp)CrC12],2THF,dioxancontain anions in which the chromium(II1)is co-ordinated by an antiprism with pentagonal (the K-CPgroup)

'I6

'17

'18

719 720 721

J. H. Espenson and J. S. Shveima, J. Amer. Chem SOC, 1973,95, 4468. J. J. Daly and F. Sanz J.S.C. Dalton, 1972 2584; J. J. Daly, F. S a w R. P. A. Sneedon, and H. H. Zeiss, ibid., 1973, 73. J. J. Daly, F. Sanz R. P. k Sneedon, and H. H. Zeiss, J.C.S. Dalton, 1973. 1497; Helu. Chim. Acta, 1973, 56, 503. W. Siedel and K. Fischer, 2. Chem, 1972, 12, 147. K Schmiedeknecht. W. Reichardt, and W. Seidel, 2. Chem, 1971, 11,432. E. Miiller. J Krausse, and K. Schmiedeknecht. J Organometallir Chem., 1972.44. 127.

116

Inorganic Chemistry of the Transition Elements

and trigonal (the three C1 atoms) faces; the IT-Cpring is significantly distorted from the five-fold symmetry of the free ligandn7,, Chromiurn(~v).-Li, CrF,, which is isostructural with Na2SnF6, has been prepared by the reaction of Li,CrO, or Li,CO,-CrCl, mixtures with F,-Ar at 300°C and 300 atm.723Other ternary fluorides containing chromium(Iv), MCrF, (M = Mg, Ca, Sr, Ba, Ni, Zn, Cd, or Hg), have been prepared in this manner and their magnetic moments (M = Ba or Sr) and lattice constants determined.724 The perovskite PbCrO, has been obtained from PbO and CrO, at high pressure, and the compound shown to be a semiconductor with antiferromagnetic behaviour below a transition temperature of ca. 160 K.725Tetrakis(3,3-dimethyl-2-butoxy)chromium(1v) has been prepared by alkoxide exchange from tetra-t-butoxychromium(1v) with an excess of pure pinacolyl alcohol sealed in an ampoule at 70°C for 36 h. This new compound is very sensitive to both 0, and H,O but is otherwise remarkably stable. The electronic spectral and magnetic properties have been determined and are very similar to those of other chromium(1v) alkoxides. 26 Octaethylporphinatochromium(II1) hydroxide undergoes a one-electron oxidation before E , of 0.79 V, which appears to result in the formation of the corresponding chromium(1v) derivative. This compound, however, was too unstable to be fully ~haracterized.~’~ The full account of the preparation of the neopentyl and related alkyls of chromium(Iv), CrR, (R = Me, CH,CMe,, CH,CMe,Ph, or CH,CPh,) has now been p u b l i ~ h e d27. ~Tetra-t-butylchromium(1v) has been prepared from CrC1,,3THF and Bu‘Li in pentane by a disproportionation reaction, and from tetra-t-butoxychromium(1v) and Bu‘Li. The compound was isolated by sublimation and characterized by e.s.r., u.v., visible, and i.r. spectroscopy. This study also reported the e.s.r. spectra of CrR, (R = Me, P~ Bu, B$ neopentyl, or methylcyclohexyl). 8n Such spectra are usually well-defined for d2-complexes and consist of a single intense peak at room temperature and a second weak absorption, corresponding to a A m = 2 transition, may also be observed at 77 K.728bThe helium(I) photoelectron spectra of Cr(CH,AMe,), (A = C or Si) have been recorded and the data obtained used to support the argument that the stability of these compounds is due to kinetic rather than thermodynamic factor^.^ 2 9 Chromium(v).-The crystal structure of barium chromate(v), Ba,(CrO,),, has been determined and the isotopy with BaJPO,), shown to extend to the details 722

723 724 725 726 727 728

729

E. Muller and J. Krausse, J. Organometallic Chem., 1972, 44, 141. G. Siebert and R. Hoppe, Z. anorg. Chem., 1972, 391, 1 1 3. G. Siebert and R. Hoppe, Z. anorg. Chem., 1972, 391, 126. B. L. Chamberland and C. W. Moeller, J . Solid State Chem, 1972, 5 39. G. Dyrkan and J. RoEek, J . Amer. Chem SOC, 1973.95, 4756. W. Mowaf k J. Shortland, N. J. Hill, and G. Wilkinson, J.C.S. Dalton, 1973, 770. (a) W. Kruse, J. Organometallic Chem., 1972,42, C39; (b) G. A. Ward, W. Kruse, B. K. Bower, and J. C. W. Chien, ibid., 1972, 42, C43. S. Evans, J. C. Green, and S. E Jackson J.C.S. Faraday 11. 1973. 69, 191.

The Early Transition Metals

117

of the atomic KMCrO, (M = Sr or Ba) have been prepared by heating K,CrO,, MCrO,, and Cr203,or K2Cr04and M,CrO, in sealed tubes. These crystals have orthorhombic unit cells and contain CrV in tetrahedral sites.731The electronic spectra of CrVdoped in various phosphate and vanadate salts have been interpreted, including considerations of effects such as the size of the cation site and possible Jahn-Teller distortions.732 On exposing single crystals of K,CrO, and KCr0,Cl to ionizing radiations at room temperature a paramagnetic species is formed which is common to both matrices. Several arguments support the assumption that this species is CrO; . 7 3 3 K[CrO(CF3C(0)C(O)CF3),1 has been prepared by dissolving K,CrO, and perfluoropinacol in EtOH-H,O (1 :2) containing H2S04and maintaining the mixture at its boiling point for 10 min. This anion is a remarkably stable chromium(v) derivative. The d-d spectrum of the complex consists of a single band at 575(171) nm and its magnetic moment in the K f or Cs' salts is ca. 1.75BM, although in the Et,N+ salt it is 2.33 BM.35 Complexes of chromium(v) with pinacol, dimethylethyleneglycol, and diethanolamine have been identified by e.s.r. spectroscopy in dilute solutions at temperatures down to 77 K.734 Chromium(vI).--Halides and Oxyhalides. The molecular structure of CrO,F, has been determined by gas-phase electron diffraction, and the relative magnitudes of the 0 . 0 4and F 4 r - F interbond angles, 102.1(4) and 118.9(5)", respectively, seem to be more consistent with ligand-ligand repulsions being the dominant non-bonded interaction, rather than valence-shell-electron-pair repulsions.73s R,N[CrO,F] (R = Me or Et) have been prepared by treating ZnCO, with H,CrO, and HF7followed by the addition of R4NCl to precipitate the salt. X-Ray powder diffraction studies have shown that Me,N[CrO,F] is isomorphous with Me,NC10, ; however, this relationship does not extend to the corresponding Et,N Mg[Cr0,C1],,9H20 has been prepared by adding MgCl,,GH,O to a solution of CrO, in aqueous HCl and the i.r. and Raman spectra of the compound recorded.737M[CrO,Br],xH,O (M = Rb or Cs) have been prepared in a similar manner and an analysis of their vibrational spectra afforded values of 6.3 and 2.9 mdyn A-l, respectively, for their Cr-0 and Cr-Br force The i.r. and Raman spectra of KCrIO, have been recorded and a structure suggested for this solid which involves CrO, tetrahedra each joined by a bridging oxygen atom to an 10, pyramid.738b

730

731

732 733 734 735 736 737

738

Hj. Mattausch and Hk. Muller-Buschbaum, Z. Naturforsch., 1972, B27, 739. R. Olazcuaga, J. M. Reau, and G. Le Flem, Compt. rend., 1972, 275, C, 135. J. B. Milstein, J. Ackerman, S. L. Holt, and B. R. McGarvey, Inorg. Chem., 1972, 11, 1178. R Debuyst, J. Ladrikre, and D. J. Apers J . Inorg. Nuclear Chem, 1972 34, 3607. Z. I. Usmanov and A. V. Il'yasov, Zhur. strukt. Khim., 1972, 13, 728. C. D. Garner. R. Mather. and M. F. A. Dove. J.C.S. Chem. Comm.. 1973, 633 W. A. Frey, V. Kubilus, and G. Mitra, J . Fluorine Chem. 1972,2, 115. V. Lepingle, G. Palavit, and S. Noel Compt. rend.,1973, 276, C, 343. (a) E. Ahlborn, E. Diemann, and A. Miiller, Z . Naturforsch, 1972 B27, 1108; (b) A. Kebir and P. Vast. Compt. rend., 1973, 276, C, 503.

118

Inorganic Chemistry of the TransitionElements

0-Donor Ligands. An X-ray photoelectron spectroscopic study of the Cr-0 system has shown that the ionization potentials of the metal's 2p-electrons are dependent primarily on the oxidation state of the metal, chromium(v1) values being some 2-3 eV higher than chromium(Ir1) ones, but that small perturbations of the energies may be attributed to crystal lattice effects.600The ground states of the [Cr04j2- and [Cr20,I2- ions have also been investigated by X-ray photoelectron spectroscopy, X-ray spectroscopy, and by MO calculat i o n ~5 *.7~3 9 ~Several studies of the vibrational spectra of chromates have been reported, including the entire i.r. reflectance spectrum of K,Cr04 which, together with the previously reported single-crystal Raman data, completes the assignment for this compound.740T12Cr04has been shown to be isomorphous with the corresponding K, Rb, and Cs salts,741and HgCr04,0.5H20has been shown to contain [Cr0412- tetrahedra linked together by Hgn atoms [ L OHgO = 176.2(9)"] to form infinite (HgCrO,) chains.742 Zr(OH),CrO, consists of infinite nets of [Zr,(OH),CrO,]~+ ions held together by [Cr04J2- ions and Zr4(OH),(Cr04),(H20), contains infinite chains of the approximate composition [Zr4(OH)6(Cr04)s]~n+ also linked by [Cr0412The crystal structures of a-Na2Cr207743aand K2Cr2077436have been refined and the a-to P-phase transition in the former was discussed. A detailed study of the i.r. and Raman spectra of K,Cr,O, as single crystals(77 K), as a melt (708 K), and in saturated aqueous solutions (298-542 K) has been accomplished, and a normal-co-ordinate analysis of the dichromate ion presented in support of the proposed assignment of these experimental data.744The vibrational spectra of each of the salts M,Cr,O,(M = K, Rb, or Cs) are unique to the extent that unambiguous identification of both the compound and its crystal form is possible.745 The crystal structure of P-Cs2Cr3010has been determined and the two Cr--C--Cr interbond angles found to be 123 and 139°.746The tetrachromate ions in Rb2Cr4013consist of four CrO, tetrahedra joined by shared corners with C r - O - C r interbond angles of 120.5, 139.3, and 147.2".747 The heats of formation of K,CrO,(g) and KHCrO,(g) have been determined as - 1040 & 20 and - 910 20 kJ mol- ',respectively, by mass spectrometric studies involving chromium with potassium-seeded molecular hydrogenoxygen flame^.^ 36 Chromium(v1) oxidations of inorganic substances have been 739

740

741 742

743

744 745

746 747

R. Prins and T. Novakov, Chem. Phys. Letters, 1972, 16, 86; D. W. Clark, J.C.S. Faraday ZI, 1972,68, 1672. D. M. Adam and M. M. Hargreave, J.C.S. Dalton, 1973, 1426. P. P. Cord, P. Courtine, G. Pannetier and J. Guillermef Spectrochim. Acta, 1972 28.4, 1601 ; M. Gaultier and G. Pannetier, Rev. chim. MinPrale, 1972 9, 271. R. L. Carter and T. N. Margulis J . Solid State Chem., 1972 5, 75. K. Aurivillius Acta Chem Scand, 1972, 26, 2113. (a) N. Ch. Panagiotopoulos and I. D. Brown, Acta CrystJ973, B29,890: (b) G. Brunton, Materials Res. Bull, 1973, 8, 271. J. B. Bates L. M. Toth, A. S. Quist, and G. E. Boyd,Spectrochim Acta, 1973. 29A 1585. R. L. Carter and C. Bricker, Spectrochim Acta. 1973, 29.4, 253. R. Mattes and W. Meschede, 2.anorg. ,Chem., 1973, 395, 216. P. Lofgren, Acta Cryst., 1973, B29, 2141.

The Early Transition Metals

119

Table 9 Mixed oxide compounds containing chromium(v1) Compound K,CrO,,LiKSO,

Na,CrO,,K,Na(SO,)z

Comments and reported properties electronic spectrum, [Cr0,12- in a site of C , symmetry electronic spectrum, [CrO,lz- in a site of C,, symmetry

Cs,CrO,,Na,SO, Na,CrO,,MoO, MzCr0,,2Mo0, (M = K or Cs)

Re$ a

b

prepared by M2Cr04 + M o o 3 at 330-365°C; i.r., X

e

In(OH)Cr04,61n(OH), CsLa(CrO,), CsLn(CrO,),,H,O (Ln = Pr-Gd) SmCrO,

prepared in InC1,-K,CrO,-H,O

system, i.r., X

f

R

9

e, i.r., t.d.

h

(a) S. Felps S. I. Foster, and S. P. McGlynq Inorg. Chem, 1973,12, 1389. (b) G. G. Diogenov and L. D. Lyzhina, Ref: Zhur. khim., 1971, Abs 24B1020 (Chem. Abs., 1972, 77, 1444132). (c) M. V. Mokhosoev, E. I. Get’man, V. L.Butukhanov, V. G. Pitsyuga, and 1. F. Kokof Zhur. neorg. Khim., 1973, 18, 1011. (dj M. Audibert, S. Peytain, L. Cot, and C. Avinenq Compt. rend., 1972, 275, C, 825. (e) k M. Slobodchikov and I. N. Lepeshkov, Zhur. neorg. Khim, 1972, 17, 1785. (fl B. N. IvanovEmin, N. I. Ushakova, V. I. Kuznetsov, and B. E Zaitsev, Zhur. neorg. Khim, 1972, 17, 2294. (8) Yu M. Golovin, V. V. Kravchenko, K. I. Petrov, and T. I. Kuzina, Zhur. neorg. Khim, 197217, 3219. (h) Ya S. Rubinchik, S. A. Prokudina, and M. M. Pavlyachenko, Vestsi Akad. Navuk. Belarusk. S.S.R., Ser. khim. Navuk, 1972, 17 (Chem Abs., 1972 77, 83 032a).

reviewed,748and the product of three-electron reduction of [CrO4J2- in molten LiCl-KCl eutectic has been shown to be [CrO,]’ -.749 Spectrophotometric studies of the equilibrium between tetraperoxychromate(v) and diperoxychromate(v1)in basic aqueous H,02, support the formulation of the latter species as [HCr0,]-.750 A new and convenient preparation of Cr0,(NO,), has been developed by treating solid NaNO, with an excess of Cr02F,, the yields being 90% or greater.751The reaction of CrO,Cl, with the totally hydroxylated surface of silica gel leads to formation of O,Cr(OSi), groups, the Cr--O--Si linkages of which are readily cleaved by HCl.752Other mixed oxide compounds containing chromium(v1) studied this year are listed in Table 9. 14* 749 750

751 752

J. K. Beattie and G. P. Haight, jun, Progr. Inorg. Chem.. 1972, 17, 93. H. A. Laitinen and L. R. Lieto, Croat. Chem. Acta, 1972,44,275. B. L. Bartlett and D. Quane, Inorg. Chem, 1973, 12, 1925. S. D. Brown and G. L. G a r d Inorg. Chem, 1973, 12, 483. A. N. Volkova, A A. Malygin, V. M. Smirnov, S. I. Kol’tsov, and V. B. Aleskovskii Zhur. obshchei Khim..1972 42, 1431.

120

Inorganic Chemistry of the Transition Elements

N-Donor Ligands. Studies of the redox reaction in aqueous solution between Crw and NCS- have provided evidence for the formation of [CrO,(NCS)]- as a complex intermediate with a formation constant of ca. 40 l2 mol-2.753Several 5 4 and the ethylenediamine adducts of CrO,Cl, have been ~haracterized,~ (NH4),Cr,07,nC,H,,N4 ( n = 2 or 4) adducts crystallized from the ammonium dichromate-cyclohexanediamine-water system. 5 5 CrO ,,4,4‘-bipyridyl has been obtained by mixing ethereal solutions of CrO, and 4,4’-bipyridyl, and transformed into (CrO5),,4,4’-bipyridy1by treatment with concentrated ethereal extracts of c r o 5 . 7 5 6 6 Molybdenum and Tungsten

Introduction.-- The spectrum of Mo7+ has been reanalysed and the ionization potential of this ion estimated as 144.0 1.0 eV.lS7 The organometallic chemistry of molybdenum has been reviewed7 and papers published in 1971 dealing with this area of chemistry for molybdenum and tungsten have been surveyed.5 4 6 Reviews discussing aspects of catalysis by tungsten compounds758and the geochemical cycle of molybdenum in the environment75 9 have been published. Coupled proton-electron transfer mechanisms have been proposed for the action of molybdenum in several enzymes to explain many experimental observation^.^^' Partly because of this biochemical interest there has been a significant increase in the numbers of papers published this year concerning the chemistry of molybdenum and tungsten, and several interesting new developments have been reported. The reduction of co-ordinated dinitrogen has been achieved by treating bis-dinitrogen complexes such as trans-[M(N,),(Ph,PCH,CH,PPh,),] (M = Mo or W) with HX (X = C1 or Br) to produce the corresponding diAlthough the form of imino-complex [MX,(N,H,)(Ph,PCH,CH,PPh,),]. the ligating N2H, remains to be established and further reduction to NH, has not yet been accomplished, these reductions are an important contribution to Significant ~’ quantities of the understanding of the action of the n i t r ~ g e n a s e s . ~ NH, have been produced by reducing ~~~~~-[MO(N,),(P~,PCH~CH,PP~ with [FeS(SCHPhCHPhS)]44- or Na+(naphthalene)-. However, it is considered that the former reaction initially involves the loss of N, from the molybdenum complex.762

7s3 754 7ss

7s6

7s8 75y

760 761

762

K. A. M. Muirhead, Diss. Abs. (B),1972,32, 5675. M. N. Majumder and R T. Mukhopadhyay, Indian J . Chem., 1973, 11, 183. L. N. Sal’mkova, R t j ; Zhur. Khim.. 1971, Abs. 7B938 (Chem Abs., 1973, 78, 8445e). V. N. Kumok Ref: Zhur. khim., 1972, Abs. 5V101 (Chem. Abs., 1972, 77, 172 093p). M. L. H, Green, Pure A p p l . Chem.. 1972, 30, 373. C . Mazzocchia. G . Terzaghi. and L Zanderighi, Chiniica e lndustria 1972, 54. 631 G . K. Billings and J. L. Sonderegger, Amer. Chem SOC.Dii: Water. Air W ahte Client. Grn Paper. 1971.11, 166 (Cheni A h . , 1973,78, 149850~). . E I . Stiefel, Proc. N a t . Acad. Sci. U . S . A . ,1973. 70, 988. J. Chatt, G. A. Heath, and R. L. Richards, J . C . S .Chem Comni.. 1972. 1010 E. E. Van Tamelen, J A. Gladysz. and J S. Miller. J . Ameu. Chenz. Soc.. 1973.95. 1347

The Early Transition Metals

121 Me

Me

/

Ai

'Me

Me (62)

A new type of electron-deficient metal cluster system, e.g. (61) and (62), has been identified by X-ray crystallography following the preparation of these compounds from [(x-Cp),MoH,] and an excess of Al,Me, in toluene. Their ease of formation suggests that a considerable range of electron-deficient transition-metal compounds of this type should be i ~ o l a b l e . ~ ~ ~ The reaction of W(CO), with LiPMe, in Et,O, followed by treatment with Et30BF,, affords the novel bis-carbene cis-[(Me,P(EtO)C},W(CO),~in low yield.55 A new class of compound containing a transition-metal-carbon triple bond, [XMC(CO),R] (M = Cr, Mo, or W; R = Me or Ph; X = C1, Br, or I), has been characterized following the reaction of the corresponding [(OC), MC(OMe)R] and BX, molecule^.^ 5 2 The molecular of the corresponding compound of composition Mo(S2CNPr2),, prepared from Mo,( O,CMe), and NH,S,CNPr,, has been shown to contain a double Mo-S bridge and a Moseparation of 270.7(2) pm is consistent with carbene bond (63); the M o ' ~ - M o ' ~ a direct interaction between these centres being maintained. 764 Conductance and spectral data obtained for the new compounds [Mo(CNR),IX, (R = Me, X = I ; R = But, X = PF, or 13) are consistent with the cations containing seven-co-ordinate r n o l y b d e n u m ( ~ i )The . ~ ~ ~first pure crystalline compound containing a biologically significant molecule as a free radical complexed to molybdenum has been characterized. MoOCl, reacts with phenothiazine (PT) (64)via electron transfer to give dark-red crystals of [ ( P T ) M o O C ~ , ] . ~NO ~ ~ inserts into the metal-carbon bonds of WMe, to afford [Me,W(ONMeNO),], the molecules of which contain eight763

764 765

766

R. A. Forder, M. L. H. Green, R. E. MacKenzie. J. S. Poland. and K Prout, J C.S. C h e n ~Conmi., . 1973,426. L. Ricard, J. Estienne, and R.Weiss, Inorg. Chem.. 1973. 12. 2182, J.C.S. C h e n ~Conlnr.. 1972. 906 M. Novotny and S. J. Lippard, J . C . S .Chem. Comm.. 1973.202. J . Selbin and J. Sherrill, J . C . S . Chem. Comm.. 1973. 120.

122

Inorganic Chemistry of the Transition Elements

co-ordinate tungsten(v1) (65) with a geometry intermediate between that of a square antiprism and a trigonal d ~ d e c a h e d r o n . ~Tris(methylviny1ketone),~ tungsten(v1)(66)has a trigonal-prismatic arrangement of the carbon and oxygen donor atoms. The n-electrons of the olefinic bonds also appear to be involved in the bonding of each enone to the metal, this latter co-ordination capping a square face of the trigonal prism.768(NP(NMe,),), reacts with MOO, in boiling H 2 0 to give [H,N,P3(NMe~,]2[Mo,0~9],and an X-ray study has confirmed the existence of discrete [ M o , O , ~ ] ~ -anions, this species being a new member of the isopolymolybdate series.769 The macroisopolyanion [Mo,,O, 12]8 -, which appears to be the largest uniform discrete ion yet proved to exist in - .770 solution, has been identified in aqueous solutions of

(65)

(66)

Carbonyl Complexes.-As indicated for chromiums only a selection of the material reported this year is presented. Wolkenstein's bond polarizability approach to Raman intensities has been applied to the terminal carbonal stretching vibrations of M(CO), (M = Cr, Mo, or W) and the general intensity formulae given. The model is valuable in providing an insight as to why the totally symmetric stretching modes of metal carbonyls and their derivatives frequently give rise to weak bands in the Raman Further studies of the reaction of molybdenum and tungsten carbonyl complexes with Lewis acids have been reported and several interesting new adducts characterized. [Mg(py)4][(n-Cp)Mo(CO)3]2 has been obtained by a metal-exchange reaction from [Hg( Mo(n-Cp)(CO),) 2] in THF, followed by recrystallization from pyridine. X-Ray crystallographic studies have shown the compound to possess the units (67), the dimensions of which suggest that an

'" S. R. Fletcher, A. Shortland, A. C. Skapski, and G. Wilkinson, J . C S . Cheni. Conini.. 1972, 922. 7h8 769

770

R. E. Moriarty, R. D. Ernst, and R. Bau, J. C. S. Chem. Comni., 1972, 1242. H. R. Allcock, E. C. Bissell, and E. T. Shawl, J. Amer. Chem. Soc.. 1972.94. '8603. K.-H. Tytko, B. Schonfield, B. Buss, and 0.Glemser, Angew, Cheni Iriternat. Edn.. 1971. 12. 330.

The Early '7).ansitionMetals

123

Mg-OC interaction perturbs the adjoining C-0 bond much less than does Al--OC ~o-ordination.'~' 1.r. spectroscopy has been used to show that [(n-Cp)Mo(CO),], forms a (1:2) complex with AIR, molecules and it is suggested that each Lewis acid co-ordinates to the oxygen atom of a bridging carbonyl group ; bridging carbonyl formation probably occurring with a shortening of the Mo-Mo bond.772 Simple Mo-420--Al(Ga) bridges appear to be formed when Mo(phen)(PPh,),(CO), is mixed with AlEt,, AlBu',, or GaMe3,773*and yhen cis-Mo(CO),(PMe,Ph),, or cis- or transMo(CO)~(P~,PCH,CH,PP~,),,is added to A1Et3.773b The redox reaction of Er-Hg and [Hg(Mo(n-Cp)(CO),),] in THF has been used to prepare

C

Er[(n-Cp)Mo(CO),], and i.r. data show that the lanthanide cation is bonded Several solid adducts of the type to the anions ilia carbonyl oxygen R,Ln[(n-Cp)M(CO),] (R = C,H, or MeC,H,; Ln = Dy, Ho, Er, or Yb; M = Mo or W) have been isolated and characterized and i.r. and 'H n.m.r. evidence has been obtained for the existence of M - C - O - L n linkages.578 Some interesting studies of molybdenum and tungsten carbonyl derivatives containing mixed metal-metal bonds have been reported this year. In [Tl{Mo(n-Cp)(CO),},] the central thallium(m) has a trigonal-pyramidal environment with TI-Mo bond distances of 296.5 pm and Mo-T1--Mo 771 772

773

774

S. W. Ulmer, P. M. Skarstad,J. M. Burlitch. and R. E. Hughes. J . Anirr. Cheni Soc., 1973.95.4469 A. Alich, N . J. Nelson, D. Stoope, and D. F. Shriver, Znorg. Chem., 1972, 11. 2976. (a) D. F. Shriver and A. Alich, Coord. Chem. Rev., 1972, 8, 15; Inory. Chenr., 1972. 11. 2984. (b) M. Areste, Gazzetta, 1972, 102, 781. M T Durney, Diss. Abs. (B), 1972.33. 2983.

124

Inorganic Chemistry of the Transition Elements

interbond angles of 119.7", the thallium being 58.6(1) pm out of the plane of the three molybdenum [Me2T1(Mo(n-Cp)(CO),)1 has been prepared by treating TlMe, with [HMo(n-Cp)(CO),] in CH,Cl, at - 78 0C.776 The salts (Me4N)[M1(M2(7c-Cp)(CO),},] (M1 = Cu or Ag; M2 = Mo or W) have been isolated from aqueous diglyme solutions of Na[M2( n-Cp)(CO),] and copper(1) chloride or silver(1) nitrate (2 : 1) by the addition of Me,NCl. Their i.r. spectra suggest that the silver(1) salts are the first examples of a linear M2-Ag'-M2 ~ y s t e m7 .7~ The tetrameric zinc alkoxide, [MeOZnMo( n-Cp) (CO),],, has been prepzred by treating [Zn( Mo(n-Cp)(CO),),] with EtOH and a structure similar to that of [MeOZnMe], proposed for this omp pound.^ The new complex (Et4N),[W(C0)8H,] has been prepared by treating Et,NBH, with W(CO), in THF under reflux for 2-4 days. An X-ray crystallo2-

L (68)

graphic analysis has shown that the anions have precise C Z hsymmetry (68), the position of the hydrogen atoms being located to a reasonable degree of accuracy. 7 9 Several new complexes between molybdenum carbonyl moieties and pyrazolylborate derivatives have been reported and some existing ones further characterized. The structural and dynamic properties of [( H,B(3,5dimethylpyrazolyl)}Mo(CO),(h3-C,H,)] have been studied by X-ray crystallography, i.r., and 'H n.m.r. spectroscopy, The co-ordination about the metal consists of a trihapto-C,H, ring, a severely bent boat form of the chelate ring, and a two-electron three-centre B-H--Mo bond. The dynamic properties of the compound follow from simple rearrangements of this static ge~metry.'~' 1.r. bandshapes and intensities of the carbonyl stretching vibrations in transition-metal carbonyls of the type cis-W(CO),L, (L = N-, 0-,P-, or Asdonor atom ligand) have been calculated and shown to be in good agreement with those measured experimentally. These results suggest that appreciable metal-ligand (d-p)7c and/or (d-d)n interactions occur when these complexes involve phosphorus and arsenic donor ligands.,* The relative emission lifeJ Rajaram and J A lbers, Inory Cherri, 1973,12. 1313 B Walther and C Rockstroh, J OrganonietalEic Clienz , 1972,44, C4 7 7 7 P Hackett and A R Manning, J C S Cliem C o m m , 1973 71 7 7 8 J M Burlitch and S E Hayes, J Organonletallic Chenr , 1972,42 C13 7 7 9 M R Churchill, S W -Y N Chang, M L Berch, and A Davison J C S Clienr Conrnr 1073 691 '*' F A Cotton, J L Calderon, M Jeremic. and A Shaver, J C S Chenr Comni, 1972 777 F A Cotton M Jeremic, and A Shaver, lnorq Chim A c t u , 1972.6. 543 J L Calderon F A Cotton and S Shaver J Organometallic Chenr , 1972.42, 419 '*' C L Hyde and D J Darensbourg lnorq Chewr. 1973 12. 1075 7^5

776

The Early TransitionMetals

125

times of W(CO),L (L = 0- or N-donor atom ligand) complexes have been used to establish relative time-scales for decay processes in this series. The relatively short lifetimes for the spin-forbidden emissions are similar to those for other systems and demonstrate the importance of spin-orbit coupling in these tungsten carbonyl complexes. The quantum yields for photosubstitution New synthetic approaches correlate with the extent of 3 E --+ ‘ A , ernis~ions.’~~ 5 6 0 . 5 6 1 a to the formation of monosubstituted M(CO),L (M = Cr, Mo, or W) complexes are described on p. 89. The systematic preparation of carbonyl fluorides of molybdenum and tungsten, using XeF, as an oxidant, has been investigated and Scheme 2 Mo(CO),CI, brown solid

HF

Mo(CO),F, yellow-orange solution

-

-HF

Mo(CO),F, --HF green solution

black solid

Mo(CO),F,

7 golden-brown solid

-HF

disproportionation Mo(CO),F, y on standing in the -yellow solution HF presence of HF

Mo(CO),F, yellow solid

I

Scheme 2

defined for molybdenum. For tungsten the only carbonyl fluoride obtained was W(CO),F,, consistent with the greater stability of WF, as compared with M o F , . ~ *The ~ compounds L,M(CO), (M = Mo or W; L = bipy or phen) undergo oxidative elimination with ICN in chlorinated solvents to give the corresponding L,M(CO),(T)(CN) derivatives. These new complexes appear to be seven-co-ordinate molecular species wholly analogous to others prepared in this manner ;the tungsten derivatives apparently exist in two configurational isomers.784 X-Ray crystallographic studies have shown that in the compound [{N,P,(NMe,),)W(CO),~, the phosphonitrile acts as a bidentate o-donor ligand by co-ordinating through one ring nitrogen atom and one exocyclic 782

783

M Wnghton, G S Hammond. and H B Gray, lnorg C h e n i , 1972. 11, 3122 iMol Plzoto~heni 1973.5, 179 T A O’Donnell and K A Phillips, lnorg C h e m , 1973. 12. 1437 M N Memering and G Dobson. J lnorg Nuclear Cheni 1973 35, 665

”‘

126

Inorganic Chemistry of the Transition Elements

NMe, group.78s The sign of the 1J(31P'83W) coupling constant has been shown to be positive in octahedral complexes of tungsten(O), suggesting that the Fermi contact interaction is the dominant one. and that the use of the mean excitation energy approximation is valid.78 6 Convenient large-scale syntheses of fuc-[M(CO),(PH,), (M = Cr, Mo, or W) have been [W(CO),P(CF,),], is formed in low yield by heating W(CO), and (CF3),P2 (1 : 1) in a sealed tube (175°C 64 h).787The reactions of APh, (A = P or As) with [(n-arene)M(CO),] ( M = Cr, Mo, or W) to yield the corresponding [M(CO),(APh,),] complexes have been re-examined, and anomalies in earlier reports resolved by the isolation of two solid-state forms of each complex and a study of their decomposition products.562 As described on p. 91, the crystallographic data obtained for compounds of the type [{ MezXCHRCFz XMe,}M(CO), (X = P or As) have been remeasured and those for two previously reported structures re-interpreted, and the results shown to be consistent with disordered arrangements of molecules with normal molecular dimension~.~~~ The kinetics and mechanisms of the reactions between LiMe and W(CO),L derivatives have been studied and the results interpreted in terms of an equilibrium concentration of trans-L( MeLi(0C)) W(CO), adducts. In the case of the hexacarbonyls M(CO), (M = Cr, Mo, or W) the analogous intermediates (L = CO) were obtained and, since the rates vary as W > Mo Cr, these reactions may involve direct attack by LiMe at the carbonyl carbon atom.572 (OC),WCPh, has been prepared and found to be surprisingly thermally stable.788Other interesting new carbene complexes reported this year include the pyran-2-ylidine molybdenum pentacarbonyl complex (48),57 and the dicyanomethylenecarbene complexes [( n-Cp)M(Cl)L, { C=C(CN), )I (M = Mo or W, L = phosphine, arsine, or phosphite). These latter compounds may be formed7 by treating the corresponding l-chloro-2,2-dicyanovinyl derivative^,^" [(z-Cp)Mo(CO),{ C(Cl)=C(CN),}], with L. The crystal structure of the trimethylphosphite derivative (69) has been determined and the molecular dimensions suggest that the dicyanomethylenecarbene group is a stronger n-acceptor than C 0 . 7 9 1 The biscarbene complexes cis-[(Me,P (EtO)C],M(CO),] (M = Cr or W) have been isolated in a low yield following thereaction between M(CO), and LiPMe2.s51(OC),MC(OMe)R(M = Cr, Mo, or W; R = Me or Ph) react with BX, (X = C1, Br, or I) in alkanes to afford the yellow-to-colourless, diamagnetic, unstable compounds XM(CO),CR, which have been extensively characterized by spectral studies. X-Ray crystallography has confirmed the occurrence of a transition-metal-carbon triple bond in the

-

7H5 786 787 788

789

791

H. P. Calhoun, N. L. Paddock, J. Trotter, and J. N. Wingfield, J C.S. C'ltent. C ' O J ~ ~1972. I ~ I , 875. W. McFarlane and D. S. Rycroft, J . C . S .Chem. Comm., 1973, 336. R. C. Dobbie, Inorg. Nuclear Chem. Letters, 1973,9. 191. C. P. Casey, and T. J. Burkhardt, J . Amer. Chem. SOC.,1973,95, 5833. R. B. King and M. S. Saran, J.C.S. Chem. Comm., 1972, 1053; R. B. King, Con Reports Announce. ( U . S . A . ) 1972, , 72. 47. R . B. King and M. S. Saran, J. Amer. Chem. Soc., 1973,95, 181 1. 1817 R M.Kirchner. J A Tbers. M. S . Saran, and R. B. King, J Amer. Chem. Sor.. 1973.95. 5775.

The Early Transition Metals

127

Q ..... .__.. (MeO)3P/f;LO\\CI (NC),C--C

P(OMe), (69)

IW(CO),CPh derivative (70), the W-CO bonds of which [214(10)pm] are slightly longer than in W(CO), [205.8(3) pm].552 Carbene intermediates have been implicated in the reactions of molybdocene and tungstocene with H,, N,, CO, aromatics olefins or acetylene^.^" [(OC), W ( C ( 0 E t ) C d P h ) l reacts with diazomethane in ether and the product has been suggested to be either (71) or (72) from i.r., 'H and I3C n.m.r. spectral studies.793 W(CO), reacts with Si216 in pentane under U.V. irradiation to afford [(OC),WSiI,],, the two centres being linked by iodo bridges between the Si" atoms.794GeI, reacts with [Hg(M(n-Cp)(CO),),l (M = Mo or W) in refluxing 0 C 1-W-

oc/

I /co

CPh

I188(10) pm

c

0

benzene to give the corresponding [(z-Cp)M(CO),GeI21 complex in reasonable yield.", Sn{CH(SiMe,),}, behaves chemically as a singlet stannylene and reacts with Mo(CO), photochemically to form ((Me,Si),CH},SnMo(CO),.s6g 1,2-Dicarba-c2oso-dodecaboraneundergoes a two-electron reduction with Na in T H F to form [B10CZH12]2-which serves as a ligand in complexes such as [(n-B,,C2H,,)M(C0),]2- (M = Mo or W).796The semibullvalene complex OEt

/

I1,C=C

/OEt

Ph

\

/

7=c\

HC,

,NH

h

''' (u) J. L. Thomas, J . Anrer. Chem. SOC.,1973,95, 793 '94 '95

796

1838; (b) C. Giannotti and M. L.H. Green, J.C.S. Chem. Comm., 1972,1114. F. R.Kreissl, E. 0. Fischer, and C. G. Kreiter, J . Organometallic Chem., 1973, 57, C9. G. Schmid and R. Bose, Chem. Ekr., 1972,105, 3306. A. N. Nesmeyanov, L. G. Makarova, and V. N. Vinogradova, l m e s t . Akad. N a u k S.S.S.R., Ser. khim., 1972, 1449. D F. Dustin, G. B. Dunks. and M. F. Hawthorne. J A n w r Chc,nr Soc.. 1073. 95. 1100

128

Inorganic Chemistry of the Transition Elements

(73) has been synthesized and the barrier height for the degenerate rearrangement determined as 50 f 4 kJ molThe cyclopentadienyl complexes 78 of chromium, molybdenum, and tungsten have been re~iewed.~

Trifluorophosphino-complexes.--An improved synthesis of M(PF,), (M = Cr, Mo, or W) has been described involving photochemically induced substitution from (n-C,H,)M(CO), by PF, under moderate pressure. Complete vibrational mode assignments for these molecules have been presented. 581 Anhydrous MoC1, and WCl, react at 250°C with PF, at 200 atm, in the presence of Cu as a chloride-acceptor to afford MO(PF,), and W(PF,),, respectively.58z Dinitrogen Complexes and Nitrogen Fixation.-Nitrogenase from Azotobacter vinelandii has been purified and the molybdoferrodoxin protein crystallized as needles.798A molybdenum-containing peptide of mol. wt. ca. 1000 has been isolated from this system and shown to contain at least ten naturally occurring amino-acids, with leucine and isoleucine being most prominent ; molybdenum is present as both Mo'" and Mov.799Tungsten has been incorporated into A. vinelandii nitrogenase and shown to become associated with the molybdoferrodoxin fraction of the enzyme. However, this tungsten-containing protein is inactive in the H, evolution, acetylene reduction, and other activities, and it is considered that the slightly larger size of tungsten as compared with molybdenum may produce conformational changes in the associated proteins which interfere with the nitrogenase The different redox characteristics of these metals will also lead to important differences in their behaviour in such systems. A nitrogenase model reaction has been accomplished in which significant amounts of NH, (0.013-0.044 mol NH,/Mo) are produced when trans[Mo(N,),(Ph,PCH,CH,PPh,),] is added to [FeS(SCHPhCHPhS)], reduced to the 4- or lower level. The molybdenum complex is also reducible by an excess of Na'(naphtha1ene)- to afford NH, (0.100--0.300 mol NH,/Mo). No N2H4 was observed in either reduction. The iron-dithiolen system alone is capable of fixing N,; at the 4- level under an N, atmosphere NH, up to 0.137 mol NH,/Fe, is produced. Addition of an excess of N a + (naphthalene)to this mixture increases the quantity of NH, produced to ca. 0.265mol NH,/Fe,. It is considered that the nitrogenase model reaction involves the loss of co-ordinated dinitrogen as the first step, followed by its reduction by 797 79R

799

80"

R. M. Moriarty, C.-L Yeh, E. L. Yeh, and K . C . Ramey. J Anier Cheni. Soc.. 1?72. 94. 9229 R C Burns and R W. F. Hardy, Methods Enzyniol., 1972,24.480. (Clzenr. Abs.. 1073.78,13058k), R C. Burns, U S . P.. 3668074 (Cheni. Abs., 1972, 77, 1 1 2 5 0 9 ~ ) V L. Ganelin. N. P L'vov, N. S. Sergeev. G. L. Shaposhnikov, and V L Kretovich. Dokludy Akad. Nuuk S . S . S . R . ,1972, 206, 1236. J . R. Benemann, G. M. Smith, P. J. Kostel, and C. E. McKenna. F E B S Letters, 1973, 29, 219 (Chern. Abs.. 1973.78, 155 180t).

The Early TransitionMetals

129

the iron-dithiolen system.762However, one of the co-ordinated dinitrogen molecules of the complexes trans-[M(N,),(Ph,PCH~CHzPPh2),] (M = Mo or W) is reduced by hydrogen halides HX (X = C1 or Br), the other N, molecule being lost, to afford the corresponding [MX,(N,H&Ph,PCH,CH,PPhz)2] complex which, when M = W and X = C1, gives the salts [WCl(N,H,) (Ph,PCH,CH,PPh,),]Y (Y = ClO, or BPh,) with LiClO, or NaBPh,. The form of the co-ordinated di-imine remains to be determined ;however, spectroscopic data favour the structure (74).761 Several new dinitrogen complexes of the type cis- and trans-[Mo(N,),L,] (M = Mo or W, L = tertiary phosphine) have been isolatedso1" and the reaction of [Mo(N,),(Ph,PCH,CH2PPh,),l with [FeH,(PEtPh,)3] in 1:1 or 1 : 2 proportions shown to form [MoH,(Ph,PCH,CH,PPh,),] and M+N' +N

I

H (74)

[FeH,(N,), (PEtPh2)3].801bThe addition of solid [Mo(N,),(Ph,PCH,CH, PPh,),J to a MeOH solution of I, (2 :7) under N, affords [Mo(Nd2 (diphos),J I,-, which appears to be the first example of a molybdenum(1) dinitrogen complex. The v(N=N) stretching frequency (2043 cm-') is shifted from that of the parent compound (1976m-') in the expected sense.8o2The hydridoligands of the complexes [(x-arene)Mo(PR,),H,] (arene = benzene, toluene, or mesitylene) are displaced by N, to give the corresponding [(n-arene)Mo (PR,),N, or [{(~~-benzene)Mo(PPh,)~}~N,] derivatives. The latter exhibits an intense Raman effect at 1910cm-' but no i.r. band corresponding to a v(N=N) stretching mode consistent with the proposed centrosymmetric molecular structure (75). Treatment of [(7c-toluene)Mo(PPh,),N2] with [(x-Cp)Fe(Me,PCH,CH,PMez)]BF, in acetone under Ar affords a brown solid for which the structure (76) has been suggested.803 The interaction between [M(N,),L,] (M = Mo or W; L = tertiary phosphine) complexes of molybdenum and tungsten and AIR, molecules has been established by i.r. spectroscopy and in some cases 7 7 3 b * crystalline 1: 1 adducts have been isolated. The reactions of molybdocene and tungstocene with N, have been further investigated and the conclusion reached that, whilst molybdocene is a reactive species which co-ordinates N,, it does not provide an easy route to the reduction of this Hydrazine reacts with p-dioxobis[triaquochloromolybenum(m)] to give a complex of MoIVcontaining bridging hydrazine and imido-groups formed by

802

803

(a) M. Aresta and A. Sacco, Gazzetta, 1972,102,755; (b)B. Bell, J. Chatt, and G. J. Leigh, J.C.S. Dalton, 1972. 2492 T A George and C D Seibold, J Anier Cherrr Soc 1972.94, 6859 M 1, H Green and W E Silverthorn. J C S Dalton. 1973. 301

Inorganic Chemistry of the Transition Elements

130

p

R3P RJPJ

Mo-N

fN-

MO

\'PR3 PR3

(75)

reduction of the hydrazine. This reaction may be similar to the latter stages of nitrogen fixation. Cs,[p-dioxobis(aquodich1oro-oxomolybdenum(v))] reacts with hydrazine with ligand substitution, but no redox changes occur.8o5 Reduction of methanolic or ethanolic solutions of MoC1, in the presence of hydrogenation catalysts such as PtO, or (Ph,P),RhCl at atmospheric pressure, followed by the application of N, at > 100 atm, and MgCl, in alkali, leads to the formation of detectable quantities of N2H4.96 An MoV glutathione complex has been shown to catalyse the reduction of acetylene to ethylene in the presence of borohydride at rates up to 4 % of the activity of nitrogenase containing an equivalent amount of molybdenum. The activity of this complex is enhanced 100-fold by ATP but ADP has no effect.806Further studies on nitrogenase model systems consisting of molydo-cysteine complexes, NaBH,, and ATP have been reported including the reduction of nitriles and CN-, N3-, and N,O, as well as of N,. These reactions mimic those of the enzyme to a considerable extent and it is therefore concluded that substrate binding and reduction by nitrogenase must occur at the molybdenum site of the molybdoferrodoxin. Iron, which cannot replace molybdenum in these model systems where it exerts a modest co-catalytic effect, is considered to assist in electron transport to the molybdenum site.807 However, little is presently known concerning the nature of the active molybdenum complexes in these model systems. A study of the specificenhancement of catalytic activity of Na,[Mo,O,-

'OS 806

'07

J. Chatt, R. H. Crabtree, and R. L. Richards. J . C S. Cheni Conrnr.. 1972. 534. J. Chatt. R. H. Crabtree, E. A. Jeffery, and R. L. Richards, J.C.S Dalton. 1973. 1167. P. C. H. Mitchell and R. D. Scarle, Nature. 1972. 240, 417. D . Werner. S . A. Russell, and H. J. Evans, Proc. N u t . Acad. Sci. U . S . A . . 1973. 70. 339. G . N. Schrauzer, P A. Doemeny. R. H. Frazier, jun.. and G. W. Kiefer. J . Anrev. Ckenr. Soc.. 1972.94.7378. G . N. Schrauzer. G . W. Kiefer. P. A Doemeny, and H Kisch, ibid. 1973.95.5582,

The Early TransitionMetals

131

(cysteine),],SH,O for acetylene reduction in the presence of various charge carriers has suggested that the species which is most effective in promoting this reduction contains Mo1v.808 Nitrosyl Complexes.-Crystals of tris(NN-di-n-buty1dithiocarbamato)molybdenum(I1) nitrosyl contain monomeric molecules each composed of three bidentate dithiocarbamato-groups and one nitrosyl group. The donor atoms are arranged in a distorted pentagonal-bipyramidal configuration with the nitrogen atom of the nitrosyl group occupying an axial position; Mo--N = 173.1(8), N 4 = 115.4(9) pm, and L MNO = 173.2(7)0.809 [H W,(CO),NO], one of the few known nitrosyl hydrido-complexes, has been prepared by treating [HW,(CO),,]- with NaNO, in acetic acid and shown by X-ray crystallography to have a distorted D,, conformation with a bent W-H-W arrangement (ca, 159"). The equatorial carbonyl groups of the two pseudo-octahedral centres are in a staggered conformation and the nitrosyl group is probably in an axial position (77).810 All of the complexes

[M(CO),(NO)X] (M = Mo or W : X = C1, Br, or I), with the exception of [Mo(CO),(NO)Cl], have been prepared by the action of NO+ upon [M(CO),X]- salts and the complexes characterized by i.r. and 'H n.m.r. spectroscopy.*' la These tungsten derivatives have been converted into the mer-[W(CO),(NO)LX] (L = PPh, or AsPh,) derivatives by refluxing in CHCl, with L; in the presence ofexcess L cis-[W(CO),(NO)L,X] is formed.8'1b Similarly, these [W(CO),(NO) X] complexes react with bis(diphenylarsin0)methane (dam) to afford mer-[W(CO),(NO)(dam)X] and cis-[W(CO),(NO)(dam),X], in which the ligand is unidentate, and the novel complex [( W(CO),NOX},(dam)] which is believed to contain both dam and halide bridges. However, bis(dipheny1phosphino)methane (dpm) forms cis-[W(CO),(NO)(dpm)X] and [W(CO)NO(dpm),X], the latter containing both uni- and bi-dentate dpm groups.811c The stoicheiometric reaction between [(IT-Cp)Mo(NO)(CO),] and X, (X, = Cl,, Br,, or BrCl) affords [(n-Cp)Mo(NO)X,], which (for X = C1 or Br) react with Lewis bases L (e.g. PPh,, AsPh,, PMe,Ph, py, bipy, or X-)to no9

'11

M. Ichikawa and S . Meshitsuka, J . Anier. Chem. SOC..1973, 95. 3411. T. F. Brennan and I. Bernal, Inorg. Chim. Acta. 1973,7, 283. M. Andrews, D. L. Tipton, S . W. Kirtley, and R. Bau, J.C.S. Cheni. Conini.. 1973. 181. (a) C. G . Barraclough, J. A. Bowden, R. Colton, and C. J. Commons. Austral. J . Cheni., 1973, 26. 241; (b) R. Colton and C. J. Commons, ibid., p. 1487, (c) R. Colton and C. J. Commons, ibid., p. 1493.

132

Inorganic Chemistry of the Transition Elements

afford [(x-Cp)Mo(NO)X,L], [(x-Cp)Mo(NO)Br(PMe,Ph),]Br, [(x-Cp)Mo(NO)Cl(bipy)]Cl, or [(x-Cp)Mo(NO)X,] : l 2 The spectral properties of these compounds have been compared with those of the corresponding iodides. The reactions of [(x-Cp)Mo(NO)X,], (X = C1 or Br) with S-donor atom ligands have been studied and the results are summarized in Scheme 3.

\

RSH in cold EtOH or acetone

*-I R

=

Me. Et, Pr, Bu', Bu, or Bz Scheme 3

[Mo(MeCN),(CO),] reacts with NOPF, in MeCN to yield cis-[Mo(NO),(MeCN),] (PF6),, whereas the corresponding sequence for tungsten produces cis-[W(No),(Co)(MeCN)),Io,. These complexes react with Hacac in the presence of Na,CO, to form cis-[M(NO),(acac),] (M = Mo or W).813The oxidative addition of NOCl at - 25°C to arylazo-complexes such as [LM(CO),(N,Ph)] [L = n-Cp, M = Mo; L = HB(pz),, M = Mo or W] yields the new, remarkably stable, arylazonitrosyl derivatives [LM(NO)(N,Ph)C1].8 The reactions of N O with chlorides of molybdenum and tungsten have been investigated in some detail with, in some instances, a tertiary phosphine being incorporated in the reaction mixture. MoCl, and MoOC1, both react with NO to afford the polymeric Mo(NO),Cl,, which has been prepared previously by the reaction of Mo(CO), with NOCl. This compound reacts with Lewis bases (L = py. PPh,, or Ph,PMe) to afford the corresponding [Mo(NO),Cl,L,] complexes, of which only L = Ph,PMe is new. If MoCl, and NO are allowed to react and Ph3P is added to the resultant mixture before separation of any products, the major compound produced is [MO(NO)~C~,(OPP~,),I).~~~ Similar derivatives have also been described for tungsten WCl, in benzene under reflux reacts with N O over 2 h to give W(NO)C1,,C6H,. Longer reaction times ( > 3 h) produce W(NO),CI, and in the presence of air WO(NO),Cl, is obtained. MoCl, in CCl, reacts with NO to give Mo(NO),Cl, which affords

"' J '13

*14

*15

A McCleverty and D Seddon, J C S Dulton. 1972, 2526 2588 M Green and S H Taylor. J C S Dalton, 1972, 2620 M. Deane and F. J. Lalor, J . Organometallic Chem., 1973,57, C61. (a) W. B. Hughes and E. A. Zuech, Inorg. Chem., 1973, 12, 471; ( b ) L. Bencze, J . Organometallic Chenr . 1Q71 56. 103

The Early TransitionMetals

133

Mo(NO)Cl,(MeCN), when dissolved in MeCN.816The complexes { Mo(NO),C12L1),,THF [L1 = p-C,H,(NH,),, n = 1, 2, or 31 and [Mo(NO),Cl,L~] [L2 = rn- or p-C&,(OMe), or p-C,H,(SMe),] have been prepared and characterized by i.r. and U.V. spectro~copy.~'~ The i.r. spectrum of [Mo(CN),NO],- has been recorded590 and discussed in relation to spectra of related complexes.28l b 1.r.spectroscopy has been used to show that [(n-Cp)M(CO),NO] (M = Mo or W) co-ordinate ilia their nitrosyl groups to lanthanide atoms bonded to cyclopentadienide Cyano- and Isocyano-complexes.-As mentioned above, the i.r. spectra of [Mo(CN),NO]~- and related ions have been reported.281b* 590 Several salts containing the [Mo(CN),I4- ion have been studied by spectroscopic and magnetic techniques. The results obtained suggest that this ion has the pentagonal-bipyramidal configuration in aqueous solutions of K4[Mo(CN),],2H,0 and in crystals of K,[Mo(CN),] and Cs,[Mo(CN),],xH20. However, solid K,[Mo(CN),],2H20 exhibits i.r. and Raman spectra which differ from those obtained for aqueous solutions of this salt, and a monocapped trigonal-prismatic co-ordination geometry has been suggested for the anion in this phase.818 The compounds [Mo(CNR),1X2 (R = Me, X = I : R = But, X = PF, or 13) have been synthesized from Mo(CO), or Ag,[Mo(CN),], and their conductance and spectral properties are consistent with the cations containing seven-co-ordinate molybdenum(xx). [Mo(CNBut),III, H 2 0 was also prepared in this The compounds (RNC),Mo(CN), (R = Me, Pr, But, or allyl) and (Ph,CNNC),Mo(CN),,CHC13 have been prepared from Ag,[Mo(CN),] and the corresponding alkyl halide. The results of the crystal structure determination of (MeNC),Mo(CN), obtained in this study are essentially the same as obtained previously (see Vol. 2, p. 134). 13CN.m.r. data for (Bu'NC),Mo(CN), obtained over a range of temperatures are consistent with the presence of only one geometric isomer in solution, although rapid interconversion of isomers cannot be excluded.819Complexes of this type have unexpectedly simple i.r. and Raman spectra in the C-N stretching region which may be a consequence of accidental degeneracies. The values of the C--NR stretching frequencies (2200-2250 cm- j suggest that these ligands function primarily as o-donors in these complexes.820 The electronic structures of the [MO(CN)~]"-( n = 3 or 4) ions have been calculated using a SCCC-MO method and the d-orbital splittings shown to be nearly identical with those calculated by crystal-field theory. Bonding considerations suggest that the stable forms of [Mo(CN),]~- and [Mo(CN),13'l''

'17

*'* *19 820

Yu A Buslaev N A Ovchinnikova, M M Ershova, and M A Glushkova I z i r \ t Ahad Nuuk S S S R Ser khini 1972, 950 E V Chechegoeva, M L Khidekel, I V Kalechits N M Klimova and E A Utkina / z z r \ t Akad Nauk S S S R Ser khim, 1973,666 G R Rossman, F -D Tsay and H B Gray, Inory Cheni 1973 12 824 M Novotny, D F Lewis, and S J Lippard J Artier Chrni Soc 1972,94,6961 R V Parish and P G Simms, J C S Dalton 1972 2389

.

134

Inorganic Chemistry of the Transition Elements

are the trigonal-dodecahedra1and square-antiprismatic ones, respectively.8 However, a square-antiprismatic geometry has been identified by X-ray crystallography for these anions in H4[M(CN),],4HCl,12H,0 (M = Mo or W).822 13C N.m.r. data suggest that the [Mo(CN),14- ions are non-rigid down to temperature of - 160°C. Anomalous features in the electronic spectrum of (Pr,N),[W(CN),] suggest that the anion in this salt may not have a trigonal-dodecahedra1 geometry.1 4 3 The co-ordination of Fe"' to [Mo(CN),I4- in acidic solution has been re-examined and the formation of a 1 :1 complex confirmed. Attempts to isolate such a derivative resulted in Fe,[Mo(cN),] ,,12H2O being obtained as an amorphous, deep-blue precipitate.,,, MFe[Mo(CN),],xH,O (M = K, Rb, Cs, or NH,) have been precipitated by mixing solutions of FeCl,, MC1, and M,[Mo(CN),] (1 :4 : 1) at 0°C. The i.r. s,-!ectra of these salts are consistent with the presence of Mo
821 823

825

H28

A. Golebiewski and R. Nalewajski, Z . Naturjor.wh. 1072,27a, 1672. L. D. C. Bok, J. G . Leipoldt, and S. S . Basson, 2. unorg. Cheni, 1972,392. 303. G. F. McKnight and G . P. Haight. jun., Inorg. Chem.. 1973,12, 1934. K. M. Mikhalevich, D. I. Zubritskaya, V. M. Litvinchuk. and Yu. A. Lyubchenko, Zhur neorg. Khim., 1973, 18. 418. W. U. Malik, B. P. Singh, and J. P. Jain, J . Radioanalyt, Chem.. 1972, 12. 5 5 3 . A. Sanotus, Proceedings of the 3rd Coordination Chemistry Conference, ed. J. Gazo, Slovak Tech. Univ. Bratislava, 1971. 291 (Chem. Abs., 1973, 78, 22442h). M. A. Beg, Kabir-ud-Din, and R.A. Khan, Austral. J . Chem., 1973,26, 671. M. A Beg. Kabir-ud-Din, and R. A. Khan. J . Inorq, Nuclear Cheni.. 1973.35. 2801.

The Early TransitionMetals

135

which affords the neutral olefin complex on treatment with a base.829"The incipient formation of electron donor-acceptor complexes between [( n-Cp),MH,] (M = Mo or W) and a number of activated olefin and aromatic molecules has been detected spectrophotometrically. These complexes are believed to be intermediates prior to M--H addition to the C 4 bond.82y"[(nCp),MH,] (M = Mo or react with Me,SnNMe,. eliminating Me,NH to yield the corresponding trimethylstannyl derivatives [(n-Cp),M(H)SnMe,]. These complexes react with organic halides to afford the corresponding [(n-Cp),M(X)SnMe,] (X = C1, Br, or I) derivative and with dimethyl acetylenedicarboxylate to produce [( n-Cp), M(SnMe3) { C(C0, Me)=CH(CO, Me)}] ,449 [(n-Cp),MoH,] reacts readily with an excess of Al,Me, in toluene at 86°C with evolution of CH,. Cooling the reaction mixture after ca. 7--10 min results in large orange crystals of [MeAl{ (n-CSH4)(7c-Cp)MoH}2(AlMe,),](61) being formed. Prolonged refluxing of the reaction mixture gives [Me,Al(n-C,H,),MoAlMe], (62). These compounds are pyrophoric in air and instantly hydrolysed to reform the parent dihydride in high yield. A saturated solution of (61) in toluene reacts rapidly with CO,, apparently with insertion of CO, into the Mo-A1 bonds.' The reduction of [WCl,(PMe,Ph),] (n = 2 or 3) by Na-Hg in THF solution in the presence ofexcess PMe,Phunder H, affords WH,(PMs,Ph), in 10--25 % yield.8O [MoH,(dmtpe),l [dmtpe = 1,2-bis-(di-m-tolylphosphino)ethane~ may be obtained in a similar manner from [MoCl,(dmtpe),], or by treating [Mo(N,),(dmtpe),] with hydrogen.830 Mo(NJ,(Ph,PCH,CH,PPh,), reacts with FeH,(PEtPhJ, to afford MoH,(P~,PCH,CH,PP~,)~and FeH,(N,)(PEtPh,),.80'" Ten hydrides of the type MH,L, (M = Mo or W, L = uni- or bi-dentate tertiary phosphine or phosphite) have been prepared by the reaction of NaBH, with MCl,L, in the presence of excess L, and their 'H n.m.r. spectra recorded. Limiting fast and slow spectra were observed for eight of these hydrides, the barriers for molecular rearrangement (50-65 kJ mol- ') being relatively high. The nature of this non-rigidity has been discussed with reference to the molecular structure of MoH,(PPh,Me),, which has been shown by X-ray analysis to contain a trigonal-dodecahedra1 MoH,P, framework, with the hydrogen atoms at the vertices of the elongated tetrahedron and the phosphorus ones at those of the flattened tetrahedron. However, 'H n.m.r. spectroscopy failed to provide any stereochemical information concerning rearrangement processes within the nine-co-ordinate WH,(PMe,Ph), and WH,(PPh,Et), m ~ l e c u l e s . ~ ~ ' Binary Compounds and Related Systems.-Halides. The thermal decomposition and reduction by H, of WCl, and lower tungsten chlorides have been studied by t.g.a. and X-ray diffraction spectroscopy, and the phase WC1,.6(s) has been

w>

'

'Iq

(u) F. W. S. Benfield, B.

R. Francis, and M. L. H. Green, J . Orgmometallic Chem.. 1972, 44, C13,

(b) A. Nakmura and S. Otsuka. J Anrer Client Sric. 1973. 95. 5091 83f 831

L. J. Archer and T. A. George, J . Organometallic Chem., 1973,54,C25. P. Meakin, L. J. Guggenberger, W. G. Peet, E. L. Muertterties, and J. P. Jesson. J . Anrer. Chenr. Soc.. 1973, 95. 1467.

136

Inorganic Chemistry of the Transition Elements

~ h a r a c t e r i z e d .Gaseous ~~~ MoCl, is stable at temperatures > 60O0C, but disproportionates at 500°C to give MoCl,., and at 40O--23O0C to form M o C ~ , The . ~ ~production ~ of MoCl, is improved by reducing MoCl, with PCl, in CCl, at 60--70"C.834 Equilibria in the molybdenum-bromine system have been measured and the heats and entropies of formation of MoBrJs), MoBr,(s), and MoBr,(g) have been determined as - 176 k 29, - 209 f 42. and - 100 f 50 kJ mol-', and 138 f 33, 218 k 50, and 460 59 e.u.. respectively.835WCl, and WCI, may be prepared by the reduction of the corresponding higher-valent chlorides by W(CO), under mild conditions836 and MF, (M = Mo or W) by reduction of MF, on a hot filament of metallic Mo or Ni, re~pectively.~~, Thermodynamic functions have been calculated for MoCl,(g), assuming ideal gas behaviour and the harmonic oscillator rigid rotator a p p r o ~ i m a t i o n . ~Halogen ~' n.q.r. transitions have been observed in W2X10(X = j5CI, "Br, or 1271) molecules and discussed in terms of metalhalogen n-bonding effects.,, WF, has been studied under electron bombardment. At energies between 1 and 10eV only F-, WF;. and WF, ions are formed and the F,W-F bond energy has been assessed as 5.2 0.1 eV from these measurements. The appearance potential data for WF; and WF; afford values of 2.3 and 0.8 eV. respectively. for the electron affinities of WF, and WF,.837 Ag metal reacts with MoF, and WF, in MeCN to produce [Ag(MeCN),I [ M o F , ~and ~ [Ag(MeCN),I [WF,]. respectively. demonstrating clearly that MoF, is a stronger oxidant than WF,. as expected from the relative values of their electron The standard enthalpy of formation of wF,(g) has been re-determined by bomb calorimetry as 1720 2 1 kJ MO1-l ,8 3 9 in good agreement with previous estimates,

,

Several catalytic applications of the higher chlorides of molybdenum and tungsten have been demonstrated. Thus MoCI, and WCI, catalyse the exchange of aromatic hydrogens between molecules such as toluene and perdeutierobenzene,,,' a mixture of WCl, and BuMgI is an active homogeneous catalyst for the disproportionation of he~t-2-ene,~,'LaAlH, and NaBH, are extremely effectiveco-catalysts with WC1, in the olefin metathesis reaction,841 and metathesis of the methyl esters of certain unsaturated fatty acids using a WCl, SnMe, catalyst affords the expected alkenes and dicarboxylic acid dimethyl 832

833 834

835 836 837

838 839 8 40

841

R. Matsuzaki and Y. Saeki. Nippon Kagaku Kaishi, 1972, 8. 1230. 1226 (Cheni Ah.\., 1972. 77. 95416d, 95417e); T. Takuma and S. Kawakulo, ibid., 1973,9,700 (Chem. 4bs. 1973.78. 167941e). R. Matsuzaki and Y. Saeki. J Less-Common .'Wet&, 1972. 29, 427. Kh. U. Ikramov, A. Kushakbaev, N. A. Parpiev, and L. D. Shevchenko, U.S.S.R. P., 356249 (Cheni. Abs.. 1973, '78, 86666s). H. Oppermann, 2 anory. Cheni.. 1973.395. 249 M. A. Schaefer. Diss. Ahs. (4. 1972.32, 5678. P. W. Harland and J C J. Thynne, lnory. Nuclear Cheni. Letters. 1973. 9. 265. internut J Mass Spectrometry lon Phys., 1973, 11. 137. A Prescott. D. W A. Sharp, and J. M. Winfield. J.C S. C ~ P Conrnr., ~ J . 1P73. 667 V. Ya. Leonidov, V. S. Pervov, L. I. Klyuev, 0. M Gaisinskaya, V A, Medvedev. and N . S. Nikolaev, Doklady Akad. Nauk S . S . S . R . , 1972, 205, 349. T. Takagi, T. Hamaguchi, K. Fukuzumi, and M. Aoyama, J.C.S. Cheni. Conrnr.. 1072. 838 J. Chatt. R.J Haines, and G J. Leigh. J C.S Chrni Cornni, 1972. 120?

The Early Transition Metals

137

esters.842 A new class of soluble reagents for deoxygenating organic molecules has been obtained, by reducing WCl, with Li or LiR. which effect the direct reductive coupling of aldehydes and ketones to olefins and the stereospecific reduction of epoxides to 0 1 e f i n s . ~ ~ ~ Oxides. Reviews discussing the stoicheiometry, structures, and properties of tungsten oxides have been publi~hed.'~, 844 The production of M o o z and WO, crystals by vapour-phase chemical transport has been described845and the Raman spectrum of single crystals of MOO, determined, at temperatures between 77 and 500K,and shown to be very similar to that of monoclinic V0,.598 The reduction of and W0,846bby H, at elevated temperatures has been studied, the non-stoicheiometric phases MOO,.,,, MOO^.^^, and WO,.,, being characterized. The optimum conditions for the preparation of M o 5 0 1 4in a transport reaction by passing HCl(g) over MOO, have been defined as 600°C and 20 1 HCl per h; the lattice constants of this oxide were determined.847 The magnetic susceptibilities of M o 5 0 1 4 and M017047 would appear to exclude the presence of any unpaired electrons and thus the existence of discrete MoVcentres in these compound^.'^^ The structure of MOO, has been classed as an infinitely adaptive one21 and the structural relationship between MOO,- and Re0,-type structures has been ~ l a r i f i e d . ' ~ ~ 1.r. spectra have shown that the activation of catalysts consisting of Mo(CO), supported on SiO,, Al,O,, or MgO causes the decomposition of the carbonyl, the active species being formed by the loss of all six CO groups and indirect evidence suggests that the active species contains the metal in an oxidation state > 0.850Magnetic and e.s.r. studies of MOO,-olefin polymerization catalysts containing CrO, and supported on SiO, have shown that the active species contains MeV' and Cr" acting in concert.619 The introduction of MOO, into the V 2 0 5lattice results in the formation of V'" centres by encouraging the release of electrons into the conduction band. This is important in determining the catalytic properties of MOO,-V,O5 systems.289The system (Mo,-,VJO,~,, (0 ,< x ,< 0.40) has been studied using d.t.a. and X-ray diffraction techniques.403 Chalcogenides. Molybdenum chalcogenides have been reviewed' and structural transitions in several transition metal chalcogenides, including MoTe,, have been discussed.2931.r.and Raman spectroscopy have shown that Mo--S- ~842

843 844

845

847

"* 840 850 851

* P. B van Dam, M. C. Mittelmeijer, and C. Boelhouver. J . C . S . Cheni. Conini . 1973. 1221 K. B. Sharples, M. A. Umbreit, M. T. Nieh, and T. C. Flood, J . Anrer. Cheni SOC.16'72. 94. 6538 B. Phillips, 'High-Temperature Oxides', ed. A. M. Alper. Academic. New York. 15'71. Vol 4. p, 109. A. N. Zhukov. R. K. Nikolaev. V. T. Ushakovskii. and V. Sh Shekhtman. Ref Zhur k h i n i . lP72. Abs. 13B522 ( C h e m Ahs., 1972.77, 144723a). (a) Khr. Vasilev and T. Pencheva, Khim. Ind. (Sqfia). 1972.44, 256 (Cheni A h . 1973.78. 91895~). (h)J. Guenot. L. Marty, and M. Figlarz, Con@. rend.. 1973. 276. C. 89. F. A. Schroder. Z . Naturforsch., 1972.27b. 498. T. Ekstrom. Acta Chem. S c a n d . 1972.26. 3381 L. A . Bursill, Acta C r y s t . , 1973, A29. 28. R. F. Howe, D. E. Davidson, and D A. Whan. J.C S . Faraday I . 1972.68. 2266 A A Opalovskii and V. E. Fedorov. Khal'kogenidv. 1070. 2. 77 (Chcnr A h s . 1973 78. 131461k)

138

Inorganic Chemistry of the Transition Elements

Mo and S-S linkages are present in the compounds MoS,X, (X= C1, Br, or I).25Single crystals of MoS, grown by chemical vapour transport have been intercalated by each of the alkali metals using the liquid NH, technique. The stoicheiometries and X-ray diffraction data of all the intercalates formed in this way have been determined and a complete indexing of the X-ray patterns achieved for Ko,4MoS, and R ~ , . , M o S , . ~MoS, ~ ~ reacts with K+(naphtha1ene)- to give K,MoS, intercalates ;however, a similar reaction with the corresponding sodium and lithium salts is followed by reduction to molybdenum New M,Mo,Se, phases have been obtained in which the metal atoms (M = Ti-Fe, Zn, Ag, Cd, Sn, or Pb) are distributed in the tunnel structure of A further determination of this structure has been reported.853b. Mo3Se4.853a Other Binary and Related Systems. The reaction of N, at elevated temperatures with MoRe alloy has been shown to afford the new phase Mo1,76Reo~24N.854 The phase diagram of the Mo--Cr--C system has been calculated from the available free energy data and shown to agree well with that determined experimentally.608At 1000°C WC reacts with Fe,O, to form Fe,W,C, which possesses a cubic crystal MoSi, reacts with Ni--20Cr at 1500°C to afford MoNiSi and Mo16Cr6Si7, the former compound may also be produced directly from MoSi, with Ni at 1600"C, and the X-ray diffraction patterns of these two new phases have been determined.856MoGe, may be obtained by the reduction of MOO, with Ge at 950-1050"C.857 Several ternary borides including (Mo,M),B, (M = Cr or Mn) and (W,Mn),B, have been characterized by X-ray diffraction studies.61' The compounds MoGa, and Mo,Ga have been identified in the Mo-Ga system.858 Compounds containing M e M o or W--W Bonds.-The reduction of highervalent molybdenum and tungsten chlorides and bromides by aluminium metal in the appropriate NaAlX, (X = C1 or Br) melt has been shown to be a convenient route to the preparation of the corresponding MX, (M = Mo or W) derivative^.^ 5 9 [(M06C1,)C1,(OAC)~]has been prepared from [(Mo6Cl,)C1,] by heating with AcOH for 2 days at 118--175"C, or by refluxing in EtOH with AcOH for 8 h.860The crystal structures of Cs,[(M6C18)Br6] (M = Mo or w> have been determined by X-ray diffraction techniques and the average M-M distances in the M, core found to be 261.5(6) and 262.00 pm, respec852 853

854

855

8 56

857

858 859

8h0

R. B. Somoano, V Hadek, and A. Rembaum, J . Chmi. Phys., 1973. 58. 697 (a) M. Sergent and R. Chevrel, Compt. rend., 1972, 274, C , 1965. (b) 0. Bars. J Guillevic. and D. Grandjean, J . Solid State Chem., 1973, 6,48. E. M. Savitskii, M. A. Tylkina, and I. A. Tsyganova, and Yu. B. Kuz'ma. Imest. Akad Nauk S . S . S . R . .neorg. Materialy, 1973.9. 498. Z A. Klimak, E, E. Kotlyar, T. I. Serebryakova, and E. V. Yukhimenko. lzwsf, Akad. N a u k S . S . S . R . ,nrorg. Materidy, 1972,8, 1600. C B. Coutinho and W. L. Bradley. Amer. Ceranr. SOC.A4L 1972. 51. 689. V. A. Bondarev and V. A. Podergin. Metallotrrni. Metody. Poluch Soedin Splaiior. ed. by A. A Kornilov, 'Nauka', U.S.S.R.,1972, 20 (Chmi. Abs., 1972. 77, 10893511). J. D. Bornand. R. E. Siemens. and L. L. Oden. J . Less-Conimon Metuls, 1973.30. 205 W C Dorman, Nuclear Sci A b s , 1972.26,43613 G Holste and H Schafer, 2 anory Chem. 1972. 391. 263

The Early Transition Metals

139

tively. Unit cell dimensions were also obtained for the isomorphous series of compounds CS,[(M,C18)&1 (M = Mo or W, X = C1, Br, or An extended Hiickel MO calculation has been performed to assess the bond energies and bond orders in the [MoC1,I2- and [Mo,C~,]~-ions, the energy of the Mo-Mo interaction in the latter being estimated as 12.9eV,862The complexes Mo,Cl,(PR,), (R = Et, Pr, Bu, OMe, or R, = PhMe,) have been prepared by treating (NH,),Mo,Cl, with the corresponding ligand in oxygenfree MeOH for 1 h. Spectral and mol. wt. data strongly support the retention of the quadruple Mo=Mo interaction in these complexes and the diamagnetic anisotropy induced by these bonds has been investigated as a means of probing the multiplicity of such systems.863The vibrational spectra of salts containing v(Mo-Mo) stretching mode identified at 342 f 8 cm-' is significantly lower the [Mo,X,I4- (X = C1 or Br) ions have been reported, and the Raman-active than those observed for the corresponding carboxylato-complexes, Mo,(O,CR), (400 f 4 cm- '), indicating a difference in Mo--Mo bond strength not previously recognized from X-ray data.864The crystal structure of Cs,[Mo,Br,], which is obtained in conc. HBr solutions of Mo,(O,CMe), containing CsBr, has been determined. The [Mo,Br813- anions have a [W,Cl,] - arrangement, but with a crystallographically disordered vacancy in the bridging position. These anions contain a strong metal-metal interaction, ' " salts (LH),[Mo2X9] [L = quinoline, phen, Mo-Mo = 243.9(7) ~ r n . * ~ The 3-Mepy, 2-, 3-, or 4-NH2py, 2,6-(NH,),py, or 2-NH2,3-Mepy; X = C1 or Br] have been prepared from MOO,, HX, and the amine hydrochloride, and their electronic spectra are consistent with the presence of an Mo-Mo bond.865b The i.r. and Raman spectra of M,[W,Cl,] (M = K, Cs. or Bu,N) have been recorded and assigned on the basis of D,, symmetry. Normal co-ordinate analyses were performed which gave good agreement between the calculated and assigned spectra, the force constant of the W-W interaction being estimated suggesting that this bond order is probably only as 1.15 f 0.1 mdyn slightly greater than Li,MoMe4,2THF has been prepared by treating MoC1,,3THF with MeLi in Et,O at -30°C; Li,MoMe,,l.S dioxan can be precipitated from solutions of the THF adduct in Et,O by the addition of dioxan.866 The reaction of neopentyl-lithium (RLO with MoCl, in ether affords MozR6, the 'H n.m.r. spectrum of which suggests that the compound has a structure similar to that of its trimethylsilyl analogue. Mo,R6 reacts rapidly with CO and NO but otherwise is rather inert.165b 861

862

863

865

866

P. C. Healy, D. L. Kepert, D. Taylor, and A. H. .White, J . C S Dalton, 1973. 646 R.Kh. Zacheslavskaya and D. V. Korol'kov, Teor. i eksp. Khim., 1973. 9. 21 (Chrni Abs . 1973. 78. 164 340x). J. San Filippo. jun., Inorg. Chem., 1972, 11, 3140. A. P. Ketteringham and C. Oldham, J.C.S. Dalton, 1973, 1067. (a) F. A. Cotton, B. A. Frenz, and Z. C. Mester, Acta Cryst., 1073. B29, 1515. (h) H . Y. Nguyen, V. V. Zelentsov, N. N Subbotina, V. I. Spitsyn, and A. T. Fal'kengof. Zhur. nrorg Khim..1972. 17. 3260. B Heyn and C. Haroske, 2. Chem.. 1972. 12. 338.

140

Inorganic Chemistry of the Transition Elements

Preparative routes to dimeric molybdenum(I1) carboxylates from Mo(CO), have been re-examined860 and these compounds, e.g. Mo,(stearate),, shown to be efficient hydrogenation catalysts.867Thus far it has not been possible to prepare dimeric tungsten@) carboxylates analogous to the molybdenum series, the products of attempted preparations appear to be polymeric [W(O,CR),], or impure [W,(O,CR),O] derivatives.860 As noted above the v(Mo--Mo) stretching frequency in Mo,(O,CR), (R = Me, Et, Pr", Ph, C6H11, or CF,) derivatives occurs at 400 4 cm- ; this is lowered by ca. 2@30 cmin the case of Mo,(O,CCF,), by the co-ordination of ligands such as PPh, or MeOH.864 K,[Mo,(SO,),], the intermediate in the preparation of Mo,,'(aq) from [Mo,C~,]~-,has been isolated as single crystals by dissolving the compound in H2S04 (0.1 moll- ') and allowing this solution to mix by diffusion through a glass sinter with a solution of K 2 S 0 4in H,SO,(O.l moll-'). These crystals contain [Mo,(SO,),]~- ions which have a geometry similar to that of the Mo,(O,CR), molecules [with Mo-Mo = 211.0(3) pm], except that each anion is linked to two others by a sulphato-oxygen atom co-ordinated to each molybdenum trans to the M o E M o bond.868 Raman spectra have been recorded for this and related compounds and the use of 488 nm excitation was 0 0 \S/

/ \

0

H

I \,P

/>-I 0 0

shown to enhance the intensity of the fundamental v(Mo--Mo) stretching mode allowing the first, second, and in some cases even the third overtone to be observed. An orange microcrystalline product has been obtained by treating Mo,(O,CMe), with aqueous oxalic acid and, since the compound exhibits a Raman band at 396 cm- a structure analogous to that for the sulphato-anion, but with bridging oxalato-groups, seems possible for the anions of this derivative.868K,[Mo,(S04),],3.5H,0 has been isolated and shown to contain the anions (78), the increase in the Mo--Mo separation over being consistent with the removal of an electron from that in K,[Mo,(SOJ,]

',

86i

T D Chan. G Martino. and C Lassau, Fr Patent. 2 120574 (Ckmi A h . 1073, 78. 89095r) C L Angell, F A Cotton, B A Frenz, and T R Webb. J C S Chmi Conini. 1973. 390

141

The Early Transition Metals

the &bonding orbital. The compound is paramagnetic and has an e a r . absorption corresponding to 1 0.3 unpaired electron per Mo, [Mo,(O,CMe),] reacts with potassium ethylxanthate K(S,COEt) in MeOH to afford two products which have been characterized by i.r. and 'H n.m.r. spectroscopy. A green compound, tentatively formulated as [Mo,(S,COEt),] but of unknown structure, is formed initially but then rearranges to give the red tetrakis-(O-ethyldithiocarbamato)dimolybdenum(II). This latter compound reacts readily with donor ligands to give Mo2(S,COEt),,2L (L = THF, py, y-picoline, or Et,As) complexes, and X-ray crystallography has shown that the THF adduct conforms to the Mo2(02CCF,),,2py-type structure, with an

(80)

(81)

Mo-Mo separation of 212.5(1)pm.870n[Mo,(O,CMe),] reacts with ammonium monothiobenzoate, NH,(OSCPh), in degassed MeOH to yield a red precipitate of [Mo,(OSCPh),]. Although this compound forms adducts with donor molecules in solution, removal of the solvent gives unchanged [Mo,(OSCPh),]. The reaction between [Mo,(O,CMe),] and Na(S,CNR,) (R = Et, Pr, or Pr') gives an immediate green precipitate of [Mo(S,CNR,),], which undergoes very rapid oxidation to the purple [Mo,O,( S,CNR2),] derivative. If these reactions are carried out in dilute MeOH or EtOH, green solids are obtained, also of formula [Mo(S,CNR,),], ; however, these are MoIVcomplexes with bridging sulphido-groups and a carbene ligand.87 0 h and the structure of the propyl derivative (63) has been determined by X-ray Xh9 870

F A Cotton. B A Frenz, and T R Webb. J Anier Ckem S o ( . 1073.95. 4431 R Weiss. lnorg Chenr, 1973, 12. 2179. (b) D F Steele and T A Stephenson, lnorg Nuclear Chem Letter.\, 1973. 9, 171 (a) L Ricard. P Karagiannidis, and

142

Inorganic Chemistry of the Transition Elements

crystallography. These derivatives are formed as a result of the oxidative cleavage of two C-4 bonds per molecular unit to afford MoIV.The Mo-Mo separation of 270,5(2)pm is perhaps indicative of a double bond.764[(nCp)Mo(H)(CO),(P(OPh),}] reacts with propylene sulphide (1 :1) in THF at 20°C to give black, oxygen-sensitive crystals of (.n-Cp),Mo,S, for which the structure (79) has been proposed. In the presence of an excess of propylene sulphide, (71-Cp),Mo,S, may be obtained in either a black or a red form and structures (80) and (81), respectively, have been proposed for these isomers.871 The i.r. and electronic spectra and magnetic properties of the thiolatocomplexes M(SR), (M = Mo or W ; R = Me, Et, Bu, or Ph), obtained by oxidative decarbonylation of their metal carbonyl complexes in the presence of R,S, indicate that they probably contain polymeric chains in which metalmetal interactions occur between adjacent, face-sharing M(SR), octahedra. Several compounds of MoV which contain bridging 0x0- or sulphidogroups also involve significant and direct Mo-Mo interactions ; however, these are discussed in a later section appropriate to this oxidation state. Molybdenum(r1) and Tungsten(~~).-Trans-[WCI,(EMe,Ph),] is reduced by NaHg under Ar in the presence of excess PMe,Ph, to form trans-[ WCl,(PMe,Ph),] which has a magnetic moment of p,wc = 2.30 BM and dissociates in solution. This W" compound reacts with CO to form [WCl,(C0)2(PMe2Ph),].801b Synthetic routes to complexes of the type [(x-Cp),ML] (M = Mo or W ; L = N,, CO, olefin, or acetylene) have been described which involve the reduction of [(n-Cp),MCl,] by Na-Hg in the presence of L.792bThe olefinic derivatives may also be obtained by reduction of [(.n-Cp),MCl,] by excess EtAICl, or a Grignard reagent, followed by the addition of a The carboxylato-complexes[(7c-C6H6)(7c-C3H5)MO(02CR)][R = H, Me, Ph, H,NCH,, H,N(CHJ,S, or CH,(Fe(CO),(x-Cp)}] have been prepared and characterized, as have the related p-diketonato-complexes, [( n-C,H,)( .nC,H,)MoL] (L = acac or MeCOCHC0,Et).873

,

Molybdenum(111) and Tungsten(rII).-The phase diagram for the MoCl,-NaCl system has been presented and the regions of stability for NaMoC1, and Na3MoCl6 defined.874The chlorine-2p ionization potentials in K,MOCl, 7 5 The salts have been determined by X-ray photoelectron spectro~copy.~ (HA),[MoC1,] (A = MeNH,, b n , or PhNHd and the neutral complexes [MoCl,L,] (L = py, PhNH,, or piperidine) have been prepared and the nature of their thermal decomposition has been studied.86 The complexes [MoX,L,] (X = C1 or Br; L = py, THF, THT, DMSO, or RCN for R = Me, Et, Pr, Pri, BuyPh, or Bz) have been isolated following the reaction of [Mo(CO),X,] with the pure liquid L. These complexes are paramagnetic (p = 3.4-3.9 BM) 871 872 873 874

875

W. Beck, W. Danzer, and G. Thiel, Angew. Chem. lnternat Edn., 1973, 12. 582 D. A. Brown. W. K. Glass. and C. O'Daly, J.C.S. Dalton, 1973. 1311. M. L. H. Green, L. C. Mitchard, and W. E. Silverthorn, J.C.S. Dalton, 1973, 1403. N. K. Nguen, R. A. Sandler. E. N. Ryabov, I. V. Vasil'kova. I. I. Kozhina. and E. F. Klyuchnikova.

Zhur. neorg. Khim., 1972.17, 2553. L E. Cox and D. M. Hercules, Electron Spectroscopy Relat. Phenomena. 1973. 1, 193

The Early TransitionMetals

143

and their electronic and 'H n.m.r. spectra suggest that they exist as the merisomers. [MoX,(MeCN),] and [MoCl,(py),] have also been isolated. In contrast to these reactions, [W(CO),Cl,] reacts with py only on heating to form [WCl,(py),], which may be reduced to [WCl,(py),] at 140"C.876MoOCl has been claimed as the product of the reduction of MoOCl, by SnC1,.877 Treatment with H, has been used to vary the Fermi level in molybdenumdoped rutile and the formation of Mo"' and MoV centres detected by e.s.r. spectroscopy. The previously unreported Mom resonances were interpreted using a spin-Hamiltonian with g, = 1.94, gilo = 1.97, gll0= 1.95, and A, = 3.83 x Ail0 = 3.50 x lo-,, and Al10 = 3.56 x 10-3~m-1.878 The zero-field splitting of Mom in yttrium aluminium garnet has been determined as 8-10 cm-' by e.s.r. spectroscopy.879The 57FeMossbauer spectrum of the spinel Fe,MoO, between 90 and 578 K suggests880"that it should be formulated as Fe"Fe'"Mo"'O,, although the results of X-ray and neutron diffraction studies favour the composition FenFe11M~'V0,.8806 In contrast to earlier reports (Vol. 1, p. 84), the electronic spectrum of [Mo(H,O),] 3 + in toluene-p-sulphonic acid contains no absorption maxima at 293 and 253 nm. Exposure to air, however, results in a significant increase in absorption at the former wavelength. The value of the magnetic moment of this ion has been calculated as 3.69 BM at 25 "C, in good agreement with values of other monomeric Mo"' complexes, by measuring the 'H n.m.r. shift of the methyl protons of toluene-p-sulphonic acid. [Mo(H,O),NCS] + appears to be formed when KNCS is added to 1,O mol 1-1 solution of Mo"' in toluene-p-sulphonic acid, the formation of this ion being characterized by an increase in absorption at 320 nm.881The stability of Mo" in aqueous media has been investigated and Eo(Mo5+/Mo3+)estimated as -0.089 V.882 Ion exchange studies have shown that the green Mo"' species produced in solutions < 2.2M-HC1 is cationic, whereas the red Mom species produced at >4.5M-HCl is Several tris-(0-diketonato)molybdenum(m) complexes, ML, (L = acac, tfac, hfac, dbm, or btfac), have been prepared by thermal or photolytic oxidative decarbonylation of Mo(CO), with HL and purified by repeated fractional sublimation. The i.r. and electronic spectra of these compounds have been obtained and their magnetic susceptibilities show Curie-law behaviour, with 876

A. D. Westland and N. Muriithi, lnorg. Chent., 1972, 11, 2971.

"' S. S. Eliseev, I. A. Glukhov, and N. V. Gaidaenko. lzuest. Akad. Nauk Taddi. S S . R . .Otd. Fiz.-Nat Geo1.-Khim., 1972, 46, (Chew. A h . , 1973, 78, 131499~),

"' W . D. Ohlsen, Phys. Rev. (B), 1973, 7, 4058. ''' Kh. S. Bagdasarov, Yu. N. Dubrov, I. N. Marov, V. 0. Martirosyan, and M. L. Meilman. Phys. 8M1 882

883

Status Solidi (4, 1973,46, K65. (a) M. Abe, M. Kawachi, and S. Nomura, J . Phys. SOC. Japan, 1973, 34, 565. (6) M. Abe. M Kawachi. and S. Nomura, ibid., 1972,33, 1296. K. Kustin. and D. Toppen, lnorg. Chem., 1972, 11,2851. A. M. El-Aggan, S. F. Sidarous, and M. A. El-Azmerlli, U . A . R . J .Cheni.. 1971, 14. 315 (Cheni. A h . , l972,77,69315p); A. M. El-Aggan and S. F. Sidarous, ibid., 1971. 14. 325 (Cheni Ahs.. 1972. 77, 69 656a). S. R. Sagi and P. R. M. Rao, Indian J . Chem., 1972,lO. 638.

Inorganic Chemistry of the Transition Elements

144

= 3.86-3.72 BM.884As described on p. 129, p-dioxobisl triaquochloromolybdenum(II1))reacts with hydrazine to yield a Mo" complex.805An earlier report of tris(quinolin-8-olato)molybdenum(111) has been shown to be incorrect ; the synthesis affords MoVderivatives.885 MoCl, or MoCl, react with difluorodithiophosphinic acid, HS,PF,. to from Mo(S,PF,), which has been characterized by i.r.. electronic, and mass spectroscopy. Molybdenum(1v) and Tungsten(Iv).-The crystal structure of Li MoF, has been determined and the Mo--F bond lengths found to range from 192.7(2) to 194.5(2)pm in the essentially octahedral anions.886Polynuclear chlorotungstate anions [WzC19]2- and [W4C1,,]2- are formed when [W(CO),Cl-l] and WC1, react in CH2C1, in the absence of C1-. The latter anion is new, it has been isolated as its Bu4N+ salt and the magnetic moment ( p = 1.95 BM) and electronic spectrum has been obtained.887The reactions of MoOC1, with other oxychlorides and chlorides of molybdenum and tungsten have been studied and the products characterized.888 'H and 'P n.m.r. spectra of the complexes mer-[TMoOX,(PMe,Ph),] (X = C1, Br, or I) have been reported and found to differ significantly from those expected from a virtually coupled pair of trans-phosphines with an isolated and unique phosphine. Calculations indicate that anomalies in the spectra of the unique phosphines could derive from chemical shift differences between the c i ~ - ~ 'nuclei.889 P [MoX,(PMe,Ph),] (X = Cl or Br) have been shown by X-ray crystallography to have capped-octahedral geometries with a halogen atom capping a face of three phosphorus atoms.890 Convenient new syntheses of tungsten(1v) halide adducts with a variety of different donor ligands have been developed. WCl, reacts with certain ligands in the ratio (1:2) to afford WC1,,2L1 (L' = MeCN, EtCN, Et,S, or THT) and new complexes WC1,,2L2 (L2 = PrCN or Ph,P) may be obtained by ligand exchange from WC14,2Et,S with L2. WX4,2MeCN ( X = C1 or Br) are formed when W(CO), in MeCN reacts with WCl, or Br,, respectively, or when WX, reacts with MeCN. These complexes have been characterized by spectral and magnetic s t ~ d i e s . ~Electrolytic ~ ~ , ~ ~ ' reduction of WC1, in ROH (R = Me or Et) containing a little HCl affords the green insoluble derivative [W,Cl,(OR), (ROH),], the solvent molecules of which, when R = Et, may be substituted by other l i g a n d ~ . ~WCI, ~ ' reacts with PhNH, in the presence of a reducing

p298K

x84 885

886

887

*'*

R89

890

891

J L Sukup Dr\\ A h \ (9,1972,32, 5680 W Andruchow jun and R D Archer. J lnory Nucleur Chenr 1'172 34 3185 G Brunton. Material\ Re\ Bull 1971.6, 555 (Cltenr Ah\ 1972 '77,8070611) W H Delphin and R A D Wentworth, Inory Chenr, 1973, 12, 1014 S S Ehseev, I A Glukhov, N V Gaidaenko and E E Vorhdaeva. Zhui nrclrq hhinr 1973 18. 895 R M Lynden-Bell. G G Mather, and A Pidcock, J C S Dalton, 1973 715 M G B Drew, J D Wilkins, and A P Wolters, J C S Chenr Conrni, 1072 1278 LJ ManojlovicMuir, lnorg N u d e a r Chent Letter\ 1973.9, 59 M A Schaefer -King, and R E McCarley, lnorg Cheni , 1973. 12, 1972 H J 5eifcrt F Petersen and H Wohrmann, J Iriorq Nuclear Cheni 1071 35 273s

The Early Transition Metals

145

agent (Zn, Al, Mg, or PCl,) to precipitate (PhNH,)[WC1,(PhNH2)PhNH].893 As mentioned on p. 143, in contrast to Mossbauer spectra, X-ray and neutron diffraction studies suggest that Fe,MoO, is an inverse spinel with MoIVon A sites.*'" 2Fe0,3Mo02 has been prepared in the Moo,-FeO-Fe,O, system and its X-ray diffraction characteristics have been reported.894 Refluxing MeV' or Wv' salts with Na-Hg in 1 : 1 MeC0,H-(MeCO),O for 1-2 h is a convenient synthesis of the corresponding [M(O,CMe),] compound.56 X-Ray crystallography has shown that (Ph,As),[M{ S,C,(CN),),] (M = Mo or W) are isomorphous despite their different electronic spectra. Both anions have an MS, framework which is close to D, symmetry, consisting of two parallel s, triangles twisted some 28" from the eclipsed configuration.895 MoOCl, reacts with difluorodithiophosphinic acid, HS,PF,, to form MoO(S,PF,), which reacts with pyridine to give [MoO(py),](S,PF,),. The i.r. and electronic spectra of these complexes have been determined.681 The five-co-ordinate MoO(S,CNRJ, (R = Me or Et) complexes react with highly activated multiple bonds, e.g. diethyl azodicarboxylate, to give a 1 :1 adduct whose i.r. spectrum is consistent with an oxomolybdenum(v~)moiety ~ ~ ~ reaction sequence is the oxidation and a co-ordinated a z o - g r o ~ pA. ~related of tertiary phosphines PR; (R' = Bu or Ph) by MoO,(S,CNRz) (R2 = Et, Pr', or Bu3 molecules to afford the corresponding RtPO and MoO(S2CNR3 derivatives. The oxidation of excess PR, may be accomplished catalytically by It is suggested that co-ordinatively unsaturated allowing access of 0,.8966 MoIV complexes and the related Mow complexes constitute valuable probes for investigating the modes of reaction of the various molybdenum-containing enzymes. The mechanism of the reduction of flavines by Mo" in a tartrate buffer (pH 2.5-5.3) has been investigated as a model for molybdenum-flavine reactions in enzymes, and a two-electron reduction mechanism involving Mow as a reactive intermediate has been developed.897 MoCl, reacts with ZnMe, in Et,O at -10°C to produce MeMoCl,, Et,0.898 The crystal structure of (7c-Cp),WS4 has been determined and the co-ordination about the metal in the constituent molecules shown to consist of two terminal sulphur atoms of the tetrasulphide chain and two ring centroids of the cyclopentadienide rings and may be described as a distorted tetrah e d r ~ n . * ~X-Ray ' studies have shown that the photochemical reaction of [(7c-Cp)W(CO),Ph] with P h C 4 P h results in the formation of [(n-Cp) (n-PhC=CPh)WO(Ph)] in which the W-0, W 4 (phenyl), and W 4 8')3

895

896

897 898

899

F

L. D. Shevchenko, Kh. U. Ikramov, and N. A. Parpiev, Uzbek. khini Zhur.. 1972. 16. 14 (Cheni. Ahs., 1972, 77, 69 514c). M. Abe, Materials Res. Bull., 1972, 7 , 1443 (Cheni. Ahs., 1973,78, 6 3 3 3 6 ~ ) . G. F. Brown and E. I. Stiefel, Inorg. Chem., 1973,12, 2140. (u) P. W. Schneider. D. C. Bravard, J. W. McDonald, and W. E. Newton, J . Anier. Cheni. Soc., 1972, 94, 8640; (b) R. Barral, C. Bocard, I. Seree de Roch, and L. Sajus. Tetrahedron Letters, 1972, 1693. G. Colovos and J. T. Spence, Biochemistry, 1972,11, 2542. K. H. Thiele and U. Dieckmann, 2. anorg. Chem., 1972,394, 293. B R Davis and I. Bernal. J Cryst. Mol. Structure, 1972,2. 135.

146

Inorganic Chemistry ofthe Transition Elements

(acetylene) bonds of length 169(2), 225(3), and 211(4) prn, respectively, are all rather short.900 The crystal structure of the molybdenum(1v)-amino-acid complexes H[(x-Cp),Mo(~-cysteinato)l,X (X = c1 or PF,), [(x-Cp),Mo (glycinate)]Cl,H,O, and [(7c-Cp),Mo(sarcosinate)]Cl,MeOH have been determined. The bis-x-cyclopentadienyl rings are in the staggered conformation in the sarcosinato- and cysteinato-chloride complexes, but in an eclipsed one in the glycinato- and cysteinato-hexafluorophosphate complexes. In these complexes the cysteinato-ligands are complexed via their N and S atoms.g01

Molybdenum(v) and Tungsten(v). Mononuclear Complexes. The fluoro-bridged complexes formed between MoF, or [MOF,]- with BrF,, AsF,, TaF,, or NbF, have been characterized by i.r., ”F n.m.r., and X-ray diffraction spectroscopy. MoF, in SO2, S02C1,, or CH2Cl, reacts rapidly with the solvent in the presence of MF, (M = As, Sb, Ta, or Nb) molecules to give a complex mixture of The interaction of MoF, and MoOF, with liquid NH, has been studied under a variety of conditions, and phases MoF,(NH3), (n = 1-5) and MoOF,,(NH,), (rn = 1 or 2) were ~haracterized.”~WCl, reacts with Bu‘Cl and XPCl, (X = Cl or Me) to produce the corresponding (RXPClJ[WCl,] salts, the magnetic susceptibilities of which have been determined.’08 The reaction of WC1, with pyridine in the presence of a reducing agent (Zn, Al, Mg, or PCl,) affords [WC12(py)4]C13.893The effective magnetic moment of WCl,,OPCl, (0.2BM) suggests that this compound consists of halogen-bridged [Cl,W(OPCl,)], d i m e r ~ . ~ Solutions ~O of WC1, in pure alcohols (R’OH) afford yellow precipitates of the corresponding (NR;) [W(OR’)Cl,] salts on addition of NR2Cl. Similar addition to ethanolic solutions of Wv containing a little HC1 produces (NR~)[WOCl,],EtOH.892 Force constants for M--O stretching in the compounds MOX, (M = Mo or W) have been shown to decrease as X = F > C1 > Br,’03 The reactions of M02Cl (M = Mo or W) with MoCl, and WCl, have been studied and the various halides and oxyhalides produced have been ~haracterized.~’~ A Knudsen effusion mass spectrometric investigation has indicated that, in the temperature range 410-690°C, solid WOBr, undergoes simultaneous evaporation and dissociation as presented in Scheme 4, with the evaporation and dissociation reactions a and b, respectively,being of primary imp~rtance.”~ Various forms of (phenH,)[MoOCl,] and its derivatives have been prepared in a manner completely analogous to those of (bipyHJ[MoOCl,] (Vol. 2, p. 144).’06 (LH,)[MoOCI,] and (LH),[MoOCl,] (L = dimethylglyoxime) 900

901

““3 904

‘05

906

N. G. Bokii, Yu. V. Gatilov, Yu. T. Struchkov, and N. A. Ustynyuk, J . Organometallic Chem., 1973, 54, 213. C . K. Prout. G. B. Allison, L. T. J. Delbaere, and E. Gore, Acta Cryst., la72. B28. 3043 (a) I. N. Belyaev, G. E. Blokhina, and A. A. Opalovskii. Zhur. neory. Khini.. 1972. 17, 2465. (b) G. E. Blokhina, I. N. Belyaev, A. A. Opalovskii, and L. I. Belan, Zhur. neorg. Khim., 1972,17,2140. R. Kergoat and J . E. Guerchais, h11.SOC. chim. Frunce, 1972, 1746 S. S. Eliseev, I. A Glukov, N. V. Gaidaenko, and E. E. Vozhdaeva, Doklady Akad Nauk Tadzh. S.S.R., 1972, 15, 32 (Chem. Abs., 1973, 78. 91 994b). S . K. Gupta, Inorg. Chem.. 1973,12, 1622. H. K. Saha and M. C. Halder, J . Inorg. Nuclear Chem.. 1972.34, 3097.

The Early Transition Metals

147

have also been prepared and characterized by i.r. and e.s.r. spectroscopy.907 MoOF,(phen) has been obtained by treating MoO(OH), with phen in the presence of HF.903 (enH,)[MoOBr,] reacts at 260°C in an atmosphere of CO, to produce MoOBr,(en), the magnetic and spectral properties of which have been reported.908aThe stepwise substitution of Br - in (NH,),[MoOBr,] by (MeO),PO- has been followed by e.s.r. spectroscopy908band the factors which affect g-values and hyperfine constants in [MoOX,Y]"- [Y is trans- to Mo=O; X, Y = F, Cl, Br, I, H2P04, H2S04, HSO,, or SC(NH,),] species have been discussed.909"Complexes of this type are labile and e.s.r. spectroscopy may be used to identify the isomers present in solution909band to characterize the nature of the products of substitution reacti~ns.~~'' WBrds)

Scheme 4

MoV centres produced in MOO, have been shown to possess. the d:,, configuration."' The ordered perovskites Ba2(Ln,M1)0, (M1 = Mo or W) Sr,(Ln,Mo)O,, (Ln = Gd, Dy, Er, or Y), and (La, Sr)(M2W)0, (M2 = Mg or Mn) have been prepared by the high-temperature reduction of mixtures of the corresponding oxides by H,, and X-ray diffraction and magnetic properties were determined." Hydroxo-complexes of MoV have been prepared by electrochemical reduction of molybdates in DMF and characterized by e.s.r. spectr~scopy."~Complexes of MoVwith the glycols MeCH(OH)CR(OH)Me (R = H or Me) and diethanolamine have been synthesized and their e.s.r. spectra reported.734 The complexes formed by adding (NH,),[MoOCl,] to a solution of 8-hydroxy-, 8-mercapto-, or 8-amino-quinoline, or 3,4-dimercaptotoluene in anhydrous DMF have been investigated by e.s.r. spectroscopy. Each of these 907

908

909

910

911

912

L. D . Shevchenko, Kh. U. Ikramov. and N . A. Parpiev. Uzbek Khinr. Zhur , 1972. 16. 12 (Chew Abs., 1972. 77, 134457~). (a) H. K. Saha, and A. K. Banerjee, 1. Indian Chem. Soc.. 1972, 49. 928. (b) G. Y S Lo. Diss Abs. (8,1972,32, 6894. (a) I. N. Marov, Yu. N. Dubrov, V K. Belyaeva, and A. N. Ermakov, Zhur. neorq K h i n i . 1872. 17, 2666; (b) I. N. Marov, Yu. N. Dubrov, V. K. Belyaeva, and A. N. Ermakov, ibid., p. 2968; (c) I. N . Marov, E. M. Reznik. V. K. Belyaeva, and Yu. N . Dubrov, ibid., p. 1351 B. R. Krasil'shchikov, B. P. Berkovskii, M. P. Votinov, and I. F. Ivanova, Ref: Zhur. fiz., 1972, Abs. 10E843 (Chem. Abs., 1973, 78, 164405~). M. Yoshimura, K. Kamata and T. Nakamura. Chem. Letters. 1972.737, 1201. A. V. Il'yasov, I. D. Morozova and Z. I. Usmanov. Doklady Akad.. Nauk S . S . S . R . ,1972, 204. 120.

148

Inorganic Chemistry of the Transition Elements

ligands forms a 100% e.s.r. active 1 :1 complex, the affinity of MoV for these ligands varying with the nature of the donor atom as S > 0 > N. The e.s.r. characteristics of the thiolato-complexes are closest to those obtained for MoV centres in enzymes lending further support to the idea that these latter involve an Mo-S i n t e r a ~ t i o n . ~MoOCl, '~ reacts with phenothiazine (64) to produce dark-red crystals of [(PT)MoOCl,] which have g-values of 2.0067 and 1.9500,corresponding to an unpaired electron associated with the organic radical and the MoV centre, r e ~ p e c t i v e l y The . ~ ~ ~complexes formed between MoV and thiourea and its derivatives in acetone solution have been investigated and dissociation constants obtained which show that the stability of such complexes decreases as (NH,),CS > (PhNH)C(S)NH, > (PhNH),CS.' l 4 [Mo(S,CNEt,),]X (X = ClO, or 13) are readily obtained by the oxidation of [Mo(S,CNEt,),], either electrochemically in acetone containing NaClO,, or by I, in benzene, respectively.'' E.s.r. characteristics of some molybdenum(v) dialkyldithiophosphato-complexes have been reported,'" and [WOCl (S,PF,),] and [WCl,(S,PF,),] have been prepared by treating difluorodithiophosphinic acid, H,SPF,, with WOCl, and WCl,, respectively.681 Optimum conditions for the quantitative precipitation of Mo" as (Et4N)Z [MoO(NCS),] have been defined.917Free radical formation has been shown to occur in Mov-phenazine reactions.918 Complexes of octaethylporphyrin (H,L), [MoO(OMe)L] and [WO(OPh)L], have been prepared5,' and the redox behaviour of MoO(0H)L has been studied." Dinuclear and Polynuclear Complexes. The reaction of MoO(OH), and bipy in the presence of HF affords [(MoOF,(bipy),},0].903 Monomer-dimer equilibria in the [Mo(X)L][(MOL),O] (M = Mo or W ; X = F, OMe, or OPh; H,L = octaethylporphyrin) system have been studied, and the presence of HX was shown to cause the expected increase in monomer concentration which is accompanied by an increase in the magnetic moment. This apparently results from a decrease in antiferromagnetic interaction which is present in the d i r n e r ~ . ~The ~ ' synthesis of four isomeric [{ MoO(oxine),},O] (Hoxine = quinolin-8-01) complexes from solutions originally containing Mo"' has been reported. Although the various geometric configurations have yet to be determined, the experimental evidence strongly suggests that these isomers differ in the relative positions of their terminal oxygen atoms. The strongly paramagnetic dimer (p ca. 1.8 BM) is suggested to have the terminal oxygens either co-axial or orthogonal to the bridging axis, whilst the slightly paramagnetic

'13 914

'15 91h 917

G. R. Lee and J. T. Spence, lnorg. Chem., 1972, 11, 2354 N. V. Ul'ko and N. N. Dubina, Ref: Zhur. khim., 1972, Abs. 2V90 (Chem. Abs., l973,78,131542m). J. F. Rowbottom and G. Wilkinson. lnorg. Nuclear Chem. Letters, 1973, 9. 675 E. V. Semenov, P. M. Solozhenkin, N. I. Zemlyanskii, and Ya. I. Mel'nik. Doklady Akad Nauk Tadzh. S.S.R., 1972, 15, 40 (Chem. Abs.. 1972.77. 54528m). Yu. G. Eremin, E. F. Kolpikova, and A. E. Dorfman. Zhur. analit. Khim., 1972. 27. 1207. D. G . Durrett, Diss. Abs. (4. 1973, 33, 3531. J -H Fuhrhop, K. M. Kadish, and D. G. Davis, J . Amer. Chem. SOC.. 1973.95. 5140.

The Early nansition Metals

149

dimers probably have the terminal oxygen axes perpendicular to the bridging axis and in a skewed configuration.s85 Biguanidinium salts (LH),[Mo204 Cl,(H,O),] [L = 1-phenyl, 1-(p-chlorophenyl), or 1 -(p-chlorophenyl)-5-isopropylbiguanidine]have been prepared and ~haracterized,~~'" and SCCC MO methods have been used to interpret the magnetic and spectral properties of the [Mo~O,C~,(H,O),]~- ion.920b The reaction between Cs2[Mo204C14(H20)2]and N2H4 involves the coordination of the hydrazine to the MoV centres with no subsequent redox rea~tion.~' Several investigations of the reactions of [Mo,0,(~-cysteinate),]~- have been reported which have possible relevance for the role of this metal in several enzymes. The simple monomer-dimer equilibrium proposed from earlier studies has been shown not to exist as a result of studies of the reaction of the complex with free ligand at pH 8-10.921 In fact a reaction occurs which produces the e.s.r. signal and colour change (at 5 8 0 4 4 0 nm) suggested to indicate monomer formation. This reaction is first-order in each reactant, cysteine being catalytically regenerated. A reaction scheme has been presented and the substances responsible for the paramagnetism and colour change were shown to be different products. Those responsible for the colour change have been identified as mono-0x0-bridged complexes, one of which (82) has been characterized in other st ~ d i e s . ~ ~

0

Y/OH

1'-

In aqueous solutions at pH < 6 the co-ordinated carboxylato-groups of [Mo,O,(~-cysteinato)~]~-are protonated and replaced by water molecules ; in phosphate or tartrate buffers, the p-0x0-ligands appear to be replaced by an oxy-anion which bridges the two metal centres. Diazomethane methylates the thiol group resulting in decomposition of the complex, suggesting that the molybdenum-thiol bond is essential for the stability of this complex. Other dimeric p-0x0-complexes of this type have been prepared, including [Mo,O, [M0~0,(8-quinolinate)~],H~O, [M0,0~(SO,)~(phen),], (ethyl-~-cysteinate)~], 3H20, [Mo,O,Cl,(phen),], and [Mo204(Mo04)(phen),],2H,0. [Mo,O,

920

92i 922

(a) P. Spacu and L. Antonescu. Reu. Roumaine Chem., 1972, 17, 18-51>(h) L Natkaniec, M F Rudolf, and B. Jezowska-Trzebiatowska, Theor. Chim. Acta. 1973. 28, 193. R. F. Stephenson and F. A. SchultG Inorg. Chem., 1973, 12, 1762. P. Kroneck and J. T. Spence, Inorg. Nuclear Chem. Letters, 1973,9, 177, J . Inorg. Nuclear Chem.. 1973,353391.

Inorganic Chemistry of the Transition Elements

150

(ethyl-L-cysteinate),(phen),] has also been isolated and it appears to contain a Mo(0)-Mo-Mo(0) arrangement. 9 2 The structures of the p-sulphido-anions in Na,[Mo,O,S,(~-cysteinate)~]~~~” (83)924bhave been determined by X-ray crystalloand Cs,[Mo,O,S,(edta)] graphy; the dimensions of their four-membered rings are very similar to those = 3,4-dimercaptotoluene) reported for related compounds. M ~ , ( t d t )(H,tdt ~ has been prepared and ~haracterized.~,’ I-

1 2 -

0

0

,c=o

o=c, o=c -

‘C H 2

H2

(33)

(34)

The crystal and molecular structure of Mo,O6Cl,(OPr)6 (84) has been reported ; the co-ordination about each metal atom is essentially octahedral with the four octahedra sharing edges in a manner equivalent to that in Ti,(OEt) 6. The stoicheiometry indicates that the compound formally possesses two MoV and two Mow centres, and weak Mo-Mo interactions are The reduction of 12-molybdophosphoric acid with SnCl, has been shown to proceed through four steps in which the heteropolyanion accepts two, four, six and eight electrons, converting the corresponding number of MoV’centres into MoV.926b Molybdenum and Tungsten Bronzes.-The results of some of the studies concerning these bronze phases are summarized in Table 10.The synthesis of 923

924

92 5

916

A Kay and P C H Mitchell, J C S Dalton, 1973. 1388 (a) B Spivak and Z Don, J C S Dalton. 1973, 1173, (6) D H Brown and J A D Jeffreys h d , p 732 M Koyama K Emoto, M Kawashima and T Fujmaga. Chrm Anal ( W u r m w ) 1472, 17. 679 (Chem A b s . 1973.78, 37529r) A Beaver and M G B Drew, J C S Dalton, 1973. 1376. (6) H K El-Shamy and M F Iskander. J Inorg Nuclear C h e m . 1973.35, 1227

(a) J

The Early 'Itansition Metals

151

Table 10 Molybdenum and tungsten bronzes Bronze Na,K, W 0

Comments and reported properties electronic spectra reported

R ej. a

O<x+y
Kcl.,,WO, Sn,WO,

single crystals grown at high temperature studied by X-ray and electron diffraction characterized by X-ray and electron diffraction

C

X-ray diffraction patterns reported

d

X-ray diffraction patterns reported

e

b

(x = 0.11, 0.25,0.27)

M,(WO),WO3 (M = Sr, Pb, or Bi) Eu,W03 (0.07 < x < 0.15)

(a) S. Fujieda, J . Inorg. Nuclear Chem., 1973, 35, 3351. (b) W. A. Denne and P. Goodman. Acta Cryst.. 1973,829.2314. (c) R. Steadman and C S. Dimbylow. Materials Res. Bull.. 1972.7. 841 (Chem. Abs., 1972, 77, 93926j), R. Steadman, ibid., 1972, 7, 1143 (Chem. Abs., 1972, 77, 169772d). (d) Refs. 519a and 519b. (e) G. 5. McCarthy, R. D. Fischer, and J. Sanzgvi. J . Solid State Chem., 1972, 5, 200.

Na,WO, bronzes as single crystals has been achieved by heating stoicheiometric mixtures of W, WO,, and Na,WO, at 850--1300°C; lattice constants were determined.927 The thermodynamic aspects of electrolytic growth of tungsten bronzes from WO,-M,WO, (M = alkali metal) melts have been investigated, and the nature of single crystals of the bronzes M,WO, formed at the cathode has been studied as a function of the decomposition potential.928" An electrolytic cell for the growth of Na,WO, crystals with predictable composition has been described and large crystals of the new triclinic compound Na4W14043 and its lithium isomorph have been obtained.928bFurther studies of the enthalpies of formation of Na,WO, bronzes have been reported, and it is now established that these values are approximately linear for 0.4 < x c 0.8.929 Tungsten bronze-type phases Mx(Lio~5xCro~5xWl -30, - 3xF3x(M = Li, Na, K, Rb, or Cs; 0.5 < x < 0.7) have been characterized by X-ray diffractometry in the corresponding M2LiCrF,-W03 Other systems containing MoV and MoIV which have been characterized include ternary phases with the Mo5014-type of structure, (Tio.04Moo.96) 02.80930 and (Mo, _xMJ02.80(M =Nb or Ta: 0 < x < 0.40),518and the new non-stoicheiometric perovskites Ln,(M,W, - J03(Ln = lanthanide, M = Nb or Ta; 0.04 < x 6 0.33).931 Molybdenum(v1) and Tungsten(vI).-Halide, Oxyhalide, and Related Cornplexes. The MF6-XeF2 (M = Mo or W) binary systems have been studied by d.t.a. and 1 :1 complexes identified at 124 and 125 "C,respectivrly. The phase

''' E. Salje and H. Hatami, Z . anorg. Chem., 1973,3%, 928

929

930 931

267. (a) M. S. Whittingham and R. A. Huggins, Nat. Bcr. Stand. ( U . S . A . )Spec. , Publ. No. 364 l?72, 51 (b) H . R. Shanks, J . Cryst. Growth, 1972. 13-14. 433. P. G. Dickens and D. J. Nield, J.C.S. Dalton, 1973, 1074, M. P. Morozova and G. P. Ovcharova. Zhur. j i z , Khim., 1972. 46,2965. T. Ekstrom, Acta Chem. S c a d . , 1972,26, 1843. G. Desgardin and B. Raveau, J . lnorg. Nuclear Chem., 1973. 35. 2295. A. Deschanvres, G. Desgardin. and B. Raveau, ibid., p. 2287. I

152

Inorganic Chemistry of the Transition Elements

diagrams for these systems also suggest the formation of the 1 : 4 complexes.932 The phase diagram of the MoF,-SbF, system has been presented.506 MoF, reacts with liquid NH, to afford NH,[MoF7],4NH,, together with some reduction to Mov.933 MoOF, affords MoOF,,SNH, in this medium.902b Hydrocarbons containing CF, groups may be prepared from the corresponding carbonyl compounds by treatment with BF, and MoF, in CH2C12.934" MoF, reacts exothermally with acetic acid to give MoOF,,HF and MeCOF : WF, yields W02F2.934h The stability constants of the [MoO,F,]- and [MoO2F4I2- ions have been determined8, and the latter has been shown to have a distorted cisoctahedral structure in its Rb' salt by single-crystal X-ray diffraction and i.r. spectral studies.935The 19Fn.m.r. spectraof MOF, and [M,O,F,]- (M = Mo or W)936a and [MoWO,F,]-, which is formed by mixing MoOF, with [WOF5]-,936bhave been recorded in MeCN at low temperature. The data obtained, together with 19F n.m.r., i.r., and Raman spectra recorded for Rb[Mo,O,F,], are consistent with the structure (85) for these anions.936c

(85)

M

=

Moor W

Detailed i.r. studies of WOF4(s) have been reported which strongly support the proposal (Vol. 2, p. 158) that this compound contains fluorine atoms in the bridging positions of the tetrameric units.93 Rb,[MoO,F,] reacts with H F and CeO, at 750°C over 33 h to form Rb12CeMo,0,Fl,, the X-ray diffraction characteristics of which have been determined.,09 The compounds (Et,N),[M,0,F,(C204)] (M = Mo or W) have been prepared from alcoholic solutions of MoO,F, and H2C204,and their reported spectral properties suggest that the anions contain quadridentate bridging o x a l a t o - g r ~ u p s .I9F ~ ~ ~N.m.r. spectroscopy has been used to show that Mo02FC1,2DMF, formed by halogen exchange from Mo02F,.2DMF. exists in three isomeric forms.939Nine complexes have been identified in a similar 932

933

934

935 93h

937

938 939

V. A. Legasov and A. S..Marinin, Zhur.fi-. Khim., 1972,46. 2649. A. A. Opalovskii and G . E. Blokhina, Zaiest. I/. U Z . Khim i khini Trchnol., 1072. 15. 1617 (Chem. A b s , l973,78,66436p). (u) F. Mathey and J. Bensoam Fr. P. 2 109416 (Chem. Abs. 1073.78. 28617r). (6) N S Nikolaev. Yu. Ya. Kharitonov. A. T Sadikova T. A. Rasskazova. and A. Z. Kororezov. / x r s t Akad Nauk S.S.S.R., Ser. khim., 1972. 757 V. S. Sergienko, M. A. Porai-Koshits, and T. S. Khodoshova Zhur. strukt. Khini. 1P72. 13, 461 (a) Yu. A. Buslaev, Yu. V. Kokunov, V. A Bochkareva, and E. M. Shustorovich, Zhur. strukt Khim., 1972, 13, 526; (b) Yu. A. Buslaev, Yu. V. Kokunov, and V. A Bochkareva. Zhur. neorg Khim. 1972.17, 3377; (c) A. Beuter and W. Sawodny, Anyew. Chem. lnternat Edn. 1072.11. 1020. L. B. Asprey, R. R. Ryan, and E. Fukushima, lnorg. Chem., 1972. 11. 3122. J. Y. Calves. R. Kergoat, and J, E. Guerchais. Compt. rend., 1972. 275, C. 1423. R Kergoat, J. Y. Calves, J E Guerchais. and M. Lenzi, Compt. rend.. 1073. 276. C . 57

The Early Transition Metals

153

manner following the reaction of WOCI, with H F in MeCN, one of them containing the [W202F9]- (85) anion.940 The reactions of MoOF, and [MOF,]- (M = Mo or W) with several 0-donor ligands in MeCN have been followed by 19F n.m.r., and the results suggest that substitution of a fluorine atom cis- to the M-0 bond occurs. This cis-effect has been discussed in terms of ligand-metal ( p d )interaction^.^,^ ~ The molecular structures of MoOCl, and WOCl, have been determined by gas-phase electron-diffraction techniques. Both molecules have the expected square-pyramidal C,, structure (86) with the metal atom some 50 pm above 0

I

c-,/,b 6; c1

c1

M=Mo W a = 167.0 168.4pm b = 227.8 228.0pm y = 103.0 102.6"

(86)

the plane of the four basal chlorine atoms.'42a The structure of WOCl, has been determined in a separate study and slightly different molecular dimensions were obtained: W-0 = 173, W-CI = 237 pm, and L O W C ~= 104°.942b The crystal structure of MoO,Cl,,H,O has been reported and the metal atom has a distorted tetrahedral environment with two terminal chlorine, and one terminal and one bridging oxygen at distances of 235.2, 167.1, and 167.8 pm, respectively. A fifth co-ordination site is occupied by a bridging oxygen atom of an adjacent unit, at a distance of 224.6 pm, and the oxygen atoms of the water molecules are 230.1 pm from the The unit cell parameters of Ca,WO, C1, have been reported.944 Preparative routes to M02Br, (M = Mo or W) have been described in which the metal is oxidized with an excess of Br,, in the presence of SO,, in a sealed tube at 400°C.945Ag,W0414 has been identified in the AgI-Ag,W04 system at ambient ternperat~res.',~ The preparation, X-ray diffraction characteristics, and other physical properties of the salts K,[MOS,X] (M = Mo or W; X = C1 or Br) have been described.947The new compounds Mo,Br,Y, (Y = S or Se) have been synthesized by treating MoBr, or MoBr, with the chalcogen at temperatures between 340 and 430°C; i.r. spectral data were obtained.948WSCI, reacts with 1,2-di-

y40 941

y42

y43 944 945 y46 941 948

Yu. A. Buslaev, Yu. V. Kokunov, and V. A. Bochkareva, Zhur. strukt. Khini . 1972. 13. 611. Yu. A. Buslaev, Yu. V. Kokunov, V. A. Bochkareva. and E. M. Shustorovich, Zhur neory. Khim., 1972, 17. 3184; J . Inorg. Nuclear Chem., 1972,34, 2861. (a) K. Iijima and S. Shibata, Chem. Letters, 1972. 1033, (b) V. P. Spiridinov, E Z Zasorin. I. M Zharskii, and G. I. Novikov, Zhur. strukt. Khim., 1972, 13, 511. F.A. Schroder and C. A. Norbund, Z . anorg. Chem., 1972,392, 107. Z. Zikmund, Czech. J . Phys., 1972.22.537 (Chem. Abs.. 1972,77, 807452). D . A. Edwards and R. T. Ward, Inorg. Nuclear Chem., Letters, 1973.9, 145. T.Takahashi, S.Ikeda, and 0.Yamamoto. J . Electrochem. Soc , 1973,120. 647. A. Miiller, W. Sievert, and H. Schulze, Z . Naturforsch., 1972. 27b, 720. A. A. Opalovskii, V. E. Fedorov, A. P. Mazhara, and I. M. Cheremisina, Zhur neorg. Khim . 1972. 17.2876.

inorganic Chemistry of the TransitionElements

154

c1

methylthioethane (dte) to form 2WSCl,,dte which has been shown by X-ray crystallography to have the centrosymmetric structure (87) in which the ligand weakly bridges between two WSCl, groups. The addition of the sixth donor atom trans to W=S appears to have little effect on the WSCl, groups, their dimensions being very similar to those found in WSC1,.g49" WSeCl, reacts with 1,2-dimethoxyethane (dme) with cleavage of one of the ether linkages to form [WSeCl,(OCH,CH,OMe)], which has the distorted octahedral structure (88).949b 0 - D o n o r Ligands. A large number of these studies concern molybdates, tungstates, and mixed-oxide compounds and the results of many of them are Se

II c ,1 C~,Vr\OMe

c1,

W-Se = 222.5(5) pm W - 0 = 246(4) pm W-O(Me) = 193(4) pm W--C1 = 234(2) pm

summarized in Tables 11, 12, and 13. Developments in the determination of tungstates have been reviewed.414 Accurate unit cell dimensions have been reported for ABO, molybdates and tungstates with either the wolframite or scheelite structures. In each case the unit cell volume of a molybdate was found to be smaller than that of the corresponding t u n g ~ t a t e . ~NaM,[(H,O)~' (Mo0,0H)(Mo04)] (M = Mn-Cu, Ag, or Cd) have been prepared by refluxing a solution of Na,Mo0,,2H,O with a suitable transition-metal salt. The crystal structure of the zinc compound has been determined and shown to contain MOO, tetrahedra which share corners with ZnO, tetrahedra.951 Several detailed vibrational spectroscopic studies of molybdates and tungstates 9 5 2 a including new data for scheelite-type comhave been pre~ented,~~'. p o u n d ~ The .~~ heats ~ ~ of formation of KHMoO,, K,MoO,, KHWO,, and K,WO, have been estimated as - 1030, - 1180, - 1080, - 1170 (all k 20) kJ mol- respectively, by mass spectrometric studies of reactions involving 949

950 951

952

(a) D. Britnell, M. G. B. Drew, G. W. A. Fowles. and D. A. Rice, lnorg. Nuclear Ckem. Letters. 1973,9, 501; (b)D. Britnell, M. G. B. Drew, G. W. A. Fowles, and D. A. Rice, ibid., p. 415 A. W. Sleight, Acta Cryst., 1972, B28,2899. M. J. Simms. Diss. Abs. (9.1972, 33, 670. (a) I. 1. Kondilenko, V. A. Pasechnii and Yu.P. Tsyashchenko, Phys. Sratus Solidi (I$. 1972, 54, 783; A. F. Commit, H. E. Hoefdraad, and G. Blase, J. Inorg. Nuclear Chem.. 1972, 34, 3401 (b) P. Tarte. and M. Liegeois-Duyckaerts, Spectrochim. Acta, 1972.28A. 2029, 2037. I

il

fl

J F

A

HV

0

X

d

X

b

U UI

X

urals6s 'OM~IV-~OM~I-I urais6s

OZX-'OM-'Oz8 urais6s P ~ ~ e 3 - v ~ ~ e ~ urais6s

"OOM-0"8

1

Y

c I

'1

6

9

f

a

P 3

uram

'OM-"OM~IT 9 '2)

urais6s

oovI-'oowz!l axnos

punodtuo3

Inorganic Chemistry of the Transition Elements

156

Properties reported

A1,,Si,Mo03, P-SnWO, Pb, ,Ge2Mo0

Pb 15 Ge 3

2

27

MSbWO, (M = K, Rb, Cs, or T1) KBi(M004) K5Bi(Mo0d4 CsBi(MoO&

Rb2S0,,2Mo0, Cs2S0,,2Mo0, Cs,SO,.MoO,

A1,O ,-SO2-MOO system SnO + WO, in evacuated silica capsule PbO-Ge02-Mo0, system Pb0-Ge02-Mo0, system

,

+

KHCO, + B i 2 0 3 MOO, at ca. 500°C C s 2 0 + Bi,O, MOO, at 600°C MZSO4-MoO3 systems

+

Ref

i.r..t.d.

U'

i.r.,R ; MOO, units have C3L.symmetry i.r..X

X

Y

st.

7

m.p.

aa

m.p. 711 "C

bb

X, pyrochlore st.

cc

m.p. 750°C m.p. 730°C m.p. 6 7 5 ° C t.d., X

dd

ix., m.p. 550°C i.r.,m.p. 575 "C ix., m.p. 560°C

ff

ee

(a) M. Parmentier. T. M. Reau, C. Fouassier. and C. Gleitzer, 13u11. Soc. chim France. 1972. 1743, W S Bower, H. S Parker. R. S Roth. and J. L.Waring,J CI.WI Growth. 1972. 16. I I S (h) Ref 517. (c) D. Gloeikles, J. P. Motte, and C. Gleitzer, Compt. rend., 1973, 276, C, 273. (d) H. F. Franzen, H. R. Shanks, and B. H. W. S. De Jong, N u t . h r . Stand. ( U . S . A . ) Spec. , Publ. No. 364, 41. (e) N. I. Leonyuk, T. D. Semenova, T. I. Timchenko, and N. N. Sheftal, Vestnik Moskoti Unit).Geol., 1972. 27, 112 (Chem. Abs.. 1972,77, 694972). (f)H. Kessler and A. Hatterer. Compt. rend.. 1972,274, C . 623. (9) I. Park, hll. Chem. Soc. Japan, 1972, 45, 2745. (h) S . S Eliseev. Kh. M Kurbanov. and N. V. Gaidenko, Doklady Akud. Nauk Tadzh. S.S.R., 1972, 15, 25 (Chem. Abs., 1973, 78, 49261k). (i) M. Audibert, S. Peytavin, L. Cot, and C. Avinens, Compt. rend., 1972, 275, C, 825. (i) V. I. Krivobok, M. V. Mokhosoev, A. P. Nakhodnova, R. M. Sedneva, and G. Ya. Samsoneva, Ukrain. khim. Zhur. 1972.38, 1201 (Chem. Abs., 1973,78, 51 848a). (k) G. J. McCarthy and C. E. Gooden, J. lnorg. Nuclear Chem., 1973,35.2669;V. M. Zhukovskii, T. N. Yanushkevich, and T. F. Tel'nykh, Zhur. neorg. Khim., 1972, 17, 2827. (0 0. I. Tokunov and I. P. Kislyakov, Zzoest. V . U . Z. Khim. i khim. Technol.. 1972. 15. 1609 (Ckcm 4 hs . 1973.78. 63 466n). (m)T. M. Yanushkevich and V. M Zhukovskii. I x e s t . Akad. Nauk S.S.S.R., neorg. Materialy, 1972,8, 2039. (n) E. R. Kreidler, J . Amer. Ceram. SOC., 1972, 55, 514. (0)A. G. Bergman, V. L. Volkov, and V. T. Mal'tsev, Zhur. neorg. Khim., 1973. 18, 1087. ( p ) M. V Mokhosoev, E. I. Get'man, R. N. Isakova, and S. A. Pavlova, Zhur. neorg. Khim., 1972. 17. 1920. (4)K. Nassau and J. W. Shiever, Nat. h r . Stand (U.S.A.)Spec. Publ. N o 364, 1972. 445. (r) S. A. Pavlova and M. V. Mokhosoev, Zhur. neorg. Khim., 1973, 18, 263. (s) V. N. Karpov and I. B. Korotkevich, Zhur. neorg. Khim., 1973, 18, 570. (t) A. A. Maier, V. A. Balashov, and M V. Provotorov, Trudy Moskou Khim. Tekhnol. lnst., 1971, 157 (Chem. Abs., 1972. 77, 1596640. (u) R F. Klevtsova and P. V. Klevtsov, Kristallografiya, 1972, 17, 955. (I)) V. A. Efremov, V. K. Trunov. and Yu. A. Velikodnyi, Kristallografiya, 1972. 17, 1135; P. V. Klevtsov, R. F. Klevtsova. and A. V. Demenev, ibid. p. 545. (w) B. N. Ivanov, L. A. Filatenko, B. E. Zaitsev, and A. I. Ezhov, Zhur. neorg. Khim., 1973. 18. 974 LT) Ref. 740 f \ 9 A Ueno and Y Kotera, Chem. Letters, 1973. 21. (z) W. Jeitschko and A. W. Sleight, Acta Cryst., 1972,828, 3174. (aa)G. A. Bukhalova, V. T. Mal'tsev, and Z. N. Machavariani, Zhur. neorg. Khim.,1973, 18, 503. (bb) A. G. Bergman, Z. N. Machavariani, and V. T. Mal'tsev, Zhur. neorg. Khim., 1972, 17, 3106. (cc) C. Michel, D. Groult, and B. Raveau, Materials Res. Bull., 1973, 8, 201, (Chem. Abs., 1973, 78, 1 0 3 0 0 6 ~ )(dd) . N. G . Kisel, and M V Mokhosoev,Ukruin. khim. Zhur., 1972,38, 743 (Chem. Abs., 1972,77, 145029r). (ee) P. V. Klevtsov, and V A. Vinokurov, Zzaest. Akad. Nauk S.S.S.R., neorg. Materialy, 1973, 9, 156. (ffl M. V. Mokhosoev, I. F. Kokot, and V. I. Lutsyk, Zhur. neorg. Khim., 1973, 18, 209.

The Early Transition Metals

157

Table 12 Molybdates, tungstates and mixed-oxide compounds of molybdenum(v1) and tungsten(vI)with d-block elements Compound Li2M(Mo0J3 (M = Ti, Zr, or Hi) Cs,V,Mol -x03 (X = 0.125, 0.25, 0.3750.40, 0.504.55) Nb2W0, NaM'M206 (M' = Nb or Ta; M2 = MoorW) KTaWO, Cr2(M04)3 (M = MoorW) Cr2(Mo, -,Wx04), NaCr(MOO,), Na,CrMoO, M2CrMo201 (M = K or Cs) M 3Cr(MoO4)3 (M = Na, K, or Cs) M,Cr(MoO,), (M = K, Rb, or Cs) Na16Cr2(Mo04)11 Sr3Cr2W0,

I

Fe2W0, Ba,Fe,WO, CoMoO, Rh2Mo0,

Properties reported X

CsVO, + MOO, at 350 "C

X

b

st

c

X

d

X, pyrochlore st.

e

X

f

X M2CrO4-MoO3 systems at high temp.

9

Cr203 + Sr3W06 at 1200°C in VQCUO Fe,O, + WO, at 800-900 "C

h

NaM'0,-M20, systems KTa0,-WO, system

+ Moo3 RhC13,xH20 + MOO,

c030,

NiMoO, NiW0, Cu3M020, ZnMo04,xH20 ZnMoO, Zn,Mo20,,H20 Zn2Mo0,,H20 . M2Zn2M0301

Source Li,MoO,-M02-MOO, systems

2

(M = Li, Na, K, or Rb) HgMO, (M = Mo or W)

at high temp and press. NiO-MOO NiO-WO, systems

m,p. 1130"C, X

Ref: a

I

i.r., st. CIX c. x

m.p. 1200"C, X m.p. 1270°C X st. refined dehydration of hydrates kr., t.d. X, two phases at 34-50 "C i.r., X aq. soln. of ZnO + MOO, M,CLZnO-MoO, substitution of Zn by Co, Ni, Cu, or Cd (1:2 :3) melts and Mo by W ; X st, isostructural

m m n 0

P

r

(a) P. V. Klevtsov and E. A. Zolotova, lzaest. Akad. Nauk. S.S.S.R., neorg. Materialy, 1973, 9, 79. (b) V. L. Volkov, G. A. Tikhonova, E. V. Tkachenko, and A. A. Fotiev, Zhur. neorg. Khim., 1972, 17, 2806. (c) M. Lundberg, Acta Chem. Scund., 1972, 26, 2932. (4 0. B. Thakre and V. S. Chincholkar, Curr. Sci., 1972, 41, 735. (e) B. Darriet, M. Rat, J. Galy, and P. Hagenmuller, Materials Res. &ll., 1971,6, 1305 (Chem. A h . , l972,77,8053Oa).(f)K. Nassau and J. W. Shiever, Nut f i r . Stand (U.S.A.) Spec. Puhl. No. 364,1972,445. (g) M. V. Mokhosoev, E. I. Get'man, V. L. Butukhanov, V. G. Pitsyuga, and I. F. Kokot, Zhur. neorg. Khim., 1973, 18, 1011; J. Bernard and M. H. Nguyen, Compt. rend., 1973,276, C, 13; M. V Mokhosoev, V. L. Butukhanov, and E. I. Get'man, lzoest. Akad. Nauk S.S.S.R.,

158

Inorganic Chemistry ofthe Transition Elements

molybdenum or tungsten with potassium-seeded molecular H,-0, flames." The ion-exchangecharacteristics of chromium(rI1)molybdate and tungstate have been investigated649band the structures of the pyrochlores ASbWO, (A = K, Rb, NH,, H,O, or Ag) have been discussed in relation to their cation exchange proper tie^."^^ A study of the outer sphere complex formation between MoOi-(acj or WOi-(acj and [Co(NH&I3+ has shown that the tendency for these associations is approximately the same, but that this is much weaker than that for The viscosities of molten M2Mo04 and M2WIO4 (M = Li, Na, or K) have been determined as a function of temperature up to 1000°C and the data satisfactorily interpreted using the Arrhenius equation.956 Molecular Cs,MoO, and Cs,WO, have been shown to possess bicyclic D,, structures by high-temperature electron-diffraction studies. No significant distortion of these tetrahedral MO, units was detected, and the Mo--O and W 4 bond lengths were determined as 180(2) and 182(2) pm, respectively.957 The new 0x0-cation W,O;+has been isolated as the complex [W205F2(bipy),] by adding a solution of bipy in MeCN to [WO,F,(DMSO),] in DMSO. This compound has been characterized by i.r. spectral and X-ray diffraction data; the broad intense absorption at 817 cm-' was assigned to the W a - W asymmetric stretching vibration.958 X-Ray crystallography has shown that Li2W,0, contains a new W - 0 motif consisting of two chains of a tungstite-type which, being connected along a common rib, form an isolated band &f composition [W,0,,]4-.959 The upper limits of the ionic charges possessed by the constituent ions of W4Nb26077have been estimated as + 1, + 1.2, and - 0.8 (all 5 0.9, respectively, from high-precision electron diffraction measurements for low sin O / A values.520 The state of Mow at low concentration in aqueous solution has been studied by dialysis, electromigration, and centrifugation. At pH 2.5-5 the predominant species is HMoO,(aq) but at lower pH MoO;+(aq) predominate^.^^' The "j

954 9s5

9sh 9s7 958

959

960

M. Farber and R. D. Srivastava Combust. Flame, 1973, 20, 33 (Chem. Abs.. 1973. 78, 115971~). D. Groult, C. Michel, and B. Raveau, J. lnorg. Nuclear Chem.. 1973. 35, 3095. W. Lyness and P. Hemmes, J. lnorg. Nuclear Chem., 1973,35, 1392. R. G . Gossink and J. M. Stevels, lnorg. Chem., 1972,11, 2180. V. V. Ugarov, Yu. S. Ezhov, and N. G. Rambidi. Zhur. strukt. Khim., 1973. 14. 359. R. Kergoat and J. E, Guerchais, &//. Soc. chim. France, 1973,494. S . A. Magarill. R. F. Klevtsova, and V. V. Bakakin, Krista/loyrafiya, 1973. 18. 269. J Burclova, J. ProiSilova, and P. BeneS, J . Inorg. Nuclear Chem.. 1973,35.909

Neorg. Muter., 1972.8, 1868. (h) D. Harari and P. Poix, Compt. rend., 1973,276, C , 265. (i) J. Galy and J. Senegas, Compt. rend., 1972, 275, C , 665; C. Parant, J. C. Bernier, and A. Michel, ibid., 1973, 276. C , 495. (1) G. Blase, J . Inorg. Nuclear Chem., 1973, 35, 680. (k) L. Dziembaj and J. Ziolkowski, hl/. Acad. polon. Sci., Ser. Sci. chim., 1972, 20, 725 (Chem. Abs., 1972, 77, 145585~).(I, L. Degueldre, L. Clerbols, Y. Gobillon, and L. Bourgeois, Ger. Offen., 2200693 (Chem. Abs., 1972, 77, 154576~). (m)E. N. Timofeeva, Yu. A. Kustov, N. E. Beresten, and I. V. Romanovich, Izoest. Akad. Nauk S.S.S.R., neorg, Materidy, 1972, 8, 1872. (n) L. Kihlborg and R. Norrestam, Acta Cryst.. 1972, B28, 3097. (0)J. Meullemeestre and E. Penigault, h l l . SOC.chim. France, 1972, 3669. ( p ) J. Meullemeestre and E. Penigault, h l l . SOC. chim. France, 1972, 1702. (4)C. Gicquel, M. Mayer, G. Perez, and R. Bouaziz Compt. rend., 1972,275, C, 265. V. A. Efremov and V. K. Trunov, Zhur. neorg. Khim., 1972, 17, 2034. (r) W. Jeitschko and A. W. Sleight, Acta Cryst., 1973, B29, 869; A. W. Sleight and M. S. Licis, Materials Res. hll.,1971. 6, 365.

The Early Transition Metals

159

Table 13 Molybdates, tungstates, and mixed-oxide compounds of molybdenum(v1) and tungsten(v1) with €-blockand related elements Rej. Properties reported Source Compound a Sc203-MOO, system X , isostructural with Sc10M03024 M'Sc(M2O4), (M' = K, Rb, or Cs; M2 = MoorW) Y2(Mo04)3 LiY(Mo0J2,2.5H20 Li,Y 3(Mo0J3 04)2

Na,Y(WO,), La2(Mo04)3

X

b

Y(NO3)3 + Li2Mo0,

t.d.

c

Y,03-Li2Mo0, Na2W04-Y2(W04) system

d, m.p. 950°C t.d., X m.p. 1205°C X m.p. 756°C X st, ordered-defect scheelite-type t.d., X

d

3

+

CsLa(WO,), Ce':'Mo,O, Na,M(MoOJ, (M = Y or Nd) Ln2(MoO&,M2S04 (M = K, Rb, or Cs; Ln = La or Nd) Lnx(OH)3x- 2(W04)3xH20 (Ln = La or Nd)

La,(WO,), CsWO, at 950°C 10 h (NHJC~(MOO,)~,H,O at 300°C Na,Mo04-M2(MoOJ X systems ix., X Ln2(Mo0J,-M2S04 systems Ln(NO,), + NaOH + Na,WO, in aq. s o h , and ppt. heated

M2(Mo0d3

(M = La, Ce, Pr, or Nd) Cs,M(MoOJ, (M = La, Pr, or Nd) KNd(W04) KEu,(MoOJ, MMo2O, (M = Eu or Sm) Eu"W0, EU2WO6 Eu2W301

2 2

Eu6W01

Eul4w4033

M2M04015

I

M2MOS021 (M = La, Nd, or Gd) Ho6W0

12

Ho, 4wo33 Ho1ow02 1 M~Mo,O~,,H~O (M = La, Sm, or Ho) Er,WO12 M Ln(M 204)2 ,xH20 (MI= Na, K, Rb, or Cs; Ln = Y or Er; M2 = MoorW)

K,MoO,-EU(MOO,)~ system M - M e 0 systems

e

f' 9

h 1

j

k

X

1

t.d., X

m

st

n 0

X

Eu- W - 0 system

X, scheelite st. X, scheelite st. X, scheelite st. X. fluorite st. X

P

M203-MOO, systems

m.p.

q

Ho203-WO, system

X

r

M(N03),--Na,Mo,02,,H20 systems P, st n.m.r., t.d.. X

9

t U

Inorganic Chemistry of the TransitionElements

160

Compound

M,MoO, M2Mo3O12 M2M0401

Source

M203-MOO, system

Properties reported

Ref

X

11

X

w

M z 0 3 - W 0 3 systems

X

X

M (M 04) 3Ln2(Mo04), system

m.p.. X

Y

5

(M = Y, La-Lu) M2(Mo04)3 M2(Wo4)3 M2(M, -*W,04)3 (M = Sc, Y,La-Ho) M~O~JWO~ (X = 0.33, 0.4, 0.57, 1, 2 ; M = La-Lu) M Ln(M 0,) (Ln = La-Lu; M2 = MoorW) M2Ln3(WOJ5 Ln = Nd, Er, or Lu) (M2 = Na, Rb,or Cs) M,Mo,O,~JH~O (M = Y, La-Lu) M(MoOJOH,xH20 (M = La-Lu) U02Mo04 UMo20,,3H20 Na2Np(Mo 4) 3 M4NP(M004)3 (M = Li or Na) MAm(M o o 4) (M = Li, Na, or K) M,Am(MoO4)4 (M = Na or K)

M(NO3)3 + Na,MoO, t.d. in H 2 0 hydrothermal synthesis t.d. ex M 2 0 3 + MOO, st t.d., X M,MoO,-Np(MoO,), X, scheelite st. systems X, scheelite superstructure M2Mo04Am2(Mo04)3 systems

X

7

aa

bb cc

dd ee

(a) A. A. Maier. V. A. Balashov, and M. V. Provotorov, Trudy Moskou Khim. Tekhnol. lnst., 1971, 157 (Chem. Abs., 1972, 77, 1596640. (b) V. A. Balashov, M. P. Slisskaya, L. S. Zevin, Z. K. Zolina, and A. A. Maier, Kristallograjya, 1972, 17, 1245. (c) E. M. Abzhieva, I. V. Shakhno, and V. E. Plyushchev, Izuest. V . . U .Z. Khim. i khim. Technol., 1972, 15, 1131 (Chem. Abs., 1972, 77, 144456r). (d) L. P. Kozeeva and P. V. Klevtsov, lzuest. Akad. Nauk S.S.S.R.,neorg. Materialy, 1972. 8, 1328. (e) A. R. Gizhinskii, lzuest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972, 8, 1326. ( J ) W. Jeitschko, Acta Cryst., 1973, B29, 2074. (g) E. M. Novikova, and A. A. Maier, Zzvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972, 8, 1619. (h) M. J. Schwing-Weill, Bull. SOC. chim. France, 1972, 1754. (9 M. V. Mokhosoev, E. I. Get'man, and L. F. Tetyukhina, Zhur. neorg. Khim., 1972, 17, 2058. (1) M. V. Mokhosoev, I. F. Kokot, and V. 1. Lutsyk, Zhur. neorg. Khim., 1972,17, 3094. (k) K. Aganiyazov and M. V. Mokhosoev, Ukrain. khim. Zhur., 1972,38,555 (Chem. Abs., l972,77,169778k). (I) L. H. Brixner, A. W. Sleight, and M. S. Licis, J. Solid State Chem., 1972, 5, 247. (m) P. V. Klevtsov, V. A. Vinokurov, and R.F. Klevtsova Kristallografiya, 1973, 18, 122. (n)R. F. Klevtsova and L. M. Volkova, Kristallograjiya, 1972, 17, 859. (0)T. P. Ryabakova and V. K. Trunov, Zhur. neorg. Khim., 1973, 18, 484. (p) G. J. McCarthy, Materials Res. Bull., 1971, 6, 31 (Chem. Abs., 1972, 77, 8055511);G. J. McCarthy, R. D. Fischer, and J. Sanzgk, J. Solid State Chem., 1972, 5, 200. ( c j S. S. Antonova, I. V. Shakhno, V E. Plyushchev, and 0. A. Nazarochkina, Ref. Zhur. khim., 1972, Abs. 1B829 (Chem. Abs., 1972,77, 169372~).(r) G. J. McCarthy and R. D. Fischer, Materials Res. Bull., 1971. 6, 591 (Chem. Abs., 1972, 77,805420. (s) S. S. Antonova, I. V. Shakhno, V. E. Plyushchev, and G. A. Znekova, Rej. Zhur. khim., 1971, Abs. 23V20 (Chem. Abs., 1972,77. 131 389w). (t) M. C. Montmory, E. F. Bertaut, and K. Lovold, Calloq. Int. Cent. Nat. Rech. Sci. No. 180, 1970, 349 (Chem. Abs., 1973; 78, 642262). (u) A. M. Golub, A. P. Perepelitsa, and A. M. Kalinichenko, Izvest. I.: U. Z . Khim. i. khim. Technol., 1972, 15, 1293 (Chem. Abs., 1973, 78, 10949r); A. M. Golub, V. I. Maksin, and A. P. Perepelitsa, Ukrain.

The Early Transition Metals

161

(89)

dimerization of Mow species in HC104 solutions (1.5-7.0 mol 1-') has been studied spectrophotometrically.961A theoretical study of the electronic structures of model Mow complexes, including (89), has been made using the allvalence-electron SCMO method. The M o = O terminal bonds were found to be mainly of the (d--p)n type, but the other bonds appear to involve a high charge separation and low bond order.962 The preparations and properties of several peroxo-molybdate and -tugstate complexeshave been investigated,the compounds reported include K, W0896 3a and hydrated salts of the [M0,I2- (M = Mo or W ; n = 5-8) anions with the cations Na', Sc3+,or Y3+ 9 6 3 b Mow peroxo-complexes have been used to oxidize secondary amides, R1C0.N(R2)SiMe3,to hydroxamic acids,964and the extraction of peroxo-molybdate ions from aqueous solution by large tetra-alkylammonium cations has been 961

962 963

964

965

~~

E. F. C. H. Rohwer, J. J. Gruywagen, and H. G . Raubenheimer. J. S. African Chem. Inst.. 1972, 25, 338 (Chem. Abs., 1973,78, 1290092). D. H. Brown, P. G. Perkins, and J. P. J. Stewart, J . C. S. Dalton, 1972, 2243. (a) N. A. Korotchenko, K. K. Fomicheva. and G. A. Bogdanov. Ref Zhur. khim.,1972, Abs. 7V5 (Chem. Abs., 1973,78, 8 3 4 3 ~ )(b) ; G . A. Bogdanov, T. L.Garkushenko, and T. F. Karpenko, ibid., 1972, Abs. 7V20 (Chem. Abs., 1972. 77, 172037~);R. I. Tereshkina, T. F. Karpenko. and G. A. Bogdanov, ibid., 1972, Abs. 7V13 (Chem. Abs.. 1972, 7?, 172038z), G. P. Aleeva, L. A. Kotorlenko, and V. A. Lunenok-Burmakina, Zhur. strukt. Khim.. 1972. 13. 632. S. A. Matlin and P. G. Sammes, J.C.S. Chem. Comm., 1972. 1222. I. M. Ivanova, L. S. Zolotareva, 1. G. Yudelevich, and L. M. Gindin. lzvest Sib.Otd. Akad. Nauk S.S.S.R.. Ser. khim. Nauk, 1972,90 (Chem. Abs.. 1972.77, 157042~). ~~~

Khim. Zhur., 1972, 38, 950 (Chem. Abs., 1973, 78, 10967~).( v ) L. H. Brixner, P. E. Bierstedt, A. W. Sleight, and M. S. Licis, Nat. h r . Stand. (U.S.A.)Spec. Publ. N o . 364 1972, 437; Materials Res. all.,1971, 6, 545 (Chem. Abs., 1972, 77, 80544h); L. H. Brixner, A. W. Sleight, and M. S. Licis, J. Solid State Chem., 1972, 5, 186; S. S. Antonova, I. V. Shakhno, V. E. PlyushChev, and 0. A. Altukhova, fziiest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972, 8? 1438. (w) K. Nassau, and J. S. Shiever, Nat. h r . Stand (U.S.A.),Spec. Publ. N o . 364 1.972, 445. (x) G. J. McCarthy, R.D. Fischer, G. G. Johnson, jun., and C. E. Gooden, Nat. h r . Stand. (U.S.A.) Spec. Publ. N o . 364 1972, 397. ( y ) M. V. Bobkova, M. V. Savel'eva, I. V. Shakhno, and V. E. PlyushChev, Zzuest. V: U.Z . Khim. i khim. Technol., 1972, 15, 654 (Chem. Abs., 1972, 77, 66849e). (y) V. E. Plyushchev, V. M. Amosov, and E. S. Razgon, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972, 8, 1615; L. Yu. Kharchenko and P. V. Klevtsov, Kristallografiya, 1972, 17, 694; R.F. Klevtsova, L. A. Glinskaya, L. P. Kozeeva, and P. V. Klevtsov, ibid., p. 768. (z)S. S. Antonova, I. V. Shakhno, and V. E. Plyushchev, Izuest. V . U.Z . , Khim. i. khim. Technol., 1972,15, 1289 (Chem. Abs., 1973,78, 10950j). (aa) A. P. Perepelitsa and V. N. Solomakha, Zhur. neorg. Khim., 1973,18,28; V. I. Protasova, L. Yu. Kharchenko, and P. V. Klevtsov, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1973, 9, 421. (bb) V. N. Serezhkin, L. M. Kovba, and V. K. Trunov, Kristallografiya, 1972, 17, 1127. (cc) V. N. Serezhkin, L. M. Kovba, and V. I. Spitsyn, Doklady Akad. Nauk S.S.S.R., 1972, 205, 861. (dd) M. Pages and W. Freundlich, J. Inorg. Nuclear Chem., 1972, 34, 2797. (ee) A. Tabuteau, M. Pages, and W. Freundlich, Radiochem. Radioanalyt. Letters, 1972,12, 139.

162

Inorganic Chemistry of the Ransition Elements

The distribution of MoV' between solutions of di-(2-ethylhexyl)phosphoric acid (H2A3in n-heptane and weakly acidic ClO, and NO, solutions has been studied for a variety of conditions. The extracted complex appears to be [MoO,A,(H,A~)].~~~ (Et4N),[M,04F,(C,04)] (M = Mo or W) have been prepared from alcoholic solutions of MO,F, containing H2C204; i.r, and 19F n.m.r. studies suggest that the anions contain quadridentate bridging oxalatoAs indicated last year (Vol. 2, p. 157) crystalline [MoO,(acac),] consists of molecules which have the expected octahedral co-ordination, with a cis-MOO, unit.967 This compound is a very active and highly selective catalyst for the epoxidation of c y ~ l o a l k a n e s A . ~ spectrophotometric ~~ study of molybdate-catechol (H,L) solutions has indicated the presence of two complexes. At pH 7.3, 25"C, and ionic strength 0.1 mol 1-', the stability constants for these complexes of composition [MoO,(OH),L]- and [MoO,L,]~-, A crystal structure are 37( f 5) and 1.5( & 4) x lo3 1 mol-l, re~pectively.~~'" determination has been reported for another Mow catechol complex, (NH4)H[Mo20,L,],~H,0. The anions consist of two cis-Mo0,L groups linked via an 0x0-bridge and a bridging catechol ligand, each MeV' centre having distorted octahedral c o - ~ r d i n a t i o n . ~Complex ~~' formation between Mow and Wv' with other phenol and with alcoholligands has been studied by other workers969 and two 2 :1 MoV'D-mannitol complexes have been isolated and characteri ~ e d . 0.r.d. ~ ~ ' curves have been obtained for fractions of a [Mo0412-~-malate mixture at pH 3.7-5.5 separated by paper chromatography, which suggest that 2 :1, 3 :7, and 3 :2 complexes are formed.971 Zso- and Hetero-polyanions. Potentiometric titrations of H + against WO: ions have shown that the product formed in the first 0.01 s of reaction is not paratungstate A, [HW6021]5-, nor any other discrete ion intermediate between this and WOZ-, but is a mixture of a number of ill-defined products. These may be colloidal hydrated Ww oxides formed very rapidly in local regions of high acidity before complete mixing can occur and which are converted into [HW6021]5- in ca. 1 s.972Steps in the aggregation of [M0,I2(M = Mo or W) ions have also been studied by cryoscopy, spectrophotometry, and pH measurement^.^^ [NP(NMe,),], reacts with MOO, in boiling H,O to afford the yellow-green, 966 961

968

969

970 971

972

973

Z. Kolaiik, J . Inorg. Nuclear Chem., 1973,35,2025. B. Kamenar, M. Penavic, and C. K. Prout, Cryst. Struct. Comrn., 1973.2.41. (a) K. Kustin and S. T. Liu, J. Amer. Chem. Soc., 1973.952487; (b) L. 0.Atovmyan, V. V. Tkachev, and T. G. Shishova, Doklady Akad. Nauk S.S.S.R., 1972,205. 609. E. N. Poluektova, and G. G. Shitareva, Zhur. analit. Khirn., 1972, 27, 1301. A. A. Fedorov and A. V. Pavlinova, ibid., p. 2409; A. A. Fedorov and A. V. Pavlinova, Zhur. Vses. Khirn. Obshchest., 1972,17. 352 (Chem. Abs., l972,77,93551h); A. N. Pant, R. N. Soni, and S. L. Gupta. lndian J . Chem., 1972,10, 859. L. Pettersson, Acta Chem. Scand., 1972, 26, 4067. M. Deodata de Azevedo, R. Gomes-Costa, and K. Jacobsohn, Enzymologia,l972.43, 105 (Chem. Abs., 1973,78,133005n). J. C. Dewan and D. L. Kepert, J.C.S. Dalton, 1973, 224. G . Wiese and D. Bose, 2. Natuijorsch.. 1972,27b. 897; B. K. Kim, Hwahak Konyhak. 1972, 10. 161 (Chem. A h . , 1973,78,79 117k).

The Early Transition Metals

163

water-insoluble, crystalline compound [NH3P3(NMe,),],[Mo,01Q]. X-Ray crystallography has shown that the structure of this new isopolymolybdate ion is that adopted by [M6Ol9I8- (M = Nb or Ta). In MeCN solution the anion exhibits absorption maxima at 257 and 325 nm, in close agreement with earlier values reported to be characteristic of this unit.769 (HL),[Mo7O2,] (L = a biguanidine) have been prepared97h and the diperoxoheptamolybdate(vr) ions in K , [ M o , O ~ ~ ( ~ ~ ) , ] , ~ Hshown , O to have the same general shape as normal heptamolybdate. Two peroxo-groups replace oxygen atoms, one at either end of the ion, and the Mow atoms to which they are co-ordinated are thus surrounded by seven oxygen atoms in an approximately pentagonal-bipyramidal manner.974bThe crystal structure of (NH,),[Mo80,,],4H2O has been reported975aand (NH4),[Mo8O2,],4H20 has been isolated from aqueous solutions of (NH,),[MO7o2,] (0.2C0.25mol 1- ’) containing NH4CI. X-Ray crystallographic studies have shown that this latter compound consists of [Mo,O,,] units which are linked together by vertex-sharing with two other such units to give a herringbone chain. This is the first isopolyanion which has been isolated as a polymer from aqueous solution.975 b The first crystalline decatungstate derivative, (Bu,NH),[W l 0032], has been isolated from strongly acidic solutions of WO, containing (Bu,NH)(MeCO,). The anion (90) consists of two [W,Ol,] units which are related by a mirror plane and bonded through four common oxygen atoms, and it has a central octahedral cavity.976A new route to metatungstate has been described342and several new metatungstate salts have been isolated.977”The crystal structure of the paratungstate (NH4)lo[H,W ,0,,],4H20 has been determined,977bthe thermal decomposition of this compound has been inve~tigated,”~~ and the i.r. spectra of several other paratungstates have been r e p ~ r t e d .7d~The macro-isopolyanion [Mo,,O1 2]8 has been obtained in aqueous acidic solutions of [MOO,]”, and its structure was suggested to comprise four nonamolybdate units linked in the ideal case to afford overall Crystals of p-K,[SiW120,0],9H20 contain anions each of which is the geometrical isomer of the Keggin-structure obtained by a 60” rotation of one W3Ol3 unit about its three-fold axis.978The conditions for the preparation of the a- and p-forms of tungstosilicates and -germanates have been further investigated979and their polarographic reduction characteristics reported.980

974

975

976 977

978

979

(a) C. Gheorgiu and L. Antonescu, An. Unit;. Wlcuresti, Chim.. 1971.20,89 (Chem. Abs.. 1973,78, 6 6 3 8 3 ~ ) (b) ; I. Larking and R. Stomberg, Acta Chem. Scand., 1972. 26. 3708. (a) L. 0. Atovmyan and 0. N. Krasochka Zhur. strukt. Khim., 1972, 13, 342. (b) I. Boschen. B. Buss, B. Krebs, and 0. Glemser, Angew. Chem. Internat. Edn., 1973. 12, 409. J. Fuchs, H. Hartl, and W. Schiller, Angew. Chem. Internat. Edn., 1973, 12, 420. (a) V. V. Kozlov and V. G. Smirnova Zhur. obshchei Khim.,1972.42, 1686. (b) H . D’Amow and R. Allman, 2.Krist., 1972, 136, 23; (c) I. K. Bhatnager, D. K. Chakrabarty, and A. B. Biswas, Indian J . Chem., 1972, 10, 1025; (4 B. A. Kiss, Acta Chim.( &dupest), 1973, 75, 351 (Chem. Abs., 1973,78, 153246~). K. Yamamura and Y. Sasaki, J.C.S. Chem. Comm., 1973, 648. P. Souchay, A. Teze, and G. Herve, Compt. rend., 1972, 275, C , 1013, V. E. Plyushchev, N. P. Krauzol’dt, V. M. Amosov, and T. A. Slivko. Zhur. neorg. Khim.. 1973, 18, 200.

164

Inorganic Chemistry of the Transition Elements

The reduction of H,[PMo,,O,o] in BuOAc has also been studied by polarography and, from the number of electrons and protons involved in these steps ( n = 2, 4, or G) have been the reduction products H,[PMO,,O,8-,(OH),] suggested.981The solvent extraction of H3[PMo1,0,,] into dibutyl sulphoxide by ascorbic acid has been reported.982The reduction of [AsMoW, ,0,0]3or TiCl, has been followed spectrophotometrically and potentiometrically and products (Amax = 500 nm) were characterized in the case of the former r e d ~ c t a n t The . ~ ~ reaction ~ of [Mo0,12- with Te(OH), in neutral solution has been monitored by cryoscopic and potentiometric titrations and X-ray fluorescence analysis, and the product [TeMo,O, 7(OH)] - fully character~ i ~ e d . The ~ ~ mechanism , of formation of the iodomolybdate ions [ I M O , ~ , , ] -. [ I , M O , O ~ ~ ] ~and - , [IMo,O,,(OH)]~- has been investigated cryoscopically and spectrophotometrically~985 The new heteropolytungstates [MW8028I4- (M = Ti, Zr, or Hf) have been prepared' O 3 and HPv effectively separated from ZrIV as pyridinium molybdozirconophosphate.217Three new tungstovanadate(1v) heteropolyanions, pinkish-purple [VW50 19]4-, brown-orange [HnV2W4019]6-", and wine-red [H,VWl,0,,]8have been prepared according to Scheme 1 (p. 50). Their electronic spectra show that these three ions are analogues of heteropoly-blue species, with low-energy intervalence charge-transfer bands in addition to the expected d-d transitions.342Other studies concerning tungstovanadate anions have also been described earlier (refs. 341, 342, 421424). 980

981 982

983

984 985

F. Umland, F. Pottkamp. and F. Alt, Z. anorg. Chem., 1973, 395, 320. M. Leyrie and G. Herve, Compt. rend., 1973, 276, C , 911; E. N. Dorokhova and E. D. Shigina. Vestnik Moskoii Unit). Khim., 1972, 13, 681 (Chem. A h . , 1973, 78, 9 1 7 3 8 ~ ) S. ; V. Lugovi and Z. Z. Odud, Rej, Zhur. khirn., 1971, Abs. 24B1556 (Chem. Abs., 1972,77, 1470158). F. Pottkamp and F. Umland, Z . Analyt. Chem., 1972.260, 185 (Chem. Abs.. 1972. 77, 121508~). M. N. Sastri and S. V. J. Swamy, Indian J . Chern., 1972,10, 561. B. E. Reznik, V. P. Statsenko, L. P. Tsyganok, and L. V. Shubina, Zhur. neorg. Khim., 1972, 17. 2752. G. Wiese and J. Wunsch, Z. Naturforsch., 1972, 27b, 1001. G. Wiese, 2. Naturforsch., 1972, 27b. 616,869, 894.

The Early Transition Metals

165

The isomorphous series of heteropolyanions [M'M2M~,03,(H20)]n(M',M2 = Fe"', Co", or Co'''; M3 = Mo or W) are convenient systems for studying the magnetic exchange between two isolated metal centres. M1 occupies a distorted octahedral site, M2 a tetrahedral site, and the two ions are 0x0-bridged with an M'--- -MZ separation of ca. 3 3 0 ~ mStudies . ~ ~ have ~ shown that the newly prepared cobalto(rI)undecatungstogallate(III)contains Gatnin the centre of the ion and Co" in octahedral sites,987 and similar derivatives (m = 2, M = Co"' or Cr"'; m = 0 or 2, M = Al"' or [ZnMW1,O,,H,]"Ga'''; rn = 0, M = V", Vv, or MeV? with Zn as the central atom have been prepared by substituting M for octahedral Zn in [Zn,Wl103,(H,0)]8-.344 Salts of the heteropolyanions [AM"Wl103,(H20)]5- (A = P or As, M = Co ; A = P, M = Ni or Zn) and [ B C O , W , ~ O ~ ~ ( H ~ O(n ) ]= ( ~2- or ~ ) 3) have been prepared. In one of these anions the water molecule has been replaced by py to give [PCo"W, 1039(py)]5-.988 The 11-tungstocobalto(I1)phosphate ion, [PCoWl1039(H,0)]S-, slowly reacts with H,O in aqueous solution at pH 7-7.5 to give a new heteropolyanion which has been shown by X-ray crystallography to have the formula [P2C04W180,8(H20)]10-.A flat central set offour edge-linked C O ~ ~ O octahedra, , resembling a fragment of a composite layer in Co(OH),, links two [PWl,040]3- units each of which has the Keggin-structure. Analogous compounds containing As (for P) and Ni, Mn, Cu, or Zn (for Co) have also been prepared.989 The mechanisms of the formation of heteropolytungstates such as [NiSiW, 1039(H20)]6- and [NiPW, 103,(H20)]4have been discussed990"and the thermal decomposition of salts containinglons of this type has been (NH,),[ReCl,] reacts with [SiWl103,]8- (1:1) under N, to yield the blueviolet [SiReWl10,,]4- ion which exhibits absorption maxima at 263 and 506 nm. A similar reaction between (NH,),[Recl,] and [P,W, 70,,]f0in the presence of air affords [P2ReWl,0,,]6-.991 A method for the isolation of the isomorphic acids H8[M1VMo120,2],nH,0 (M = Ce, Th, or U) has been described and their. Raman and i.r. spectra were reported.,,, S- and Se-Donor Ligands. Molybdenum(v1) and tungsten(w) thio- and selenohalide complexes are described on p. 153.

986

987

989

990

992

L. C. W. Baker, V. S. Baker, S. H. Wasfi, G. A. Candela, and A. H. Kahn. J Anzer. Chem. SOC.. 1972, 94, 5499; A. Barrett, Diss. Abs. ( g ,1972. 33, 1475. 0.W. Rollins, lnorg. Chem., 1972,11,3114. T. J. R. Weakley, J.C.S. Dalton. 1973, 341. T. J. R. Weakley, H. T. Evans, jun., J. S. Showell, F. Tourne, and C. M. Tourne, J.C.S. Chenz. Comm., 1973, 139 (a) R. Ripan, M. Pucasu, D. Stanescu, and P. Boian, Z. anorg. Chem., 1971,384,297; (b)R. Ripan, M Pucasu. D. Stanescu, and P. Boian, ibid.. 1972, 391. 183, R. Ripan. D. Stanescu. and M. Pucasu, ibid., 1972, 391, 187: 1973, 397, 63. B. Charreton and R. Meunier, Compt. rend., 1972. 275, C. 945 L. P. Kazanskii, E. A. Torchenkova, and V. I. Spitsyn, Doklady Akad. Nauk S . S . S . R . . 1973, 209, 141; V. I. Spitsyn, and E. A. Torchenkova, Vestnik Moskou Uniii. Khim.. 1972. 13. 259 (Chem. A h . , 1972, 77, 121 561g).

166

Inorganic Chemistry of the TransitionElements

The preparations of C U , [ W S , ] ~ ~ and ~ (HL),[MoS,] (L = a g ~ a n i d i n e ) ' ~ ~ have been described, the conditions under which [MoO,S,-,]~- ions are prepared in H 2 0 have been in~estigated,"~"and the thermal decomposition of(NH,),[MoO,S,] and(NH,),[MS,] (M = Moor w) has been described.994b Vibrational studies of salts containing the ions [MO,S,-,]Z- (M = Mo or W ; n = 1 4 ) and [MO,Se4-,I2- (M = Mo or W; rn = 2 or 3) have been presentedgg5and the data obtained were discussed with reference to photoelectron spectral data measured for these ions.995"The electronic spectra of the chargetransfer transitions in [MoS,Se,-,12- (n = 1, 2, or 3) and [WSSe31z- have been reported and assignments given.996 The crystal structure of MoO,(S,CNEt,), has been reported,997u the molecules being shown to have the expected octahedral structure with a cis-MOO, unit (Vol. 2, p. 158). Other dithiocarbamato-complexes of MeV' have also been prepared.997cWCl, reacts with o-mercaptophenol to afford [W(oSC,H,0)3].1 79a Mow and W" complexes with dimethylaminoethanethiol have been in~estigated,"~and Mo(tdt), (H,tdt = toluene-3,4-dithiol) has been ~repared.'~ N-Donor Ligands. [W205F,(bipy),] has been precipitated by adding a solution of bipy in MeCN to [W02F2(DMS0)2]in DMSO and characterized by i.r. spectral and X-ray diffraction data.958 A theoretical study of an octahedral MoV' complex containing a fuc-MOO, group has been reported,962this complex being chosen as a model for the known complexes involving diethylenetriamine or edta bound to such a unit. The stepwise stability constants for MoV' or Wv' chelate formation with asparagine or glutamine have been r e p ~ r t e d79a ,~ and nitriloacetic acid (H3L) has been shown to react with H,[MoO,] or (NH,),[MoO,] to form [Mo02(HL)H,0],2H,0 or (NH,)[MoO,L],H,O, respe~tively.~~' Organornetallic Compounds. The complete account of the preparation and characterization of WMe, has now been published and some reactions of this compound described. 0, and MeOH both convert WMe, into W(0Me); ; CO, PR,, and AlCl, all react to some extent, although the products have not yet been completely characterized.looONO inserts into the W-Me bonds 993 994

99s

996 997

998 999

'Oo0

A. Miiller and R. Menge, Z . anorg. Chem., 1972.393. 259.

K U.Z . Khim. i khim. Technol., 1972. 15. 1623 (Chem. A h . . 1973, 78. 6 3 0 3 4 ~ ) (6) ; T. P. Prasad, E. Diemann, and A. Miiller. J . Znorg. Nuclear Chem., 19-73,35,1895; Z . anorg. Chem., 1972,391,107. (a) A. Miiller, Ch. K. Jorgensen, and E. Diemann, Z . anorg. Chem.. 1972. 391. 38, (6) A. Miiller. N. Weinstock, K. H. Schmidt, K. Nakamoto, and C. W. Schlaepfer, Spectrochim. Acta, 1972, 28A, 2289; (c) K. H. Schmidt and A. Miiller, ibid., p. 1829. A. Muller, E. Diemann. F. Neumann, and R. Menge, Chem. Phys. Letters, 1972. 16, 521. (a) A. Kopwillen, Acta Chem. Scand., 1972, 26, 2941; (b) T. Kojiman, T. Yano, and K. Ueno, Kyushu Daigaku Kogaku Shuho, 1972,45, 209 (Chem. Abs., 1972.77, 1346180. P.C . Jain and H. L. Nigam, Vijnana Parishad Anusandhan Patrika, 1972, 15, 91 (Chern. Abs., l972,77,169446a). M. G. Voronkov, S. V. Mikhailova, V. A. Pestunovich, D. Zaruma, and I. Zuika, Khim. geterotsikl Soedinenii, 1972, 606 (Chem. A h . , 1972,77, 134471~). A. J. Shortland and G. Wilkinson, J.C.S. Dalton, 1973. 872.

(a)L. I. Lebedeva, I. K. Gromozova and M. N. Ptushkina, Zzuest.

The Early Transition Metals

167

to afford [WMe,(ON(Me)NO},], which has been shown by X-ray crystallography to possess the structure (65) in the solid state. However, 'H n.m.r. spectra for the compound in CD,Cl, solution indicate that the molecules are (69 has been shown to have n ~ n - r i g i dTris(methylvinylketone)tungsten(vI) .~~~ an unusual co-ordination geometry about the metal, the three carbon and three oxygen ligand donor atoms defining a trigonal prism with the olefinic systems also co-ordinated to the metal, each one capping a square face of the prism.768 Tetrakis(fluoreny1)oxo-molybdenum(vI) and -tungsten(vI), [M(O)(C,,H,),] (M = Mo or W), have been reported to be formed by treating MOC1, with NaC13H9.1001aThe analogous cyclopentadienyl and indenyl (R) compounds of molybdenum(vI) have been prepared in a similar manner, from MoOCl, and RH in dry benzene; they react with phenols (HL) to afford the corresponding [R,MoOL,] complex in good yield.1001b

7 Technetium and Rhenium Introduction-The organometallic chemistry of technetium and rhenium has been the subject of three reviews.loo2 Interesting new developments in the chemistry of these elements reported this year include the first preparation and characterization of ReOCl, which, compared with the other oxochlorides of rhenium, is relatively stable with respect to reaction with air or water, it is however markedly thermally unstable.1003Re0,I has been observed by mass spectrometry in the vapour from a mixture containing ReO, and AgI.loo4 Preliminary experiments have indicated that the preparation of acylazorhenium(1n) complexes from dinitrogenrhenium(1) complexes is a general synthetic method. Thus [ReCl(N,)(PMe,Ph),L] (L = PMe,Ph or py) react with organic acid halides, RCOCl, to form the deep-red acylazo-complexes [ReCl,(N,COR)(PMe,Ph)J for which an X-ray diffraction study has confumed the formation of a C-N b0nd.l O o 5 Methyleneamido-complexes of rhenium(II1) have been obtained by the deprotonation of alkylimido-complexes by bases. Thus, for example, treatment of truns-[ReCl,(NMe)(PPh,Me),] with py produces [ReC1,(N==CHJpy(PPh,Me)2]. These appear to be the first transition metal complexes of the -N=CH, ligand, although its C-substituted derivatives are well known.loo6 The preparation of the novel p-hydrido-derivatives HMRe(CO),, (M = Cr, Mo, or W) has been achieved and the structure of the chromium compound (42) determined by X-ray cry~tallography.~~ The hydridopolynuclear carbonyl

(a) S. Kapur, R. K. Multani, and B. L. Kalsotra, Current Sci., 1973. 42. 237, (b) K. M. Sharma and S. K. Anand, J . prakt. Chem.. 1973,315, 258. loo' H. C. Lewis jun. and B. N. Storhoff, J . Organometallic Chem., 1972, 43, 1; H. Wojcicki, ibid., 1972,45, 335; P. M. Treichel, ibid., 1973,58, 273. l o o 3 P. W. Frais, H. E. Howard-Lock, and C. J. L. Lock, Canad. J . Chem., 1973,51, 828. loo' H. Rabeneck, K. Rinke, and H. Schaefer, Z . anorg. Chem., 1973,397, 112. ' O o 5 J. Chatt, G. A. Heath, N. E. Hooper, and G. J. Leigh, J . Organometallic Chem., 1973,57, C67. loo6 J. Chatt, R. J. Dosser, and G. J. Leigh, J.C.S. Chem. Comm., 1972, 1243. 'Ool

168

Inorganic Chemistry of the Bansition Elements

clusters (Ph,As),[H6Re4(CO),,] and (Ph,As),[HRe,(CO),,],THF have been isolated and characterized following the reduction of Re,(CO), with NaBH,. The former anion contains a tetrahedral arrangement of rhenium atoms with six p-hydrido-groups and in the latter the metal atoms are arranged in a triangular manner.1oo7 Carbonyl Complexes.-As indicated for chromium only a selection of this material is reported. Using '3C-enriched Re(CO),Cl, isotopically enriched Re,( CO) has been prepared and i.r. and Raman spectra obtained in the v ( C ~ 0stretching ) region and assigned.1008Activation enthalpies for the reactions of several metalmetal bonded carbonyl molecules have been shown to correlate well with the force constants for M-M stretching, and with the energies of a U.V. absorption band that may be assigned to a 0 -+ 0" transition between the orbitals of the metal bond. The available data thus support the conclusion that reactions proceed via homolytic fission of the M-M bond with the relative strengths of M-M bonds varying as (OC),Re-Re(CO), > (OC),Mn-Re(CO), > ( O C ) , T C - T C ( C ~ ) , . ~A~study ~ ~ of the photoreaction of Re,(CO),, with CC1, has provided evidence supporting efficient and symmetrical Re-Re bond fission upon photoexcitation. The major product of the reaction using either 313 or 366 nm light is Re(CO),Cl; however, prolonged irradiation at either of these wavelengths produces [Re(CO),C1],.'O'O The Re(CO), monomers produced at this latter wavelength seem to be capable of abstracting a hydrogen atom from a hydrocarbon to form the corresponding free radical. This abstraction leads to the initiation of polymerization for unsaturated molecules such as methyl methacrylate or acrylonitrile.lO1 ReCo(CO), has been reported for the first time and characterized by i.r., Raman, and mass spectrometry.1°12 The reduction of Re,(CO),, by NaBH, has been shown to afford the polynuclear carbonyl clusters [H,Re,(C0),,]2and [HRe3(C0),,]2- which have been isolated as their Ph,As salts. X-Ray crystallographic studies have shown that the former contains a tetrahedron of metal atoms, each Re-Re distance being spanned by a p-hydrido-atom, and the metal atoms of the latter are arranged in a triangular manner. [HRe,(CO) ,SnMe,] has been obtained by treating [HRe,(C0),,]2- with Me,SnCI, and shown to contain a tin(1v) atom bridging across an Re-Re bond, the metal atom arrangement thus being similar to that of [Re,(CO) 6 ] 2 - . [HRe,(CO),CI] apparently contains p-chloroand p-hydrido-atoms and thus is closely related to the derivatives [Re(CO),X], (X = H or C1).1007(Et,N)[CrRe(CO),,] may be converted into a mixture of

,

,

'

-+

,

S. W. K'irtley, Diss. Abs. (B), 1973, 33, 3535. W. T. Wozniak and R. K. Sheline, J. Inorg. Nuclear Chem., 1972,34, 3765. l o o 9 J. P. Fawcett, A. J. P d , and M. W. Twigg, J.C.S. Chem. Comm., 1973, 267; D. DeWit, J. P. Fawcett, A. J. Po&,and M. W. Twigg, Coord. Chem. Rev., 1972, 8, 81. 1010 M . wrighton . and D. Bredesen, J. Organometallic Chem., 1973,50, C35. lo'' C. H. Bamford and M. U. Mahmud, J.C.S. Chem. Comm., 1972, 762. lo'' G. Sbrignadello, G. Bor, and L. Marnesca, J. Organometallic Chem., 1972,46,345;W. T. Wozniak and R. K. Sheline, J. Inorg. Nuclear Chern., 1973,35, 1199. 1007

'Oo8

169

The Early Transition Metals

HCrRe(CO),,, HRe,(CO),,, and Cr(CO), by stirring in an n-pentane slurry over 85 % H,PO, for two days. The first of these products has been separated by fractional sublimation and shown to contain molecules with a p-hydridogroup linking the two M(CO), centres (42). Other members of this series of compounds HM'M2(CO),, (M' = Mn or Re; M2 = Cr, Mo, or W) have been prepared in a similar manner. Re(CO),F,ReF, an$ [Re(CO),] [Re2Fl have been obtained from ReF, and Re,(CO),, in anhydrous HF. Both compounds are very sensitive to moisture and their structures have been confirmed by X-ray crystallography. The former (91) contains essentially octahedral Re(CO),F and ReF, units

(91)

linked by a bridging fluorine atom, with the ReV-F-Re' interbond angle = 141(1)'. The Re-F bridging distances lend little support to any significant contribution from the ionic formulation [Re(CO),] [ReF,] -. It is, however, remarkable that this adduct is formed from moieties containing metal atoms in two so dissimilar oxidation states. The other product of the reaction, howThese results ever, comprises discrete ions, [Re(CO),]+ and [Re2F, '] - .' suggest that the proposed formation of Re(CO),F by treating a limited amount of ReF, with Re2(CO)10 [initially Re(CO),F, was suggested1014" as the reaction product] merits further study. However, Re(CO),F, can be obtained by the fluorination of Re(CO),F with XeF2.1014bThe new carbonyl halide complexes Re(CO),X (X = C1, Br, or I) have been prepared by the thermal decomposition of the corresponding Re(CO),X compounds. They are suggested to possess a trinuclear structure which contains bridging halide groups, each rhenium atom possessing three terminal carbonyl groups.' O 1 Re(CO),Br(THF), has been prepared from [Re(CO),Br], in T H F ; Re(CO),Br affords Re(CO),Br (THF), in this medium.' l 6 The anionic carbonyliodo-complexes have been prepared by [Re,(CO),I,] -, [Re(CO),I,]-, and [Re(CO),I,]'treating (Ph,MeA)I (A = P or As) with [Re(CO),I]2.'0'7 Bis(p-chlorotricarbonyl-(1-phenyl- 1 -hydroxobut-1-en-3-one)rhenium(I)), [Re(CO),Cl(PhC(OH)=CHCOMe)l,, is one of a series of compounds which have been obtained by treating Re(CO),Cl with P-diketones and it has been +

'',

lo'' lo''

D. M. Bruce, J. H. Holloway, and D. R. Russell, J.C.S. Chem. Comm., 1973, 321. (a) T. A. O'Donnell and K. A. Phillips, Inorg. Chem., 1972,11, 2563; (b) T. A. O'Donnell, K. A. Phillips, and A. B. Waugh, ibid., 1973, 12, 1435. R. Colton and J. E. Garrard, Austral. J. Chem., 1973,26, 1781. D. Vitali and F. Calderazzo, Gazzetta, 1972, 102, 587. K. Moedritzer, Syn. Inorg. Metal-Org. Chem., 1972, 2, 209.

170

Inorganic Chemistry of the ThnsftionElements

characterized by i.r. and 'H n.m.r. spectroscopy and X-ray crystallography. The dimeric halves of the molecule are held together by two bridging chlorine atoms [Re-Cl = 251.1(5) pm]. The structure therefore resembles that of [Re(CO),Cl] with the two neutral P-diketo-enol molecules [each co-ordinated via its ketone group, R e - 0 = 216(1) pm] replacing two CO groups. The arrangement of the keto-enolato-groups is such that hydrogen bonding can occur between Another compound characterized in these studies is bis { p - 0 - 1,3-diphenylpropane- 1,3-dionato -tricarbonylrhenium(I)>, [Re(CO),(PhCOCHCOPh)],. These molecules have been shown to involve the two Re(CO), moieties bridged by two oxygen atoms, one from each P-diketonatogroup. The other oxygen of each ligand is co-ordinated exclusively to one metal Re(CO),Cl reacts with tetraethylthiuram disulphide in refluxing benzene to produce at least five diethyl dithiocarbamato-complexes that can be separated by fractional crystallization or chromatography. The main reaction product is [Re(CO),(dtcEtJ,] which is monomeric and diamagnetic ; its i.r. spectrum contains a single v ( C ~ 0 stretching ) frequency at 1870 cm-' and bands characteristic of chelated dithiocarbamato-groups. The complex is remarkably unreactive even at elevated temperatures and the molecular structure has been suggested to involve eight-co-ordinate Rein with the ligand donor atoms perhaps being located at the vertices of a bicapped trigonal prism

(92)

of ideal D,, symmetry. [Re(dtcEtJ,] [Re(CO),Cl(dtcEt2)] has also been characterized as a product of the above reaction, This compound is diamagnetic and a 1 :1electrolyte, and its cation has been separated as the BPh, salt and its anion as the Bu,N+ one. Re(CO),Cl or [Re(CO),Cl], reacts with thallium dithiocarbamates to afford [Re(CO),dtc] which contains dithiocarbamatobridges which may be cleaved by PPh, to afford the corresponding [Re(CO),(PPh,)(dtc)] complex, These compounds may be prepared directly by treating T1(dtc) with [Re(CO)(, PPh ), Cl] . lo'' 'OL9

M. C. Fredette and C. J. L. Lock, Canad. J . Chem., 1973,51, 1116. J. C. Barrick, M. Fredette, and C. J. L. Lock, Canad. J . Chem., 1973, 51, 317

The Early Transition Metals

171

Re,(CO),, reacts with meso- tetraphenylporphine in decalin under reflux to afford (meso-tetrapheny1porphinato)bisi tricarbonylrhenium(1)) which has been shown by X-ray crystallography to involve the basic structural unit (92). Each Re' atom is 142 pm out of the macrocyclic plane. The metal-metal separation of 312.6 pm is rather long for any direct interaction.'020 Similar complexes containing two Re(CO), groups or one Re(CO), and one Tc(CO), group have been prepared with mesoporphyrin IX dimethyl ester.1021 The He' (21.22 eV) photoelectron spectra of Re(CO),SiH,, Re(CO),GeH,, and Re(CO),H have been reported and the data obtained shown to provide no evidence for any n-interaction between the rhenium atom and the MH, (M = Si or Ge) groups.'o22 Dinitrogen Complexes.-The full account of the preparation of rhenium(1) and rhenium(@ dinitrogen complexes via treatment of the benzoylazo-complexes [Re(N=NCOPh)Cl,(PPh,),L,] (L = a unidentate, or L, a bidentate, ligand; x = 0 or 2; x + y = 3) with Iigands such as tertiary phosphines in boiling MeOH, has now been p u b 1 i ~ h e d . ltrans-[ReH(N,)(Ph,PCH,CH,~~~ PPhJ,] has been obtained by treating(Et,N),[ReH,] with Ph,PCH,CH,PPh, in propan-2-01 under N, at 25 "C. This compound is moderately air-stable and is readily protonated to afford the corresponding seven-co-ordinate cationic species. MeX (X = Br or I) react with trans-[ReH(N,)(Ph,PCH,CH,PPh,),] replacing the hydrido-ligand by X, and H,, C,H,, and CO (L) all replace the dinitrogen with L. * The i.r. absorption intensities of the v(N=N) stretching mode in a series of rhenium(1) dinitrogen complexes have been determined and the intensity found to increase with decreasing frequency in agreement with the synergic model of Re-NSN bonding '02' (cf. Vol. 2, p, 132). Acylazo-rhenium(rI1) complexes, [ReCl,(N,COR)(PR,),], have been prepared from rhenium(1) dinitrogen complexes, [ReCl(NJ(PR,),], by treatment with organic acid chlorides, RCOCl. This appears to be a general reaction provided that a labile ligand is present in the initial complex.'005 The dinitrogen molecules of the compound [ReCl(NJ(Ph,PCH,CH,PPh,),] have been converted into NH, in low yield by treatment with an excess of Na'(naphtha1ene)- .762 [ReCl(NJ(PMe,Ph),] has been shown to interact with [ReOC1,X(PPh3),] (X = C1 or OMe) in CHCl, to yield the corresponding bridging dinuclear Re'-N-N-Rev species. The equilibrium constant for this process is very dependent upon the nature of the ReV complex; K270C= 0.28 or 0.004 1 mol-', respectively, for X = C1 or OMe. The i.r. intensities of the v(N=N) stretching mode in these bridged adducts have been determined and discussed in terms of the bonding

'

D. Cullen, E. Meyer, T. S. Srivastava, and M. Tsutsui, J. Amer. Chem. SOC.,1972, 94, 7603. M. Tsutsui and C. P. Hrung J . Amer. Chem SOC.,1973, M,5777; D. Ostfeld, M. Tsutsui, C. P. Hrung, and D. C. Conway, J . Coord. Chem., 1972,2,101. loZz S. Cradock, E. A. V. Ebsworth, and A. Robertson, J.C.S. Dalton, 1973, 22. loz3 J. Chatt, J. R. Dilworth, and G. J. Leigh, J.C.S. Dalton, 1973, 612. loZ4 M. E. Tully and A. P. Ginsberg, J. Amer. Chem. Soc., 1973, 95,2042. l o Z 5 B. Folkesson, Acta Chem. Scand., 1973, 27, 276. loZo

Ioz1

172

Inorganic Chemistry of the Transition Elements

in these complexes.'o26 The formation of simple adducts containing the Re-N=N-AlR, group has been monitored by 1.r. spectroscopy and the relative base strengths of ligating dinitrogen in a series of related complexes have been assessed ;in some instances crystalline 1 :1 adducts were isolated.804 Nitrosyl Complexes.-[(n-Cp)Re(CO) 2NO]+ reacts with NaBH, in THF to afford [(IT-Cp)ReMe(CO)NO], and with Et,N in H,O-acetone to produce [I(~F-CP)R~H(CO)NO].~~~~ [ReH,(PPh,),] reacts with NO in refluxing EtOH in the presence of R,NX (R = Me or Et; X = C1, Br, or I) to produce the corresponding [Re(PPh,),(NO),X] complex. Under these conditions [ReO(OEt)X,(PPh,),] forms both (R,N),[Re(NO)X,] and [Re(NO)X,(PPh,),] (R = Me, Et, Bu, or P h ; X = C1 or Br); [Re(NO),I(PPh,),] is obtained from ReO(OEt)I,(PPh,), in the absence of a tetra-alkylammonium salt.1028Several new rhenium nitrosyl complexes have been prepared according to Scheme 5 and characterized by analytical and spectroscopic studies. 0 2 9

/'

CO (1200 Zn-Etp.s.i.) OH

j

excess 1

Scheme 5 Cyanide Complexes.-The i.r. and Raman spectra of K,[M(CN),] (M = Mn, Tc, or Re) have been recorded from 40 to 4000 cm-', and the frequencies observed assigned with the aid of normal-co-ordinate analyses. The low C-N force constants obtained suggest that the M 4 bond has considerable n-character, especially in the case of the technetium complex.'030 An improved synthesis of K,[Re(cN),],H,O has been reported, which consists of heating an aqueous suspension of K,[ReCl,] with KCN. The unit-cell characteristics of this compound have been determined.' 03' H[ReOFD. J. Darensbourg, Inorg. Chim. Act4 1972,6, 527. R. P. Stewart, N. Okamoto, and W. A. G. Graham, J . Organornetallic Chem., 1972,42, C32. l o 2 * D. Giusto and G. Cova, Gazzetta, 1972,102, 265. 1 0 2 9 J. R. Norton and G. Dolcetti, Inorg. Chem., 1973.12, 485. W Krasser. E. W. Bohres, and K . Schwochau, Z. Naturforsch., 1972,27a. 1193 0.E. Skolozdra, K. N. Mikhalevich, and A. N. Sergeeva, Vim. L'viv. Politekh. lnst., 1971, 60, 23 (Chem. Abs. 1972,77,55 792e); 0. E. Skolozdra and A. N. Sergeeva, Zhur. ric.org, Khini., 1973, 18. 552. 1*26

lo2'

The Early Transition Metals

173

(H,O)(CN),] has been prepared by boiling K,[ReO,(CN),] with 40"/, aqueous HF.'032Thisacid(pK30ec= 3.3)isweaklyparamagnetic(p = 0.40BM) and the rates of oxygen exchange between H,O and several of its salts and between H,O and [Re2O,(CN),J4- have been determined. For the latter, the rate of terminal oxygen exchange is ca. 40 times faster than that for bridging exchange.'033 Hydrido-complexes.- Several rhenium hydrido-complexes have already been described in the preceding sections. The synthesis and reactivity of hydridocomplexes have been reviewed.' 0 3 , The first observation of magnetic equivalence of ligand nuclei in seven-co-ordinate complexes has been reported for the compounds [ReH,(L,),] (L = Ph,ACH,CH,APh,, A = P or As). Their low-temperature 'H n.m.r. spectra indicate that two of the three hydridoligands are equivalent, as expected for a pentagonal-bipyramidal co-ordination geometry, and it is suggested that an A atom of each chelate occupies an axial site in this structure. However, the apparent magnetic equivalence of the phosphorus atoms of the diphosphino-complex at - 50 "C suggests that these complexes are probably not completely rigid even at this temperature The related [ReH,L,(PPh,),] complexes have also been studied, although no indication of any preferred conformation could be obtained. 035 Stereochemical non-rigidity has also been observed by 'H n.m.r. spectroscopy for the eight-co-ordinate complexes [ReH,(APh,Et),] (A = P or As) : three distinct fluxional processes were frozen-out between 30 and - 135"Cand the observed pattern of hydrido-proton equivalence was accounted for by geometries based on the trigonal dodecahedron, the truncated octahedron, and the bicapped octahedron. These structures all have C , symmetry and differ only by small displacements of the hydrido-groups. '03, The internal vibrations and hindered rotation of [ReHgI2- ions have been studied by neutron scattering spectroscopy for both the Na' and K + salts.'037 Binary Systems and Related Compounds.-HaEides. The vapourization characteristics of ReBr, have been studied by effusion techniques and the enthalpy and entropy of sublimation determined as 200 kJ mol- and 227 e.u. (per mole of trimer), r e s p e ~ t i v e l y . ' The ~ ~ ~X-ray characteristics of rhenium(@ iodide, prepared from HReO, and HI in MeOH at 80-90 "C, have been reported.1039 The crystal structure of the p-form of ReCl, obtained by the reaction of Re,CI, or SbCI, with ReCI, has been investigated. This polymorph is composed of Re,Cl, units, each of which comprises two face-sharing ReC1, octahedra, linked by shared terminal chlorine atoms. The Re-Re separation in

'

1034

1036

lo3'

M. C. Chakravorti and M. K. Chaudhuri, .I Inorg. . Nuclear Chem., 1972,34, 3479. D. L. Toppen and R.K. Murmann, Inorg. Chem., 1973,12,1611. D. Giusto, Inorg. Chim. Acta, Rev., 1972,26,91. A. P. Ginsberg and M. E. Tully, J . Amer. Chem. SOC., 1973,95,4749. A. P. Ginsberg, S. C. Abrahams, and P. B. Jamieson, J. Amer. Chem. SOC., 1973,95,4751 J. W. White and C. J. Wright, J.C.S. Faraday. ZZ, 1972.68, 1414. R. W. Lins and R. J. Sime, High Temp. Sci., 1973,5, 56, (Chem. Abs., 1973.78.102742~). D . V. Drobot and L. G. Mikhailova, Zhur. neorg. Khim., 1973,18,31.

174

Inorganic Chemistry of the Transition Elements

the dimeric units of 272.8(2) pm is indicative of a direct metal-metal interaction. X-Ray powder diffraction patterns have shown that the form of ReCl, obtained by the dechlorination of ReC1, with CCl,=CCl, is not isostructural with P-ReC14.1040 ReF, may be prepared by the reduction of ReF, on either a rhenium or tungsten filament.283 The enthalpies of formation of R ~ C ~ , ( S ) ' ~and ~'* R ~ B ~ , ( s ) " ~have ' ~ been estimated as -360 & 3 and - 195 kJ mol-' from hydrolysis measurements and by treating ReBr, with Br,, respectively. Halogen n.q.r. transitions have been observed for the dimeric Re,X,, (X = ,'Cl, "Br, or 1271) molecules and discussed in terms of metal-ligand x-bonding intera c t i o n ~s . ~ A report claiming the resolution of the PQR structure in the i.r. vibrational spectrum of ReF, has been challenged following further studies with improved resolution. The features attributed to the resolved branches are probably due to ReOF, contamination.'042b The enthalpy of formation of ReF,(g) has been estimated as - 1350 & 10 kJ mol-' from hydrolysis measurements. i h e reaction of ReF, with BCl, under various conditions has been shown to yield ReCl, as the only major solid phase, and thus the existence of ReC1, is further q ~ e s t i o n e d . " ~ ~ " The fundamental vibrational frequencies of ReF,(g) have been assigned on the basis of a normal-co-ordinate analysis assuming regular pentagonalbipyramidal symmetry.'043 Oxides. Single crystals of ReO, have been synthesized by chemical transport at 850-900 "C using iodine as a carrier.845 ReO, has been classed as an infinitely adaptive structure2' and the structural relationship betweefi MOO,-type and Re0,-type lattices has been clarified.*4yA number of bronze and tunnel structures may be derived from that of ReO, by a simple geometric operation; examples include the tetragonal bronze and related MosO14 and LiNb,O,,F structures. They have been shown to form families of crystallographic shear structures of a new type.'044 The magnetic susceptibility of ReO, has been measured from 77 to 300 K and the values obtained emphasize the structural relationships between the ReO, and Na,WO, lattices; their magnetic properties are very similar as x approaches unity.'045 Nitrides and b r i d e s . Nitridation of a MoRe alloy has afforded the new phase Moi .7 ,Re,. 2 4Na8 Phase equilibria in the Re-Al-B system have been studied, and one ternary compound Re,Al,B was found to be in equilibrium with several binary

,

lo40 1041

1042

1044

F. A. Cotton, B. G. DeBoer, and Z. Mester, J . Amer. Chem. SOC., 1 9 7 3 , s . 1159. (a) J. Burgess, C. J. W. Fraser, I. Haigh, and R. D Peacock, J.C.S. Dalton. 1973, 501; (6) K. V. Ovchinnikov, S. E. Logai, and N. I. Kolbin, Zhur. obshchei. Khim., 1972, 42, 1180, 1183. (a) W. Levin, S. Abramowitz and A. Mueller, J . Mol. Spectroscopy, 1972. 41, 415, (b) R. S. McDowell and L. B. Asprey, ibid., 1973,45, 491. E. Wendling and S. Mahmoudi Rev. chim. Min&ale, 1972, 9, 291. B. G. Hyde and M. O'Keeffe, Acta Cryst., 1973, A29, 243 J. D. Greiner and H. R. Shanks, J. Solid State Chem., 1972,5, 262

The Early Transition Metals

175

compounds including Re,B and Re7B3.1046The ternary borides Cr,Re,B,, CrRe3B4-,, and MnRe,B, have been characterized by X-ray diffractometry.6 Compounds with Tc-Tc or Re-Re Bonds.-A number of such metal-metal bonded compounds have been mentioned in the sections describing carbonyl complexes and binary compounds. K3[Tc,C1,],2H2O has been shown to be isostructural with the corresponding Cs' and NH: salts. The [Tc,Cl8l3- ions thus have approximate D,, symmetry and the Tc-Tc and T c 4 l bond lengths have been determined as 213 and 230 pm, re~pectively."~~ The salts M8[Tc,C18],,xH,0 (M = K, Cs, or NH,; x = 2 or 4) have been prepared by reducing the corresponding M[TcO,] derivative by H, in HC1, at an initial pressure of 30 atm at 170°C, for 5 h. The spectral and magnetic properties of these salts have been determined and these data, together with the stoicheiometry of the compounds, suggest that they contain both [Tc,C~,]~- and [Tc,C~,]~- ions.'048 The relationship between the length and multiplicity of Re-Re bonds has been discussed with reference to the length of this bond (229 pm) in [Re,Cl,(C,H,,SZ)z].1049 The diamagnetic anisotropy induced by M-M multiple bonds has been examined as a technique for probing the multiplicity of such systems for compounds containing strong Mo-Mo and Re-Re interaction~.~ The reactions of ReCl, with unidentate N-donor ligands (L = py. b- and y-picoline, isoquinoline, quinaldine,. or benzimidazole) have resulted in the formation of a new class of dark green-black rhenium(I1)derivativesof stoicheiometry [ReCl,L]. Related reactions have also been observed for or-picoline, 2,6-lutidine, 2-vinylpyridine, and quinoline, but the dark blue-purple products precipitate before reduction to Re" is complete. Heterocyclic tertiary amines of pK, c 3 do not undergo redox reactions with ReCl, but instead form simple adducts [ReCl,,L] (L = pyrazines or 3-chloropyridine). By using very short reaction times the similar intermediates [ReCl,,py] and [ReCl,.,,py] have been isolated from the py system. All of the above.products react with MeOH-HCl to afford the corresponding (amineH),[Re,Cl, salt. The results of spectral, magnetic, and conductance studies oh the [ReCl,L] and [ReCl,.,,py] phases suggest that they are best considered as polymeric [Re3C1,,3L], and [Re,Cl,. ,,3py], structures, respectively.' 0 5 0 The unit-cell parameters of ReSn(thiourea),C1,,H2O, prepared by treating HReO, in HCl (3 mol 1- ') with thiourea and a solution of SnCl, in HCl (10 mol 1-'), have been determined,'05' and this rhenium(@ compound merits further study. The reduction

''

N. F. Chaban and Yu. B. Kuz'ma, Izvest. Akad. Nauk S.S.S.R., neorg. Materialy, 1972, 8, 1065. N. A. Koz'min, G. N. Novitskaya, and A. F. Kuzina, Zhur. strukt. Khim., 1972, 13, 941. lo4* M. I. Glinkina, A. F. Kuzina, and V. I. Spitsyn, Zhur. neorg. Khim., 1973, 18, 403. P. A. Koz'min, Doklady. Akad. Nauk S.S.S.R., 1972, 206, 1384. l o 5 0 D. G. Tisley and R. A. Walton, Inorg. Chem., 1973,12, 373. 'OS1 V. G. Kuznetsov, G. N. Novitskaya, P. A. Koz'min, and L. V. Borisova, Zhur neorg. Khim., 1973,18, 1135.

176

Inorganic Chemistry of the Transition Elements

of [Re,X8I2- (X = Cl or Br) has been followed by d.c. polarography, cyclic voltammetry, and controlled potential coulometry and shown to proceed in two distinct steps; the first of these is reversible for [Re2C1,]2-.1052 Acridine (L) reacts with an acetone solution of ReC1, to afford (HL),[Re,CI,] which contains the previously unknown polymeric [Re,Cl,]:"anion. The structure of this species has been discussed with reference to spectral measurements which include the X-ray photoelectron determination of the rhenium-4f' and chlorine-2p binding energies. Related studies have also been made for several salts containing [Re,C1,,I3- and [Re,C1,,]3The chlorine-2p binding energies afford a distinction between bridging and terminal chlorine atoms in [Re,Cl,]"- ( n = 1 or 2)lo5, and [Re3C1,,3L] (L = PPh,, DMP. or p y r a ~ i n e ) complexes. '~~~ ReCl, reacts with anhydrous liquid NH, at its boiling point to produce [Re,Cl,(NH,),(NH,),], which appears to retain the triangular Re,Cl, arrangement intact and to include one terminal C1. one NH,, and one NH, moiety per rhenium.'055 ReCl, reacts with the mixed ligand (Ph,AsCH,CH,),PPh (L) in boiling MeCN to afford the brown [Re,Cl,L,] complex. O 5 (Bu,N),[Re,Cl,] undergoes halogen replacement with KSeCN which has been characterized by in MeCN to yield (Bu,N),[Re,(NCSe),], spectral and t.g.a. studies.1057 Technetium(n1) and Rhenium(IIr).-The majority of studies concerned with this oxidation state are included in the preceding section. Methyleneamidocomplexes of rheniump) have been obtained by the deprotonation of alkylimido-complexes by bases such as py or Et,N. Thus [ReCl,(N=CH,)py(PPh,R),] (R = Me, Et, or Ph) have been prepared by the action of py on trans-[ReC1,(NMe)(PPh2R),]. Et,N also deprotonates this complex ;however, stable complexes are only obtained in the presence of other potential ligands and [ReCl,(N=CH,)(PMe,Ph),] has been prepared in this manner. These green solid methyleneamido-complexes, but not their solutions, are stable in air and electronic considerations suggest that they contain a linear Re--N-< system.'Oo6 Technetium(1v) and Rhenium(rv).-The preparation, isolation, and characterization of ReOC1, have been reported. This oxyhalide may be prepared by a variety of methods, including the reactions between ReO, and ReCl, or ReOC1,. Although the unit-cell parameters have been determined. multiple crystal growth and/or twinning effects prevented a complete structural characterization. However, possible structures have been discussed with reference to the unit-cell data and i.r. spectrum, which surprisingly contained no absorption in the v ( R e 4 1 ) stretching region. Compared with other oxochlorides of rhenium, ReOCl, is stable with respect to air and H 2 0 , but is markedly 1052 1053 1054

'05'

R. R. Hendriksma and H. P. Van Leeuwen, Electrochim. Acta, 1973. 18, 39 D. G. Tisley and R. A. Walton, .I. Inory. Nuclear Chem.. 1973,35, 1905. D. G. Tisley and R. A. Walton, J.C.S. Dalton, 1973, 1039. D. A. Edwards and R. T. Ward, J . lnorg. Nuclear Chem., 1973,35, 1043. R. B. King and R. N. Kapoor, Inorg. Chim. Acta, 1972,6, 391. R. R. Hendriksma, Innrg. Nuclear Chem. Letters, 1972.8, 1035.

The Early Transition Metals

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thermally unstable and decomposes to a variety of ReC1, reacts with NH,Cl at 195°C to give ReCl,,NH, which affords ReCl,(NH,) and ReNCl at 250 and 400 "C, respectively. This rhenium(1v) nitride chloride is paramagnetic and decomposes in an inert atmosphere at 450°C to form Re2NC1.'05* The salts M,[TCX,] (M = NH,, X = C1, Br, or I ; M = K. X = C1 or Br; M = Rb or Cs, X = C1) have been prepared and their unit-cell parameters determined. The M,[TcCl,] compounds have the K,[PtCl,]-type structure.'059 (AH),[Tccl,] (A = py, bipy, or quinoline) have been obtained by adding a solution of the corresponding base in aqueous HCl to a saturated solution of K,[TCC1,] in HCl (11.6 mol 1-').'060 The i.r. spectra of M,[TCCl,] (M = K or Cs) have been recorded and assigned with the aid of normal-co-ordinate analyses.lo6' The crystal structure of (Me,N),[Tc(NCS),] has been determined'062" and the anions [Tc(NCS),I2 - and [Tc(NCS),]- have been shown to form a redox system, E",,,, = + 0.53 V'0626 Far-ix. spectra of the hexahalogeno-complexes of rhenium(1v) have been determined for benzene solutions of these anions dissolved with the aid of high-formula-weight alkyl ammonium cations. O 6 The effective magnetic moments of octahedral rhenium@) complexes have been shown to be affected by magnetic exchange interactions between anions in crystals. The use of large organic cations as a diluent diminishes this effect, the magnetic behaviour then following the Curie-Weiss law with low 8 values.1064 X-Ray photoelectron spectroscopy has been used to determine the rhenium 4f and chlorine 2 p binding energies in [ReX,]'-(X = C1, Br, or NCS)lo5, the results being interpreted on a MO ~ c h e m e . " ~The splitting of the rhenium 5d orbitals in K,[ReCl,] has been observed by examining the structure of the metal's LIII X-ray absorption di~continuity,''~~ and n.m.r. measurements on single crystals of this compound have been interpreted as indicating that the R e 4 1 bonds have ca. 8 % n-character,1066Bu,PO, and related organophosphates effectively extract [Recl,]'from aqueous into organic phases ; however. [ReOC1,,J4- is not extracted in such systems.'067 [ReCl,(acac),] has been

'

1058

'060

1065

lo''

G

Yu. A. Buslaev, M. A, Glushkova, and A. M. Bol'shakov, Izvest. Akad. Nauk S.S.S.R., neory. Materialy, 1973,9, 500. L. L. Zaitseva, M. I. Konarev, P. B. Kozhevnikov, I. V. Vinogradov, A. A. Krylov, and N. T. Chebotarev, Zhur. neorg. Khim., 1972, 17, 2411; A. F. Kuzina, P. A. Koz'min, and G. A. Novitskaya, ibid., 1973, 18, 841. A. F. Kuzina, A. A. Oblova, and V. I. Spitsyn, Zhur. neorg. Khim., 1972, 17, 2630. M. Baluka, J. Hanuza, and B. Jezowska-Trzebiatowska, Bull; Acad. polon. Sci., Ser. Sci. chim., 1972, 20,271 (Chem. A h . , l972,77,54341v). (a) J. Hauck and K. Schwochau, Inorg. Nuclear Chem. Letters, 1973,9, 303; (6) K. Schwochau. L. Astheimer, and H. J. Schenk, J . Inorg. Nuclear Chem., 1973,35,2249;(c) J. Hauck, K. Schwochau, and R. Bucksch, Inorg. Nuclear Chem. Letters, 1973,9, 927. D. A. Kelly and M. L. Good, Spectrochim. Acta, 1972, 28A, 1529. V. V. Zelentsov, N. A. Subbotina, V. I. Spitsyn, 1. A. Emel'yanova, A. I. Busev, and V. K. Akimov. Doklady Akad. Nauk. S.S.S.R., 1972, 205, 1124. C. Mande, A. V. Pendbarkar, and M. C. Chakravorti, Proc. Zndian Acad. Sci. (A), 1972. 75, 209 (Chem. Abs., 1972,77, 144973g). A. G. Brown, R. L. Armstrong, and K. R. Jeffrey, J . Phys. (C), 1973,6, 532. N. Iordanov and M. Pavlova, Chem. Anal. (Warsaw), 1972,17,819(Chem. Abs., 1973,78,89 175s).

178

Inorganic Chemistry of the Transition Elements

shown by X-ray crystallography to consist of trans-octahedral monomeric molecules in the solid state, in contrast to the dimeric structure claimed to exist in solutions.lo6*Rhenium(rv) complexes with amino-acids, K,H,[Re20L4(SO,),(OH),] (HL = aspartic or glutamic acid), have been synthesized by refluxing K,[ReCl,] with HL in H2S04.Their i.r. spectra indicate the presence of R e 4 - R e units, co-ordinated and unco-ordinated carboxylate groups, and protonated amino-groups. The aspartate complex is diamagnetic and the glutamate one slightly paramagnetic.' 069 Technetium(v) and Rhenium(v).-The anion of the salt [Re(CO),]+[Re ,F, obtained from the reaction of ReF, with Re,(CO),, in anhydrous HF, has been shown by X-ray crystallography to be centrosymmetric. The Re-F--Re bridge is therefore linear and Re-F terminal and bridging bond lengths have been determined as 184(2) and 201( 1) pm, respectively. 'O C1

(93)

The compound previously reported as 0-ReOC1, has been shown by X-ray (93).'070 A re-investigation crystallography to be [(Re,O,Cl,)(ReO,C1),] of the properties of M,[ReOCl,] (M = Rb or Cs) has shown that they contain low-spin ReV centres. The products previously reported appear to have been contaminated with [ReC1,I2- and/or [ReO,] -.'07' The i.r. and electronic spectra of M,[TcOCl,] (M = K, Cs, or NH,) and [TcO,(en),]Cl have been recorded and assigned with the aid of model calculations.'061 A large range of [ReOC1,I2- salts has been prepared, including those with cations derived by protonation of bases such as py, bipy, phen, a-picoline, 1,2-propylenediamine, or quinoline. The thermal decomposition of these complexes affords the corresponding [ReOCl,L,] complex (L = unidentate or bidentate l i g a n d ~ ) . ' ~ ' ~ [TcO,(py),]Cl,xH,O has been prepared by neutralizing an aqueous HC1 solution of K,[TcCl,] with py1060 and the unit cell parameters of this and the isostructural rhenium(v) compound have been determined.' O 7 The crystal structure of [ReO, (en),]Cl has been determined; the 0-Re--0 group is essentially linear and the average Re-0 and Re-N distances are 175 and

lo6'

lo''

''''

I. D. Brown, C. J. L. Lock, and C. Wan, Canad. J . Chern., 1973,51, 2073. S. M. Basitova, F. Sh. Shodiev, N. K. Kobilov, and M. P. Sokolova, Doklady Akad. Nauk S.S.R., 1972, 15. 30. C. Calvo, P. W. Frais, and C. J. L. Lock, Canad. J. Chern., 1972,50, 3607. J. E. Fergusson and J. L. Love, Austral. J. Chern., 1971, 24, 2689. R. D. Swarnakov and D. K. Chakrabarty, Indian J . Chern., 1972, 10, 528. V. G. Kuznetsov, G. N. Novitskaya, P. A. Koz'min, and A. S. Kotel'nikova, Zhur. neorg. Khirn., 1973,18, 1060.

The Early Transition Metals

179

216 pm, r e s p e ~ t i v e 1 y . lMe,N[Tc(NcS),] ~~~ has been studied by i.r. and U.V. spectroscopy and X-ray crystallography. The anions contain the ambidentate ligands co-ordinated oia their nitrogen atoms. [ReNC1(Ph2PCH,CH,PPh3,1C1 has been prepared by treating the diphosphine with [ReO,] - and N2H,,2HCl in neutral or weakly acidic followed by further solution to produce [ReOCl,(Ph,PCH,CH,PPh,)], reaction with N2H,,2HC1 in EtOH containing the p h o ~ p h i n e . " ~This ~ and related compounds may also be prepared by ligand displacement reactions from [ReNCl,(PPh,),]; thus [ReNX,(PPh,),] (X = C1, Br, or I) react with ligands [L, = py,, Ph,P(CH,)nPPh,; n = 1, 2, or 31 to produce the corresponding [ReNX(L,) ,]X salt.' [Re(dtcEt,),][Re(CO),Cl(dtcEt,)] (dtcEt, = diethyldithiocarbamato) has been separated as one of the products following the reaction between Re(CO),CI and tetraethylthiuram disulphide; the cation was separated as its BPh, - salt. The oxidation and reduction characteristics of this cation have been determined in acetone solution with NaClO, as the supporting electrolyte, and an oxidation wave at 0.23 V (us. SCE) and two reduction waves at -0.65 and - 1.14V ( Z I S . SCE) were ~bserved.~" Cyano-complexes of rhenium(v) are described on p. 172,and the comparative rates of oxygen-exchange between the' H,O and the terminal and bridging 0x0-atoms of [Re,0,(CN),]4- have been investigated. Other dinuclear 0x0-rhenium(v) complexes studied this year include [(ReOL),O] (H,L = ~ctaethylporphine)'~" and H, [(C,0,)(HO),ReORe(OH)3F2] and its Na+,K + , and NH4+ salts, the acid being prepared by boiling freshly precipitated ReO, with oxalic acid and 40% aqueous HF.1077The full report of the crystal structure of [Re,O,(en),Cl,] has been published.lo7* Rhenium( VI).-A high-yield synthesis of ReOF,, by the partial hydrolysis of ReF, using moist glass, has been reported and the compound further characterized. X-Ray crystallography has shown that the compound previously reported as P-ReOCl, is in fact poxo-bis{oxotrichloro(o-perrhenyl chloride) rhenium(vI)) (93)composed of a dimeric Re,O,Cl, unit with a bridging oxygen atom on the centre of symmetry, R e 4 = 184.7(1)ppm. The remaining oxogroup on each rhenium, cis- to the bridging atom, is strongly bonded [ R e 4 = 169(2) pm] and the position trans- to the terminal 0x0-group is occupied by a weak bond to an oxygen atom of a perrhenyl chloride molecule.'070 Technetium(vI1) and Rhenium(vr~).-Pr[TcO,] ,,4H,O has been prepared by the interaction of Pr,Ol in 50 % excess with a solution of HTcO,, and X-ray

1075

'07'

1077

T. Glowiak, T. Lis, and B. Jezowska-Trzebiatowska,Bull. Acad. polon. Sci., Ser. Sci. chim., 1972,20,957 (Chem. Abs., 1973,78, ~ 1 1 9 9 ~ ) . W. Jabs and S. Herzog, Z . Chem., 1972, 12,268. (a) W. Jabs and S. Herzog Z . Chem., 1972, 12, 297; (b) N. P. Johnson, J . Inorg. Nuclear Chem., 1973,35, 3141. M. C. Chakravorti and M. K. Chaudhuri, J . Inorg. Nuclear Chem., 1973,35949. T. Glowiak, T. Lis, and B. Jezowska-Trzebiatowska, f i l l . h a d . polon. Sci., Ser. Sci. chim., 1972, 20, 199 (Chem. Abs., 1972,77, 534918). R. T. Paine, Inorg. Chem., 1973,12, 1457.

Inorganic Chemistry of the Transition Elements

180

studies have shown that the compound is isomorphous with its rhenium(vr1) analogue.1080 1.r. and electronic spectra have been reported for M[TcO,] (M = K or Ag)'06' and low-temperature electronic absorption spectra obtained for [Tc04]- and [ReO,]- doped in KC10,.1081 The splitting of the main discontinuity in the L,,, X-ray absorption edge of Re in [ReO,]- salts has been determined and discussed with respect to the electronic structure of this ion.'065 Pure quadrupole resonance spectra have been recorded for M[ReO,] (M = Na, NH,, or Ag) salts and the frequencies of both transitions for both rhenium isotopes recorded at room temperature. The lack of accurate structural data for these salts precludes a detailed interpretation of this information.'082 The solvent extraction of [Re04]- ions by Bu,PO, and related organophosphorus compounds has been studied.' 0 6 7 Borohydride reduction of perrhenate has been shown to produce a mixture of species. the effective overall oxidation state of metal in the products being between 11 and 111.

Og3

A mass spectrometric study has revealed the existence of both Re,O, and [Ba(ReO,),] in the vapour above BaCReO,], at elevated temperatures.' O S 4 Electron diffraction studies have shown that Re,O,(g), obtained by decomposition of Ni[ReO,], at ca. 500°C, consists of two ReO, tetrahedra linked by a common vertex, the R e 4 - R e interbond angle being 165 f 15". The low deformation frequency for the bending of this angle, 177 cm-', contributes to the uncertainty in its value. The R e 4 terminal and bridging bond lengths were estimated as 170(2) and 1 8 q 9 pm, r e s p e ~ t i v e l y . ' ~ ~ ~ The vibrational spectrum of Tc0,Cl has been measured over a temperature range and shown to resemble closely those of Re0,Cl and The 2 :1 complex formed between Re0,Cl and Re,O,Cl has been shown to have the structure (93).'070 The evaporation of a mixture of ReO, and AgI in a mass spectrometer has afforded evidence for the formation of ReO,I. The ionization potential of this molecule has been estimated as 10.9eV and its Colourless crystals of t-butyl enthalpy of formation as -445 kJ mol- '.'Oo4 perrhenate, [Me,COReO,], which are stable below - 4"C, have been prepared from R e 2 0 7and (Me,C),O. The compound and its silicon analogue react with D M F to afford Re,O,-DMF complexes.' O 8

'OSo

'08'

1085

lo''

L.L. Zaitseva, A. V. Velichko, and N. T. Chebotarev,Zhur. neorg. Khim., 1972, 17, 2634, 2639. H. U. Giidel and C. J. Ballhausen, Theor. Chim. A c t 4 1972,25, 331. M. T. Rogers and K. V. S. Rao, J. Chem. Phys., 1973,533,3233, R. A. Pacer, J. Inorg. Nuclear Chem., 1973,35, 1375. G. A. Semenov, E. N. Nikdlaev, and I. G. Opendak, Zhur. neorg. Khim., 1972,17, 1819. V. S. Vinogradov, V. V. Ugarov, and N. G. Rambidi Zhur. strukt. Khim., 1972, 13, 715. A. Guest, H. E. Howard-Lock, and C. J. L. Lock, J. Mol. Spectroscopy, 1972,43, 273. C. Ringel and G. Boden, Z . anorg. Chem., 1972,393,65.

The Early Transition Metals

181

8 Appendix Reviews relevant to the early transition elements which have not been referred to in the text include : ‘Valence in Transition Metal Complexes’, R. Mason, Chem. SOC.Reu., 1972, 1, 431. ‘Low Temperature Condensation of High Temperature Species as a Synthetic Method’, P. L. Timms, Adu. Znorg. Chem. Radiochem,, 1972, 14, 121. ‘Ligand Design and Synthesis’, D. S. Black and A. J. Hartshorn, Coord. Chem. Rev., 1973,9,219. ‘Stereochemical and Electronic Structural Aspects of Five Co-ordination‘, J. S. Wood, Progr. Inorg. Chem., 1972, 16, 227. ‘Geometry of Pentaco-ordinate Complexes‘, B. F. Hoskins and F. D. Whillans, Coord. Chem. Reu., 1973, 9, 365. ‘Trigonal Prismatic uersus Octahedral Stereochemistry in Complexes Derived from Innocent Ligands‘, R. A. D. Wentworth, Coord. Chem. Reu., 1972,9, 171. ‘Kinetics and Mechanisms of Isomerization and Racemization Processes of Six-co-ordinate Chelate Complexes’, N. Serpone and D. G. Bickley, Progr. Znorg. Chem., 1972, 17, 391. ‘Metalloprotein Redox Reactions’, L. E. Bennett, Progr. Znorg, Chem., 1973, 18, 1. ‘Excited States of Metal Complexes and their Reactions’, P. D. Fleischauer, A. W. Adamson, and G. Sartori, Progr. Znorg. Chem., 1972,17, 1. ‘Organometallic Structures of the Transition Metals-Annual Surveys for 1971 and 1972’, M. I. Bruce, J. Organometallic Chem., 1973,48, 303; 1973, 53, 141 ; 1973,58,153. ‘Transition Metals (Organometallic) Results of General Interest-1971 Annual Survey’, P. S . Braterman, J . Organometallic Chem., 1973, 53, 97. ‘The 16- and 18-Electron Rule in Organometallic Chemistry and Homogeneous Catalysis’, C. A. Tolman, Chem. SOC.Rev., 1972, 1,337. ‘Insertion Reactions of Transition Metal-Carbon o-Bonded Compounds, I : Carbon Monoxide Insertion’, A Wojcicki, Adu. Organometallic Chem.. 1973, 11, 88. ‘Transition Metal Complexes Containing Carbenoid Ligands’. F. A. Cotton and C. M. Lukehart, Progr. Znorg. Chem., 1972,16,487. ‘Transition Metal-Carbene Complexes’, D. J. Cardin, B. Cetinkaya, and M. F. Lappert, Chem. Rev., 1972,72,545. ‘The Chemistry of Transition Metal-Carbene Complexes and their Role as Reaction Intermediates‘, D. J. Cardin, B. Cetinkaya, M. J. Doyle, and M. F. Lappert, Chem. SOC.Reu., 1973, 2, 99. ‘Reaction of Organometallic Compounds of the Transition Metals with N, and CO’, M. E. Vol‘pin, Zhur. uses. Khim. Obshchest., 1972, 17, 396. ‘Dinitrogen Complexes of the Transition Metals’, A. D. Allen, R. 0.Harris, B. R. Loescher, J. R. Stevens, and R. N. Whitely, Chem. Reu., 1973,73, 11.

182

Znorganic Chemistry of the Transition Elements

‘Recent Developments in Transition Metal Nitrosyl Chemistry’, N. G. Connelly, Znorg. Chim. Acta, 1972, 6, 47. ‘Polynuclear Transition Metal Cyanides’, A, Ludi and H. U. Giidel, in ‘Structure and Bonding’, Springer-Verlag, Berlin, 1973, vol. 14, p. 1 . ‘Transition Metal Isocyanide Complexes’. P. M. Treichel, Adz,. Organometa//ic Chem., 1973, 11, 21. ‘Transition Metal Hydrides‘, ed. E. L. Muetterties, Dekker, New York, 1971. ‘Crystal Structure Transformations in Binary Halides’, C. N. R. Rao and M. Natarajan, Nat. Bur, Stand., 1972, NSRDS-NBS 41. ‘Halides and Oxyhalides of the Early Transition Series and their Stability and Reactivity in Non-Aqueous Media’, R. A. Walton, Progr. Znorg. Chern., 1972,16, 1. ‘Carbides and Silicides’, H. Nowotny, H. Boller, and G. Zwilling, Nat. Bur. Stand ( U S . ) Spec. Publ. No. 364 1972,487. ‘Crystal Chemistry of Metal Rich Refractory Sulphides’, H.-Y. Chen and H. F. Franzen, Nat. Bur. Stand. (U.S.)Spec. Pub/. No. 364, 1972, 651. ‘Metal Alkoxides and Dialkylamides’, D. C . Bradley, Adz]. Znorg. Chem., Radiochem., 1972, 15,259. ‘NN’-Ethylenebis(salicy1ideneiminato)Transition Metal Ion Chelates’, M. D. Hobday and T. D. Smith, Coord. Chem. Rev., 1973,9,311. ‘Thio- and Seleno-compounds of the Transition Metals with the d” Configuration’, E. Diemann and A. Muller, Coord. Chem. Reu., 1973. 10, 79. ‘Electronic Spectra of Tetrahedral 0x0-, Thio-, and Seleno-Complexes Formed by Elements of the Beginning Transition Groups’, A. Muller, E. Diemann, and C. K. Jerrgensen, in ‘Structure and Bonding’, SpringerVerlag, Berlin, 1973, vol. 14, p. 23. ‘Transition Metal Dithio- and Diseleno-phosphate Complexes’, J R. Wasson, G. M. Woltermann, and H. J. Stoklosa, Fortschr. Chem. Forsch., 1973, 35, 65. ‘Metal Complexes of S-containing Amino-acids‘, C. A. McAuliffe and S . G. Murray, Znorg. Chem. Acta Rev., 1972,6, 103. ‘Transition Metal Nitrido-Complexes’, W. P. Grifith, Coord. Chem. Rev.. 1972,8, 369. ‘The Co-ordination Chemistry of Pyrazole-Derived Ligands‘, S . Trofimenko, Chem. Reu., 1972,72, 497. ‘Transition Metal Complexes Containing Bidentate Phosphine Ligands’, W. Levanson and C. A. McAuliffe,Adv. Znorg. Chern. Radiochern., 1972,14,173. ‘Phosphine Complexes with Metals‘, G . Booth, in ‘Organic Phosphorus Compounds‘, Interscience, New York, N.Y., 1972, Vol. 1, p, 433. The notation used to summarize the physical properties reported for a particular compound is explained in Table A.

The Early Transition Metals

183

Table A Shorthand notationforphysicalproperties" Symbol C

ch d e e.d. e.s.r. AH i.r. K m.p. m.s. m.w. n.m.r. pol R S

st t.d. P

X

Physical propertyltechnique

conductance (electrical properties) chromatography density electronic spectrum electron diffraction electron spin resonance spectrum heat offormation infrared spectrum formation constant melting point mass spectrum molecular weight nuclear magnetic resonance spectrum polarography Raman spectrum solubility molecular and/or crystal structure thermal gravimetric analysis, differential thermal analysis, or thermal decomposition magnetic moment at room temperature X-ray powder diffraction pattern and/or unit cell dimensions

(a) It has been assumed that all compounds reported have been characterized by elemental analysis

2 Elements of the First Transitional Period BY R. DAVIS

1 Manganese

Carbonyl Compounds.-Irradiation studies on Mn,(CO) have been reported by two groups. Photolysis of the carbonyl (A = 350nm) in T H F yields the paramagnetic species Mn(CO);, identified by e.s.r. methods. The radical reacts with iodine to give Mn(CO),I and reverts to Mn,(CO),, on storage.' An e.s.r. study of y-irradiated Mn,(CO),, and Mn(CO),Br at 77 K has led to the identification of the corresponding radical anions. The unpaired electrons are largely confined to Mn-Mn and Mn-Br a-orbitals, respectively., When Zn[Mn(CO),], is treated with dry methanol, { MeOZn[Mn(CO),]), is formed in 75 % yield. The corresponding ethoxy-compound has also been r e p ~ r t e d .A~ second structural study4 on Hg[Mn(C0)5]2 and a complete report of the X-ray structural study' on [(2,2' :6',2"-terpyridyl)Cd(Mn(CO)s)2] discussed in Volume 2 (p. 179) have appeared. Reaction of gallium metal with ] ~which , Mn,(CO),, in a sealed tube gives red crystals of G ~ , [ M ~ I ( C O ) ~for the structure {[(CO),Mn]Ga-Ga[Mn(C0),1,) is proposed on the basis of i.r. and Raman spectral evidence. (In[Mn(CO),],] can be prepared by a similar reaction6 Treatment of Na[ Mn(CO)'] with Ph2T1Cl in ether yields Ph2Tl[Mn(CO),] ; however, the corresponding reaction with PhTlC1, gives ClTI[Mn(C0),],.7 A vibrational spectroscopic study of the mixed metal carbonyls (CO),MCo(CO), (M = Mn or Re) has been reported.8 The structure of [Mn,(CO),(SiPh,),] has been determined.g The dimer is formed by two cis-Mn(CO), units symmetrically linked to each other by two bridging Ph,Si moieties. The Mn,Si, ring is planar, but has Mn-Si-Mn bond separation of 2.871A [cf. Mn-Mn = angles of 73.4" and a Mn-Mn 2.923 A in Mn,(CO),,] indicating the presence of an electron-pair manganesemanganese bond. An X-ray structure study on [(Me, Si),SiMn(CO),] has also appeared." The relative orientationsof the Me,% and C O groups in the approxiS. A. Hallock and A. Wojcicki, J. Organometallic Chem., 1973, 54, C27. 0. P. Anderson and M. C. R. Symons, J.C.S. Chem. Comm., 1972, 1020. J. M. Burlitch and S . E. Hayes, J. Organometallic Chem., 1972,42, C13. M. L. Katcher and G. L. Simon, Znorg. Chem., 1972, 11, 1651. W. Clegg'and P. J. Wheatley, J.C.S. Dalton, 1973, 90. H. J. Haupt and F. Neumann, Z . anorg. Chem., 1972,394,67. H. J. Haupt and F. Neumann, J. Organometallic Chem., 1973,50, 63. * W. T. Wozniak and R. K. Sheline, J . Jnorg. Nuclear Chem., 1973,35, 1199. G. L. Simon and L. F. Dahl, J. Amer. Chem. SOC.,1973.95783. l o B. K. Nicholson, J. Simpson, and W. T. Robinson, J . Organometallic Chem., 1973,41,403.

185

Inorganic Chemistry of the Transition Elements

186

mately octahedral complex are such that the energy due to non-bonding interactions is minimized. The Mn-Si bond length of 2.564A indicates that the bond has no multiple character. Treatment of the respective metal carbonyl dimers with HSiF, at elevated temperatures yields [F,SiMn(CO),] and [F,SiMn(CO),PPh,]." Photoelectron spectroscopy of H,M- Mn(CO), (M = Si or Ge) gave no evidence for M-Mn (d-d)n bonding." The reaction of NaMn(CO), with Me,SiCl, followed by the addition of Ph,P and acetic acid, led to the accidental isolation of [(MeCO,)Mn(CO),(PPh,),]. A structural study has shown the phosphine ligands to be mutually trans and the acetate group to be bidentate.13 New methods reported for the synthesis of [Me,SnMn(CO),] involve treatment of Mn,(CO),, with either (Me,Sn),O or (Me3Sn),Nl4 or with Me,SnH;' however, the latter gives much lower yields than other established routes. [Me,SnMn(CO),] has been found to be unaffected by water, methanol, or aqueous NaOH ; however, 1,2-dibromoethane and HgCl, produce quantitative cleavnge of the Sn-Mn bond and CF,COCl and HSiCl, give [Me,ClSnMn(CO)5].1sThe reaction ofiodine with [Me,SnMn(CO),]and[(CH,---=CHCH,),SnMn(CO),] has also been studied. The former gives Sn-Mn bond cleavage, whereas for the latter S n 4 bond cleavage is observed.16 The same paper also reports the reactions of Mn,(CO),, with MCI,(M = Si, Sn, or Ti), ZnCl,, and HgCl,. Treatment of Mn(CO),Br with MeSnL (L = dithiocarbamates, monothiocarbamates, ureas, or thioureas) led to the isolation of [Mn(CO),NMe2

(?'\I

c c,

Ph, 0

,C

Y

I

0

\

c

I

NMe (2) X

=

0 or S

(S,CNMe,)] and [Mn(CO),L], (L = OSCNMe,, PhNCONMe,, and PhNCSNMe,). The dithiocarbamate ligand is bidentate and structures (1) and (2) are proposed for the dimeric Ph,Pb[Mn(CO)5]2 has been isolated from the reaction of Ph,PbCl, and NaMn(CO),. Treatment of M. E. Redwood, B. E. Reichert, R. R. Schrieke, and B. 0. West, Austral. J . Chem., 1973,26,247. l2

S.Cradock, E. A. V. Ebsworth, and A. Robertson, J.C.S. Dalton, 1973,22.

l3

W. K. Dean, G. L. Simm, P. M. Treichel, and L. F. Dahl, J . Organometallic Chem., 1973,50,193. E. W. Abel and M. 0. Dunster, J . Organometallic Chem., 1973,49,435. R. A. Burnham, F. Glockling, and S. R. Stobart, J.C.S. Dalton, 1972, 1991. R. M. G. Roberts, J . Organometallic Chem., 1973,47,359. E.W. Abel and M. 0. Dunster, J.C.S.Dalton, 1973,98.

l4 l6

''

Elements of the First Transitional Period

187

this diphenyl compound with halogens in chloroform yields X,Pb[ Mn(CO),], (X = C1 or Br). Decomposition of the dibromo-complex has been observed in acetone yielding PbBr, and Mn,(CO), ,. The corresponding complex Me,Pb[Mn(CO),], is formed, together with Me,Pb, when Me,Pb[Mn(CO),] is treated with THF.' The reaction of Mn,(CO),, with PPh,Me in petroleum spirit or n-propanol gives trans-[HMn(CO),(PPh,Me),], an X-ray structural study of which yields an Mn-H bond length of 1.5 A.1yc i ~ - [ H M n ( c o ) ~ ( P P hhas ~ ) ] been shown to be an effective reductant at room temperature towards a wide range of organic halides, and evidence was presented which indicates a free-radical mechanism for these reactions involving the Mn(CO),(PPh,). species.,' [HMn(CO),L] (L = CO or PPh,) reacts with aziridine (3) in T H F at 20°C to yield initially [LMn(CO),CH,CH,NH,] and finally (4), whereas reaction of HMn(CO), with 2-methylthiiran ( 5 ) under similar conditions gives [(CO),Mn(p-SH),Mn(CO),] and CH,=CHMe. The thio-bridged dimer is thought to arise via the intermediacy of Mn(CO),SH, but this was not isolated.,'

(3)

Mn(CO),X and [Mn(CO),X], (X = C1 or Br) have been found to coexist in equilibrium in benzene, the position of equilibrium depending on the carbon monoxide concentration. Similarly, [Mn(CO),L,X] and [Mn(CO),LX], [L = methylmethacrylate (mma) or MeCN] are also easily interconverted. Irradiation (A = 435.8 nm) of [Mn(CO),LX], (L = CO, mma, or MeCN) gives Mn,(CO),,, the yield of which is dependent on the nature of L. [Mn(CO),L,X] also yields Mn,(CO)lo onirradiationinconditions wherethereaction [Mn(CO),L2X] -P [Mn(CO),LX] + L is not inhibited by excess L. [Mn(CO),(mma),X] has been found to be an active photoinitiator of polymerization, whereas Mn(CO),X alone is not.,, Factors affecting the limiting substitution of Mn(CO),Br have been examined.,, Thus, reactions with P(OMe),, P(OEt),, P(OMe),Ph, PMe,, PMe,Ph, and AsMe,Ph givefac- and trans-[Mn(CO),L,Br] and terminate at mer-[Mn(CO),L,Br], indicating that higher substitution is little affected by the electronic properties of L, but require trans-CO groups in the substrate and attack by small ligands. This is illustrated by the reaction l8

l9 2o 21

22 23

H. J. Haupt. W. Schubert, and F. Huber, J . Organometallic Chem., 1973,54, 231. M. Laing, E. Singleton and G. Kruger, J. Organometallic Chem., 1973,54, C30. B. L. Booth and B. L. Shaw, J. Organometallic Chem., 1972,43, 369. W. Beck, H. Danzer, and R. Hofer, Angew. Chem. Internat. Edn., 1973,12, 77. C. H. Bamford, J. W. Burley, and M. Coldbeck, J.C.S. Dalton, 1972, 1846. R. H. Reimann and E. Singleton, J.C.S. Dalton, 1973, 841. J . Organometallic Chem., 1972,44, C18.

Inorganic Chemistry of the Transition Elements

188

times given in Scheme 1. trans-[Mn(CO),(P(OMe),),Br] can be prepared by hydrazine reduction of trans-[Mn(CO),{ P(OMe),) ,Br]PF, and further treatment of this product with P(OMe), yields trans-[Mn(CO){ P(OMe)3)4Br].23

Mn(CO),Br

Br

2L

0.5 h

Br

Scheme 1 (L

Br

=

PMe,)

In a similar study, Butler et al. have reported the complexes [Mn(CO),L,X] [X = C1, L = P(OMe),; X = Br, L = P(OMe),, P(OEt),, P(OCH,CH,Cl),, P(OCH,CH=CH,),, or PMe,Ph] and [Mn(CO),(triphos)X]. The complexes [ Mn(CO),L,X] react with diphos (Ph2PCH2CH2PPh2)and triphos [PhP(CH,CH,PPh,),] to yield [Mn(CO),L(diphos)X] and [Mn(CO),L(triphos)X], the latter containing triphos bound in a bidentate manner. Some of diphos complexes were also prepared from fac-[ Mn(CO),(diphos)X] and L. mer[trans-{(PhO),P},Mn(CO),X] (X = C1 or Br) reacts with bidentate donors (AA) to yield [Mn(CO),(P(OPh),}(AA)X] and small amounts of fac-[Mn).~~ also (CO),(AA)X] (AA = diphos or P ~ , A s C H ~ C H , A S P ~ , Mn(CO),Br reacts with (Ph,AsCH,CH,),PPh (L) to yield Mn(CO),LBr.25 The reaction of Mn(CO),Br with methyl isocyanide in T H F has been studied under a variety of conditions. Treatment at room temperature for 48 h yields [Mn(CO),(CNMe),Br], refluxing for 6 h yields [Mn(CO),(CNMe),Br] and refluxing for 24 h gives a mixture of [Mn(CO),(CNMe),Br], [Mn(CO)(CNMe),Br], and [Mn(CO)(CNMe),]Br. The monosubstituted product, [Mn(CO),(CNMe)Br] is obtained from a reaction between Mn2(CO),Br2 and CNMe and the series of cationic complexes [Mn(CO), -,(CNMe),] + from treatment of [Mn(CO), -,(CNMe),Br] with aluminium trichlorideand CO(x = 1-4). The reactions of Mn(CO)5X (X = c1 or Br) and CNPh in T H F have been reinvestigated as part of this study. The product distribution is again found to depend on the conditions employed and the compound previously reported

24

25

I. S. Butler, N. J. Colville, and H. K. Spendjian, J . Organometallic Chem., 1972,43, 185. R. B. King and P. N. Kapoor, Inorg. Chim. Actn, 1972,6, 391.

Elements of the First Transitional Period

189

as Mn(CNPh),Br has been shown to be a mixture of [Mn(CO)(CNPh),]Br and [Mn(CNPh),]Br; however, the compound Mn(CNPh),Br has also been isolated. Chemical oxidation of [Mn(CO)(CNMe),]PF, yields [Mn(CO)(CNMe),](PF,),, but oxidation of the related CNPh compounds is more diffi~ult.,~ The structure of cis-[Mn(CO),(CNMe),Br] has been determined and the Mn-CO bond length trans to Br is the shortest yet reported. Bond length considerations and MO calculations lead to the conclusion that backbonding to CNMe is o~curring.’~ The structures of [Mn,(CO),(MMePh,),] (M = P or As) have been reported. The phosphine ligands are axially disposed, while the arsine ligands are equatorial. However, this has little effect on the Mn-Mn bond length (2.90A when M = P, 2.948 8, when M = As).,, The reaction of triferrocenylphosphine, P(C,H,FeC,H,),, with Mn,(CO),, gives Mn,(CO),L. On the basis of CottonKraihenzel force constant calculations, triferrocenylphosphine is said to be a better donor than PPh,.” When Ph,C,AsMn(CO), is heated or irradiated with light [Ph,C,AsMn(CO),], is formed initially, which could not be isolated in a pure state. The final product is Ph,C,AsMn(CO),, an X-ray structural study of which shows the C,As ring to be n-bonded to the metal atom.,’ Fluorocarbon-bridgeddi(tertiary phosphines and arsines) react with Mn,(CO), under a variety of conditions to yield (L-L)Mn,(CO),, which are !igandbridged complexes. These react readily with iodine to cleave the metdl-metal [L-L = Me,Ask=CAsMe,CF,kF, bond and form ( L a ) Mn(CO),I], F, (f,fos)]. In the reaction with f,fars (f,fars) or Ph,PC=CPPh,CF, (CO),~nMe,AsMn(CO),Me,AsC=~CF~CF2 is also formed by a ligand rearrangement reaction.” The stiucture of (p-f,fars) [Mn(CO),], has been reported. Each metal atom is bonded to four CO groups and one arsenic atom (Mn-Mn = 2.971 A), the molecule being twisted about the Mn-Mn bond such that similar co-ordinating groups on each metal atom are staggered?, The structure of ~~c-[M~(CO),(M~,A~CH~CH~CH,ASM~~)C~] has also been rep~rted.~’“ The complexes [Mn(CO),L,Br] and [Mn(CO),LBr] (L = PH,Ph and PHPh,), [Mn(CO),(PH,Ph)Ph], and [ ( K - M ~ C ~ ) M ~ ( C O ) , ( P H P ~ , ) ] undergo deprotonation at the phosphine hydrogen atoms on treatment with either BunLi or NaOMe and the reactions of the resulting lithio-species have been studied. Thus, (i) reaction with methyl iodide giving the corresponding methylphenylphosphine complexes, (ii) dimerization uia p-phosphido-bridges with CO elimination, and (iii) intramolecular elimination of LiBr have been observed. Typical of type (iii) reactions is that of [Mn(CO),(PPh,Li)Br]

,

%

P. M. Treichel, G. E. Dirreen, and H. J. Much, J . Organometallic Chem., 1972,44, 339. A. C. Sarapu and R. F. Fenske, Inorg. Chem., 1972,11,3021. M. Laing, T. Ashworth, P. Sommerville, E. Singleton, and R. Reimann, J.C.S. Chem. Comm., 1972,1251. 29 C. U. Pittman and G. 0. Evans, J . Organometallic Chem., 1972,43,361. 30 E. W. Abel, I. W. Nowell, A. G. J. Modinas, and C. Towers, J.C.S. Chem. Comm., 1973, 258. 3 1 J. P. Crow, W. L. Cullen, and F. L. Hou, Inorg. Chein., 1972,11,2125. 3 2 L. Y. Y. Chan and F. W. B. Einstein, J.C.S. Dalton, 1973, 1 1 1 . 3 2 0 C .A. Bear and J. Trotter, J.C.S. Dalton, 1973, 673. 26

”

190

Inorganic Chemistry of the Transition Elements

yielding [Mn(CO)4PPh,],.33 The reaction of Mn(CO),Br with Ph,P(oC,H4CN) in refluxing CH,Cl, yields the complex [Mn(CO),{Ph,P(oC,H,CN)fBr]. On the basis of the shift in CN stretching frequency, .rc-type co-ordination of the nitrile group is indicated as shown in (6).34The structure of (7) has been reported.,,

Treatment of [Mn(CO),(PPh,),CO,Me] with methylamine gives the carbamoyl complexes [Mn(CO),(PPh,),C(O)NHMe], which on treatment with methmol yield the starting material. trans-[Mn(CO),L,]+ cations (L = PPh,, PPh,Me, or PPhMe,) react with azide ions or hydrazine to form trans[Mn(CO),L,(NCO)], which can also be prepared by treatment of [Mn(CO),(PPh,),CO,Me] with hydrazine.,, A spectroscopic investigation of SO, insertion into Mn(CO),R in organic solvents has shown the reaction to proceed via the 0-bonded sulphinate intermediate which rearranges to the thermodynamically more stable and isolable S-bonded isomer. However, 0-bonded sulphinates are reasonably stable in the presence of The reaction of Mn(CO),Br with the monothiophosphinates, R,POSNa (R = Et or Ph), gives [R,POSMn(CO),] in low yields. In contrast to the analogous dithiophosphinate complexes, these compounds can be substituted by PPh,. Ph,PSNH, reacts with Mn(CO),Br to give [Ph,PSNH,Mn(CO),Br], HBr elimination not being observed in this The preparation of the anion, [H,Mn,(CO),,]has been reported.38 The reaction of Mn(CO),Cl with 8-aminoquinoline, 7-azaindole, and pyrido[2,3-b]pyrazine, all of which have structural features of adenine, yields complexes of the type [Mn(CO),L,C1].39 The di-imine complex, trans-N,H,[(n-Cp)Mn(CO),], has also been ~ r e p a r e d . ~ ' Nitrosyl Compounds.-Mn(NO),PF, has been prepared by two methods : 33

34

35 36

37 37u 38

39 40

P. M. Treichel, W. M. Douglas, and W. K. Dean, Inorg. Chem., 1972, 11, 1615; P. M. Treichel, W. K. Dean, and W. M. Douglas, J. Organometallic Chem., 1972,42, 145. D. H. Payne and H. Frye, Inorg. Nuclear Chem. Letters, 1973,9, 505. G. B. Robertson and P. 0. Whimp, J . Organometnllic Chem., 1973,49, C27. R. W. Brink and R. J. Angelici, Inorg. Chem., 1973, 12, 1062. S. E. Jacobson, P. Reich-Rohrwig, and A. Wojcicki, Inorg. Chem., 1973,12, 717. E. Lindner and H. S. Ebinger, J. Organometallic Chem., 1973,47, 133. G. 0.Evans, J . Slater, D. Guisto, and R. K. Sheline, Inorg. Nuclear Chem. Letters, 1971, 7 , 771. R. J. Angelici and J. J. Hoffmann, Bioinorg. Chem., 1972, 1, 187. D. Sellmann, J . Organometallic Chem., 1972.44, C46.

Elements of the First Transitional Period

191

firstly, by condensation of manganese vapour, NO, B F , and PF341and secondly by photolysis of Mn(CO)(NO), and a twentyfold excess of PF3.42In
42

43 44

45

46 47 48 49

51 52

53 54

R. Middleton, J. R. Hall, S. R. Simpson, C. H. Tomlinson, and P. L. Timms, J.C.S. Dalton, 1973, 120. 0. Crichton and A. J. Rest, Inorg. Nuclear Chem. Letters, 1973,9, 391. H. Brunner and M. Langer, J. Organometallic Chem., 1973,54,221. R. A. Bailey and K. L. Marshall, Synth. Inorg. Organometallic Chem., 1973,3, 205. J. Goodyear and D. J . Kennedy, Acta Cryst., 1973, B29, 744; T. Li, G . D. Stuckey, and G. L. McPherson, Acta Cryst. 1973, B29, 1330. C. J. J. van Loon and G. C. Verschoor, Acta Cryst., 1973, 829, 1224. F. Birkelund and S. J. Jensen, Acta Chem. Scand., 1972,26, 1358. M. Amit, A. Horowitz and J. Makovsky, Israel J. Chem., 1972,10,715. G. L. McPherson and J. R. Chang, Znorg. Chem., 1973,12,1196. G. N. Papatheodorou, J. Znorg. Nuclear Chem., 1973,35,465. H. J. Seifert and E. Dau, Z . anorg. Chem., 1972,391, 302. H. U. Giidel, H. Stucki, and A. Ludi, Znorg. Chiin. Acta, 1973,7, 121. R. Y. Aliev, A. D. Kuliev, and N. G. Klyuchnikov, Russ. J. Znotg. Chem., 1972,17, 1726. L. M. Vallarino, V. L. Goedken, and J. V. Quagliano, Znorg. Chem., 1972, 11, 1466.

192

Inorganic Chemistry of the Transition Elements

and phenanthroline in aqueous solution,55and the complexes [Mn(phen),X,] (X = F, Cl, Br, I, CN, NCO, NCS, or NCSe) have been prepared, all of which . ~ ~ data have been reported for the have a cis arrangement of X l i g a n d ~Far-i.r. complexes MnLX, (L = phen or bipy, X = C1 or Br).57 H

H,C

H C CH, \

$/

The complex [Mn(napy),](ClO,), (napy = 1,8-naphthapyridine) has been prepared. The analogous iron(1r) complex has been previously shown to be eight-co-ordinate with an arrangement of nitrogen atoms best described as a dodecahedron and the geometry of the manganese complex has been discussed in terms of a similar structure.58 The related complex [Mn(napy),(NO,),] has also been isolated and appears to be the first example of a neutral mixed ligand eight-co-ordinate complex of this metal.” 1,2-Dimethylirnidazole (L) forms the complexes MnL3(N03)260 and MnL,X, (X = Cl, Br, or I, n = 1 or 2; X = NCS, n = 3 or 4).61 The nitrate complex is thought to be five-co-ordinate, whereas the others are assigned pseudo-tetrahedral structures. The six-co-ordinate complexes [Mn(NCPh),]X, (X- = SbCl,, InCl,, and FeC1,) have also been reported.,, syn-Phenyl-2pyridylketoxime [PhC(NOH)C5H4N,HPPK] forms the octahedral complex [Mn(HPPK),Cl,], for which co-ordination via the pyridine and oxime nitrogen atoms is proposed.63 Reduction of manganese(@ phthalocyanine with sodium in T H F or by electrochemical methods produces four distinct anionic complexes corresponding to the stepwise addition of electrons. Electronic spectra of the reduced species indicated that the added electrons are confined essentially to phthalocyanine ring orbitals.64 Hg[ Mo(CO),(x-Cp)], reacts with metallic manganese in THF. After recrystallization of the product from pyridine, [(7c-Cp)Mo(CO),],Mn(py), was isolated. The analogous chromium and tungsten compounds have also

’’ D. G. Holah and C. N. Murphy, Inorg. Nuclear Chem. Letters, 1972,8, 1069. R. E. Morcom and C. F. Bell, J . Inorg. Nuclear Chem., 1973,35, 1865. ’’ R. E. Wilde, T. K. K. Srinivasan, and S. N. Ghosh, J . Inorg. Nuclear Chem., 1973,35, 1017.

56

R. L. Bodner and D. G. Hendricker, Inorg. Chem., 1973,12, 33. D. G. Hendricker and R. J. Foster, Inorg. Chem., 1973, 12,349. 6 o J. Reedijk, Rec. Trav. chim., 1972,91, 1373. J. Reedijk, J . Inorg. Nuclear Chem., 1973,35,239. C. D. Jansen-Ligthelm, W. L. Groeneveld, and J. Reedijk, Inorg. Chim. Acta, 1973,7, 113. 6 3 B. Sen and D. Malone, J . Inorg. Nuclear Chem., 1972,34, 3509. “ D. W. Clack and J. R. Yandle, Inorg. Chem., 1972,11, 1738. 59

Elements of the First Transitional Period

193

been prepared and i.r. data indicate that in all cases co-ordination around the manganese atom is [MnN,O,], the two oxygen atoms being those of two of the carbonyl groups of the Group VIB metal units. This suggested structure is analogous to that of the corresponding magnesium complex, whose structure has been determined by X-ray methods.65 0-Donor ligands. The compounds MMnP0,,6H20 (M = Rb or Cs) have been isolated from reactions of MnC1, and M,PO, in aqueous solution.66 The structures of Mn,(PO,)X (X = C1 or F) have been determined. The structural unit of the chloride is best described as two distorted edge-sharing octahedra of anions arranged about the two non-equivalent manganese atoms, which are further linked through edge-sharing phosphate tetrahedra. The fluoride is isostructural with the mineral, t r i ~ i t e The . ~ ~enthalpy changes for the interaction of sulphate ions with manganese@) ions in aqueous solution have been re-investigated.68 The thermal stability of [Mn(acac),] has been investigated6' and the new adducts of this compound, [Mn(acac),L,] (L = quinoxaline or quinoline) and [Mn(acac),L] (L = 4,4'-bipyridine or pyrazine) have been prepared.70,7 1 The complex bis(benzoylacetonato)manganese(II)-pyrazine has also been reported." Cationic acetylacetonato-complexes of Fe"', Co", and Ni" have been prepared by treating the neutral complexes with picric acid; however, similar treatment of [Mn(acac),] led to complete replacement of the acac ligands by picrate ions.72 The preparation of a manganese@) complex of neutral acetylacetone (acacH) has now been reported in detail (see Vol. 1 p. 123).The complex [MnBr,(acacH),], which can be prepared either by direct addition of acacH to the anhydrous metal halide or by reaction of [Mn(acac),] with dry HBr in CH,Cl, containing free acacH, is octahedral, the acacH molecules in their enolic form being co-ordinated in a unidentate fashion.73 The same group have also reported the preparation of Mn(etmalH)Br, (etmalH = ethylmalonate acting as a neutral ligand); however, in this case, the geometry of the complex is uncertain.74The complexes [MnL,](SbCl,), [L = p-MeC,H,CHO, o-ClC,H,CHO, p-ClC,H,CHO, Me,CO, Ph,CO, PhCHO, HCOMe, EtOAc, or CH,(CO,Et),] have also been ~ r e p a r e d . ~ ' In an attempt to prepare complexes of trialkylamines (RiN) by reaction with the alcohol solvates Mn(R'OH),X, ( n = 6-9, X = ClO, or BF,), the T. Blackmore and J. M. Burlitch, J.C.S. Chem. Comm., 1973, 405. B. V. Martynenko and M. V. Goloshchapov, Russ. J . Inorg. Chem., 1973,18, 142. J. Rea and E. Kostiner, Acta Cryst., 1972, B28, 2505, 2525. G. R. Hedwig and H. K. J. Powell, J.C.S. Dalton, 1973, 798. " M. Z. Gurevich, T. M. Sas, N. E. Lebedeva, V. V. Zelentsov, and B. D. Stepin, Russ. J . Znorg. Chem., 1972, 17,556. 7 0 F. Cariati, D. Galizzioli, F. Morazzoni, and L. Naldini, Inorg. Nuclear Chem. Letters, 1973,9,743. 7 1 S. Ambe and F. Ambe, J . Inorg. Nuclear Chem., 1973, 35, 1109. 72 M. M. Aly, J. Znorg. Nuclear Chem., 1973,35, 537. 7 3 Y. Nakamura, K. Isobe, H. Morita, S. Yamazaki, and S . Kawaguchi, Inorg. Chern., 1972,11, 1573. 74 H. Morita, Y. Nakamura, and S. Kawaguchi, Bull. Chem. SOC.Japan, 1972,45, 2468. " P. L. Verheijdt, P. H. Van der Voorst, W. L. Groeneveld, and W. L. Driessen, Rec. Trau. chim., 1972,91, 1201. 65

66

67

194

Inorganic Chemistry of the Transition Elements

expected ligand exchange was not observed but an acid-base reaction gave products of the type Mn[R~'NH]n(R~N),(R1O-)nX, (n = 1-8, m = 0-3, R' = Me, Et, or n-pentyl, R2 = Me or Et).76 Molecular weight determinations and conductivity measurements on Mn(O,CR), (R = Me or Et)provide further evidence for the conclusion reached on the basis of i.r. data that the Mn-0 bonds are covalent in solution.77 The structure of Cs,Mn,(C,0,),,3H20 has been r e p ~ r t e d . ' ~ The 2,6-lutidine N-oxide (LNO) complex [Mn(LNO),(NO,),] has been isolated and shown to be five-co-ordinate with one unidentate nitrate group and one bidentate.79 The related complexes [Mn(PNO-H),] (PNO = 2picolinic acid N-oxide)" and [Mn(PyzNO),(ClO,),] (PyzNO = pyrazine Noxide)" have also been isolated. The latter contains ionic perchlorate, on the basis of the i.r. spectrum run as a nujol mull, although KBr disc spectra show the perchlorate groups to be co-ordinated and free ligand to be present, the discrepancy presumably arising as a result of the application of high pressure in disc preparation. Trimorpholinephosphine oxide (morPO) forms the complexes [Mn(morPO),X,] (n = 0.54,X = BF,, NO,, NCS, C1, Br, or I).82In all cases the ligand is co-ordinated via the oxygen atom and a comparison with other phosphine oxide complexes indicates that the sizes of both the anion and the ligand control the co-ordination number achieved. The new complexes, [Mn(HMPA),(NO,),] and [Mn(NIPA),(NO,),] NIPA = nonamethyldiphosphor(HMPA = hexamethylphosphoramide amide), containing co-ordinated NO, groups have been isolated.*, (Me,N),P(O)NMeP(O)(NMe,)NMeP(O)(NMe,), (TRIPA) forms the complexes [Mn(TRIPA),X,] (n = 1 or 2, X = BF,, BPh,, NO,, or Cl). The bis-complexes contain the ligand bound in a terdentate form giving rise to octahedral coordination, whereas the mono-complexes are probably five-co-ordinate when X = NO, and dimeric when X = C1. s-fac- and u-fac-isomers are observed when X = BF,, but the mer-isomer appears to be sterically unstable.84 The pseudo-octahedral complexes [Mn(O,SR),(py),] (R = Ph or p-MeC,H,) can be prepared by reaction of (RSO,),Mn(OH,), with pyridine. No linkage isomers of the compounds were detected; however, [(RSO,),Mn(bipy)] can be isolated in both 00-and S-bonded forms depending on the preparative of the ligands 1,3-dithiane-monosulphoxide conditions e m p l ~ y e d . Complexes ~' and 2-phenyl-l,3-dithiane-monosulphoxide, [MnL,]X, (X = ClO, or BF,) "

M. W. G. De Bolster and W. L. Groeneveld, J . Inorg. Nuclear Chem., 1973,35,2106.

'' C. V. Gurumurthy, Chem. and Ind., 1973, 529.

H. Siems and J. Lohn, Z. anorg. Chem., 1972,393,97.

'' N. M. Karayannis, C. M. Mikulski,L. L. Pytlewski, and M. M. Labes, J . Inorg. Nuclear

83 84

Chem., 1972,34,3139. T. J. Delia, M. A. Little, and D. X. West, J . Inorg. Nuclear Chem., 1973, 35, 1400. A. N. Speca and L. L. Pytlewski, Inorg. Nuclear Chem. Letters, 1973,9, 365. M. W. G. D e Bolster, I. E. Kortram, and W. L. Groeneveld, J . Inorg. Nuclear Chem., 1973,35, 1843. M. W. G. De Bolster, F. J. Wiegerink, and W. L. Groeneveld, J . Inorg. Nuclear Chem., 1973,35,89. M. W. G. D e Bolster, .I.Den Heijer, and W. L. Groeneveld, Z . Naturjorsch., 1972,27b, 1324. E. Lindner, I.-P. Loren& and G. Vitzthum, Chem Ber., 1973, 106, 211.

Elements of the First Transitional Period

195

have been isolated. Both ligands co-ordinate via the sulphoxide oxygen atom.86 The octahedral complexes [MnL,(OH,),](ClO,), (L = p-dioxan or 1,2dimethoxyethane) have also been r e p ~ r t e d . ~ ’ S-donor ligands. The complexes Mn[S,PX,], (X = CF,, Me, or Ph), all of which appear to possess pseudotetrahedral [MnS,] cores, have been isolated; however, both monomeric and polymeric forms have been observed depending on the nature of X and the physical state of the complex.88 The structure of the high-spin tetrahedral complex [Mn(SPPh,NPPh,S),] has been reported8’ and the complex [Mn(TX),(OH,),](ClO,), (TX = p-thioxan) prepared.87

-0

(9)

Mixed donor ligands. The complex [Mn(bipyNO),](ClO,), [bipyNO = (9)] has been isolated, in which the ligand acts as a bidentate NO-donor. Spectrochemical parameters indicate that (9) is a stronger ligand than (10) but weaker than bipy.” MnCl, reacts with ethoxy-6-methylpyridine-2-phosphonate (E6MPP) to form the complex, [Mn(E6MPP),I2 in which the metal atom is five-co-ordinate, two of the E6MPP ligands acting as bridging groups between metal atoms.g1 The structure of di-p-(NN-diethylnicotinamide-0N)tetrathiocyanatodimanganese(I1) has been determined. Each metal atom is octahedrally co-ordinated by two amide oxygen atoms, two pyridine nitrogen atoms and the nitrogen atoms of two thiocyanate groups, pairs of NN-diethylnicotinamide molecules bridging the metal atoms.92 The high-spin complexes of NN-diethyl- and NN-dimethyl-urea (L), [MnL,X,] (X = C1, Br, or I), [MnL,]I, and [MnL,](ClO,),, have also been r e p ~ r t e d . ’ ~ Mono-, di-, and tri-ethanolamine (MEA, DEA, and TEA, respectively) form the complexes MnLX, (L = MEA, DEA, or TEA, X = C1 or iSO,) in which the ethanolamine ligands are chelating.’, Manganese@) complexes of tris(hydroxymethy1)aminoethane and 2-amino-2-(hydroxymethyl)propane1,386

” 88

89 90

91

92

93 94

A. H. M. Driessen-Flew and W. L. Groeneveld, Inorg. Chim. Acta, 1973, 7 , 139. N. M. Karayannis, C. M. Mikulski, A. N. Speca, J. T. Grenin and L. L. Pytlewski, Inorg. Chem., 1972,11,2330. P. G . Cnvell, E. D. Day, W. Byers, and P. M. Wdtkins, Inorg. Chem., 1972,11, 1759. 0. Siiman, M. Wrighton, and H. B. Gray, J . Coord. Chem., 1972,2, 159. A. N. Speca, N. M. Karayannis, L. L. Pytlewski, L. J. Winters, and D. Kandasamy, Inorg. Chem., 1973,12,1221. A. N. Speca, R. Mink, N. M. Karayannis, and L. L. Pytlewski, J . Inorg. Nuclear Chem., 1973.35, 1833. F. Bigoli, A. Briabanti, M. A. Pellinghelli, and A. Tiripicchio, Acta Cryst., 1973, B29,39. J. P. Barbier and R. Hugel, J . Znorg. Nuclear Chem., 1973,35,781; 3026. E. Jozefowiz, M. Kunaszewska, and C. Wyganowski, Roczniki Chem., 1972,46,731.

Inorganic Chemistry of the Transition Elements

196

diol have also been ~ r e p a r e d . ’ P-Furfuraldoxime ~ (11) forms the octahedral complex [MnL,Cl,] in which the ligand chelates via the furan oxygen and the oxime nitrogen atoms.96 An n.m.r. study of a range of metal-flavoquinone complexes involving the ligand (12) has shown co-ordination to occur via CH,(CHO,CMe),CH,O,CMe

I

the carbonyl group in the 2-position in the case of manganese.” The six-coordinated complexes [Mn(dtpp)X]X,nH,O (X = C1 or Br) and [Mn(dtpp)I],C10, [dtpp = (13)] have been prepared and contain the ligand in its quinquedentate form in which co-ordination occurs via one sulphur and four nitrogen atoms.98 The complex MnL, (LH = H,N-C,H,*S*CH,CO,H) has also been prepared.” The ligand (14) forms the complex [MnLCl,] which probably

II

CH

has a six-co-ordinate halogen-bridged structure.100 The five-co-ordinate complexes [MnLX,] (X = Cl, Br, or I), the octahedral complexes [MnLJY, (Y= ClO, or BF,), and the polymeric octahedral complex MnL(NCS), [L = (15)] have been isolated.”’

95

96

” 98 99

loo

R. L. Dotson, J . Inorg. Nuclear Chem., 1972,34, 3131. B. Sen and M. E.Pickerell, J. Inorg. Nuclear Chem., 1973,35,2573. J. Lauterwein, P. Hemmerich, and J. M. Lhoste, Z. Naturjorsch., 1972, 27b, 1047. S. E. Livingstone and J. D. Nolan, Austral. J. Chem., 1973,26, 961. Y. Takahashi, T. Omura, M. Nakatani, and A. Ouchi, J. Inorg. Nuclear Chem., 1973,35,650. M. Akbar-Ali, S. E. Livingstone, and D. J. Phillips, Inorg. Chim. Acta, 1972,6, 552. B. Chiswell and K. W. Lee, Inorg. Chim. Acta, 1972, 6, 567.

Elements of the First Transitional Period

197

H

(15)

R'

=

H or Me: R2 = Me or Et

Oxides. When stoicheiometric quantities of MnO and WO, are ground together in a vibrating mill, the tungstate MnWO, is formed.192 Manganese(in).-Halides and Pseudohalides. Addition of tetramethylammonium chloride or n-cetylpyridinium chloride to an ethereal solution of the product formed by the reaction of acetyl chloride with MnO, results in formation of the green solids [Me,N],[MnCl,H,O] and [n-cetpyH],[MnCl,]. Both compounds are high-spin and it is suggested that both anions are octahedral, the latter achieving this by formation of halogen bridges.' O 3 Other workers have also prepared M,MnCl, (M = Me,N, Me,NH, or Cs), M,MnCl,H,O (M = NH,, Rb, or K), and [Me,NH,],MnCl,EtOH and have found that in all cases the anions are five-co-ordinate in acetone solution.104 The new fluoroperovskites, Rb,NaMnF,, Rb,KMnF,, and Cs,NaMnF,, have been isolated and the presence of Jahn-Teller distortions and the values of lattice energies discussed.lo5 The structures of Cs,LiM(CN), (M = Mn, Fe, or Co) have been determined and the M-C bonds found to decrease markedly in progressing from manganese to iron, although the C-N bond lengths do not change significantly. These results have been discussed in terms of M - C G- and x-bonding.lo6 Complexes. N-Donor ligands. The reaction of Mn(OAc),,4H,O and H2TPC in gldcial acetic acid yields of mixture of [MnCl(TPC)] (TPC = apyli-tetrdphenylchlorin) and [MnCl(apy&tetraphenylporphin)] which can be separated by column chromotography. The former shows a half-wave reduction potential to manganese(I1) of -0.15V (measured with respect to the standard calomel ele~trode)."~ A detailed study has been made of the 0x0-bridged manganese(II1) phthalocyanines [(pyMnPc),O], of which there are conflicting reports in the literature. The complexes [(LMnPc),O] (L = N-methylimidazole, 3-picoline, or piperidine) have also been prepared and all show weak paramagnetism. However, it is suggested that the complexes are probably diamagnetic, the samples examined containing a small amount of high-spin manganese(n1) lo'

lo'

Io4

lo'

R. Albrecht and R. Mobius, Z. anorg. Chem., 1972,392, 62. A. K. Das and D. V. R. Rao, Chem. and Ind., 1973, 186. W. Levason and C. A. McAuliffe, J.C.S. Dalton, 1973,455. G. Siebert and R. Hoppe, Z. anorg. Chem., 1972, 391, 1 1 7. B. I. Swanson and R. R. Ryan, Inorg. Chem., 1973,12, 283. L. J. Boucher and J. W. Klinehamer, Bioinorg. Chem., 1973,2,231.

198

Inorganic Chemistry of the Transition Elements

impurity.108 An n.m.r. study of some paramagnetic manganese(II1) porphyrins has been reported.' O9 0-Donor ligands. Anhydrous Mn(NO,), has been prepared by the reaction of MnF, with a mixture of N 2 0 5 and N204.A similar reaction with pure N 2 0 5 yields the complex NO,[Mn"'(NO,),] and reaction of KMnO, with N 2 0 4 in either acetonitrile or nitromethane yields K,[Mn"(NO,),]. The anhydrous trinitrate reacts with bipy and phen (L) to form [Mn(NO,),L] and with Ph,PO undergoes a reduction, forming [Mn(NO,),(Ph,PO),]. It also forms an adduct with acetonitrile and undergoes decomposition to yield MnO(N0,). The authors suggest that the trinitrate probably has a polymeric structure with bridging nitrate groups. It was also found that NO,[Mn(NO,),] has a higher thermal stability than Mn(NO,),."' The structure of [Mn(NO,),(bipy)] has been determined by X-ray methods. The metal atom is seven-co-ordinate with approximately pentagonal-bipyramidal geometry. The equatorial ligand atoms consist of one nitrogen atom of the bipyridyl ligand and four oxygen atoms of two bidentate nitrate groups. The remaining nitrogen atom of the bipyridyl molecule and the co-ordinated oxygen atom of a unidentate nitrate group occupy the axial positions. The equatorial nitrate groups differ in that one is symmetrically bidentate, whereas the other is co-ordinated in an asymmetric bidentate manner.' '' Recently reported stereochemical rearrangements of metal tropolonatocomplexes have now been demonstrated for tris(a-isopropeny1)- and tris(a-isopropy1)-troponolatomanganese(II1). These stereochemically non-rigid complexes attain the fast exchange limit at approximately 0°C; however, no separate kinetic processes of inversion and isomerization were observed and only isomerization was detected.' l 2 The thermal decomposition of tris(oxa1ato)-manganese(1n)complexes has been studied.", S-Donor ligands. In an X-ray structural study of [Mn(S,CNEt,),], it was found that the [Mn(S,C),] core of the molecule shows a large distortion from the D , point symmetry. This is attributed to the ' E g electronic ground state (0, approximation) of the molecule which is expected to show a large Jahn-Teller distortion.' l 4 The magnetic properties of complexes of the type [Mn(S,CNR,),] have been studied at very low temperatures.' Mixed donor ligands. KMn(DCTA)H,O (DCTA = trans- 1,2-diaminocyclohexanetetra-acetate) has been isolated. In neutral aqueous methanol, the complex anion exists as [Mn(DCTA)H,O]-, whereas in basic and acidic solutions, [Mn(DCTA)(OH)]' - and HMn(DCTA)H,O, respectively, are

'

lo*

lo9 'lo 11' 11* '13

'I4 'I5

G. W. Rayner-Canham and A. B. P. Lever, Inorg. Nuclear Chem. Letters, 1973,9, 513. T. R. Janson, L. J. Boucher, and J. J. Katz, Inorg. Chem., 1973, 12,940. D. W. Johnson and D. Sutton, Canad. J . Chem., 1972,50,3326. F. W. B. Einstein, D. W. Johnson, and D. Sutton, CanadJ. Chem., 1972, 50, 3332. S. S. Eaton, G. R. Eaton, R. H. Holm, and E. L. Muetterties, J . Amer. Chem. SOC.,1973,95, 1116. K. Nagase, Bull. Chem. SOC. Japan, 1972,45,2166: 1973,46, 144. P. C. Healy and A. H. White, J.C.S. Dalton, 1972. 1883. B. N. Eiggis and G. E. Toogood. J.C.S. Dalton, 1972, 2177.

199

Elements of the First Transitional Period

formed.lf6A crystallographic study of this compound shows the metal atom to possess a very distorted octahedral co-ordination sphere, the ligand DCTA being sexidentate." The Schiff base (16) reacts with MnC12,4H20 in methanol to produce darkbrown crystals of [Mn"'(OMe)L]MeOH [LH, = (17)]. Spectroscopic and

'

magnetic properties of the complex have been reported and an X-ray structural study shows it to be dimeric with two distorted octahedral manganese(rr1) ions bridged by two methoxide groups. The ligand acts as a bridge between adjacent dimers, co-ordinating to one manganese atom uia a nitrogen and two oxygen atoms and to another uia a single nitrogen atom, thereby giving rise to a polymeric structure.'l8 Higher Oxidation States of Manganese.-The manganese(Ir1) compound Mn(pic),H,O (picH = pyridine-2-carboxylic acid) is readily formed by peroxydisulphate oxidation of aqueous manganese@) salts in the presence of the sodium salt of the acid. However, it has now been found that the oxidation proceeds further yielding polymeric compound [Mn(pic),O], which contains Mn-0-Mn 1inkages.llg It has been reported that in a lithium-potassium nitrate eutectic, MnV is stabilized as a blue suspension in solutions containing OH-, 02-, or 0;ions at concentrations of greater than 0.1 moll- '. In solutions containing these ions at lower concentrations, black Mn"' is precipitated. In a sodium-potassium nitrate eutectic, green soluble MnV' is stabilized by the presence of OH- ions and blue soluble Mn' is stabilized in the presence of 02-or 0;-ions (the concentration of added ions being greater than 0.1 moll- in all cases). When the concentration of added ions is less than 0.1 moll-', a mixture of the two oxidation states is formed, the proportion of each present depending on the

'

'16

'18

B. L. Poh and R. Stewart, Canad. J. Chem., 1972,50, 3422. S . J. Rettig and J. Trotter, Canad. J . Chem., 1973,51, 1303. A. Mangia, M. Nardelli, C. Pelizzi, and G. Pelizzi, J.C.S. Dalton, 1973, 1141. D. L. Hoof, D. G. Tisley, and R. A. Walton, Inorg. Nuclear Chem. Letters, 1973,9, 571.

Inorganic Chemistry of the Transition Elemciits

200

manganese: oxygen ratio.',' The photolysis of KMnO, has been studied, the overall reaction leading to formation of Mn02.121 2 Iron

Carbonyl Compounds.-An X-ray crystallographic study of [(Ph,P),N][FeH(CO),] has been published. The anion exhibits trigonal-bipyramidal stereochemistry in which the hydrogen atom, which was located, occupies an axial position. The Fe-H bond length is 1.57(12) 8, and the equatorial carbonyl groups are bent towards the hydrogen.'22 Several new mixed-metal iron carbonyl compounds have been reported. trans-[(CO),Fe{ Pt(py),Cl},] has been isolated as an orange solid from the reaction of Na,Fe(CO), and trans[Pt(py),Cl,] in methan01.l~~ Fe,(CO), reacts with Pt[P(OPh),], to give a trinuclear complex originally thought to be [(PhO),P](CO),Fe.Pt(CO)[P(OPh),] * Pt(CO)[P(OPh),]. However, it has now been shown by X-ray methods that the true structure is (CO),Fe. Pt[P(OPh),]; Pt(CO)[P(OPh),] (Fe-Pt = 2.583 and 2.5508,, Pt-Pt = 2.633 A).123a [(cod)RhCl],, Rh(CO),Cl,, or RhC1,,3H20 in methanol and [(cod)Rh(THF),] in T H F react with excess [(IT-MeCp)Fe(CO),(PPh,)]in the presence of PF, to produce (Rh[Fe(n-MeCp)(CO),(PPh,)],}PF,. An X-ray study has shown the cation to have a non-clustered structure (18) (Fe-Rh = 2.671 and 2.660A) rather than the structure (19) which might be predicted on the basis of the eighteenelectron rule. It is suggested that the triangulo-structure is unstable with +

oc, ,co Ph2P /kh-\

Ph2

Ph2

PPh

\ I co qc, Fe! /Fe' Me' p C

'MeCp

respect to the open form as a result of the presence of the strongly basic PPh, groups. The analogous iridium complex has also been prepared, as have the corresponding rhodium complexes with bridging SR (R = Et or But) groups replacing the PPh, groups.'24 The reaction of C,H,FeC,H,AuPPh, with previously thought HBF, produces the cation [(C,H,)Fe(C,H,)Au,(PPh,),l to have the structure (20). However, it has now been shown that structure (21) is adopted, this being the first reported ferrocene derivative possessing a direct metal-metal bond (Fe-Au = 2.818 A).',' Air-stable orange-yellow crystals of +

B. J. Brough, D. A. Habboush, and D. H. Kerridge, Znorg. Chim. Acta, 1972,6, 366. E. G . Prout and C . M. Lownds, Znorg. Nuclear Chem. Letters, 1973,9,377; 617. 12' M. B. Smith and R. Bau, J . Amer. Chem. SOC.,1973,95,2388. 1 2 3 B. Munchenbach and J. Dehand, Naturwiss., 1972,59, 647. 2 3 u V. G. Albano, M. I. Bruce, G. Shaw, and F. G . A. Stone, J. Organometallic Chem., 1972,42, c95. lZ4 R. J. Haines, R. Mason, J. A. Zubieta, and C. R. Notte, J.C.S. Chem. Comm., 1972,990. l Z 5 V. G. Andrianov, Y. T. Struchkov, and E. R. Rossinskaja, J.C.S. Chem. Comm., 1973,338. lz0

Elements of the First Transitional Period

20 1 ~

AuPPh 3

I

-...IA : , A

C 5H,- AuPPh,

uI

P3

P

~

AuPPh,

I

Fe

Fe

I C5H5 (20)

[(n-Cp)Fe(CO),(C=CPh)CuCl], have been obtained from the reaction of [(x-Cp)Fe(CO),Cl) and CuC=CPh. An X-ray study has shown that the complex adopts structure (22).126Zn[Fe(CO),(Cp)], reacts with dry alcohols to form [ROZnFe(CO),(Cp)], (R = Me or Et)., Shifts in the CO stretching frequencies of [(x-Cp)Fe(CO),], and [(n-Cp)Ph L

,%,

,c 0

Fe(CO)], on treatment with AlR, (R = Et or Bu’) indicate a stepwise interaction of aluminium with the oxygen atoms of each of the bridging carbonyl groups for both compounds.127 The complex (Me,Si),Fe,(CO), (see Vol. 1, p. 139),was suggested to contain trimethylsilyl ether type linkages (23).However, an X-ray structural study has shown it should be formulated as (Me,Si),Fe,(CO),,, with structure (24).’28Na[(.n-Cp)Fe(CO),] reacts with R,SiCl in THF to form [(z-Cp)Fe(CO),SiR,] [R, = Me,Ph, MePh,, Ph,, Ph,(CH=CH,), and MePh(1-naphthyl)]. The last-named complex is isolated as a racemic mixture, although use of the reagent ( +)MePh( 1-naphthy1)SiCl produces ( - )-[(x-Cp)Fe(CO), (SiMePh(l-naphthyl)}].129 Reaction of [(x-Cp)Fe(CO),], with SiF,H at elevated temperatures gives [F,SiFe(C0)2(7c-Cp)].11 Monochlorogermane undergoes reaction with Na,Fe(CO), in n-butane to give a mixture of (H,Ge),Fe(CO),, (H,Ge)(H)Fe(CO),, and H,Fe(CO),. The germyl complexes are both cis-octahedral monomers and the bis-germyl

12*

M. I. Bruce, R. Clark, J. Howard, and P . Woodward, J . Organometallic Chem., 1972,42, C107. A. Alich, N . J. Nelson, D. Strope, and D. F. Shriver, Znorg. Chem., 1972,11,2976. M. J. Bennett, W. A. G. Graham, R. A. Smith, and R. P. Stewart, J . Amer. Chem. Soc., 1973,95,

12’

1684. R. J. P. Corriu and W. E. Douglas, J . Organometallic Chem., 1973,51, C3

lZ6

lZ7

Inorganic Chemistry of the Transition Elements

202

derivative reacts with HCl to give a 46% yield of the hydride-monogermyl compound. Treatment of the bis-compound with HgC1, leads to Ge-Fe bond cleavage with formation of GeH,Cl, GeH,, and HCl. [H,GeFe(CO),(n-Cp)] has been isolated from the reaction of H,GeCl with the corresponding anion.I3* OSiMe

I

Me, SiO

\

c-c

Me,SiOILUJ3

I

SiMe

OSiMe,

/

-0 Si Me,

,

(23)

A new method of preparation of [Me,SnFe(CO),(n-Cp)] by treatment of [Fe(CO),(n-Cp)], with either (Me,Sn),O or (Me,Sn),N has been r e p ~ r t e d . ' ~ Reaction of [Me,SnFe(CO),(n-Cp)] with iodine gives rise to Sn-C bond cleavage, whereas a similar reaction of Me,Sn[Fe(CO),(n-Cp)], produces cleavage of the Sn-Fe bond. The Me,Sn complex also reacts with MeHgCl producing initially MeHgFe(CO),(.n-Cp) and Me,SnCl and finally Me,Sn, Me,Hg, He[Fe(CO),(n-Cp)], and C1HgFe(CO),(n-Cp).16 Dipole moment measurements on Ph,SnFe(CO),(NO)L [L = CO, PPh,, AsPh,, or P(OPh),] indicate the ligand L to be cis to the axial Ph,Sn group. In Hg[Fe(CO),(NO)P(OPh),], it appears that the phosphite groups both occupy equatorial [(n-Cp)Fe(CO),],SnClz undergoes reaction with Na,S, or positions.' K S to give the new compound [(n-Cp)Fe(CO),],SnS, which contains an ring.',, The compounds [R,MFe(CO),], (M = Ge, Sn, or Pb, R = alkyl or aryl) undergo homolytic cleavage reactions in the co-ordinating solvents (B) to produce the germylenes (CO),FeGeR,B (R = Me or Ph), stannylenes (CO),FeSnR,B (R = Me, Bu, or Ph), and plumbylenes (CO),FePbR,B (R = Bun or Ph) in which a solvent molecule B (B = THF, Me,CO, MeCN, Et,O, py, or DMF) acts as a donor ligand towards the maingroup element.' Arylazo-iron carbonyl compounds have been reported by two groups. Fisher and S ~ t t o n ' have ~ ~ found that Fe(CO),(PPh,), reacts with [p-XC,H,N,] BF, (X = F, C1, Br, H, NO,, OMe, OH, but not NEt,), replacing

'

,,

13' 131

133 134

S. R. Stobart, J.C.S. Dalton, 1972, 2442. S. Sorriso, G. Distefano and A. Foffani, J . Organometallic Chem., 1973, 47, 139. C. Ungurenasu, G. Stiubiani, and E. Streba, Synth. Inorg. Organometallic Chem., 1973,3, 211. T. J. Marks and A. R. Newman, J . Amer. Chem. SOC., 1973,95,769. D. R. Fisher and D. Sutton, Canad. J . Chem., 1973,51, 1697.

Elements of the First Transitional Period

203

an equatorial carbonyl group to form [Fe(CO),(PPh,),(N,C,H,X)] BF, and that azo-groups in the products are resistant to hydrogenation. Carroll and L a 1 0 r ' ~have ~ also reported the complexes with X = H or F and the analogous rn-fluoro-complex. A preliminary report of the crystal structure of the complex, X = H, shows the Fe-N-N and Ph-N-N bond angles to be 180 and 120°, respectively. "F N.m.r. spectra of the p - and rn-fluoro-complexes indicate only a small amount of Fe-N back bonding. These authors also studied the reaction of Fe(CO),NO and PhNlBF, at -70°C. A red solution was formed that undoubtedly contained an arylazo-complex; however, on warming the solution, decomposition occurred. Treatment of this solution with Ph,P prior to warming to room temperature yielded the complex (25). Similar low-temperature reactions with [Ph,SnFe(CO),] -, [(n-Cp)Fe(CO),] -, [Mn(CO),] -, and [(n-Cp)Ni(CO)J- are also reported, but no products could be isolated.

The reaction of diaz (26) with Fe,(CO), yields [(diaz)Fe,(CO),] which contains no N-N bond and two non-equivalent iron atoms. Spectral studies and an X-ray crystallographic determination have also been reported. [(diaz H,)Fe,(CO),] [diaz H, = (27)] has also been isolated and spectroscopic studies of this compound indicate that it possesses a similar structure to [(diaz)Fe,(CO),], but with somewhat greater distortions at one of the octahedral iron atoms.' 36 Reactions of phthalazine with iron carbonyls have also been studied and are outlined in Scheme 2.',' The p-acyl compounds [Fe,(CO),(p-COR),] react with donor ligands (L) to form [Fe,(CO),L(p-COR),] (R = Me or Ph; L = NH,, Et,NH, PhNHNH,, py, or C,H,,NH) and with thiols and selenols to form [Fe(CO),(p-X)], (X = SEt or SePh) and the aldehydes PhCHO and MeCHO. Reaction of [Fe,(CO),(pCOPh),] with three molar equivalents of PR, gives (28),Fe(CO),(PR,), (R = Ph or Pri),and carbon monoxide.'38 The structure of (29) has been d e t e r ~ i n e d . ' ~ ' The compound previously thought to be [Fe(SMe)(CO)(S,C,(CF,),}], has [Fe,been shown by X-ray crystallography to be [Fe,(p-SMe),(CO),] { S2C2(CF3),},]-. The cation, which has not been previously reported, consists of two face-shared octahedra with bridging MeS groups. The Fe-Fe distance of 3.062 %, indicates no direct metal-metal interaction and the metal atoms can +

136 13' 13* 139

W. E. Carroll and F. J. Lalor, J . Organornetallic Chem., 1973,54, C37. D. P. Madden, A. J. Carty, and T. Birchall, Inorg. Chem., 1972, 11, 1453. H. Alper, J . Organornetallic Chern., 1973,50,209. V. Kiener and E. 0. Fischer, J . Organometallic Chem., 1972,42, 447. G. Le Borgne and D. Grandjean, Acta Cryst., 1973, B29, 1040.

Inorganic Chemistry of the Transition Elements

204

Scheme 2

be formalised as Fe". The anion is a centrosymmetric dimer containing squarepyramidal metal co-ordination. Anion dimerization occurs via formation of Reversible oxidation of cis- and trans-[Fe(n-Cp)(CO)SR] Fe-S linkages. to cis- and trans-[Fe(n-Cp)(CO)SR]+ and cis- and trans-[Fe(n-Cp)(CO)(SR)];+ has been achieved. Thus the neutral dimer (R = Me) reacts with oxygen in

Ph-C=O

I

L /*

Fe (CO),PR

Ph-C=O (28) R

=

Ph or Pr'

(29)

acidic media to give the mononuclear cation and this reaction can be reversed by the addition of hydroxide ions to an aqueous solution of cation. The reduction can also be achieved by N,H,, piperidine, or Et,NH, all in the presence of water, sodium amalgam, NaBH,, or excess iodide. Oxidation of the neutral dimer with excess bromine in solution yields the dimeric cation, which can also be formed from the mononuclear cation by passing air through an aqueous solution of this species at pH 2. Reduction of the dimeric cation to the mono14"

A. I . Schultz and R. Eisenberg, Inorg. Chern., 1973,12, 518.

Elements of the First Transitional Period

205

nuclear cation can be achieved by a variety of reducing agents including BPh, . The oxidation-reduction cycle for neutral dimer + mononuclear cation is stereospecific, in that the cis- or trans-configuration is always maintained.',l The reactions :

+ R,Se, + [Fe(CO),SeR], (R = Me, Et, CF,, or C,F,) [(n-Cp)Fe(CO),], + R,Se, -, [(n-Cp)Fe(CO)SeR], (R = Et or Prn) Fe,(CO),,

[(n-Cp)Fe(CO),],

+ R,Se,

+

[(n-Cp)Fe(CO),SeR] (R = CF,, C,F,, or C,F,)

have been reported.',, Fe(CO),I,, [Fe(n-Cp)(CO),Cl], and [(n-allyl)Fe(CO),I] react with NN-dimethyldithiocarbamate to form [Fe(CO), I(S, CN Me),], [(n-Cp)Fe(CO)(S,CNMe,)], and [(n-allyl)Fe(CO),(S,CNMe,)], respectively, all of which contain bidentate dithiocarbamate groups. The complexes [Fe(CO),(siphos),], [Fe(CO),(siphos)], and Hg[Fe(CO),(NO)(siphos)], [siphos = (Me,SiCH,),P] have been reported',, and the ~~ reaction of Fe(CO), with P(C,H,FeC,H,)3 (tfp) yields [ F e ( C O ) , t f ~ l .The reaction of Fe,(CO), with a range of phosphines at 25°C yields [Fe(CO),(phos)] [phos = MePH,, PhPH,, Ph,PH, (p-MeC,H,),PH, Me,PH, Et,PH, or PhMePH]. Small amounts of [Fe,(CO),(phos-H),] are also usually formed and, in the case of the secondary phosphines, [Fe,(CO),(phos-H)(H)] was also observed. The latter are better obtained, however, by deprotonation of [Fe(CO),(phos)] with butyl-lithium followed by the addition of Fe,(CO),. The action of heat or irradiation on [Fe(CO),(phos)] also gives rise to [Fe,(CO),(phos-H)]. Treatment of Fe(CO), with PhPH, at 190"C yields only Fe,(CO),(PPh), which undergoes further reaction with P(OMe), to form [Fe,(CO),-,(PPh),(P(OMe),)J (n = 1, 2, or 3).14, Deprotonation of [Fe(CO),(phos)] (phos = PPh,H or PPhMeH) with butyl-lithium followed by reaction in situ with methyl iodide gives the corresponding methylphenylphosphine complexes. [Fe,(CO),(PPhH),] also undergoes deprotonation to form a dilithio-species which again reacts with Me1 and Br(CH,),Br.,, Deprotonationsof[(n-Cp)Fe(CO),L]X(X = Br,L = PhPH,;X = I,L = Ph,PH) have also been achieved by the same method, and reactions of the resulting lithio-species investigated. Thus reaction with methyl iodide, dimerieation to the p-phosphido-complexes with concomitant CO loss, and intramolecular rearrangements have been observed. The last-named rearrangements are of the type:

+ LiPF, [(n-Cp)Fe(CO)(PPh,Li)]Br -+ [(n-Cp)Fe(CO)PPh,], + LiBr

[(n-Cp)Fe(CO),(PPhLi,)]PF,

14' 142 143

144

+

[(n-Cp)Fe(CO),Li]

J. A. De Beer, R. J. Haines, and R. Greatrex, J.C.S. Chem. Comm., 1972, 1094. P. Rosenbuch and N. Wekman, J.C.S. Dalton, 1972,1963. A. T. T. Hsieh and G. Wilkinson, J.C.S. Dalton, 1973, 867. P. M. Treichel, W. K. Dean and W. M. Douglas, Znorg. Chem., 1972.11.1609.

Inorganic Chemistry of the Transition Elements

206

U.V. irradiation of [(n-Cp)Fe(CO),(PPh,H)]PF, yields a dimeric salt which possibly has structure (30).,, The phosphoranes p-XC,H,CH=PPh, (X = H, Me, or OMe) react with iron carbonyls to form stilbenes, Fe(CO),PPh,, Ph,PO, and unstable organometallic complexes. Similar reactions with alkyl - CH=PPh, also give

I

PPh,-PPh,

x-Cp

\

Ph,HP/

Fe

PPh,H / Fe / \ \PPh2-PPh2 x-Cp

/

\

(30)

Ph,PFe(CO), and unstable organometallic complexes, but in only two cases were substituted ethylenes i~olated.'~'Treatment of Fe(CO), with AsF, in benzene at 120°C yields dark violet crystals of As,[Fe(CO),],, an X-ray structural study on which shows it to have structure (31) (Fe-Fe = 2.62, Fe-As = 2.35A).'46 Reaction of Na,Fe(CO), with Ph,E'Cl gives the trigonal-bipyramidal anions [Fe(CO),E'Ph,] - (El = P or As). These anions react with organic halides to produce (Ph,RE')Fe(CO), [El = P, R = Me or CH,CMe=CH,; E' = As, R = PhCH,, CH,CMe=CH,, CH,CO,Et, CH,C=CH, GePh,, or (Cp)Fe(CO),] and with Ph,E2Cl to form Fe(CO),E1Ph,-E2Ph, (El = E2 = P or As; El = P, E2 = As; E' = As, E2 = The reactions of EX, (E = As, Sb, or Bi, X = halide) with carbonyl anions and iron-iron bonded carbonyl dimers produce complex cations of the type (X = C1 or Br; E = Sb or As) (XSb[Fe(CO),(X,E[Fe(CO),(n-Cp)]}'

(x-Cp)],}+ (X = C1 or Br) and (Sb[Fe(CO),(NO)(PPh,)],)+. The neutral compounds, X,EFe(CO),(n-Cp) (E = As, X = C1 or Br; E = Sb, X = I; E = Bi, X = Cl), Cl,EFe(CO),(NO)PPh, (E = As or Bi) and Bi[Fe(CO),(NO)L], (L = CO or PPh,) were also isolated. The reaction of SbX, with [XFe(CO),(x-Cp)] gives X,Sb[Fe(CO),(x-Cp)],, whereas reaction of SbCl, with [Fe(CO),(x-Cp),] produces { [Fe(CO),(n-Cp)],Cl) [SbC16].148[Fe(CO),14'

147

14*

H. Alper and R. A. Partis, J . Organometallic Chem., 1972,44.371. L. T. J. Delbaere, L. J. Kruczynski, and D. W. McBride, J.C.S. Dalton, 1973, 307. J. P.Collman, R. G. Komoto, and W. 0. Siegl, J . Amer. Chem. SOC.,1973,95,2389. W.R. Cullen, D. J. Patmore, and J. R. Sams, Znorg. Chem., 1973,12,867.

207

Elements of the First Transitional Period

(Me,PCH,CH,PMe,)] can be isolated from the reaction of [(cot)Fe(CO),] and the ligand in refluxing toluene. 1.r. data indicate that the complex has a trigonal-bipyramidal structure with phosphorus atoms in axial and equatorial sites, and 13C n.m.r. data are consistent with a non-rigid structure down to - 80 0C.149The structure of the related compound [Fe(CO),(Ph,PCH,PPh,)] has been reported and co-ordination geometry is intermediate between trigonalreacts bipyramidal and square-pyramidal.' 5 0 [(n-Cp)Fe(CO),(Me,CO)] with Ph,P(CH,),PPh, (n = 1, 2, or 3) to form the cations {(n-Cp)Fe(CO),in which the diphosphine ligands are unidentate. The [Ph,P(CH,),PPh,]} free phosphorus atom can take part in further co-ordination and the dinuclear (n = 1, 2, or 3; cations [(n-Cp)Fe(CO),(Ph,P(CH,),PPPh2}Fe(CO)2(~-Cp)]X2 X = ClO, or PF,) and [{(n-Cp)Fe(CO),[Ph,P(CH,),PPPh2]}2CoC12] X, (n = 2 or 3, X = C10, or PF,) have been isolated. 2,SDithiahexane and pyrazine act similarly as bridging ligands forming { [(n-Cp)Fe(CO),],(L-L)}(ClO,), [L-L = MeS(CH,),SMe or NC,H,N]. The mononuclear cations [(n-Cp)Fe(CO),(Ph,P(CH,),PPh}]+ eliminate CO upon irradiation to form [(n-Cp)Fe(CO)(Ph,P(CH,),PPh,}]+ (n = 1 or 2) in which the phosphine is ~he1ating.l~' The complex [LFe(CO)(COMe)(n-Cp)] (L = Ph,As(CH,),PPh) has been prepared., Complex (32) can be prepared by irradiation of the ligand and Fe(CO), in hexane. A similar reaction in benzene yields a mixture of ~e(CO),(P(OCH,),P}], [Fe(CO),{P(CH,O),P)], and [(OC),FeP(OCH,),PFe(CO),] which can be separated by chromatography. Evidence reported earlier for the non-axial isomer of [Fe(CO),{P(OCH,),P}] has been reinterpreted as arising from a mixture of the ligand, the trans-disubstituted compound (32), and the axial isomer.152 L ' m F , ) , , , , (L' = Me,As or Ph,P; L2 = Me,As, Ph,P; n = 4, 6, or 8, but not all possible combinations) reacts with iron carbonyls. The mixed ligands yield eight different types of complex, two of which [(L-L2),Fe,(CO),] (n = 3 or 4), were previously unknown.'53 The structure of [{ Ph,PC=C(AsMe,)CF,CF,}2Fe,(CO)4] has been reported. The two iron atoms are in different environments: one has distorted octahedral co-ordination +

+

P-CH2-O-P\CH,-O'

''41

Is*

Fe-P-CH2-0-P \CH,-O 0 0

c/ \c

/

M. Akhtdr, P. D. Ellis, A. G. MacDiarmid, and J. D. Odom, Znorg. Chem., 1972,11,2917. F. A. Cotton, K. I. Hardcastle, and G. A. Rusholme, J . Coord. Chem., 1973,2,217. M. L. Brown, J. L. Cramer, J. A. Ferguson, T. J. Meyer, and N. Winterton, J . Amer. Chem. SOC., 1972,94,8707. D. A. Allison, J. Clardy, and J. G. Verkade, Znorg. Chem., 1972, 11, 2804. L. S. Chid, W. R. Cullen, and D. A. Harbourne, Canad. J . Chem., 1972, 50, 2182.

Inorganic Chemistry of the Transition Elements

208

arising from two bidentate PAS donors and a terminal CO group with the other iron atom in the sixth position (Fe-Fe = 2.869 A); the second iron atom is in a trigonal-bipyramidal environment, being bonded to two terminal CO groups and the olefinic bond of one ligand molecule in the equatorial plane, with the axial positions being occupied by a third CO group and the other metal atom.lS4

The structure of the related compound (33) has also been reported.lS5 Two diastereoisomers of PhMeAsC(CF,)=C(CF,)AsMePh (L-L) have been prepared and their reactions with Fe(CO), give (L-L)Fe(CO), and (L-L)Fe,(CO),. Two of three possible geometrical isomers of the latter were obtained, as were minor amounts of [Fe(CO),AsMePh],.' 5 6 Compound(34)reactswith Fe,(CO), to give (35) and (36), the complex (36) being produced via (35). The related ligand (37) undergoes a similar reaction to give (38).15'

CF3-C=C-CF3

I

CF3- P5

C

F

cF3mc

3

'

I

CF3- P -P -CF3

P -+ Fe (CO),

I

Fe (CO) 3

CF3 (341

CF3 \P-P

I

/

P-P

CF3

,CF3

I

CF3-P-P-CF3 \

CF3

1x1

(CO),Fe

(37)

154 155 156

15'

F. W. B. Einstein and R. D. G. Jones, Inorg. Chem., 1973, 12, 255. F. W. B. Einstein and R. D. G. Jones, J.C.S. Dalton, 1972, 2563. W. R. Cullen and L. Mihichuk, Canad. J. Chem., 1973,51,936. A. H. Cowley and K. E. Hill, Inorg. Chem., 1973,12, 1446.

Fe (CO),

EIements of the First Transitional Period

209

The carbonyl complexes [(n-ring)Fe(CO)L(CONH,)] (n-ring = n-C,H,, L = CO, PPh,, or PEt,; n-ring = n-C,H,CHPh,, L = CO or PPh,; n-ring = n-C,H,CPh,, L = CO) have been isolated from the reaction of [(n-ring)Fe(CO),L] with liquid ammonia. The corresponding isocyanate complexes are obtained by oxidative degradation of the carbamoyl compounds with I,.',, The synthesis of the diastereoisomers ( +)- and ( -)-[(x-Cp)Fe(CO)(PPh,)(CO,C,,H,,)] has been described. No racemization occurs in solution even at elevated temperatures. Transesterification of these menthyl esters with methanol gives the methyl esters in their optically inactive forms.'59 [(n-dienyl)Fe(CO),], reacts with RNC to form [(n-dienyl),Fe,(CO),_,(CNR),] (n-dienyl = n-Cp, n-MeCp, or n-C,H,, n = 1 or 2, R = Me, Et, or cyclohexyl). These complexes exist as a mixture of cis and trans C O and RNC bridged tautomers in solution, with the p-RNC species decreasing in importance as the bulk of R increases.16' ClS0,NCO undergoes an insertion reaction with [(n-Cp)Fe(CO),CHCR'=CR2R3]. When R' = Me and R2 = R3 = H, the amide [(n-Cp)Fe(CO),N(SO,Cl)CO CR2R3CR1=CH,] is formed, not the ring compound (39). The amide reacts with aniline to give [(x-Cp)Fe(CO),and with Et,N to give [(n-Cp),Fe,(N(S0,NHPh)CO CH,CMe=CH,)] +

-

CH2 ( x - C ~ ) ( C O ) ~ F ~ - -1'C R N- S0,CI

'

R2'

\c-4 \

R3

%o

(39)

(CO),]. However, when R' = H, R2 = R3 = Me, or R' = R3 = H, R2 = Ph, the ring compounds are produced. A mechanism for these reactions has been suggested and the different reaction products were rationalized. 16' When Na[(n-Cp)Fe(CO),] in T H F is treated with thirty-fold excess of SO, at - 75 "C and then warmed to room temperature over a period of 45-60 mins, red crystals of [(x-Cp)Fe(CO),],SO, are formed together with a trace of (n-Cp),Fe,(CO),SO,. Attempted sublimation of the former led to decomposition and reaction with Me1 yields (n-Cp)Fe(CO),SO,Me and (n-Cp)Fe(CO),I. A structural study has shown that the SO, molecule bridges the two iron atoms via Fe-S bonds, the bond lengths (2.280A) of which give no indication of multiple character.' 62 The intermediacy of 0-bonded sulphinates in SO, insertion reactions of (n-Cp)Fe(CO),R has been demonstrated by spectroscopic measure-

''* J. Ellermann, H. Behrens, and H. Krohberger, J . Organometallic Chem., 1972.46, 119. lS9

16'

H

H. Brunner and E. Schmidt, J . Organometallic Chem., 1973,50, 219. M. J. Boylan, J. Bellerby, J. Newman, and A. R. Manning, J . Organornetaflic Chem., 1973,47, C33. Y. Yamamoto and A. Wojcicki, J.C.S. Chem. Comm., 1972, 1088. M. R. Churchill, B. G. DeBoer, K. L. Kalva, P. Reich-Rohrwig, and A. Wojcicki, J.C.S. Chem. Comm., 1972, 981.

Inorganic Chemistry of the Transition Elements

210

merits.,' The reduction of [(x-Cp)Fe(CO)(CNMe),] with BH, yields (40), whose structure has now been confirmed by X-ray methods.16,

Nitrogenyl and Nitrosyl Compounds.-[FeH,(N,)(PEtPh,),] reacts with ethylene (1 atm) in benzene, toluene, or THF. The product was not isolated, but spectral measurements in solution indicated that it can be formulated as [FeH(Et)(PEtPh,),L] (L = PEtPh, or solvent). The mechanism suggested for its formation is outlined below.'64 [FeH,(N,)(PEtPh,),]

+ solvent(S) -+

[FeH,(N,)(PEtPh,), S]

[FeH,(N,)(PEtPh,),S]

+ C,H,

+

+ PEtPh,

[FeH,(C,H,)(PEtPh,),S]

+ N,

1 [FeH(C,H,XPEtPh,), S ]

A non-enzymic model for nitrogen fixation has been reported by van These authors found that significant amounts of ammonia Tamelen et with were produced by treatment of [Mo(N,),(Ph,PCH,CH,PPh,),] (n = 4 or greater). This is the first example of ammonia [Fe,S,(S,C,Ph,),]"production by direct reduction of a relatively stable nitrogenyl complex in a model system of the ferredoxin structural type. Further work has been reported on nitrogen fixation by the FeC1,-Mg-THF system. The compounds [(THF),.,[(C,H,)FeCl,Mg(THF),],6H,O, MgCI,Fe]N,, [(THF)FeCl,],Mg(THF),, and [(C,H,),FeC1,Mg2(THF),1,6H2O have been isolated from the system under nitrogen and the first of these reacts with HCl to produce hydrazine. The C,H, ligand is formed by dehydration of T H F by anhydrous FeC1, and is o-bonded to either Fe or Mg in the products.166 The structure of Hg[Fe(CO),NO(PEt,)], has been determined. There is a disordering of N O and CO groups and the Fe-Hg-Fe unit is linear with staggered XO groups (X = C or N).16' In a study of reductive nitrosylation of Group VIIIB metals, FeC1, was reduced by Et,N and NO in methanol giving [FeCl,(NO),] -. The authors view this reaction, together with those of cobalt complexes discussed later, as the first example of stoicheiometric reduction of a metal complex by NO, followed by dissociation of the oxidized form of N O 163

164

ld5 166

16'

W.M. Butler and J. H. Enemark, J . Orqanometallic Chem., 1973,49,233. V. D. Bianco, S. Doronzo, and M. Aresta, J . Organometallic Chem, 1972,42, C63. E. E. van Tamelen, J. A. Galdysz, and J. S . Miller, J . Amer. Chem. SOC.,1973,95, 1347. B. Jezowska-Trzebiatowska and P. Sobota, J. Organometallic Chem., 1972,46, 339. F. S. Stephens, J.C.S. Dalton, 1972, 2257.

Elements of the First Transitional Period

21 1

and reco-ordination of free NO.'68 Photolysis of Na,[Fe(CN),N0]'69 and the thermal decomposition of M[Fe(CN),N0]170 (M = large range of cations) have been reported.

Other Iron(0) and Iron(1) Compounds.-Iron vapour reacts with PF, and benzene to form [(C,H,)Fe(PF,),].41 Although this organometallic compound will undoubtedly receive attention in the Chemical Society Specialist Periodical Report on that subject, it is included here as it constitutes the first example of an entirely new class of organo-iron complexes. Few paramagnetic transition-metal hydrides are known and most have only been detected in solution. However, treatment of either [FeHCl(diphos),] or [FeH(diphos), JBPh, with sodium in benzene yields [FeH(diphos),] (peff = 1.80BM between -175 and 24°C). Treatment of this compound with HC1 or I, at,room temperature gives [FeHX(diphos),] (X = C1 or I) and treatment with edcess HC1 at 80°C gives [FeCl,(diphos), 1. The dichloro-compound also undergoes sodium reduction in benzene in the presence of diphos giving [FeCl(diphos),] (peff= 2.11 BM between -174 and 25°C) (diphos = Ph,PCH2CH2PPh2).171 Iron( ri).-Mossbauer data have been reported for a range of iron(I1) complexes with stereochemistries intermdiatebetween octahedraland trigonal prismatic.' 7 2 Halides and Pseudohalides. When FeCl, in ether is treated with methyl-lithium at room temperature or just below, a mixture of FeCl, and Li,FeCl, is formed. However, reaction at - 78 "C gives partial precipitation of pure Li,FeCl,, 4Et,0.'73 The compounds MFeF, (M = Na, K, Rb, or Cs) have been prepared by four different routes. These are treatment of FeF, with MCl, treatment of FeC1, with MF, treatment of FeF, with MF and reaction of MCl, FeCl,, and HF.17, Thermal dehydration of FeC1,,6H,O proceeds via FeCl,,nH,O ( n = 4,2, or 1) to anhydrous FeC1,.17, Thermochemical data for the formation of CsFeCl, (x = 3,4, or 5) in a lithium-potassium chloride eutectic have been rep~rted.~ Single crystals of Prussian Blue, Fe,[Fe(CN),],,14H20 have been grown for the first time by diffusion of aerial oxygen and water vapour into a solution of FeC1, and K,[Fe(CN),] in IOM-HC1, contaminated with 1-2% of KCl. Prussian Blue is constructed from three different co-ordination units, Fe'IC,, Fe'I'N,, and Fe"'N,0,.'76 Na,Fe(CN),NH, reacts with the donor ligands L to produce [Fe(CN),LI3- [L = py, 4-Mepy, 4-Clpy, 4-(HO),CHpy, 4-py-4C02H, 4,4'-bipy, pyrazine, N-Mepyrazinium, (41), or (42)].177 E.s.r. studies on a-

''' 16')

O''

174

17' 177

D. Gwost and K. C. Caulton, J.C.S. Chcrti. Comm.. 1973, 64. R. P. Mitra, B. K. Sharma, and S. P. Mittal, J . Inorg. Nuclear Chem., 1972,34,3919. G . B. Seifer and Z. A. Tarasova, Russ. J. Znorg. Chem., 1972, 17, 705. M. Gargano, P. Giannoccaro, M. Rossi, and A. Sacco, J.C.S. Chem. Comm., 1973,233. W. M. Reiff, J . Amer. Chem. SOC.,1973,95, 3048. H. J. Berthold dnd H. J. Spiegel, Z. anorg. Chem., 1972,391, 193. G. Elbinger, A. Funke, P. Kleinert, P. Roseman, and W. Keilig, 2. anorg. Chem., 1972, 393, 193. K. P. Pribylov, S. I. Kleshnina, and R. A. Manapov, Russ. J . Inorg. Chem., 1973,18, 7. H. J. Buser, A. Ludi, W. Petter, and D. Schwarzenbach, J.C.S. Chem. Comm., 1972, 1299. I+ E. Toma and J. M. Malin, Inorg. Chem., 1973,12, 1039.

212

Inorganic Chemistry of the Transition E Iements

irradiated K,Fe(CN), in various host lattices showed that four major iron(1) species are formed: [Fe(CN),H,0I4-, formed from [Fe(CN),H,0I3impurity and containing one CN group slight bent away from the Fe-CN axis; a second product containing a pair of trans-CN groups which are both

also bent away from the axis; and two halogen-containing products, [Fe(CN),(CN)(Hal)] - and [Fe(CN),(Hal),]' - in which CN' represents a non-linear cyanide group. A species containing an Fe-CNH linkage was also observed.' 78 When Fe(CN),,- is dissolved in liquid HF, [Fe(HCN),I2+ is formed.' 7 8 a Hydrides. The volatile colourless liquid H ,Fe(PF,), has been obtained from Fe(PF,), by a photochemical reaction with hydrogen. The dihydride reacts with alkali-metal t-butoxides to form M,[Fe(PF,),] and M[FeH(PF,),] (M = alkali metal) and with sodium amalgam to form Na[HFe(PF,),]. Reaction with ethylthiol or iodine under U.V.irradiation gives (F,P),Fe(pSEt)(p-PF,)Fe(PF,), and (F,P),Fe(p-I)(p-PF,)Fe(PF,),, respectively.' 79 'H, 19F, and ,'P n.m.r. studies on H,Fe(PF,), showed that near the boiling point (87 "C) the PF, ligands are arranged around the metal in a tetrahedral fashion, while the hydrogen atoms are stereochemically non-rigid. Mossbauer data at -70°C indicated the presence of cis- and trans-isomers. Similar n.m.r. and Mossbauer studies have shown [Fe(PF,),12- to be tetrahedral and [HFe(PF,),] - to be trigonal-bipyramidal. A comparison of I,FeL,, FeL,, H,FeL,, [HFeL,]-, and [FeL,I2- (L = C O or PF,) has shown that the geometries of the pairs of carbonyl and PF, complexes are identical in all cases and that the sum of the o-donor and n-acceptor abilities of PF, is lower than that of CO.I8O Fe(PF,), also reacts with ethereal solutions of cyclopentadiene under U.V. irradiation to form yellow [(n-C,H,)Fe(PF,),] which, in the presence of weak bases, is converted into orange [(n-Cp)FeH(PF,),]. This hydride reacts with KOBu' to yield K[(7c-Cp)Fe(PF,),].'81 [HFe(PF,),]- has also been examined by Muetterties and co-workers,182They suggest that the ground-state geometry is neither truly trigonal-bipyramidal nor square-pyramidal, the anion being stereochemically non-rigid. The lowest energy pathway for fluxional motion of this pseudo-tetrahedral [FeP,] species is suggested as being a movement of the hydrogen atom towards an edge of the tetrahedron with a concomitant Fe-P bending motion that enlarges this tetrahedral angle. The authors term this 'tetrahedral tunnelling'.' 8 2 The same group have also studied the complexes

17'

lS2

M. C. R. Symons and J. G. Wilkinson, J.C.S. Dalton, 1973, 14. R. J. Gillespie and R. Hulmes, J.C.S. Dalton., 1973, 1261. T. Kruck and R. Kobelt, Chem. Ber., 1972,105, 3765. T. Kruck and R. Kobelt, Chem. Ber., 1972,105, 3772. T. Kruck and L. Knoll, Chem. Ber., 1972,105, 3783. P. Meakin, E. L. Muetterties, and J. P. Jesson, J . Amer. Chem. Soc., 1972,94, 5271.

Elements of the First Transitional Period

213

H,ML, (M = Fe or Ru; L = a wide range of phosphines, phosphites, phosphinites, and phosphonites) and have shown two types of complexes to exist by n.m.r. One type is present as the cis-isomer with essentially no trans-form present, the other type has both cis- and trans-isomers present in equilibrium. Barriers to rearrangement for the iron complexes are largely insensitive to steric and electronic changes in L and such rearrangements are discussed in terms of the 'tetrahedral jump' m 0 d e 1 . l ~ ~ Complexes. Pyridine and related ligands. Atactic poly-4-vinylpyridine reacts with iron(r1) compounds in ethanol to yield Fe12(P-4VP), and FeX2(P-4VP), (X = C1, salicylaldehydate, o-nitrophenolate, X, = acac; P-4VP = a poly-4vinylpyridine monomer unit).' 84 A full report of the crystal structure of [(FB(ONCH C H ,N), P>Fe"] BF,,CH C1, has been published. The ligand was designed to force trigonal-prismatic stereochemistry on the metal atom and this is found to be the case for the analogous nickel complex. However, in the case of the above iron complex the geometry is intermediate between trigonalprismatic and octahedral. [Fe(bipy),](ClO,), has been found to be completely dissociated in conc. HCl yielding bipyH+ cations and [FeC1,I2- anions. In conc. HNO,, HClO,, or H,SO,, pale blue solutions thought to contain Fe"' are formed and the complex [Fe(bipy),(NO,),]ClO, has been isolated from nitric acid.' A series of iron@) complexes which lie near to the magnetic crossover point, FeL,X,,nH,O (X = NCS or NCSe; L = a ring substituted analogue of 1,lOphen or 2,2'-bipy) has been prepared and studied. Small modifications in the molecular structures are found to produce dramatic changes in the magnetic properties. Thus some of the complexes have near equi-energetic high-spin and low-spin states, both of which are thermally populated and other show complete crossover within a very narrow temperature range. Some of the remaining complexes show magnetic behaviour between these two extremes, whereas others have temperature-independent magnetic moments which are intermediate between high- and low-spin values and are attributed to a triplet ground state.187*187a Iron(1r) complexes of 2-methyl-1,lO-phenanthroline(L) have been prepared. FeL,X, (X = C1, Br, NCS, N,, or malonate) are all high-spin, the CNS complex containing N-bonded anions in a cis arrangement. FeL,(CN), is low-spin, and it is concluded that the crossover point for FeL,X, is exactly at the position of L in the spectrochemical series, in contrast to the analogous 1,lO-phen complexes where this point is lower than the average ligand-field

P. Meakin, E. L. Muetterties, and J. P. Jesson, J . Amer. Chem. SOC.,1973,95, 75. H. G. Biedermann, J. Obwander, and K. Wichmann, Z . Naturforsch., 1972,27b, 1332. l E 5 M. R. Churchill and A. H. Reis, Inorg. Chem., 1972,11,2299. G. B. Briscoe, M. E. Fernandopulle, and W. R. McWhinnie, Inorg. Chim. Acta, 1972,6, 598. 18' A. J. Cunningham, J. E. Fergusson, H. K. J. Powell, E. Sinn, and H. Wong, J.C.S. Dalton, 1972, 2155. 187aE. J. Halbert, C. M. Harris, E. Sinn, and G. J. Sutton, Austral. J . Chem., 1973, 26, 951. 183

184

214

Inorganic Chemistry of the Transition Elements

strength.'88 The complexes FeL,X, (L = phen or bipy; X = C1 or Br) have been isolated and their far-i.r. spectra examined.57 [Fe(phen),](xanthate), has been prepared by the reaction of potassium xanthate, FeCl,, and phen in aqueous solution. The complex is diamagnetic5' D.t.a. measurements on optically active [Fe(phen),]X,,nH,O complexes show a specific exothermic peak in the case of X = I or ClO,, which is attributed to racemization occurring.'*' In the thermal decomposition of [Fe(phen),]X,,nH,O (X = C1, Br, I, or SCN), [Fe(phen),X,] has been i~olated.''~ The complexes FeL,X, (L = 1,2-dimethylimidazole, X = C1, Br, or I, n = 1 or 2; X = NCS, n = 3 or 4) have been isolated.61 The syntheses of several new terdentate N-donor ligands based on pyrrole, pyrazole, and indene have been described. The ligands have been designed to present their donor sites to a metal at positions very close to the normal octahedral sites and iron(@ complex cations have been isolated. The ligands undergo deprotonation when co-ordinated, leading to neutral complexes; however, no changes in colour or magnetic moment are observed on d e p r o t ~ n a t i o n . ' ~ ~ Macrocyclic N-donor Iigands. The ligand [14]aneN, (43) forms the six-coordinate tetragonal complexes Fe([14]aneN4)X, (X = CN, NO,, NCS, Cl, Br, I, OAc, or BF,) and the cation [Fe([14]aneN4}(MeCN)J+. The iron atom is low-spin in the complexes containing strong axial ligands (X = CN, NO,, NCS, or MeCN). These are first reported examples of stabilization of the spin-paired state with saturated nitrogen atoms as the most abundant donors, and this is attributed to enhanced ligand-field strength due to the constrictive effect of the mechanically confining in-plane ring. It is inferred by the authors that other 14-membered macrocyclics having unsaturated N-donors produce five-co-ordinate high-spin complexes, because the high-spin metal atom is too large to remain symmetrically encompassed by the ring.'92 A detailed systematic study has been made of iron@) complexes of the macrocyclics (43)-(51), the ligands forming a distinctive series of compounds containing different degrees and types of unsaturation. All nine complexes are low-spin six-coordinate with MeCN occupying the axial sites. Complexes of (43) and (45) can be synthesized by treating iron(u) salts with ligand in methyl cyanide. These complexes react in a stepwise manner with oxygen in MeCN to give dehydrogenated products. Thus [Fe(43)I2' finally gives [Fe(48)I2t and [Fe(45)I2+ yields complexes of (46) and (50). The complex having four isolated imine groups [Fe(50)I2+ undergoes a novel tautomeric process to produce the complex containing an a-di-imine grouping [Fe(49)I2'. This reaction is slow in acetonitrile but is promoted by the presence of the corresponding iron(m) complex. The selectivity in positioning of the double bonds in the processes described above is a remarkable illustration of the special stabilization of the 18'

19' 192

E. Konig, G. Ritter, K. Madeja, and A. Rosenkranz, J . Inorg. Nuclear Chem., 1972, 34, 2877. Y. Yamamoto, K. Akabori, and T. Seno, Inorg. Nuclear Chem. Letters, 1973,9, 195. K. Akabori, H. Matsuo, and Y. Yamamoto, J . Inorg. Nuclear Chem., 1973,35, 2679. B. Chiswell. Inorg. Chim. Acta, 1972,6, 629. J. C. Dabrowiak, P. H. Merrell, and D. H. Busch, Znorg. Chem., 1972,11,1979.

215

Elements of the First Transitional Period

aromatic chelate ring (52). The dependence of the stabilization of the various oxidation states of iron on the degree of unsaturation of the ligands and the unique stabilizing influence of the a-di-imine residue on iron@)are demonstrated by electrochemical studies on the complexes. In all complexes, iron@) is

n ' (45)

(44)

(43)

NH

d,

N N

J

(47)

reversibly electrochemically oxidized to iron(m), but only complexes containing a-di-imine rings are reversibly electrochemically reduced. For example, [Fe(48)I2+ shows three well-defined reduction steps corresponding to Fe', Fe', and Fe-'. The complexes with isolated imine groups are all reduced irreversibly and there is no evidence for oxidation above the + 3 state.lg3 The complexes [Fe(CO)L(base)] [L = (53), base = MeCN, py, 4-picoline, or N,H,] have been prepared by reaction of free ligand with an anhydrous source of iron@) under an atmosphere of CO. The structure of the low-spin 193

J. C. Dabrowiak, F. V. Lovecchio, V. L. Goedkin, and D. H. Busch, J . h e r . Chem. SOC..1972,94, 5502.

Inorganic Chemistry of the Transition Elements

216

N \F€!2+' '

\

3

N

I

hydrazine complex has been determined and the macrocyclic ligand is not flat but saddle-shaped, owing to steric interactions. This is the first detailed structural study on carbon monoxide in a similar environment to that in haeme proteins.'94 The reaction of iron(x1)with butane-2,3-dione dihydrazone and formaldehyde is illustrated in Scheme 3 (M = Fe). The complex (55) is low-spin, with MeCN co-ordinated in the axial sites, (56) is also low-spin and very stable in acidic solution.'95 2+

2+

I NH2

Schem 3

Iron(I1)-deuterioporphyrin(1X) is rapidly oxidized by alkyl halides in N methylpyrrolidone-acetic acid mixtures at room temperature. The stoicheiolg4

lg5

V. L. Goedkin, J. Molin-Case, and Y . 4 . Whang, J.C.S. Chem. Comm., 1973, 337. V. L. Goedkin and S.-M. Peng, J.C.S. Chem. Comm., 1973,62.

Elements of the First Transitional Period

217

metry, stereochemistry, and kinetics of these reactions are consistent with an initial breaking of the C-halogen bond with formation of a free radical and an iron(m) p~rphyrin.''~In a complementary paper, the same authors reported that bromomalonitrile and bromodiethylmalonate rapidly and quantitatively oxidize dilute solutions of iron@) human haemoglobin and sperm whale myoglobin at 18 "C to give iron(m) proteins without protein denaturation. Under identical conditions, iron@) cytochrome (from horse heart) is inert and only reacts with a large excess of bromomalonitrile. The halides are converted into the corresponding alkanes. Various halides oxidize human haemoglobin, thus verifying recent theoretical predictions and demonstrating that bromomalonitrile is an efficient reagent to probe axial inner-sphere electron transfer reactions.' 97 The reaction of FePc (Pc = phthalocyanine) with thionyl chloride gives Fe"'PcC1, which contains a phthalocyanine radical species.' '* Reduction of iron@) phthalocyanine with sodium in T H F or by electrochemical means yields four distinct anions corresponding to the stepwise addition of electrons. Electronic spectroscopy shows electron addition to occur into both metal and ligand orbitals.64 Other N-donor ligands. Decomposition of the iron(r1)complex of N-(2-pyridylmethylene)-4-methylaniline with edta provides a convenient route to the parent Schiff base (57); however, decomposition in an acetone-water mixture yields (58), indicating that the C=N bond is activated by comp1exation.'''

(57)

Six new clathro-chelates of iron(r1) have been prepared in a rapid onc-step reaction of Fe2+, dmgH,, and either boric acid and an alcohol or BF,. The products (59)are produced in greater than 50 % yield, the yields being improved by addition of sodium acetate to reduce the acidity of the solution. It is suggested that the iron atoms provide a template on which three dimethylglyoximatogroups become bound in an anti-conformation prior to reaction with the boron-containing moieties. The cage-like nature of the fluoro-complex has been established by crystallography, the co-ordination geometry being intermediate between trigonal-prismatic and trigonal-antiprismatic.200 Polymeric

19' 19* 199

R. S. Wade and C. E. Castro, J. Amer. Chem. SOC.,1973,95, 226. R. S. Wade and C. E. Castro, J. Amer. Chem. SOC.,1973,95,231. G. W. Rayner-Canham, J. Myers, and A. B. P. Lever, J.C.S. Chem. Comm., 1973,483. D. J. Farrington and J. G. Jones, Znorg. Chim. Acta, 1972,6, 575. S. C. Jackels, D. S. Dierdorf, N. J. Rose, and J. Zektar, J.C.S. Chem. Comm., 1972, 1291; Znorg. Chem., 1973, 12, 1232.

218

Inorganic Chemistry of the Transition Elements

1: 1 chelates of Fe" and the tetraoximes. MeC(NOH)C(NOH)CH,CH,(CH,),CH,CH,C(NOH)C(NOH)Me (n = 2 or 6) have been prepared. The complexes are low-spin and square-planar.20' The related tetraoximes MeC(N0H)-

(59) X = F, OH, OMe, OEt, OPr', or OBu"

C(NOH)RC(NOH)C(NOH)Me (R = C,H,. 0 C,H,, C,H,* C,H,, or 2,6bipyridyl) form similar complexes: however, these are paramagnetic in the solid state and diamagnetic in solution.202Iron@) complexes of substituted 2-pyridinalphenylimines, [FeL,](ClO,), and FeL,(NCS), have been prepared. The complexes can be high- or low-spin or show a temperature-dependent spin equilibrium, dependhg on the position and nature of the substit~ent.,'~ The azoimine complexes (60) and (61) have been prepared.,', Benzonitrile forms the complexes [Fe(NCPh),]X, (X- = SbC1,-, InCl;, or FeCl;),, anc' the crystal structure of [Fe(NCMe),][FeCl,], has been de-

termined.205 The cationic ligand (8) forms trigonal-bipyramidal complexes [FeX,(LH+),]X [X = C1 or Br, LH' = (8)].54 0-Donor ligands. 1: 1 Adducts of Fe(acac), and both 4,4'-bipyridine and pyrazine have been reported.'l The halogenation of Fe(acac), by bromine and SO,Cl, and its oxidation with oxygen have been studied.,', Antipyrine (Apy) and pyridine N-oxide (py0) complexes of iron@) have been reported. The tetrahedral complexes Fe(Apy),X, (X = C1 or Br) and the octahedral complexes [Fe(Apy),](ClO,), and Fe(Apy),I, have been isolated, the last-named of these undergoing dissociation in solution, whereas the others 201

202

203 *04 205

'06

J. Backes, I. Masuda, and K. Shinra, Bull. Chem. SOC.Japan, 1972,45, 1724. J. Backes, I. Masuda, and K. Shinra, Bull. Chem. SOC.Japan, 1972,45, 1061. P. Barth, G. Schmauss, and H. Specker, 2. Naturforsch., 1972,27b, 1149. S. Gupta and A. Chakravorty, Inorg. Nuclear Chem. Letters, 1973,9, 109. B. A. Stork-Blaisse, G. C. Verschoor, and C. Romers, Acta Cryst., 1972, B28, 2445; G. Constant, J.-C. Daran, and Y. Jeannin, J . Organometallic Chem. 1972,44, 353. H. G. Biedermann, K. E. Schwarzhans, and W. Wiedemann, Z. Naturforsch., 1972,27b, 1329.

Elements of the First Transitional Period

219

are non-electrolytes. [Fe(pyO),C1,],,2H20, [Fe(pyO),Br,],, and [Fe(pyO)Cl,(H,O),], were also obtained, all of which are octahedral.,07 The complex Fe(py~NO),(Cl0,)~(pyzNO = pyrazine N-oxide) has also been reported and, as with the related manganese complex, the C10, groups become co-ordinated to the metal atom on the application of pressure in preparing a KBr disc of the material.81 The free radical (62) reacts with iron@) perchlorate in the presence of triethylorthoformate to form FeL,(ClO,),. It is thought that the complex is most probably polynuclear with bridging perchlorate groups. Magnetic and

e.s.r. studies have been interpreted in favour of a partial spin-spin coupling between unpaired electrons on the ligands and those on the Trimorpholinophosphine oxide (morPO) forms the complexes [Fe(morPO),X,] (n = X = BF,, NO,, NCS, C1, Br, or I) in which the ligand morPO is co-ordinated by the oxygen atom.82 The complexes [FeL,X,] [X = BF,, BPh,, NO,, or C1, L = (Me,N),P(O)NMeP(O)(NMe,)NMeP(O)(NMe,), n = 1 or 21 have also been isolated. The bis-complexes are octahedral with ligands co-ordinating in a terdentate-0, manner. [FeL(NO,),] is possibly five-co-ordinate, whereas the analogous chloro-complex is probably dimeric. S-fac-and u-fac-isomers occur when X = BF,.84 The sulphinate complexes [Fe(O,SR),(py),] (R = Ph or p-MeC,H,) have been obtained from reactions of [(RSO,),Fe(OH,),] with pyridine. The complexes do not exhibit linkage isomerism of the sulphinate groups, although the isomers [{ MeS(O)O),Fe(bipy),] and [(MeSO,),Fe(bipy),] have been isolated.85 . The complexes [FeLIX, (L = 1,3-dithianemonosulphoxide or 2-phenyl-l,3-dithiankmonosulphoxide,X = C10, or BF,) have been prepared.86 Iron complexes of quinones, FeL2,2H,O (L = lawsone or phthicol), FeL, (L = lapachol), FeL3,2H,O (L = norlapachol), and FeL, (L = lapachol or phthicol) have been reported.209A study has been made of the solvation of FeCl, in the solvents MeCN, DMF, DMSO, MeOH, py, TBP, H,O, and HMPA by means of Mossbauer spectroscopy.21 Attempted preparation of trialkylamine complexes by reaction of Fe(R'OH),X, (n = 6-9) with RiN, led to the unusual products FeR~NH(R~N),(OR'),X, (n = 1-8; m = 0-3;

w,

*O' 208 209

*lo

C. P. Prnbhakaran and C. C. Pdtel, J. Inorg. Nuclear Chem., 1972,34,3485. N. M. Karayannis, C. M. Paleos, C. M. Mikulski, L. L. Pytewski, H. Blum, and M. M. Labes, Znorg. Chim. Acta, 1973,7, 74. A. Dufresna, C. G. de Lima, J. Knudsen, and J. E. Moreira, J. Znorg. Nuclear Chem., 1973,35, 789. A. Vertes, M. Palfalvy, K. Burger, and B. Molnar, J. Znorg. Nuclear Chem., 1973, 35, 691.

220

Inorganic Chemistry of the Transition Elements

X = C10, or BF,; R' = Me, Et, or n-pentyl; R2 = Me or Et).76The complexes [FeL,],(ClO,),, (L = dioxan or 1,2-dimethoxyethane) have been isolated and contain either four-co-ordinate monomeric or five-co-ordinate dimeric cations.87 S-Donor and P-donor ligands. The reaction of [(CF3),C,S2l2- (L) with Fe(CO), in the presence of H,S gives the black crystalline compound of empirical formula Fe,L,S6H, which, when dissolved in hydrocarbon solvents, exhibits many of the properties of the reduced two iron-sulphur proteins. Thus the e.s.r. spectrum of the compound as a frozen solution in the presence of isopropyl disulphide is similar to reduced adrenodoxin and putidaredoxin and indicates the presence of one unpaired electron per two iron atoms. ENDOR experiments have shown that the unpaired electron resides almost exclusively on an F e d centre.," Reaction of FeCl, in methanol with three equivalents of sodium mercaptide followed by one equivalent of methanolic sodium hydrosulphide and sodium methoxide yields [Fe,S4(SR),l2- (R = alkyl or aryl) which were isolated as their Et,N+ salts. The structure of the tetrabenzyl compound has been reported and the [Fe,S4] core found to be distorted from cubic symmetry such that each face of the polyhedron is a non-planar rhomb. Two of the Fe-Fe separations are 2.776 %, and the other four are 2.732 A, indicating direct interaction. Comparison with structural and spectroscopic properties of the active sites of the reduced high-potential iron protein from Chromatium and the oxidized ferredoxin from P. aerogenes shows that the three structures are unmistakably similar, and this appears to be a synthetic analogue of the active sites in bacterial iron-sulphur proteins.211" The structure of [Fe,S,(S,C,(CF3),)I2- has been determined and exhibits a cubic array of iron and sulphur atoms which alternate at the corners. One bidentate dithiolene ligand is co-ordinated to each iron atom. Mossbauer data have been reported for this anion and the analogous monoanion and neutral compound, and the results compared with similar data for various ferredoxins.212 Reaction of [(n-Cp)Fe(CO),], with ethylpolysulphide in refluxing methylcyclohexane gives a low yield of [(n-Cp)Fe(SEt)S],, the structure of which has been determined. The iron-iron separation is 3.318, and the metal atoms are bridged by two SEt groups as well as by an Fe-S-S-Fe bridge. Although such a disulphur bridge has not been previously reported, its presence has been suggested in the oxyform of oxygen-binding haemerythin. The compound is diamagnetic at room temperature.,' The high-spin pseudo-tetrahedral complexes [Fe(S,PX,),] (X = CF,, Me, or Ph) have been reported,88 as have the pseudo-octahedralcomplexes [FeL,X,] [X = C1, Br, or I; L = (63)J214 p-Thioxan (TX) forms the complex [Fe(TX),(OH,),](C104),.87 211 211rr

'12 213

214

K. A. Rubinson and G. Palmer, J . Amer. Chem. SOC.,1972,94, 8375. B. A. Averill, T. Herskovitz, R. H. Holm, and J. A. Ibers, J . Amer. Chem. Soc., 1973,95, 3523. 1. Bernal, B. R. Davis, M. L. Good, and S.Chandra, J . Coord. Chem., 1972,2, 61. G. T. Kubas, T. G. Spiro, and A. Terzis, J . Amer. Chem. SOC.,1973,95, 273. F. Petillon, J. E. Guerchais, and D. M. L. Goodgame, J.C.S. DaZton, 1973, 1209.

Elements of the First Transitional Period

22 1

[(n-Cp)Fe(P(OPh),),]BF, reacts with LiSn,Me, in the T H F to form (n-Cp)Fe[P(OPh),] [Sn(SnMe,),].21

, s

V

R R2

1

(63) R' = R2 = H or Me R' = Me,R2 = H R' = C,H,$R2 = H R' = Ph, R Z = H R1 = C,H,O, R2 = H

Mixed donor ligands. The reaction of [Fe(salen)] with a range of quinones yields [{ Fe(salen)) ,(quin)] (quin = p-benzoquinone, tetramethyl-p-benzoquinone, and tetrachloro -p-benzoquinone) which probably contain quinone ligands. With 9,lO-phenanthraquinone and lY2-naphthaquinone,[Fe(salen)(quin)] is The reactions of Fe(sa1en) with a variety of organic halides and nitro- and nitroso-compounds have been studied. With PhNO,, [Fe"'(salen),O], and PhN(O)=NPh are formed whereas the PhNO reaction yields the same iron(m) compound and PhN=NPh. Reaction with RNO (R = 2-biphenyl or 4-Me2NC,H,) yields [Fe(salen),O], RN=NR, and RN(O)=NR, but no carbazole which might be expected from a nitrene intermediate. Reaction with RX gives quantitative formation of [Fe(salen)X] and R-R (R = PhCH,, X = C1 or Br; R = allyl, X = Cl).2'7 Mossbauer and magnetic data for iron@) and iron(n1) complexes of salen and related ligands show the lower valent complexes to be high-spin and to have normal Mossbauer parameters. Previous reports of unusual Mossbauer parameters for these compounds are thought to be due to failure to appreciate their air sensitivity.,18 Treatment of the

related ligand acacenH, with Et,OfBF, in CH2Cl, followed by NaHS in ethanol yields dithioacacenH, (64),which reacts with Fe(OAc), in ethanol to give [Fe(dithioacacen)]. This complex reacts with oxygen in solution.219

'I6

'I7 218 219

W. Klaue and H . Werner, J . Organometallic Chem., 1973,54, 331. C. Floriani, G. Fachinetti, and F. Calderazzo, J.C.S. Dalton, 1973, 765. C. Floriani and G. Fachinetti, J.C.S. Chem. Comm., 1973, 17. B. W. Fitzsimmons, A. W. Smith, L. F. Larkworthy, and K. A. Rogers, J.C.S. Dalton, 1973, 676. R. M. C. Wei and S. C . Cummings, Inorg. Nuclear Chem. Letters, 1973,9,43.

222

Inorganic Chemistry of the Transition Elements

The octahedral complex (65) has been reported in which the terdentate ligands adopt mer-configurations.220 The high-spin complex [Fe(bipyNO),](ClO,), [bipyNO = (9)] has been prepared and compared with the related low-spin bipy complex and the di-N-oxide (10). It is found that (9) is a weaker ligand than bipy, but stronger than (lo).” The complexes (Et,N),[FeL,]H,O and [Fe(L-2H),]C1,,2H20 [L = (66)] have also been prepared.,,’ Iron(r1) salts react with 1,lO-phenanthroline-2-carbothioamide (L) to form the range of complexes [FeL,]X,,nH,O (X = C1,n = l ; X = l , n = 2 ; X = NO,,n = O;X, = SO,,n = 1 ; X = CIO,, n = 1; X, = Fe(NCS),, n = 0) and [Fe(L-H),],H,O, the ligand being terdentate in all cases. The related complex FeLCl,,H,O has been shown to exhibit a singlet-triplet spin equilibrium, whereas the bis-complexes are all low-spin.222 The thiosemicarbazide of benzoylformic acid forms complexes with iron@) in which the ligand is also terdentate.’,,

Me/NH

HN

‘Me

7-Nitroso-8-hydroxyquinoline-5-sulphonicacid (H,L) reacts with iron@) salts to form the complex H[Fe(HL),],,,, and FeCl, reacts with ethoxy-6methylpyridine-2-phosphonate (E6MPP) at high temperature to yield [Fe(E6MPP),] in which the metal atom is co-ordinated to both bidentate and bridging ligand anion^.^' An n.m.r. study of iron(r1) complexes of (12) shows the ligand to chelate via N-5 and 0 - 6 whereas in the corresponding iron(rr1) complex, co-ordination occurs via 0 - 2 only.97 Iron(ni).-Halides and Pseudohalides. The preparation of FeC1, in very high purity has been reported.225It has been found that photo-reduction of FeCl, to iron@)in aqueous solution involves [Fe(OH)]”, not [FeC1l2+,as the photoactive species.226The structure of (MeNH,),[FeBr,]Br shows the complex anion to be tetrahedral.2271.r. data have been reported for the related complex anions [FeCl,Br,-,]- (n = O--4).228 220

221 222

223 224

223 226

”’ 228

M. Kurahashi, A. Kawase, K. Hirotsu, M. Fukuyo, and A. Shimada, Bull. Chem. SOC.Japan, 1972, 45, 1940. E. Gagliardi and A. Popitsch, Monatsh., 1953,103, 1337. H. A. Goodwin, F. E. Smith, E. Konig, and G. Ritter, Austral. J. Chem., 1973,26, 521; E. Konig, G. Ritter, H. A. Goodwin, and F. E. Smith, J. Coord. Chem., 1973,2,257. N. V. Gerbeleu and V. G. Bodyn, Russ. J. Inorg. Chem., 1972.17, 1431. M. M. Aly, M. Makhyoun, and S. El-Ezaky, J. Inorg. Nuclear Chem., 1973,35, 2727. L. E. Topol and S. J. Yosim, Synth. Inorg. Organometallic Chem., 1973,3, 47. P. G. David, J.C.S. Chem. Comm., 1972, 1294. G. D. Sprout and G. D. Stucky, Inorg. Chem., 1972,11,1647. G. P. Bhavsar and K. Sathianandan, J. Mol. Structure, 1973,16, 343.

223

Elements of the First Transitional Period

Turnbull's Blue and Prussian Blue are the same material, ferric ferrocyanide. The isomer of this compound, ferrous ferricyanidej has now been isolated by vacuum pyrolysis of ferric ferrocyanide at 4Oo0C, with the loss of entrapped water. The product is stable if kept dry but reverts to ferric ferrocyanide on contact with warm dilute HCl or moist air.229The structure of H,Fe(CN), consists of layers of Fe(CN)i - octahedra joined by very short N-H - N bonds. Structural studies on H,.,[Fe~.,Fe~!,(CN),]H,Oand H,.,[Fet.,Fe~!,(CN),], 1.6H20 have also been reported. The former contains Fe(CN), octahedra arranged in layers which are connected by N-H...N bonds and [H502]+ ions and should thus be represented as [H502][H,Fet.,Fe',",(CN),]. The latter contains sheets of Fe(CN), octahedra and [Hg04 H Hg0,I3+ ions230 H,. [Fe". Fe!, ,(CN),] ,2.66H20 contains eigh t-membered chair-shaped rings of Fe(CN), octahedra. The rings share edges in such a way as to form infinite zig-zag chains with large channels containing [H502]+ ions.23' The structures of Cs2LiFe(CN),lo6 and K,Fe(CN),232 have also been determined. Complexes. N-Donor ligands. Three full-length papers encompassing the studies on Fe[N(S;Me,),], cited in Vol. 1 (p. 138) have appeared. A crystallographic study show, the complex to be of D, symmetry with Fe-N bond lengths of 1.917(4)A233 and e.s.r., electronic spectral, and magnetic data have been interpreted on the basis of crystal field calculations.234 Photo-reduction of [(phen)2(H20)Fe-O-Fe(H20)(phen)2]4+ in aqueous solution appears to continue even after cessation of irradiation, and it has been suggested that the thermally labile peroxo-bridged dinuclear complex

--

,, ,

[(phen),(H,O)Felll-O-Felll(H

I

,0)(phen),]

+

hv 350nm

['O-Fe"'( H,O) (phen),],

+

+ [(phen),( H,O)Fe':]

\ [(phen),( H, O)Fe''l-O-O-Felll(

' "

[Fe"(phen),12'

H ,O) (phen),14

+

/ 0,

+ 2 [(phen),(H,0)Fe1']2+ + [Fe"(phen),]'+ Scheme 4

229 230

231

232 233 234

J. G. Cosgrove, R. L. Collins, and D. S. Murthy, J . Amer. Chem. SOC.,1973,95, 1083. R. Haser, C. E. de Broin, and M. Pierrot, Acta Cryst., 1972, B28,2530; R. Haser'and M. Pierrot, ibid., p. 2538, 2542. R. Haser, C. Penel, and M. Pierrot, Acta Cryst., 1972, B28,2548. N. G. Vannerberg, Acta Chem. Scand., 1972,26,2863. M. B. Hursthouse and P. F. Rodesiler, J.C.S. Dalton, 1972, 2100. D. C . Bradley, R. G. Copperthwaite, S. A. Cotton, K. D. Sales, and J. F. Gibson, J.C.S. Dalton, 1973, 191; E. C . Alyea, D. C. Bradley, R. G. Copperthwaite, and K. D. Sales, ibid., p. 185.

Inorganic Chemistry of the Transition Elements

224

undergoes thermal reduction and rearrangement to the mononuclear triscomplex of iron@) as outlined in Scheme 4.235 The complexes Fe,O(phen),(NCS),, [Fe,(bipy),O]X, (X = C1, Br, or NCS), and [FeL,(NCS),]NCS (L = phen or bipy) have been isolated despite earlier claims that they could not be prepared.,,, The a-benzildioximate (HDf) complexes [Fe(HDf),L,],H,O, when treated with dry chlorine in ether form dark-brown solutions containing [Fe(HDf),L,]C1, which have been isolated as the blue-black solids [Fe(HDf),L,]Cl,mHCl, nH,O (L = py, p- and y-picoline, py-CONH,, ethylnicotinate, or 3-benzoyl~ y r i d i n e ) . , ~Similar ~ complexes, [Fe(HDf),L,]Br,nHBr, have been isolated from analogous reactions.238 The octaethylporphine (oep) complexes [Fe(oep)X] (X = OAc, F, C1, Br, I, N,, or NCS) and [Fe(oep)L,]ClO, (L = ypicoline, imidazole, or benzimidazole) have been prepared., 0-Donor ligands. An X-ray structural study on Fe(NO,),, 1.5N,O, indicates that it should be reformulated as 3NO+, NO;, 2[Fe(N03),]- in which the complex anion has a geometry similar to that of [Ph,As] [Fe(NO,),] discussed in Vol. 1 (p. 138). Crystallographic evidence indicates that the three NO' ions and the NO, ion are weakly bound by coulombic interactions to form an N,Oi ion and vibrational spectroscopic evidence is also presented for this cation, both in the solid state and in nitric acid solution. This is the first report of the N,Oi' ion and rationalizes many of the inconsistencies found in earlier reports of the existence of the N,Ol ion.240 Structural studies have also been reported for (NH,),[Fe(S03)6]241 and NH,Fe(S0,),,2H,0.242 The former contains an octahedral iron atom co-ordinated to six unidentate sulphite groups, and the latter is also octahedral, in this case the metal atom being co-ordinated to four sulphate oxygen atoms and two water molecules. The system Fe,(S0,)3-(NH,),S0,-H,0 has been investigated.,,, The structure of P-NH,Fe(CrO,), consists of a three-dimensional framework of FeO, octahedra linked by CrO, tetrahedra,,,, and that of KFe(Cr0,),,2H20 contains (FeO,, 2H,O) octahedra again linked by CrO, tetrahedra.245Studies on the thermal dehydration of FePO,,nH,O (n = 2 and 2.5) have been reported.,,, Tris(acetylacetonato)iron(m) reacts with picric acid to form [(acac),Fe(H,O)](pi~rate).~~ The structure of the adduct formed between [Fe(acac),] and +

235 236 237 238 239

'*I

'*'

243

244

245 246

P. G. David, J.C.S. Chem. Comm., 1972, 1151. P. G. David, J . Inorg. Nuclear Chem., 1973,35, 1463. D. G. Batyr, I. I. Bulgak, and K. I. Turta, Russ. J . Inorg. Chem., 1972, 17, 531. D. G. Batyr and I. I. Bulgak, Russ. J . Inorg. Chem., 1972, 17, 1767. H. Ogoshi, E. Watanabe, Z . Yoshida, J. Kincaid, and K. Nakamoto, J. Amer. Chem. SOC., 1973, 95, 2845. C. C. Addison, L. J. Blackwell, B. Harrison, D. H. Jones, N. Logan, E. K. Nunn, and S. C. Wallwork, J.C.S. Chem. Comm., 1973,347. L. 0. Larsson and L. Niinisto, Acta Chem. Scand., 1973, 27, 859. K. J. Palmer, R. Y. Wong, and K. S. Lee, Acta Cryst., 1972, B28, 236. L. Kristanova and D. Trendafelov, Monatsh., 1972,103,951. A. Hardy and F. Gaboriaud, Acta Cryst., 1972, B28,2329. P. Gravereau and A. Hardy, Acta Cryst., 1972, B28,2333. L. N. Shchegrov, V. V. Pechkovskii, and L. S. Eshchenko, Russ. J . Znorg. Chem., 1972, 17, 486.

Elements of the First Transitional Period

225

AgClO, has been reported. The silver ion is co-ordinated to the middle carbon atom of an acac ring, the oxygen atom of another, and the perchlorate If anhydrous FeC1, is added to a solution of acacH and piperidine in dry methanol and the reaction mixture shaken for one hour at room temperature (the procedure being repeated until all the chloride is removed), then [Fe(acac)(OMe),] is formed. Magnetic and spectroscopic evidence favours a dinuclear structure for this compound.248 Reaction of trichloroacetic acid with [Fe(acac),] in chloroform yields the compound [Fe(acac),(Cl,C0,)].249 The iron(m) complex of 2,4-acetoacetxylidide, [Fe{(C,H,Me,)CO CHCO NHMe),] has been r e p ~ r t e d , ~as ” have the complexes [Fe(3-alacac),] and [Fe(3-prnylacac),] (3-alacac = 3-allylacetoacetonate, 3-prnylacac = 3-propylideneacetylacetonate)., Reaction of FeCl, with the sodium salts of carboxylic acids (RC0,Na) yields [Fe,(O,CR),O(H,O),]+ (R = H, Me, CCl,, PhCH,, or Ph) in which the three metal centres are bridged by six carboxylate groups and a central triply-bridging oxygen atom.,’, Thermal decomposition of tris(oxa1ato)iron(111) has been investigated.’ The high-spin octahedral salicylamide complex [Fe(OC,H,CONH,),] has been isolated and it was found that the ligands chelate via both oxygen atoms.253The new complexes [FeL,(NO,),] (L = HMPA or NIPA; n = 1-4) have been reported, and all except Fe(NIPA),(NO,), contain co-ordinated NO, groups.83 (Me,N),P(O)NMeP(O)(NMe,)NMeP(O)(NMe,), (L) forms the range of complexes [FeL,X,] (n = 1 or 2; X = BF,, BPh,, NO,, or C1) in which the donor ligand is terdentate.84 The octahedral complex [FeLJNO,), (L = 2,6-lutidene N-oxide) has also been i~olated.~’Direct thermal reactions of Fe(CO), or Fe,(CO), with 9,lOphenanthraquinone (quonH) yields [Fe(q~on),].~’~ The structure of ferricrocin (67), which contains a cyclic peptide, has been determined.25s

’

Fe

(67)

247

248 249 250 251

252 253 254

’”

L. R. Nassimbeni and M. M. Thackeray, Inorg. Nuclear Chem. Letters, 1973,9, 539. E. Kokot, G. M. Nockler, and G. L. Sefton, Austral. J . Chem., 1973,26, 875. M. M. Aly, Inorg. Nuclear Chem. Letters, 1973,9, 253. A. D. Taneja and K. P. Srivastava, J . Inorg. Nuclear Chem., 1973,35, 1397. H. A. Tayim and M. Sabri, Znorg. Nuclear Chem. Letters, 1973,9, 753. G. J. Long, W. T. Robinson, W. P. Tappmeyer, and D. L. Bridges, J.C.S. Dalton, 1973, 573. B. S. Pannu and S. L. Chopra, Z. anorg. Chem., 1973,398,33. C . Floriani, R. Henzi, and F. Calderazzo, J.C.S. Dalton, 1972, 2640. M. Llinas and J . B. Neilands, Bioinory. Chern., 1973,2, 159.

226

Inorganic Chemistry of the Transition Elements

S-Donor and Se-donor ligands. Magnetic measurements have been made on iron(II1)dithiocarbamatecomplexes at very low temperatures.' The structure of (Bu",),[Fe(edt),], (edt = ethane-1,2-dithiolate) has been determined. The anion contains a planar Fe,S, ring which is nearly square (68), the iron atoms being in distorted trigonal-bipyramidal environments. There is no direct Fe-Fe bonding.256 R'NHC-NH-CNHR'

!

sII

s

s

II

II

R~NH-C-NH-C-NHR' (68)

R 1 = R2 = Ph R' R'

= R2 =

p-tolyl Ph, R2 = o-tolyl R' = Ph, R2 = p-tolyl R' = Me,RZ = p-tolyl =

The disubstituted biureto-complexes (69) have been reported.257 Tris-(2mercaptoethylamine)cobalt(IrI) reacts with hydrated FeCI, in acetone to form a complex in which the tris-chelated cobalt compound is co-ordinated to iron(111), [(CoL,),Fe]Cl3,2H2O, which is l ~ w - s p i n . ,The ~ ~ six-co-ordinate monomericcompounds[Fe(S,PX,),] (X = CF,, Me, or Ph)88and [Fe(Se,COEt),]259 have been reported. Mixed donor ligands. The reaction of FeC1, with quinolin-8-01 (oxH) has been previously suggested to proceed in the following manner: FeCI,

+ 2 oxH -+ FeCl,(ox) + (oxH2)FeC1, 1oxH FeClJox),

However, a "Fe tracer study shows that the reaction is not a simple sequential process and is far more complex.260 Iron(m) complexes of salicylaldehyde and pyruvic acid thio- and seleno-semicarbazones and salicylaldehyde-4phenyl thiosemicarbazone have been prepared. It was found that small changes 256

257

"*

259 260

M. R. Snow and J. A. Ibers, Inorg. Chem. 1973,12,249. N. K. Agarwal and K. P. Srivastava, J . Znorg. Nuclear Chem., 1973,35, 698. G. Frech, K. Chapman, and E. Blinn, Inorg. Nuclear Chem. Letters, 1973,9,91. C. Cauletti and E. Cervone, J . Znorg. Nuclear Chem., 1973,35, 593. M. J. Frazer and L. I. B. Haines, J.C.S. Dalton, 1973, 115.

Elements of the First Transitional Period

227

in ligand structure and, in the cases of anionic complexes, the nature of the counter-ion, have marked influences on the spin states of the compounds, some of which show a temperature-dependent spin equilibrium. However, the complexes of thiosemicarbazidediacetic acid are all high-spin independent of temperature.26' 3,4,5-Pyrazine-trithiol (H,T) forms the complex Fe(H,T),, 3H20.262The compounds Fe(TEA)Cl,,H,O and Fe,O(TEA),(OH),-, (TEA = triethanolamine, n = 1 or 2)94 and iron(@ complexes of H2NC(CH,0H), 95 have been reported. f3-Furfuraldoxime (11) forms the octahedral complexes [Fe(P-ffdox),Cl,] and [Fe(P-ffdox),Cl,], the oxime ligand being co-ordinated in a bidentate manner in the former and a unidentate manner in the latter.96 Iron(iS) Compounds.-Oxidation of Fe[S,CN(Me)CH,Ph], with air in the presence of BF, yields [Fe{ S,CN(Me)CH,Ph},]BF, which exhibits a magnetic moment of 3.01 BM in the solid state and 3.02BM in solution. The complex cation undergoes intramolecular rearrangement, the trigonal twist mechanism being responsible for the low-temperature process, a high-temperature process involving C-N bond rotation also being observed.263 Reaction of Fe(dtc), with either FeC1, or Fe(ClO,), yields [Fe(dtc),]X (X- = ClO, or FeC1;; dtc = Et,NCS, or Me,NCS,). Magnetic measurements are consistent with the iron(1v) atom being in a distorted environment and having a triplet ground The compounds [Fe'"(dtc),]BF,, [Fe"'(dtc),], [Fe"(dtc),(bipy)], and [Fe"(dtc),(phen)] have been studied by n.m.r. spectroscopy (dtc = dithiocarbamate). The barriers to C-N bond rotation have been found to be dependent on the formal oxidation state. The trend of increasing activation energy, Fe" < Fe"' < Fe'", is interpreted in terms of increasing Fe-S ( d 4 ) x back-bondingin thelower oxidation states,thereby destabilizingthe R,N=CSq resonance Higher Oxidation States of Iron.-Chemical and magnetic evidence has been reported for the formation of FeVO:- when molten NaNO, is electrolysed between iron electrodes or when iron salts are added to molten nitrite solutions of Na,0,.26s M,FeVIO, (M = K, Rb, or Cs) can be prepared in good yield using hypochlorite as the oxidizing agent and hydroxide as the precipitating medium. The corresponding barium salt can be prepared from K,FeO,, and all show magnetic moments of 2.8 BM. The potassium, rubidium, and caesium salts are all isostructural with P-K2S04.266 Oxides, Hydroxides, and Sulphides.-Treatment of alcoholic anhydrous FeCl, with H,O, yields dark-red FeO, (AGO = - 106 & 10 kcal mol- '). It has been V.V. Zelentsov, A. V. Ablov, K. I.Turta, R. A. Stukan, N.V. Gerbeleu, E. V. Ivanov,A. P. Bogdanov, N. A. Barba, and V. G. Bodyn, Russ. J . Znorg. Chem., 1972,17, 10o0. 2 6 2 J. S. Dwivedi and U. Agarwala, J . Znorg. Nuclear Chem., 1973,35,2229. 263 D. J. Duffy and L. H. Pignolet, Znorg. Chem., 1972, 11, 2843. 263"R.M. Golding, C. M. Harris, K. J. Jessop, and W. C. Tennant, Austral. J . Chem., 1972, 25, 2567. 264 B. L. Edgar, D. J. Duffy, M. C. Palozzotto, and L. H Pignolet, J . Amer. Chem. SOC.,1973,95,1125. 265 T. B. Temple and G. W. Thickett, Austral. J . Chem., 1973,26, 1137. R. J. Audette and J. W. Quail. Znorg. Chem., 1972, 11, 1904. 261

228

Inorganic Chemistry of the Transition Elements

shown by Mossbauer spectroscopy that the surface layer formed when Fe,O, is treated with acid is identical with Fe0,.267 y-FeO(0H) is formed when dilute solutions of FeSO,, H,SO,, HCl, HNO,, or HOAc in which iron powder is dispersed are oxidized, below 80 "C, by passing air through them. In some cases a-FeO(OH), a-Fe203, or Fe,O, are also formed.268 The structures of BaO, 2Fe20,269 and Ba,Fe,WO, 2 7 0 have been reported. Fe20,,6SeO,,xH,O have been prepared by hydrothermal reactions at 120°C (x = 2) and 180°C (x = q . 2 7 1 Hydrothermal treatment of precipitated FeS yields ferromagnetic Fe,S,, which has a spinel type structure.272The structure of CuFeS, has also been reported.

3 Cobalt Carbonyl Compounds.-When Zn[Co(CO),], is dissolved in dry methanol and stored in the dark in an inert atmosphere for 20 h, colourless crystals of (MeOZn[Co(CO),]}, are formed in 63 % yield, together with HCO(CO),.~ The structure of [C12HgCo(CO),(~-Cp)]has been determined. The idealized co-ordination at the mercury atom is trigonal-planar, but two long Hg-Cl bonds are formed with neighbouring molecules (Co-Hg = 2.578 The same authors have also reported the structure of (n-Cp)Co(C0),,3HgC12 and this complex is best formulated as [(n-Cp)(CO),CoHgCl] +Cl- with two additional molecules of HgC1, per unit cell (Co-Hg = 2.504 A).275Co,(CO), -,,L,, reacts with metallic mercury to from the new compounds HgCo,(CO),-,L,, [n = 0; L = PMe, or PPh,, n = 1; L = PMe,, PEt,, PPh,, or PMe2Ph, n = 2; L = PMe, or PEt,, n = 3; L = PMe,, PEt,, or P(OMe),, n = 4;L = P(OMe),, n = 61. Bridged and non-bridged forms of Co,(CO),L, Hg[Co(CO),], reacts with [L = PMe, or P(OMe),] were also bidentate donors (L-L) to give (L-L)Hg[Co(CO),], (L-L = bipy or phen) and with [Co(CO),]- or halide ions (X-)to give X H ~ [ C O ( C O ) , ] , . ~ ~ ~ " Co,(CO), reacts with thallium in benzene or toluene at room temperature to form Tl[Co(CO),], together with traces of Tl[Co(CO),], if traces of oxygen are present. However, the latter can be removed by washing with hexane. Tl[Co(CO),] is a convenient source of the tetracarbonyl anion and undergoes the reactions outlined in Scheme 5.277 267

N. G. Klyuchnikov, I. G. Gorichev, and V. S. Dukhanin, Russ. J . Inorg. Chem., 1972, 17, 1216.

'" M. Kiyama, T. Akita, S. Shimizu, Y. Okudo, and T. Takada, Bull. Chem. SOC. Japan, 1972, 45, 3422; M. Kiyama and T. Takada, Bull. Chem. SOC. Japan, 1972,45, 1923. S. Okamoto, S. I. Okamoto, and T. Ito, Acta Cryst., 1973, B29, 832. 2 7 0 G. Blasses, J . Inorg. Nuclear Chem., 1973,35, 680. 271 V. P. Volkova, G. F. Pinaev, and V. V. Pechkovskii, Russ. J . Inorg. Chem., 1972, 17, 484. "l' S. Yamaguchi and H. Wada, Z . anorg. Chem., 1973,397,222. 273 S. R. Hall and J. M. Stewart, Acta Cryst., 1973, B29, 578. 274 I. W. Nowell and D. R. Russell, J.C.S. Dalton, 1972, 2393. 2 7 5 I. W. Nowell and D. R. Russell, J.C.S. Dalton, 1972, 2396. 2 7 6 D. De Montauzon and R. Poilblanc, J . Organometallic Chem., 1973,54, 291. 276aH.L. Conder and W. R. Robinson, Inorg. Chem., 1972,11, 1527. 2 7 1 S. E. Pedersen, W. R. Robinson, and D. P. Schussler, J . Organometallic Chem., 1972,43, C44. 269

229

Elements of the First Transitional Period

Scheme 5

The structure of In[Co(CO),], has been determined and shows an In-Co bond length of 2.594A, which is not consistent with the presence of (d-d)xbonding between the metals.278 When Me,SiCo(CO), is heated at 105 "C under vacuum for 15 h, Me,SiOCCo,(CO), and (Me,SiOC),Co,(CO), are formed in the ratio 2: 1. The former is also obtained from the reaction of Me,SiCo(CO), with THF at room temperature for one hour. Structure (69a) is suggested for the latter. The lowtemperature reaction .has relevance to the non-isolation of the expected compounds when some metal carbonyl anions are treated with triorganosilyl halides in THF.279Photoelectron spectroscopy of H,MCo(CO), (M = Si or Ge) shows no evidence of M-C (d-d)n-bonding.12 An X-ray crystal structure study of BrSn[Co(CO),], shows the cobalt atom geometry to be essentially

R

R

R

R

(69a) R

=

OSiMe,

trigonal-bipyramidal and that of the tin atom to be tetrahedral (Co-Sn = 2.60 A)."* A structural study of [(l-Me,Sn)Co(x-Cp)(CO)-J2has shown that the tin and cobalt atoms alternate around a planar four-membered ring, the geometry at the tin atoms being slightly distorted tetrahedral and that at the cobalt atoms being octahedral (the IT-Cpligand is assumed to occupy three 278 279

280

W. R. Robinson and D. P. Schussler, Inorg. Chem. 1973,12, 848. W. M. Ingle, G. Preti, and A. G. MacDiarmid, J.C.S. Chem. Comm., 1973,497. R. D. Ball and D. Hall, J . Urganometallic Chem., 1973, 52, 293.

Inorganic Chemistry of the Transition Elements

230

a].281

sites) [Co-Sn = 2.542(2) These are the first reports of cobalt-tin bond lengths. When [Co(CO),] is treated with Ph2NiBF, at - 70 “C a red solution is formed, which undoubtedly contains a phenylazocobalt complex ; however, this decomposes on warming. Addition of PPh, to the solution prior to warming to room temperature, however, yields [CO(CO),(PP~,)(N,P~)].~~~ Structural and magnetic studies on [Co,(CO)(.n-Cp),S], [Co,(n-Cp),S,] and [Co,(n-Cp),S,]+ have been reported by Frisch and Dah1282 and the results have been used as a test case for the apparent correlation between metal-metal bond lengths in cluster compounds and the number of extra d-electrons over the ‘magic number’ for each metal atom, which has recently been extensively studied by Dahl and co-workers (see Vol. 2 p. 207). The first two of the cobalt-sulphur clusters have been reported previously and the cation was prepared by addition of iodine to the neutral analogue and was isolated as the iodide. The structures of the three compounds substantiate the predictions concerning the dominant influence of anti-bonding valence electrons on the metal-metal bond lengths of the cluster system and also provide evidence that the presence of these electrons can induce a dramatic Jahn-Teller distortion of the cluster. The results are evidenced by the data presented in Table 1.282

Table 1 Structural and electronic data for cobalt-sulphur cluster compounds Compound

Point Group o j cluster

N o . of unpaired

Co-Co bond lenyth/A

electrons

Treatment of the cluster compound [Co,(n-Cp),S,] with Ph,P in toluene yields [Co,(n-Cp),S,], which can be oxidized to [Co,(n-Cp),S,] ‘PF; by means of AgPF, in dichloromethane. Structural studies have also been reported for these two compounds.283Thus, both contain a tetrahedral array of metal atoms with triply-bridging sulphur atoms arranged above each triangular face, an hS-Cp ligand being bonded to each metal atom. The neutral cluster compound has Co-Co bond lengths ranging from 3.236 to 3.343A (average 3.295 A) and its symmetry is cubic. The metal atoms can be viewed as cobalt(II1) which each formally achieve the 18-electron state without the necessity of forming Co-Co electron-pair bonds. The cation is tetragonally distorted with two long Co-Co bonds (3.330 A) and four shorter ones (3.172 A). The observed tetragonal distortion and the shortening of four of the bonds are compatible .I.Weaver and P. Woodward, J.C.S. Dalton, 1973, 1060.

’” P. D. Frisch and L. F. Dahl, J . Amer. Chem. SOC., 1972,94,5082. ’” G. L. Simon and L. F. Dahl, J . Arner. Chem. SOC.,1973,%, 2164.

Elements of the First Transitional Period

23 1

with a metal cluster M O model in which an electron is removed primarily from a triply degenerate anti-bonding Co, symmetry combination in the neutral molecule, a Jahn-Teller distortion arising in the cation, the unpaired electron occupying a non-degenerate Co, symmetry combination. On this basis, the two long bonds in the cluster cation are presumed still to represent non-bonding Co-Co distances, and each of the four shorter bonds reflects a localized increase in individual valence bond order from zero to 0.125 between such pairs of cobalt atoms. This represents a total metal-metal valence bond of 0.5.283 [(x-Cp)Co(CO),] reacts with white phosphorus to give [Co,(n-Cp),P,] in low yield as greenish black air-stable crystals. The compound was synthesized in order to test the effect of metal-metal interactions on the cubane system when sulphur is exchanged for phosphorus as the triply-bridging ligand. The compound also shows a D,, distortion, but it is different from that observed for [Co(n-Cp),S,]' and more like that of [Fe,(n-Cp),S,], but much more severe in degree. The cobalt-phosphorus cluster contains two short Co-Co bonds of mean length 2.504 A and four longer ones of mean length 3.630 The reaction of Co,(CO), with P(OMe), (L) has been studied and substitution products of the type [Co,(CO),-,L,] are formed, together with the cations [Co(CO),-,L,] +. The unexpected third type of product produced by these reactions is the acyl complexes [MeCOCo(CO), -,L,]. Spectroscopic evidence suggests the cations are stereochemically n ~ n - r i g i d . ~The *~ compounds [Co,(CO),,-,L,] (L = PEt,, n = 2 or 3; L = P(OMe),, n = 1-4; L = PMe,Ph, n = 1 or 2; L = P(OMe),Ph, n = 2 or 3) have also been prepared. A preliminary study of the temperature dependence of the n.m.r. spectra of the four complexes containing P(OMe), indicate these molecules may also be stereochemically n ~ n - r i g i d . ' ~The ~ complexes [Co(CO),(siphos)][Co(CO),], [Co(CO),(siphos),], and Tl[Co(CO),(siphos)], [siphos = (Me,SiCH,),P] have been reported and they react with halogenated solvents to form [CoCl(CO),(siphos)],, the first reported dicarbonylmonophosphine complex of cobalt.143 SbX, (X = halogen) reacts with Co,(CO),(PPh,), to form the cation ( S ~ [ C O ( C O ) , P P ~ , ] , ) ~and , the related neutral complex of bismuth, Bi[Co(CO),PPh,], has been obtained from a similar r e a ~ t i 0 n . lPhP(CH,~~ CH,CH=CH,),(L) reacts with HCo(CO), at low temperature to yield HCo(CO),L as the main product. At 0 "C, the hydridophosphine is converted into the non-bridged form of [Co(CO),L],. The olefinic phosphine also reacts with Co,(CO), to form [Co(CO),L,] [Co(CO),] which on heating is also converted into the non-bridged form of the monophosphine dimer. There is no evidence for co-ordination of the olefin groups in any of the complexes.287Co,(CO), also reacts with the acetylinic phosphines R1R2PC,CR3 (R' = R2 = Ph, 284

286

"'

G. L. Simon and L. F. Dahl, J . Amer. Chem. SOC.,1973,95,2175. S. Attali and R. Poilblanc, Inorg. Chim. Acfa, 1972,6,475. D. Labrouc and R. Poilblanc, Inorg. Chim.Acta, 1972,6,387. T. J. Baillie, B. L. Booth, and C. A. McAuliffe, J . Organometallic Cliem., 1 9 7 3 , s . 275.

232

Inorganic Chemistry of the Transition Elements

R3 = H, CF,, Ph, Me, or Bu'; R'

=

R2 = Ph, R3 = C,H,Me;

R' = Ph,

R2 = R3 = Me). Four types of product were characterized from these reactions; [(R1R2PC,R3)Co,(CO),] (R' = R2 = C,F,, R3 = Ph or Me; R' = R2 = Ph, R3 = Bul), [(R1R2PC2R3)Co,(CO),o] (R' = R2 = Ph, R3 = H, CF,, Ph, or Me;R1 = R2 = C,F,,R3 = Me;R' = Ph,R2 = R3 = Me), [(R1R2PC2R3),Co,(CO),] (R' = R2 = Ph, R3 = Bu'), and [(R1R2P(O)C,R3}Co,(C0),] (R' = R2 = Ph, R3 = But; R' = R2 = C,F,, R3 = Ph). The first type of product exhibits only alkyne co-ordination, the second shows alkyne and phosphine co-ordination, the third is a simple disubstituted phosphine of Co,(CO), and fourth type are p-alkyne derivatives of acetylenic phosphine oxides., A new arsine-bridged complex of Me,Ask=CAsMe,CF,&F, (f,fars), [Co,(CO), (f,fars)], has been reported.,,, When this complex is heated under reflux in hexane, cleavage of a Me,As group from the ligand with subsequent dimerization of the cyqlobutenyl residue is observed, [ ( M e 2 A s m F 2 ) 2 (Me, As),Co,( CO),H,] being formed.29o [Co(CO),PPh ,]C1,HCl reacts with dimethylamine to give the very stable carbamyl complex [Co(CO),(PPh,)(CONMe,)]. If liquid ammonia is used as the reactant, then [HCo(CO),PPh,], NH,NCO, and NH,Cl are formed, the carbamyl complex being a likely intermediate. Treatment of [Co(CO),(PPh,)I] with liquid ammonia gives the moderately stable compound, [CO(CO),(PP~~)(NH~)(CO,NH~)].~~~ Co,(CO), reacts with X,BNEt, or Br,AlNEt, in benzene at 60°C to give Co,(CO),COYX,NEt, (Y = B or Al; X = C1 or Br). The related compound Co,(CO),CO,AlBr,,AlBr, is obtained by treating Co,(CO), with aluminium tribr~mide.~,,Co,(CO),,AlBr, has also been prepared and shows one of its CO stretching frequencies at 1600 cm-' which is interpreted in favour of the aluminium atom co-ordinating to the oxygen atom of one of the bridging CO groups. [(n-Cp)Fe(CO),],,BX, ( X = F, C1, or Br) and both the 1: 1 and 1 :2 adducts of [Fe(CO)(n-Cp)], and BX, also show similar properties293 and these two papers further extend the range of acceptors from bridging C O groups. Co,(CO), reacts with isocyanides, (R = Me, Et, or cyclohexyl) to form [(RNC),Co] [Co(CO),] and the covalent carbonyl-bridged complexes [(RNC),CO,(CO),-,] (m = 1-3).16*

Nitrogenyl and Nitrosyl Compounds. There has been a suggestion that, in the reductive degradation of various cobalt(m) complexes, ammonia is evolved (when nitrogen-containing ligands are present) which is formed by fixation of N,. Detailed studies on [Co"'(tpps)] [tpps = rneso-tetra-(psulphonatopheny1)-

288

289

291

292

293

H. A. Patel, A. J. Carty, and N. K. Hota, J. Organornetallic Chem., 1973, 50, 247. W. R. Cullen and A. J. T. Hall, Canad. J. Chern., 1973,51, 1521. F. W. B. Einstein and R. D. G. Jones, J.C.S. Dalton, 1972, 2568. H. Krohberger, H. Behrens, and J. Ellermann, J. Organometallic Chem., 1972,46, 139. G. Schmid and V. Batzel, J. Organometallic Chem., 1972,46, 149. J. S. Kristoff. N. J. Nelson, and D. F. Shriver, J. Organornetallic Chem.. 1973.49, C82.

Elements of the First Transitional Period

233

porphinate] have shown, however, that all the ammonia is produced from the N-donor ligand.294 (CF,),PH,, (n = 1 or 2) (L) reacts with [Co(NO)(CO),] to form [Co(NO)(CO),L]. 1.r. evidence suggests that the donor powers of the ligands are very similar to those of (CF,),P.195 A similar reaction with (CF,),PCN is nearly quantitative whereas that of (CF,)P(CN), is less efficient and the yield for the reaction involving P(CN), is very poor. The yields are governed by the ease of formation of polymeric by-products and the instability of the desired product. 1.r. data indicate that these ligands are more effective than any phosphines previously used for attacting metal electrons and so minimize the back-bonding to the carbonyl [Co(NO)(PR,),] can be prepared from [CoCl(NO),], and PR, (R, = Ph, or Ph,Me) in the presence of sodium amalgam in THF, and undergoes a range of oxidative additions. Thus, with HCl, [CoCI,(NO)(PR,),] and [CoCl,(PR,),] are formed, with p-MeC,H,SO,Cl, [CoCl(NO),(PR,),] and [CoCl,(PR,)] are formed, and with iodine or mercuric iodide, [CoI,(NO)(PR,),] is produced. The iodide is unstable in methanol and is transformed into [CoI(NO)(PR,),] and [COI,(PR,),].~~' Lr., n.m.r., and X-ray photoelectron (ESCA) evidence has substantiated the existence of conformational isomers of [CoCl,(NO)(PMePh,),]. One isomer is of trigonalbipyramidal geometry with a linear (NO') group, while the other is believed to have square-pyramidal geometry with a bent (NO-) group at the apex. The structure of the trigonal-bipyramidal isomer has been reported and there is no evidence for co-existence of the other isomer within the crystal used for the d e t e r m i n a t i ~ n . , Data ~ ~ from X-ray photoelectron spectroscopy of the NO adduct of [Co"' (benzacen)] are in accord with structural studies and indicate the presence of an NO- group.299 When NO is bubbled through a solution of CoCl, and NNN'N'-tetramethylethylenediamine (tmeda) in anhydrous methanol, [Co(NO),(tmeda)] is formed, which was isolated as its BPh, or PF; salts. The complexes [Co(NO),L,]BPh, (L = PPh,, L, = disphos) have been prepared from reactions of CoCl,, L, and NEt,. Methyl nitrite and Et,NHCl were also isolated from these reactions. In the absence of L, Et,NH[Co(NO),Cl,] is formed and the overall equations for these reactions are postulated as: +

CoCI, CoCl,

294

295 296

297 298

299

-

+ 3 N 0 + 2L + NEt, MeOH

[Co(NO),L,]Cl

+ MeONO + Et,NHCI

+ 3 N 0 + NEt, M [Co(NO),Cl,] s + MeONO + Et,NHCl Et,NH[Co(NO),Cl,] + MeONO

J. Chatt, C. M. Elson, and G. J. Leigh, J . Amer. Chem. SOC., 1973, 95, 2408. I. H. Sabherwal and A. B. Burg, ZnQrg. Chem., 1973,12,697. I. H. Sabherwal and A. B. Burg, Znorg. Chem., 1972,11,3128. G. Dolcetti, N. N. Hoffmann, and J. P. Collman, Znorg. Chim. Actu, 1972,6, 531. C. P. Brook, J. P. Collman, G. Dolcetti, P. H. Farnham, J. A. Ibers, J. E. Lester, and C. A. Reed, Inorg. Chem., 1973,12, 1304. J. W. Lauher and J. E. Lester, Znorg. Chem., 1973, 12, 244.

234

Inorganic Chemistry of the Transition Elements

Regardless of the assignment of oxidation state to co-ordinated NO, there has clearly been an oxidation of NO to MeONO and the authors view this as the first example of stoicheiometric reduction of a metal complex by NO, followed by dissociation of the oxidized form of N O and reco-ordination of free NO.168 The structure of the compound of stoicheiometry Co(NH,),N02Br3-x(N03)l+x, 2H,O (x 0.5) has been reported and the complex cation is dinuclear, the metal atoms being bridged by a cis-[N,0,I2-

-

Cobalt(I).-U.v. irradiation of [HCo(PF,),] yields [(PF,),Co(H)(PF,)Co(PF3)3] and similar treatment of a mixture of [HCo(PF,),] and HIr(PF,), gives [(PF,),Co(H)(PF,)Ir(PF,),I. Co,(PF,), could not be isolated under these conditions.301 [HCo(PF,),] and [HCo{P(OEt),},] have ground-state geometries that are neither truly trigonal-bipyramidal nor square-pyramidal and both are fluxional molecules. It has been suggested that the lowest energy pathway for fluxional motion of the pseudo-tetrahedral [COP,] complexes is motion of the hydrogen atom towards an edge of the tetrahedron with a concomitant Co-P bending motion that enlarges this tetrahedral edge, and is termed 'tetrahedral tunnelling'.182 [Co(CNCMe,),]+, [Co(CNMe),]+, [Co(CNCMe,),MR,]+, and [Co(CNMe),MR,]+ (M = P or As) are all highly fluxional down to -120°C. Ligand lability is observed, but is very complex and catalysed ligand exchange is also observed. For example, [Co(CNCMe,),]+ and [Co(CNCMe,),(pMeC,H,),]i show no evidence for reaction or ligand exchange to form [Co(CNCMe,),(p-MeC,H,),P]+ except in the presence of oxygen ; however, the equilibrium: [Co(CNCMe,),(AsPh,),]+

+ [Co(CNCMe,): + 2[Co(CNCMe,),AsPh,]'

lies well to the right even at 40 "C. N.m.r. evidence indicates that the dissociation

+L

COLl s COLi

has a relatively low activation energy and the formation of CoL; is probably a key step in the reaction of CoLf. Catalysis by oxygen probably proceeds via formation of CoL,O,f as the first step (L = CNMe, or CNMe).,', The

O H

0-0

Ia

H

I

CO

$J$J ... ...

300

301 302

CO

. ..

',.

I

-...

B. F. Hoskins and F. D. Whillans, J.C.S. Dalton, 1973, 607. T. Kruck, G. Sylvester, and I. P. Kunau, Z . Naturforsch., 1973, 28b, 38. E. L. Muetterties, J.C.S. Chem. Comm., 1973, 221.

Elements of the First Transitional Period

235

reactions of [Co(CNBu‘),]+ with a range of mono- and poly-phosphines and -arsines have been reported.302aAdducts of Co(CNPh),ClO, with chlorinated hydrocarbons have been reported.303 Cobaltocene reacts with dry oxygen in ether at -78 “C to form (70), which is unstable in air. Treatment of this compound with phosphoric acid yields H,O, and [(Cp),Co][H,PO,], and reaction with PhCOCl gives dibenzoyl peroxide and (Cp),CoCl. This is the first example of a transition-metal coordinated to an organic peroxide.304 Cobalt( n).-Halides and Pseudohalides. The preparation of MCoF, (M = Na, K, Rb, or Cs) has been effected by four methods. These are reaction of MCl with CoF,, reaction of MF with CoCl,, reaction of MF with CoF or treatment of a mixture of the binary chlorides with HF.17, 1.r. data have been reported for C S C O C ~ ,The . ~ ~ preparation of (D+),[CoCl,] (D+ = the 2-methyl-4phenyl-l,5-benzodiazepiniumcation) has been r e p ~ r t e d , ~as ” have structural data for R ~ , [ C O C ~ , ]Thermochemical .~~ parameters have ‘been determined for the formation of CsCoC1, (x = 3-5) in a lithium-potassium chloride e ~ t e c t i c .The ~ ~ crystal structure of [(N,P,(NMe,), ,CoCl)],f [CO,CI,]~-, 2CHC1, has been determined. The cobalt atoms in the cations are bonded to four nitrogen atoms of the phosphazene ring and one chlorine atom in a geometry intermediate between square-pyramidal and trigonal-bipyramidal. The anion contains two bridging and four terminal chlorine atoms giving complete tetrahedral co-ordination of both metal atoms. This is the first report of a dinuclear chlorocobaltate.306Previous-studieson the ionization equilibria of anhydrous CoCl, in acetonitrile have given ambiguous results, one group proposing the existence of the neutral dimer [CoCl,, 3MeCN], which dissociates to [Co(MeCN),]’+ and [COCI,]~-, while a second group have denied the existence of the dimer and proposed that dissociation produces [Co(MeCN),]” and [CoCl,MeCN]-. Bobbitt and Gladden307 have now suggested that the ionic dimer [CO,CI,]~- (see also above) is formed in appreciable amounts. When COCl, in acetonitrile was treated with R,NCN, the presence of [(MeCN),Co(CN),], [(MeCN)Co(CN),]-, and Co(CN)i- was demonstrated by a range of physical measurements. The relative concentrations of these three species depend on the Co2+:CN- concentrations. (R4N)3[Co(CN),] (R = Et or Bun) were isolated and these react with oxygen to form (R4N)3[Co(CN),O,],l .5H,0.308 Other workers have reported on the oxidationreduction properties of [(CN),C~-O,-CO(CN),]~-, formed by a redox

302a

303

304 305

306 307

308

R. B. King and M. S. Saran, Inorg. Chem., 197211,2112. C. A. L. Becker, J. Inorg. Nuclear Chem., 1973,35,1875. H. Kojima, S. Takahashi, and N. Hagihara, J.C.S. Chem. Comm., 1973,230. A. Furuhashi, S. Komatsu, and A. Ouchi, Bull. Chem. SOC.Japan, 1972,45,2942. W. Harrison, N. L. Paddock, J. Trotter, and J. N. Wingfield, J.C.S. Chem. Comm., 1972, 23; W. Harrison and J. Trotter, J.C.S. Dalton, 1973, 61. J. L. Bobbitt and J. K. Gladden, Inorg. Chem., 1972,11,2167. D. A. White, A. J. Solodar, and M. M. Blaizer, Inorg. Chem., 1972,11,2160.

236

Inorganic Chemistry of the Transition Elements

addition between molecular oxygen and [Co(CN),I3 -. The dinuclear anion decomposes at pH 12 in two stages, with the formation of the intermediate product [ C O ( C N ) , O , ] ~ - . ~Monomeric ~~ aliphatic nitroso-compounds react with [Co(CN),I3- in aqueous alcohol to give the radical anions [(CN),Co-N(alkyl)O'] - and/or alkylN - 0 - ., Co(NO,),, 6 H 2 0reacts with Ba(CN), in aqueous solution to give the purple, air-stable complex Ba3[Co2(CN),,],13H2O. The anion has a staggered arrangement of cyanide groups and a metal-metal bond length of 2.798(2) A. Unlike Mn,(CO),,, the axial Co-C bonds are significantly longer than the equatorial ones.311 Hydrides. The paramagnetic hydrido-complexes [CoHL,]X [L = P(OEt),Ph, P(OMe),Ph, or P(OPh),; X = PF, or BF,] have been prepared by reaction of HCoL, with the appropriate trityl salt. The cobalt(I1) hydrides are very air-sensitive and the reaction can be reversed by treatment with sodium amalgam. Interestingly, trityl acts as a one-electron oxidizing agent not as a hydride-abstraction agent., l 2

Complexes. Amine complexes. The reaction of CoC1,(PPh3), with LiN(SiMe,), yields the high-spin complex [Co{N(SiMe,),},PPh,]. The green, air-sensitive complex has been shown to be a three-co-ordinate monomer by X-ray crystalIf trans-[Co(NH,),Cl,]NCS is suspended in DMSO at room 10graphy.~'~ temperature for 24 h, the solid slowly dissolves and subsequent evaporation of the solvent yields bluish crystals of ~~U~~-[C~(NH,),(NCS)C~]C~. Vibrational and electronic spectra and magnetic measurements have been (peff = 4.54 BM, between - 160 and reported for [Co(NH,),](ReO,), 24 O C ) . , 1 5 The hydrazine complexes, [Co(ox)(N,H,)] and [Co(ox)(N,H,),] have been prepared by the reaction of cobalt(I1) oxalate with hydrazine in water. On the basis of spectral measurements, it is suggested that both contain bidentate oxalate groups and bridging hydrazine ligands.,', Reactions of (71) and (72) with M(BF,), (M = Co, Ni, or Cu) did not yield any metal com-

. J. Hanslik and A. A. Vleck, Coll. Czech. Chem. Comm., 1973,38,957. 310 W. A. Waters, J.C.S. Chem. Comm., 1972, 1087. 3 1 1 G. L. Simon, A. W. Adamson, and L. F. Dahl, J . Amer. Chem. SOC., 1972,94, 7654. 312 J. R. Sanders, J.C.S. Dalton, 1973,748. 3 1 3 D. C. Bradley, M. B. Hursthouse, R. J. Smallwood, and A. J. Welch, J.C.S. Chem. Comm., 1972,872. 314 K. S. Mok, C. K. Poon, and H. W. Tong, J.C.S. Dalton, 1972, 1701. J's A. Muller, P. Christophliemk, and I. Tossidis, J. Mol. Structure, 1973, 15, 289. 316 T. B. Shkodina, E. I. Krylov, and V. A. Sharov, Russ. J. Inorg. Chem., 1972, 17, 945. 309

Elements of the First Transitional Period

237

plexes, but only adducts of (71) and (72) with BF3.,” The complexes [Co(spart)X,] ( X = C1, Br, or I, spart = (7311 have been prepared.318The cationic ligand [EtN(CH,CH,),PEt,] (L) forms the complex [CoCI,L], which has a structure in which the cobalt atom is in a pseudotetrahedral environment in a dinuclear cation (74) rather than being a ~witterion.~”

Pyridine and related ligands. The crystal structures of [M(py),(NO,),] (M = Co, Cu, or Zn) have been determined and the overall molecular geometries are very similar for all three compounds. In all of these complexes the nitrate groups are co-ordinated in an assymetric bidentate manner, the degree of assymetry following the order: Co < Zn Cu.,,’ Cobalt complexes of the linear quinquedentate ligand pyDPT (75) have been isolated. They are [Co(pyDPT)X]X,H,O (X = C1, Br, I, or NO,), [Co(pyDPT)](PF,),, and

+

(cH,), NH( CH,)

[Co(pyDPT) (NCSe)](NCSe). The chloro-, bromo, and nitrato-complexes are extremely hygroscopic and their magnetic moments are a function of the degree of hydration. In the solid state, the stronger ligands form octahedral complexes, whereas the iodide and hexafluorophosphate are five-~o-ordinate.~ The pseudo-octahedral com&exes [Co(PDAEP)X,] [X = Br, I, or NCS, PDAEP = (76a)l and [Co(MePDAEP)S,],BuOH [MePDAEP = (76b)l have been prepared. The magnetic moment; of t k iodo-complexes are temperature dependent between the doublet and quartet ground state^.^ 2 2 syn-Phenyl-2-pyridylketoxime (HPPK) forms the octahedral complex, [Co(HPPK),] (NO,),, in which it is suggested the ligands chelate via the pyridine- and oxime-nitrogen atoms.63 Atactic poly-4-vinylpyridine reacts with the appropriate cobalt salts to form Co12(P-4VP), and CoX2(P-4VP),

317 318 319

320 321

322

T. R. Musgrave and T. S. Lin, J. Coordination Chem., 1973,2,323. S . F. Mason and R. D. Peacock, J.C.S. Dalton, 1973, 226. R. H. Marvich and J. T. Yoke, Inorg. Chem., 1973,12,243. A. F. Cameron, D. W. Taylor, and R. H. Nuttall, J.C.S. Dalton, 1972, 1603. C. T. Spencer and L. T. Taylor, Inorg. Chem., 1973, 12,644. M. Bacci, F. Mani, and S. Midollini, Gazzrrta, 1972, 102, 1019.

238

Inorganic Chemistry of the Transition Elements

(76)a:R b;R

= =

H Me

(X = Cl,salicylaldehydate, or o-nitrophenolate, Y, = acac; P 4 V P = a poly4-vinylpyridine monomer unit).Ig4 The 1,lO-phenanthroline complexes, [Co(phen),X,],nH,O (X = C1, n = 3.5; X, =SO,, n = 8; X = B r , n = O ; X = N O , , n = 2 ; X, =CO,, n = 7 ; X = NCS, n = 0; X = NO,, n = 1; X = I, n = 5; X = I, n = 2) have been reported.323 [Co(phen),](xanthate), has been isolated from reaction of CoCl,, potassium xanthate, and phen in aqueous s ~ l u t i o n . The ~ complexes CoLX, (L = bipy or phen; X = C1 or Br) have also been prepared.57 The eight-co-ordinate complex [Co(napy),](ClO,), (napy = 1,8-naphthapyridine) has been isolated and its structure discussed in terms of a distorted dodecahedra1 structure similar to that reported for the analogous iron@) compound.58 The related complex [Co(napy),(NO,),] has also been reported and appears to be the first example of a neutral mixed-ligand eight-co-ordinate complex of this Irnidazole, pyrazole, and related ligands. [Co(imidazole),Cl,] has been found by X-ray crystallography to be tetrahedral with a [CoN,Cl,] core.324 The complexes of 1,2-dimethylimidazole (L), CoL,&, (X = ClO,, NO,, or BF,)60 and CoL,X, (X = C1, Br, or I, n = 1 or 2; X = NCS, n = 3 or 4)61 have been isolated. The related complexes Cd,,Br, (L = methylthio-2-methyl-3-imidazole or dimethyl-1,3-thione-2-imidazole)325and Co(abi),X, (X = C1. Br, I, NCS, or OAc, abi = 2-aminobenzimidazole), Et,N[Co(abi)X,] (X = Cl, Br, or I), [Co(abi),12],2acetone, [Co(abi)SO,],acetone, and C ~ ( a b i H ) , ~ , ~ have been isolated. When aqueous solutions of CoSO, are treated with adenine (AdeH), the is obtained. The cation complex [Co,(H,0),(Ade),](AdeH),(S04)2,6H,0 is centrosymmetric and contains unidentate Ade ligands co-ordinated uia N-9.326a 2-hinothiazole (atm) and 2-bromothiazole (brt) form the octahedral 323 324 325

326 326g

D. M.Palade, E. S. Il'ina, and G. V. Chudaeva, Rum. J . Znorg. Chem., 1972,17, 1296. (2. J. Autti and B. K. S. Lundberg, Acta Chem. Scand., 1972,26,3995. N. Khedder, A. Samat, R. Guglielmetti, and J. E. Guerchais, Compt. rend., 1973, 276, C , 653. M. J. M. Campbell, D. W. Card, R. Grzeskowiak, and M. Goldstein, J.C.S. Dalton, 1972, 1687. P. De Meester, D. M. L. Goodgame, D. J. Richman, and A. C. Skapski, Nature, 1973,242,257.

Elements of the First Transitional Period

239

complexes, [Co(atm),X,] (X = C1 or Br) and the distorted tetrahedral complexes, [CoL,X,] (L = atm, X = C1, Br, or I; L = brt, X = C1 or Br).327 Several new terdentate N-donor ligands containing pyrrole, pyrazole, and indene residues have been prepared. They were specifically designed to present their donor atoms at positions very close to the normal octahedral sites of a metal atom. Cobalt cationic complexes have been prepared and these can be deprotonated at the ligand to yield neutral complexes. No change in colour or magnetic moment is observed on deprot~nation.'~' Cobalt(I1) chloride reacts with dipyrazol-1-yl ketone in THF to yield (CoC1,[(C,H,N,),CO]) and, if the reaction is carried out in acetone, the complex is formed.328The structure of the dipyrazolylalkane {CoCl,[(C,H,N,)CMe,]} of bisdihydro-bis-(1-pyrazolyl)boratocobalt(n) has been determined : the metal atom is co-ordinated in a distorted tetrahedral fashion.329 Macrocyclic N-donor ligands. A zinc porphyrin linked to a cobalt porphyrin by a peptide linkage containing either a p-C,H, or C,H, group has been prepared. Energy transfer within the linked system has been studied.330 Cobalt@) tetraphenylporphin reacts with tetracyanoethylene (tcne) to yield a 1:1 N-bonded complex. This product functions as a one-electron donor and undergoes reversible electron transfer to give the paramagnetic compound [Co"'(TPP)tcne] +(tcne)- . 3 3 1 Reduction of cobalt(I1) tetraphenylporphin with sodium and benzophenoneketyl in THF yields the reduced compound Na[Co(TPP)],STHF in which the extra electron is mainly located on the cobalt atom.332 Electrochemical studies on the hemiporphyrazine complex (77) shows reduction can occur in four steps involving one, one, two, and one electrons, respectively. A one-step oxidation involving one electron only is also observed. It is suggested that the reduction steps involve only M O s that are primarily of ligand character.333 The diamagnetic cobalt(@ corrin complex, iodo-cobalt(I1)-cobyrinicacidheptamethylester (78), dissolves in benzene or toluene to give monomeric paramagnetic complexes which form 1: 1 adducts with molecular oxygen in fast and reversible reactions.334 Reaction of [Co"Pc] (Pc = phthalocyanine) with thionyl chloride or bromine yields CoPcX, ( X = C1 or Br). Physical and chemical measurements on the compounds indicate they contain a phthalocyanine radical and a cobalt(m) ion. This is the first report of the isolation of a phthalocyanine radical in the solid state.lg8 Reduction of [Co"Pc] with sodium in THF or by electrochemical means leads to the formation of five

327

"*

329

330

'"

332 333

334

E. J. Duff, M. N. Hughes, and K. J. Rutt, Inorg. Chim. Acta, 1972,6,408. K. I. Tht and L. K. Peterson, Canad. J . Chem., 1973,51,422. L. J. Guggenberger, C. T. Prewitt, P. Meakin, S. Trofimenko, and J. P. Jesson, Znorg. Chem., 1973, 12, 508. F. P. Schwarz, M. Gouterman, Z. Muljiani, and D. H. Dolphin, Bioinorg. Chern., 1973,2, 1. B. B. Wayland and D. Mohajer, Inorg. Nuclear Chem. Letters, 1973,9, 633. H. Kobayashi, T. Hara, and Y. Kaizu, Bull. Chem. SOC. Japan, 1972,45,2148. C. G. Birch and R. T. Iwamoto, Znorg. C h m . , 1973,12,66. A. von Zelewsky, Helv. Chem. Actn. 1972. 55, 2941.

240

Inorganic Chemistry of the Transition Elements

distinct anions. Electronic spectroscopy indicates that electron addition takes place into both ligand and metal orbitals.64

ROC

ROC

ROC (77)

COR

(78) R = M e

Other N-donor ligands. 8-Amino-2-methylquinoline (maq) forms the complexes [Co(maq)X,],nH,O (0= C1, Br, or I) which are tetrahedral in the solid state and in acetone and nitrobenzene solution and octahedral in methanol. The complexes [Co(maq),X,],nH,O ( X = C1, Br, I, or NO,), which are octahedral in the solid state and in methanol and tetrahedral in nitrobenzene, have also been isolated.335 The complexes [Co(PhCN),]X, (X- = SbC1; or FeCl;, n = 6; X = InCl,, n = 7),62 [Co(adn),](ClO,),, (CoCl,adn),, (CoCl,,adn, H,O),, (CoCl2adn,2H,O), (CoBr,adn),, CoBr2adn,4H,0 and [Co(adn),]) ~ ~ ~been isolated. Adiponitrile acts as a uni(CoI,) (adn = a d i p ~ n i t r i l e have dentate ligand in all cases. The structure of [Co(amben)] (79) has been determined. The cobalt atom

(79)

lies 0.14 8, above the N, plane but there is no evidence for dimer formation as is observed for [Co(salen)]. Thus, it is now possible to eliminate dimer formation in explaining the reactivity of [Co(amben)] and it is unlikely that the slight variations in bond lengths in the [CON,] unit compared with the 335 336

L. F. Power and J. A. King, Austral. J . Chem., 1972,25, 1863. D. L. Greene and P.G. Pears, J . Inorg. Nuclear Chem., 1973,35, 1471.

Elements of the First Transitional Period

24 1

[Co02N,] unit in [Co(salen)] are important in a spatial sense. It seems more likely that the differences in reactivity between the two compounds are due to electronic differences. That is, [Co(amben)] has a B , ground state, whereas that of [Co(salen)] is A,.337The pseudo-tetrahedral complexes, Co(btat)X and [Co(btat)],(CoYJ (H,btat = bis(trifluoroacetylacetone)triethylenetetramine, X = Br, I, NO,, or ClO,, Y = C1 or SCN) have been prepared.338 0-Donor ligands. The structure of [Co(H,O),](SiF,) has been reported.,,' Attempted preparation of trialkylamine complexes of cobalt(1r) by reaction of the complexes Co(R'OH),X, (n = 6-9; X = ClO, or BF,) with R:N was unsuccessful and instead yielded the compounds Co[R~NH],(R~N),(R'O),X, n = 0_3).76 The (R' = Me, Et, or n-pentyl; R2 = Me or Et; n = 1-8, compounds CoL,(SbCl,), [L = Me,CO, Ph,CO, PhCHO, p-MeC,H,CHO, o-ClC,H,CHO, p-ClC,H,CHO, HCOOMe, EtOAc, or CH,(CO,Et), J have been reported.75Cobalt(rr) acetate reacts with excess benzoin in methanol to give the tetrahedral monomer C ~ ( b e n z o i n ) , . ~The ~ ' structure of [Co,L,,]

n

HNKNH 0 (ClO,), [L = (SO)] has been reported. The octahedral metal atoms are each co-ordinated to two bridging and four terminal L ligands.,,' Cobalt(rr) benzoate reacts with quinoline in ethanol to give [Co(quin),(O,CPh),] which has a magnetic moment of 4.1 1 BM at 293 K and 1.71 BM at 98 K. The maximum value of the magnetic moment is observed at 268 K and thus this complex shows a weak antiferromagnetism. An X-ray crystallographic study shows the compound to be dimeric with four bridging carboxylate The structure of Co','(CF,CO,),groups, the CoCo separation being 2.83 CI(S0,) (dme), has also been reported (dme = dimethoxyethane). The cobalt atoms form an equilateral triangle with chlorine triply-bridging the three metal atoms on one side and sulphate acting in the same manner on the other. The carboxylate groups bridge pairs of metal atoms and the dme ligands are bidentate.,,, The structure of Co[(-)-malate],3H20 has been determined,344 and thermal decomposition studies on cobalt(rr) oxalate have been published.' 337

338

339 340 341

342 343 344

I

R. Kdrlsson, L. M. Engelhardt, and M. Green, J. Chem. SOC.Dalton, 1972, 2463. S. C. Cummings and R. E. Sievers, Inorg. Chem., 1972, 11, 1483. H. Lynton and P.-Y. Siew, Canad. J . Chem., 1973,51, 227. K. C. Malhotra and S. C. Chaudhry, Chem. and Ind., 1972,606. M. E. Brown, J. 3. Brown, and L. M. Trefonas, Inorg. Chem., 1972,11, 1836. J. Drew, M. B. Hursthouse, P. Thornton, and A. J. Welch, J.C.S. Chem. Comm.. 1973. 52. J. Esteinne and R. Weiss, J.C.S. Chem. Comm., 1972,862. L. Kyger and S. E. Rasmussen, Acta Chem. Scand., 1972,26, 2349.

242

inorganic Chemistry of the Transition Elements

The high-spin tetrahedral compound Co(OC,H,CONH,), has been prepared and i.r. data indicate that the ligands chelate uia both oxygen atoms.253 The tetrahedral complex [CoCl,(acacH)] (acacH = acetylacetone) has been prepared by treating anhydrous CoCl, with a ~ a c H . ~Spectral , studies and molecular weight measurements on [Co(P-dik),] in dichloromethane (P-dik = acac, benzoylacetonate, dibenzoylmethane, trifluoroacetylacetonate, or benzoyltrifluoroacetonate) have shown them all to be polymeric.345Adducts of a range of cobalt(I1)-P-diketonates with piperidine, piperazine, methylpiperazine, m ~ r p h o l i n epyrazine, , ~ ~ ~ and 4,4-bipyridine7 have been reported. Thermal studies have been performed on [ C o ( a ~ a c ) , ] . ~Cobalt(1r)-acetyl~ acetonate reacts with picric acid in a benzene-ethanol mixture to give [Co(a~ac),(H,O),](picrate).~~ Halogenation and oxidation of cobalt complexes of acetylacetonate, salicylaldehydate, and methylsalicylaldehydate have been studied.’06 Oxidation of a mixture of Co(OAc),, acacH, and KOH in methanol with hydrogen peroxide gives Co,(OMe),(MeCO,),(acac),. A crystallographic study shows this compound to have a distorted cube-like framework with cobalt atoms and methoxide oxygen atoms occupying alternate corners. The octahedral co-ordination of each metal atom is completed by a chelated acac ligand and by an oxygen atom of one of the acetate groups which bridge the top and bottom faces of the cube. The Co-0 distances around one pair of metal atoms are consistently shorter than those around the other, indicating On the basis of spectral that the former are Co1I1,whereas the latter are studies, [Co( P-dik),L] (P-dik = heptane-3,5-dionate or nonane-4,6-dionate, L = H,O; P-dik = 2,8-dimethylnonane-4,6-dionate, L = MeOH) have been shown to be dimeric. These compounds are oxidized by air to form cobalt(rr1) (LH,) reacts with cobalt(I1) ~ h e l a t e s . ~1,7-Diphenylheptane-1,3,5,7-tetraone ,~

’

salts in the presence of either sodium hydroxide or sodium acetate in methanolwater or acetone-water to give M,L,B, (B = H,O or Me,CO), which is thought to have structure (81).349 Chelates of heptane-2,4,6-trione (H,daa), 345 346

347 348

3c9

A. Choplin, J. Mol. Structure, 1972, 13, 295.

G . C. Pellacani, R. Battistuzzi, and G. Marcotrigiano, J. Inorg. Nuclear Chem., 1973, 35, 2243. J. A. Bertrand and T. C. Hightower, Inorg. Chem., 1973,12,206. I. Yoshida, H. Kobayashi, and K. Ueno, Bull. Chem. SOC.Japan, 1972,45, 2768. B. Andrelezyk and R. L. Lintvedt, J. Amer. Chem. Soc., 1972,94, 8633.

Elements of the First Transitional Period

243

[Co(Hdaa),],2H20, [Co2(daa),],4H,O, and [Co2(daa),],4py and of 1,sdiphenylpenta-1,3,5-trione(H,dba), [Co2(dba),L,],2L (L = H,O or py), have also been r e p ~ r t e d . ~ Ethylacetoacetate ” and ethylmalonate act as neutral ligands (L) in forming the complexes CoLX, (X = C1 or Br), which are both tetrahedral. 7 4 The six-co-ordinate monomer [CoL,(ONO,)(O,NO)], the five-co-ordinate dimer [L,(SCN)Co(SCN),Co(NCS)L,] (L = 2,6-lutidene N-~xide),~’CoLa, 0.5H20(L’H = 2-picolinic acid N-oxide)80and cobalt (11) complexes of triazine 1-oxides3 have been reported. 2,2,6,6-Tetramethylpiperidine-nitroxide radicals [tmpNO (62)] reacts with cobalt(I1)perchlorate in the presence of triethylorthoformate to yield [Co(tmpNO)(ClO,),], which is probably polynuclear with bridging perchlorate groups. Magnetic and e.s.r. data have been interpreted in favour of a partial spin-spin coupling between unpaired electrons H,N

CO,H

0

on the ligand and the metal atom.,’* Similar complexes of (82) (L’H) and (83) (L2), Co(L’),, and C0(L2),I, have also been Electronic spectroscopy and spin-echo n.m.r. have been used to investigate the complexes formed when Co(NO,), is extracted from aqueous solution with (BuO),PO, Bu,PO, and B U , ( B U O ) P O . The ~ ~ ~trimorpholinephosphine oxide (morPO) complexes [Co(morPO),X,] (n = 0.5-4; X = BF,, NO,, NCS, Cl, Br, or I) have been prepared and the ligand was found to co-ordinate uia the oxygen atom.82The pseudo-tetrahedral complexes CoLX, [L = Ph2P(0) *CH,CH,*P(O)Ph,, X = C1, Br, I, NCS, or NO,; L = Ph,P(S)*CH,CH,P(S)Ph,, X = C1, Br, or I], the five-co-ordinate complex Co[Ph,P(O)CH,CH, P(O)Ph,] ,(ClO,),,BuOH, and the si x-co-ordinate complex { Co[ Ph,P(O)CH, CH P(0 ) P P h,] ,( H O),) (ClO,), have been reported,, 4-3 as have the related complexes, (Co[Ph,P(O)CH,P(O)Ph,],} (COX,) (X = C1, Br, or I) and (Co[Ph,P(0)CH,CH,CH,P(O)Ph2]X2} (X= C1, Br, or I).356 The structure of the tetrahedral complex C O C ~ , [ P ~ , P ( O ) N H C H , P ~containing ]~

,

35”

351 352 353 354 355

356

F. Sagnra, H. Kobnyashi and K. Ueno, Bull. Chem. SOC.Japan, 1973,46,484;I . Kuszaj, B. Tomlonovic, D. P. Murtha, R. L. Lintvedt, and M. D. Glick, Znorg. Chem., 1973, 12, 1297. P. S. Zdcharias and A. Chakravorty, Znorg. Chim. Acta, 1972,6, 623. D. Jahr, K. H. Rebhan, K. E. Schwarzhans, and J. Wiedermann, Z . Naturforsch., 1973, 28b, 55. T. Y. Vereshchagina and A. A. Vashman, Russ. J . Inorg. Chem., 1973,18, 81. B. J. Brisdon, J.C.S. Dalton, 1972, 2247. F. Mani and A. Scozzofava, Gazzetta, 1972,102, 1109. F. Mani and M. Bacci, Znorg. Chim. Acta, 1972,6,487.

244

Inorganic Chemistry of the Transition Elements

the [CoO,Cl,] core has been reported.357 The new complexes [Co(HMPA),(NO,),] and [Co(NIPA)(NO,),] have been reported and both contain coordinated NO, groups.83 (Me,N),P(O)NMeP(O)(NMe,)NMeP(O)(NMe,), (L), forms the complexes CoL,X, (n = 1 or 2; X = BF,, BPh,, NO,, or Cl). The bis-complexes contain octahedral metal atoms, the ligand L acting as a terdentate donor, whereas the mono-complexes are probably five-co-ordinate when X = NO, and dimeric when X = Cl. s-fac and u-fac isomers have been observed when X = BF,.84 Two forms of cobalt(r1) dioctylphosphinate have been prepared. A tetrahedral polymer is formed when Co(OAc), is treated with (C,H,,),P(O)OH and a new modification that is probably six-co-ordinate, but may well contain more than one structural type, has been obtained by treating anhydrous CoCl, with the phosphinic acid in ethanol, followed by removal of the solvent and heating the residue to 60 "C in vacuum., 5 8 Bis-di-(2-ethylhexyl)phosphonatocobalt(I1) dihydrate has been isolated.359 9,lO-Phenanthraquinone (Hquon) undergoes a direct thermal reaction with Co,(CO), to give C o ( q ~ o n ) , .The ~ ~ ~tetrahedral complexes Co(nau),X, (nau = N-allylurea, X = C1, Br, or I) have been reported.360 Dioxan (dx) and 1,2-dimethoxyethane (dme) form the complexes [ C O ( ~ X ) ~ ( H ~ O ) ~ ( C ~ O , ) ~ ] and [Co(dme),(H,0),(C10,)2],87and 1,3-dithane-monosulphoxideand its 2-phenyl analogue form the complexes CoL,X, ( X = C10, or BF,).86 The pseudo-octahedral complexes Co(O,SR),(py), (R = Ph or p-MeC,H,) have been prepared by the reaction of (RSO,),Co(OH,), with pyridine. No linkage isomers of the bis-pyridine complex were d e t e ~ t e d . ~ Anhydrous cobalt(I1) perchlorate has been prepared by dehydrating the corresponding hexahydrate. The dehydration can be effected either by use of a large excess of dimethoxypropane or by controlled heating under high-vacuum over several weeks.361 DMSO in the presence of SO, oxidizes anhydrous cobalt(1r)sulphite to the pyrosulphate Co(DMSO),S,O,. Thermal decomposition of this DMSO solvate yields a mixture of anhydrous CoSO, and anhydrous has been carried out into the thermochemistry C O S O , . ~A~re-investigation ~ of the Co2+-SOi--H,O system.68a- and ~-[Co(IO3),],2H,0 and [Co(IO,),],4H,O have been isolated as single crystals and their heats of formation and stabilities discussed.363 The structure of Co,P,O, has been reported.364 It has been shown that the first stage in the reduction of Co" by hypophosphite ions is the formation of a 1:1 complex.365 Salts of MCo"W, 1040H;- (M = P, n = 5; M = As, n = 5; M = B, n = 7) and BCO"'W,,O,,H~- have been 357 358 359

360 361

362 363 364 365

R. M. Roy dnd J. W. Jeffery, Acta Cryst., 1973, B29, 1083. H. D. Gillman, Inorg. Chem., 1972,11, 3124. T. Sato and T. Nakdmurd, J . Inorg. Nuclear Chem., 1972,34,3721. P. P. Singh and I. M. Pdnde, Canad. J. Chem., 1972,50,2603. R. E. Elson and J. E. Stuckey, J . Inorg. Nuclear Chem., 1973,35, 1029. R. Maylor, J. B. Gill, and D. C. Goodell, J.C.S. Dalton, 1973, 534. E. H. P. Cordfunke, J . Inorg. Nuclear Chem., 1973,352699. N. Krishnamachari and C. Calvo, Acta Cryst., 1972, B28,2883. R. I. Novoselov and V. Belevdntsev, Russ. J . Inorg. Chem., 1972,17, 521.

Elements of the First Transitional Period

245

prepared. There is evidence that the constitutional H,O molecule is present actually as a molecule of water and that it can be replaced by pyridine. Replacement is fast for Co" but slow for Co"': the anion [ P C O ~ ~ ( ~ ~ ) W , , O ,has ,]~been isolated.366

S- Donor and Se-donor ligands. Reaction of thiourea (tu) with COX, ( X = C1 or Br) produces a mixture of [Co(tu),X,] and [ C ~ ( t u ) , X , l . ~[Co(tu),Cl,] ~~ reacts with N-donor ligands and phenylarsenic acid to produce [Co(tu)(phen), Cl] C1, [Co(tu)(bipy),CI] C1, [Co(tu),(py), Cl,], and [Co(tu)(Ph OAs), CI], all of which are ~ i x - c o - o r d i n a t e .The ~ ~ ~ structure of the triclinic form of [C~Cl,(NN'-diethylthiourea)~]has been reported. The molecules are linked by hydrogen bonds between chloro- and NH-groups into polymeric chains, the cobalt atoms being in tetrahedral environment^.^^' The tetrahedral complexes [Co(natu),X,] (X = C1, Br, I; natu = N-allylthiourea) and [Co(su),]X, (X = C10, or NO,; su = selenourea) have been reported.360,3 7 0 The pseudo-tetrahedral complexes [Co(S,PX,),] (X = CF,, CH,, Ph, OEt, or F) and [Co(S,AsMe,),] have been isolated from the reactions of cobalt(I1) salts with the appropriate sodium salt.88>3 7 1 The stable tetrahedral complexes, [Co(sps),](ClO,),, [Co(sps),X,],nTHF (X = Br, n = 0; X = I, n = O S ) , and [Co(spse)X,],nTHF (X = Cl, n = 0; X = Br, n = 0.5; X = I, n = 0.75) have been isolated, where sps and spse represent Ph,P(S)CH,P(S)Ph, and Ph,P(Se)CH,P(Se)Ph,, respectively. By way of comparison, the corresponding complexes of Ph,P(O)CH,P(O)Ph, are octahedral.372 The tetrahedral complexes [CoL,]Cl, (L = 1,5-diphenyl-, 1,5-di-p-tolyl-, 1,5-di-o-tolyl-, 1-phenyl-5-o-tolyl-, 1-phenyl-5-p-tolyl-, or 1-methyl-5-p-tolyl2,4-dithiobiuret) have been prepared.373 The reaction of Co(S,C,Ph,) with P(OR),, PR(OR),, and PR,(OR) (R = Et) in acetone has been followed by e.s.r. Initially, one molecule of the phosphine is introduced into an axial position and, subsequently, a second molecule enters trans to the first, which is followed by a rearrangement to the cis-structure. A similar series of reactions with PCl,, PCI,(OR), PCl(OR),, and P(OR), (R = Ph) gives only the fiveco-ordinate complexes.374 Cobalt@) complexes of pyridine-2- and -4-thiol and 2-methylpyridine-6-thiol have been reported.375 P-Donor and As-donor ligands. The high-spin tetrahedral mixed-ligand complex [Co(PPh,)(OPPh,)I,] has been reported.376 and the five-co-ordinate com366

367 368

369 370 371 372 373 374

375

376

T. J. R. Weakley, J.C.S. Dalton, 1973, 341. N. Meneces and C. R. P. MacColl, J . Znorg. Nuclear Chem., 1972,34,3711. M. M. Khan and A. U. Malik, J. Znorg. Nuclear Chem., 1973,35,247. M. Bonamico, G. Dessy, V. Fares, and L. Scaramuzza, J.C.S. Dalton, 1973, 876. G . B. Aitken, J. L. Duncan, and G. P. McQuillan, J.C.S. Dalton, 1972,2103. W. Kuchen, M. Forster, H. Hertel, and B. Hohn, Chem. Ber., 1972, 105, 3310. W. E. Slinkard and D. W. Meek, J.C.S. Dalton, 1973, 1024. N. K. Agar and K. P. Srivastava, J . Znorg. Nuclear Chem., 1973,35, 1040. A. D . Troitskaya, Y. V. Yablokova, A. V. Ryzhmanova, A. I. Razumov, and P. A. Gurevich, Russ. J . Znorg. Chem., 1972, 17, 1640. B. P. Kennedy and A. B. P. Lever, Canad. J. Chem., 1972, 50, 3488. J. Rimbault and R. Hugel, Inorg. Nuclear Chem. Letters, 1973, 9, 1.

246

Inorganic Chemistry of the Transition Elements

plexes [CoL,X]BPh, and [CoL,(NCS),] [L = PhP(OEt),, X = C1, Br, I, NCS or N,) have been prepared.377E.s.r. studies on CoL3X, [L = Me,NPF, or (Me,N),PF; X = C1. Br, or I] are consistent with a configuration inter[(Et,P),mediate between square-pyramidal and trig~nal-bipyramidal,~~~ COX,] (X = C1 or Br) reacts with HgY, (Y = Cl or Br) to form (Et,P),Co(pX) H Y ,the structures of which are inferred from spectroscopic and magnetic evidence.,379 [Co(dpe),(CN),] undergoes reduction when treated with hydrazine hydrate in ethanol yielding the red, air-sensitive, diamagnetic complex [Co(dpe),CN]. This cobalt(1) compouna undergoes oxidation with iodine in benzene and molecular oxygen in the presence of NaClO, in ethanol yielding [Co(dpe),I(CN)] and [Co(dpe),CN]ClO,, respectively. It also undergoes reaction with CO in ether to give [Co(dpe)(CO),CN] (dpe = Ph,PCH2CH,PPh,).380 Treatment of COX, with SnX, and dpe in non-aqueous solvents yields [Co(dpe),SnX,] (X = C1 or Br), which can be isolated in two forms, red and green, both evidently low-spin five-co-ordinate, the only difference in their absorption spectra being the greater intensity of bands for the green isomer. The structures of red [Co(dpe),Cl] SnCl, and green [Co(dpe), Cl] SnCl ,PhC1 have been determined. The former shows square-pyramidal co-ordination with an apical chlorine atom, whereas the latter is trigonal-bipyramidal with two axial phosphorus atoms. The isomers interconvert in solution and the favoured mechanism is one involving dissociation of one phosphorus atom of a chelating ligand, followed by interconversion and bond reformation. This work represents the first accurate structural results on the two limiting stereochemical configurations of a five-co-ordinate cobalt(@ complex with the same donor ligands, and demonstrates the need for caution in the interpretation of absorption spectra.381 The five-co-ordinate complex cations [Co(dmp),X]+ and the six-co-ordinate cation tr~ns-rCo(dmp),X,] [dmp = Me,P(CH,),PMe,; X = Cl, Br, or I] have been isolated.382 PhAs(o-C,H,AsPh,), and PhP(o-C,H,AsPh,), form the complexes [CoLX,] (X = Br or NCS), and the complexing ability of these ligands has been compared with that of similar ligands with aliphatic substituents on the arsenic atoms.383 The zwitterionic complexes [CoX;(L-L+)] [X = Cl, Br, +

t

or I; (L-L') = Ph,PC,H,NHR, (R = H, Me, or Et)] have been prepared by reaction of L-L+X- with COX,; when R = Me or Et, the products can also be prepared by reaction of COX, with L-L in ethanol. Spectral and magnetic properties indicate a total lack of influence of the cationic site on the ligating properties of the donor phosphorus atom. The complexes [CoBr, 371 378 379 380 381 382 383

A. Bertacco, U. Mdzzi, and A. A. Orio, Inorg. Chem., 1972,11,2547. T. Nowlin, S. Subramanian, and K. Cohn, Inorg. Chem., 1972, 11,2907. M. I . Braithwaite and R. S . Nyholm, J. Inorg. Nuclear Chem., 1973,35, 2237. P. Rig0 and M. Bressan, Inorg. Nuclear Chem. Letters, 1973, 9, 527. J. K. Stalick, P. R. Corefield, and D. W. Meek, J. Amer. Chem. Soc., 1972, 94, 6194. J. C. Cloyd and D. W. Meek, Inorg. Chim. Acta, 1972,6,480. W. E. Hill, J. Dalton, and C . A. McAuliffe, J.C.S. Dalton. 1973, 143.

247

Elements of the First Transitional Period

(P-P’)] (P-P’ = monobenzylated derivatives of cis- and trans-Ph,PCH= CHPPh, afid Ph,PC=CPPh,) have also been isolated.384 Mixed donor ligands. The complexes, [Co(deaH)H,O]X (X = C1, Br, or NO,), [Co(deaH)dea]Br, [Co(MedeaH),]X, (X = C1, Br, I, or NO,), and [Co(MedeaH),](NO,), (deaH = diethanolamine, MedeaH = N-methyld i e t h a n ~ l a m i n e )and ~ ~ ~cobalt(r1) complexes of tris(hydroxymethy1)aminoethane and 2-amino-2-(hydroxymethyl)propane1,3-di01~~ have been prepared. The structure of the high-spin, five-co-ordinate complex { [2-{ [2-(diethylamino)ethyl]amino}ethyl]diphenylphosphine oxideldi-isothiocyanatocobalt(11) has been determined. It has distorted trigonal-bipyramidal geometry with one oxygen and two nitrogen donor atoms in the equatorial plane, the apical sites being occupied by nitrogen atoms.386 The complex [Co(bipyNO),](ClO,), [bipyNO = (9)] has been prepared and the ligand field strength ’of (9) compared with those of bipy and (lo).” Cobalt (11) carbonate or hydroxide reacts with pyridine-2,6-dicarboxylic acid (dpcH,) in hot aqueous solution to form [Co(dpcH),],3H20 or [Co(dpc)(H,O),] depending on the molar ratios of the reactants. The former product contains two terdentate dpcH ligands and lattice water, while dpc is also terdentate in the latter which has co-ordinated water molecules.387 Ethoxy-6-methylpyridine-2-phosphonate (E6MPP) forms the complex [Co(E6MPP),], which has ligands in both terminal and bridging position^.^' The red adduct [Co(salen)],NaBPh4,2THF can be isolated from a reaction of [Co(salen)] and NaBPh, in THF. An X-ray crystallographic study indicates the presence of discrete [Co,(salen),Na(THF),II cations, in which the sodium ions are in an approximately octahedral array surrounded by six oxygen atoms, two from each salen ligand and two from the T H F molecules which are in mutually cis positions. The adducts [Co(3-MeO-salen)],NaBPh4,2THF, [Co(salen)],NH,SCN,THF, [Co(3-MeO-salen)]NH4SCN, [Co(salen)LiX],THF (X = Br, I, or SCN), [Co(3-MeO-salen)]LiX (X = Br or SCN) were also obtained.388 [Co(salen)] reacts with p-benzoquinone in pyridine to give [Co(salen)(py)], (p-bquin), for which a dimeric structure with the benzoquinone molecule bridging two six-co-ordinate cobalt atoms is The related diamagnetic compounds [Co(acacen)L(py)] (L = por o-benzoquinone) have also been isolated and appear to be dimeric in the solid state, but monomeric in pyridine solution.389 Polarographic studies have been reported for cobalt(1r) complexes of NN’-ethylenebis(acety1acetiminate) and NN’-ethylenebis(salicyla1dehydeiminate)in D M F solution.390 The structures of meso- and optically active forms of NN’-butylenebis+

R. A. Kolodny, T. L. Morris, and R. C. Taylor, J.C.S. Dalton, 1973, 328. M. N. Hughes, B. Waldron, and K. J. Rutt, Znorg. Chim. Acta, 1972,6,619. 386 C. A. GhiIardi and A. Biachi-Orlandini, J.C.S. Dalton, 1972, 1698. 387 R. W. Matthews, A. D. Hamer, D. L. Hoof, D. G. Tisley, and R. A. Walton, J.C.S. Dalton, 1973, 1035. 388 C. Floriani, F. Calderazzo, and L. Randaccio, J.C.S. Chem. Comm., 1973, 384. j a gG. Tauzher, R. Dreos, A. Bigotto, and G. Costa, Znorg. Nuclear. Chem. Letters, 1973,9,797. 390 M. Kodama, Y. Fujii, and M. Sakurai, Bull. Chem. SOC. Japan, 1972,45, 1729. 384

385

Inorganic Chemistry of the Transition Elements

248

(salicylaldehydeiminato)cobalt(II) have been determined. The structures are similar, the cobalt atom having slightly distorted square-planar stereochemistry. The main differences are found in the butylene bridge, the methyl groups being both pseudo-axial in the optically active form and in pseudo-axial and pseudo-equatorial positions in the meso-form. The observation that the meso-form shows an uptake of oxygen in pyridine solution that is lo3 times greater than that of the optically active form is intriguing.391 Complexes of cobalt(r1)with Schiff bases derived from salicylaldehyde and a range of substituted ethylenediamines have been prepared together with their five-co-ordinate pyridine adducts. Spectral and magnetic data have been reported and their reactions with molecular oxygen studied. Oxygen uptake is discussed in terms of the electronic configuration of the metal and the steric substitution on the ligand~.~~~

(84) X

391

392

=

0 or S

(85) X

=

0 or S

M. Calligaris, G . Nardin, and L. Randaccio, J.C.S. Dalton, 1973,419. C. Busetto, F. Cariati, A. Fusi, M. Gullotti, F. Morazzoni, A. Pasini, R. Ugo and V. Valenti, J.C.S. Dalton, 1973, 754.

Elements of the First Transitional Period

249

The ligands RH, (84) react with Co(OAc),,4H20 in methanol under nitrogen to form [RCo,(OAc)],xH,O. The complexes react with oxygen in methanol to form [RCo,(OMe)(OAc)] not the related peroxy-bridged compound (85). Recrystallization of the methoxy-compound from ethanol yields RCo,(OH)(OAc)(H,O)EtOH, the structure of which has been determined and shown to be (86).393 Polymeric cobalt(I1) compounds of (87) and (88) have been isolated and their properties compared with those of the monomeric analogues of the ligands (89) and The ligand (91) forms a five-co-ordinate complex with cobalt(rr), one of the ethereal oxygen atoms remaining ~nco-ordinated.~’~

\=N

393 394

395

0

(CHI),--0

N-/

0 0

B. F. Hoskins, R. Robson, and D. Vince, J.C.S. Chem. Comm., 1973,392. N. Dunski and T. H. Crawford, J . Inorg. Nuclear Chem., 1973,35, 2707. I. Murase, K. Yamanouchi, and S. Yamada, Bull. Chem. SOC.Japan, 1972,45, 2138.

250

Inorganic Chemistry of the Transition Elements

The structures of bis-(a-nitroacetatophenonato)cobalt(II) and its addition compound with a- and y-picoline have been determined. The bis-complex and the adduct in y-picoline are pseudo-octahedral, whereas the a-picoline adduct is tetragonal-pyramidal, the nitrogen base being co-ordinated on the basal plane in the five-co-ordinate structure and in an equatorial position in the octahedral a d d ~ c t The . ~ ~ complexes ~ [Co(salAA)(H,O),] (salAA = N-salicylideneamino-acid dianion of the amino-acids Gly, L-Ala, L-Phe, L-Leu, and L-Met) have been prepared by reaction of salicylaldehyde with the respective amino-acids followed by addition of Co(OAc),,4H20. [Co(salGly)] has also been prepared and all the complexes are octahedral and possibly d i m e r i ~ . ~ ~ ' The quadridentate amino-acid-like ligand 1,5-diazacyclo-octane-NN'-diacetate (dacoda) forms the complex [Co(dacoda)H,O], the square-pyramidal complex being formed because an alkyl proton ofthe ligand blocks the sixth co-ordination site. This cobalt(1r) complex is stable to oxidation under conditions normally employed to oxidize the related amino-acid complexes.398 The bis-cobalt(I1) complex of o-H,N C,H, S * CH,CO,H has been reported.99 P-Furfuraldoxime (1 1) forms the octahedral complex [Co(ffdox),Cl,] :6 and the tetrahedral complexes [CoL,X,] [X = C1, Br, or I; L = (92)] have been prepared from the reactions of COX, and L in 8-Hydroxy7-nitrosoquinoline-5-sulphonic acid (H,L) reacts with cobalt(I1) salts to form H[CO(HL),],,~~ and the complex CoL, (L = 2-benzenesulphonamidomethyl-

-

benzimidazole) has been prepared by a metathetical rea~tion.~"An n.m.r. study of the chelate formed by (12) shows the ligand to be co-ordinated by N-5 and 0-6.97Pyruvic acid amide (L) forms the complexes CoX,L,nEtOH (X = C1, Br, or NO,; X = SO,) whereas pyruvic acid diethylamide does not form cobalt(r1) compounds.401 Reaction of (64) with Co(OAc),,4H20 in ethanol produces a cobalt(r1) chelate., l 9 The potentially quinquedentate ligands NN'-bis(salicy1idene)2,2'-bis(aminoethy1)sulphide and its 5-bromo, 5-methyl, 5-nitro, and 3-isopropyl derivatives form neutral tetrahedral cobalt(I1) complexes.402 2-(0Hydroxypheny1)benzothiazoline reacts with cobalt(r1) salts in a 2: 1 molar ratio to form chelates of o-H,NC,H,SN; however. 2-phenylbenzothiazoline

,

396 397

398 399 400

401

402

M. Bonamico, G. Dessy, V. Fares, and L. Scaramuzza, J.C.S. Dalton, 1972, 2477. G. 0. Carlisle and L. J. Theriot, J . Inorg. Nuclear Chem., 1973,35,2093. D. F. Avrill, J . I. Legg, and D. L. Smith, Inorg. Chem., 1972,11, 2344. M. R. Udupa, G. Krishnan, and G . Aravamudan, Inorg. Nuclear Chem. Letters, 1973,9,491. N. N. Ghosh and A. Bhattacharyya, J . Inorg. Nuclear Chem., 1973,35, 517. A. V. Ablov, N. I. Belichuck, and L. A. Nezhel'skaya, Rum. J . Inorg. Chem., 1972,17,859. S . R. Edmundson. W. M. Coleman. and L. T. Taylor. Inorg. Chem., 1973, 12, 1191.

Elements of the First Transitional Period

25 1

undergoes similar reactions to form bis(benzilideneaminothiopheno1ato)cobalt(r1)which has a [CoN,S,O,] core.4o3The ligand (14) forms the complexes CoLX, (X = C1, Br, or I), CoL(NCS),H,O, [CoLNO,]NO,, [CoL,](ClO,),H,O, and [CoL,](BF,),, which all contain the ligand bound by two nitrogen atoms. The nitrato-complex is probably five-co-ordinate, the others being tetrahedral.'" The tetrahedral compounds rCoL,1 rL = (93)l have also been as has the octahedral polymer [Co(LH),(H,O),J [L = (94)].405

N=N

Ph (93) R

=

H or Me

(94)

The complexes Co(H2T),,6H,O (H,T = 3,4,5-pyra~ine-trithiol),'~~ CoL,, and CoL,H,O (L = o-mercapto-N-methylbenzanilide)406have been prepared. The structure of high-spin [Co(nnpp)I]I [nnpp = NN-bis-(2-diphenylphosphinoethyl)-N-(2-diethylaminoethyl)amine~has been reported. It has square-pyramidal geometry distorted towards a tetrahedr0n.4'~ The structure of the related complex [Co{N(CH,CH,PPh,),}Cl] PF, shows the metal atom to be surrounded by three phosphorus atoms and the chlorine atom in a distorted tetrahedral array. A very long Co-N bond [2.675(10) A] completes the co-ordination sphere.408The complexes [Co(nnp)X2 ] and [Co(Mennp)X,] [X = halogen or NCS; nnp = Et,N(CH,),NH(CH,),PPh,, Mennp = Et,N(CH,),NMe(CH,),PPh,] have been prepared. All the halogeno-complexes are high-spin and five-co-ordinate in the solid state, but in solution they are either partially (nnp) or totally (Mennp) tetrahedral. The thiocyanato-complex of Mennp is also high-spin, but the nnp complex shows a temperature-dependent spin-equilibrium in the solid state and in solution it irreversibly oxidizes to [Co(nnp)(NCS),] and the cobalt(I1)-phosphine oxide complex [Co(nnp(O)}(NCS),].409 The complexes [CoLX,] [X = halogen, NCS, or NO,; L = (99, 403 404

40 5 406

407

408 409

E. Uhlemann and V. Pohl, Z. anora. Chem., 1973,397, 162. A. D. Garnovskii, N. F. Krokhina, T. A. Zayakina, and L. I. Kuznetsova, Russ. J. Inorg. Chem., 1972,17,1201. B. Singh and R. Singh, J . Inorg. Nuclear Chern., 1972,34. 3449. A. C. Patel, J. J. Brooks, G. Geoffroy, and T. H. Crawford, J. Inorg. Nuclear Chem., 1973, 35, 1855. A. Bianchi, P. Dapporto, G. Fallani, C . A. Ghilardi, and L. Sacconi, J.C.S. Dalton, 1973, 641. M. Di Vari and A. B. Orlandini, Inorg. Chem.. 1973,12. 1292. R. Morassi, F. Mani, and L. Sacconi, Inorg. Chem., 1973,12, 1246.

Inorganic Chemistry of the Transition Elements

252

(96), or (97)] have been prepared. The halogeno-compounds are thought to be five-co-ordinate; however, in the case of the others it was not possible to distinguish between the possibilities of five- and six-~o-ordination.~'

NMe,

NHMe

(95) R = Me or Et

AsMe,

(96)

AsMe,

H

(97)

Other Cobalt@) Compounds. The binding of cobalt(1r) to plasma proteins has been examined.41 The structure of partially exchanged, fully dehydrated zeolite A has been reported. The cobalt(r1) ions were found to be in trigonalplanar environment^.^'^

Cobalt( III ).-The optical activity associated with d-d transitions in dissymmetric cobalt(II1) complexes has been examined in terms of a model which incorporates both ligand field theory and the one-electron static-coupling theory of optical activity. Expressions have been obtained which relate the sign of the net or total d-d rotatory strength to specific stereochemical features in the ligand environment. Sector rules based on these expressions have been proposed and tested.413 A model for predicting the photo-reactions and quantum yields of cobalt(u1) complexes has been devised., l4 Halides and Pseudohalides. MCoF, complexes have been prepared by elemental fluorination at temperatures between 250 and 500°C of a variety of starting materials including MCoCl, (M = Li, Rb, or Cs) and MCoF, (M = Na or K). All the tetrafluoro-complexes have magnetic moments of about 3.5 BM and they act as fluorinating agents towards organic compounds.41s The structure of H,Co(CN), has been determined and consists of layers of Co(CN)Z- octahedra joined together by very short N-H...N bonds.230 410 411 412 413 414

415

B. Chiswell and K. W. Lee, Inorg. Chirn. Acta, 1973,7,49. A. K . N. Nandekar, P. K. Basu, and F. Friedberg, Bioinorg. Chem., 1973,2, 149. P. E. Riley and K. E. Seff, J.C.S. Chem. Cnmm., 1972, 1287. F. S. Richardson, Inorg. Chem., 1972.11. 2366. J. I. Zink, Inorg. Chem., 1973,12, 1018. A. J. Edwards, R. G. Plevey, I. J. Sallomi, and J. C . Tatlow. J.C.S. Chem. Comrn., 1972, 1028.

Elements of the First Transitional Period

253

The structures of M,Co(CN), [M, = K,, Cs,Li, or Co(NH,),] have also been r e p ~ r t e d . ' ~ ~ ,Co,[Co(CN),], ~~~? has been prepared and it is suggested that the compound previously reported as Co(CN),,xH,O is in fact a contaminated form of this compound.417Thermal decomposition of Co(CN);gives a range of products terminating in Co(CN),, Co(CN), and finally metallic cobalt.,' Adamantyl iodide reacts with [Co(CN),I3- to form [(1-adamanty1)Co"'(CN),I3- which was isolated as its potassium salt. The anion's stability in neutral or alkaline solution is comparable with that of [M~CO(CN),]~; however, it undergoes facile acid-catalysed decomposition to 1 -adamantyl cyanide and 1-adamantan~l.~l' (n-Cp)Co(PPh,)I, reacts with cyanide to form [(n-Cp)Co(PPh,)(CN),], whereas a similar reaction of [(n-Cp)Co(CO)I,] gives [(n-Cp)Co(CN),] - . Alkylation of the anion yields [(n-Cp)Co(CN),(CNMe)] or [ ( ~ - C ~ ) C O ( C N E ~ ) , ] ~ + . ~ ~ ~ Complexes. Ammine and rnonoamine complexes. The structure of [Co(NH,),]SbCl, has been and 59C0 n.m.r. spectra of [Co(NH3),l3+, [Co(NH3)s co3 1 + [Co(NH3)4CO31 +, [Co(NH3 )3 (co3)c1], [C d N H3 ) 2 (C03)2]-, [CO(NH,)(CO,)(NO,),]~-, and [CO(CO,),]~- have been exarnir~ed.,~~ [Co(NH,),H,O] (ClO,), reacts with DMSO to form [Co(NH,),DMSO] (C104)3.Nitrate and chloride salts were obtained by anion exchange. An investigation into the synthetic use of this complex has been made, taking advantage of the lability of DMSO and the method reported for the preparation of [Co(NH3),(py)l3+ salts shows advantages over those previously Irradiation of neutral buffered solutions of [Co(NH,),CO,] + and [Co(en),C03]+ (254 nm) gives [Co(aq)I2+ in relatively low quantum yields, and the former also gives [Co(NH3),(H,0),J3+ (quantum yield = 0.1 1). [Co(NH,),CO,]+ can also be photo-reduced and flash photolysis of all three cations yields the transient COSY radical anion. It is proposed that photochemical excitation of the complexes in the intense ligand-to-metal charge-transfer band gives the charge-transfer singlet state which generates, via a radiationless transition, the charge-transfer triplet state and a ligand excited state. The charge-transfertriplet state is the precursor of the oxidation-reduction reactions and protonation of the carbonate ligand in the excited state is viewed as the cause of ring opening and a q ~ a t i o n . ~[Co(NH,),(acac)](N03), ,~ has been prepared by treating [Co(NH,),CO,]NO, with a~etylacetone,~~' and treat41h 417

419 420 421

422 423 424

M. Iwata and Y. Saito. 4cta Cryst., 1973, B29, 822. P. S. Poskozim, R. Shute, R. Taylor, and J. Wysocki, J. Inorg. Nuclear Chem., 1973,35, 687. B. Moahi, 2. anorg. Chem., 1972,392,287;H. Inoue and S. Yanagisawa, J. Inorg. Nuclear Chem., 1973,35,2561. S. H. Goh and L.-Y. Goh, J. Organometallic Chem., 1972,43, 401. J. A. Dinein and P. L. Pauson, J. Organometallic Chem., 1972,43,209. D. R. Schroeder and R. A. Jacobson, Inorg. Chem., 1973,12,210. N. S. Biradar and M. A. Pujar, 2. anorg. Chem., 1972,391. 54. C. R. P. MacColl and L. Beyer, Inorg. Chem., 1973,12,7. V. W. Cope, S. Chen, and M. Z. Hoffmann, J. Amer. Chem. SOC., 1973,95,3116. E. Danilczuk, Roczniki Chem., 1972, 46, 1006.

254

Inorganic Chemistry of the Transition Elements

ment of [Co(NH,),CN(OH)]Cl with conc. HCI in glacial acetic acid yields trans-[Co(NH,),Cl(CN)]+ cations.426 cis- and trans-isomers of [Co(NH,),X,]"+ (X, = CO,, n = 1 ; X = H,O, n = 3; X = C1, Br, or NO,, n = 1) can be distinguished by broad-line n.m.r.427 Thermal deaquation-anation reactions of cis-[Co(N,)X(H,O)]Y, [N, = (NH3), or (en),; X = Cl or Br; Y = Cl, Br, or NO,] have been studied. Some of the reactions have been found to show stereochemical changes, the products being considerably affected by the nature of Y. Thus, when Y = C1, deaquation occurs with the retention of the &-configuration, but when Y = Br, the trans-isomer is formed.428 Thermal isomerization of [CoCl,(NH,),(en)]Br,H,O in the solid phase has been Treatment of sodium cobaltinitrite with methylamine yields the complexes [CO(M~NH,),-,(NO,),]"~ (x = 4, n = 1; x = 3, n 9). Methylamine is much more easily displaced than ammonia.430 =I

Diarnine complexes. The pK, values determined for a range of cobalt(II1)-amine chelates indicated enhanced acidity for the protic chelate complexes compared with those with related unidentate ligands.,,' Complete resolution of rac[Co(en)J3+ cations has been achieved by paper electrophoresis in a background of d-tartrate and AlCl,.432 The crystal structure of ( +),-[Co(en),](NO,), has been determined.433 The very low quantum yields for the photoreactions of [Co(en),13+ have been explained as due to the lack of ligand field excitation for this ion. However, convincing evidence is presented for the reaction of [Co(en),13 i-and [Fe(CN),I4- under photochemical conditions indicating that this is an efficient photochemical reaction of the cobalt-amine complex in a ligand field excited state (quantum yield ca. 0.2)., A modified synthesis of trans-[CoCl,(en),]Cl has been reported in which CoCl, and en are cooled to 0-5 "C and H,O, is then added. The mixture is then warmed to 60-70 "C for 15-20 min and HC1 added.435Other preparations of [CoX,(en),]+ have also been The structures of [trans-CoC1,(en),] [T1C1,]437 and ( -)589-[Co(N0,),(en),]( +)589-[Co(en)(malonate)2],in which both cation and anion have A configurations and all en ligands have the o b - c o n f ~ r r n a t i o n ,have ~ ~ ~ been determined. Structural studies on ( - ) 5 8 9 [Co(en),(ox)]Br,H,O. show the cation to have the absolute configuration

426

427 428

429 430 431

432 433 434 435

436

437 438

C. K. Poon and H. W. rong, J.C.S. Dalton, 1973, 1301. S. E. lJlrich and B. A. Dunell, Inorg. Nuclear Chem. Letters, 1973, 9, 85. R . Tsuchiya, M. Suzuki, and E. Kyuno, Bull. Chem. Soc. Japan, 1972,45, 3105. R. Tsuchiya, M. Suzuki, and E. Kyuno, Bull. Chem. Soc. Japan, 1972,45, 1065. A. G. Gantsev. S. S. Tukhtaev, and K. U. Ikrarnov, Russ. J. Inorg. Chern., 1972,17,717. L. E. Bennett, R. H. Lane, M. Gilroy, F. A. Sedor, and J. P. Bennett, Znorg. Chem. 1973,12, 1200. H. Yoneda and T. Miura. Bull. Chem. Soc. Japan. 1972,45,2126. D. Witiak. J. C. Clary, and D. S. Martin, Acta Cryst., 1972, B28, 2694. N. A. P. Kane-Maguire and C . H. Langford, J.C.S. Chem. Comm., 1973. 351. M. Krishnamurthy, J. Inorg. Nuclear Chem., 1972,34, 3915. M. Nakahara and M. Mitsuya, Bull. Chem. Soc. Japan, 1972,45,2209. K. Brodersen, J. Rath, and G . Thiele, Z . anorg. Chem., 1972,394, 13. K. Matsumoto and H. Kuroya, Bull. Chem Soc. Japan, 1973.45 1755.

Elements of the First Transitional Period

255

A(6h) and the chelating oxalate and en ligands to be in the ob-lel-conformati~n.~, Treatment of ci~-[CoBr(amine)(en),]~+(amine = MeNH,, BuNH,, py, PhNH,, HOCH,CH,CH,NH,, and HOCH,CH,NH,) with water gives [C~(H,O)(amine)(en),]~ +. [Co(HOC2H4NH2)(en),13+was also isolated in which the ethanolamine is bidentate.440 Salts of [Co(en),LC1I2 in which L stands for a unidentate en ligand have been isolated and tentatively assigned a cis-configuration. In 0.1M acid solution, they exist as [Co(en),(LH)C1I3 +.441 The related dinuclear complexes [(~~),C~CO(NH~(CH~),NH,)COC~(~~)~ (X = C1 or Br; n = 2, 3,4,or 6) have also been reported.442 The three possible enantiomeric pairs of [Co(ox),(NN’-Me,en)] - have been studied by n.m.r. and all three pairs were shown to be present in an equilibrium mixture in solution.443 New preparations of [Co(en),sal] (sal = salicylate, 3-methyl- or 5-methyl-salicylate, or 3-hydroxy-2-naphthoic acid) and [Co(trien)sal] (sal = salicylate or 5-methylsalicylate) have been reported. These involve treatment of [Co(en),Cl,]Cl with salH, and NaOH or reaction of [Co(en),C03]CI04 with perchloric acid to form [Co(en),(H,0),-J3 +,followed by addition of salH, and NaOH. Spectroscopic studies show that protonation of these complexes occurs at the phenolate oxygen atom, and all of the complexes can be oxidatively degraded with acidified permanganate to yield the corresponding oxalato-complexes.444 Separation of isomers of [ C ~ ( p n ) ~ ] has ~ + been achieved by column c h r ~ m a t o g r a p h y ,and ~ ~ ~strain energy calculations have been reported for tris(l,3-~ropanediamine)-and tris-(RR)-(2,4-diaminopentane)-cobalt(111) cat i o n ~ The . ~ ~ literature ~ preparations of cis-[Co(pn),Cl,]Cl have been found to yield a mixture of isomers; however, these can be separated by ion-exchange c h r ~ m a t o g r a p h y . ~Treatment ~’ of [Co(R)-(pn),CO,]ClO, with each optical isomer of lactic acid in turn gives [Co(R)-(pn),( -)-(R)-lactate)]ClO, and [Co(R)-(pn),( + )-(S)-lactate)]ClO,; a detailed study of the optical activity of A structural study on [Co(en),pn]Br, these complexes has been carried shows the absolute configuration to be A.449 Diastereoisomers of [Co(ox)(H,N* CH,CH,CHMeNH,),]+ have been synthesized.450New complexzs containing optically active [ ( R R ) and (SS)] and meso ( R S ) pentane-2,4-diamine have been prepared. The conformations of the (RR)-[or (SS)-] and (RS)- chelates have been assigned to h (or 6 ) twist and chair forms, respectively. [Co(RS)-(2,4-ptn),] has a fuc-structure with +

+

+

+

439 440

441

442 443 444 445 446 447 448 449

450

T. Aoki. K . Matsumoto, S. Ooi. arid M. Kuroya. Bull. Chew. SOC.Jrrpan. 1973,46, 159. V. V. Udovcnko, L. G. Reiter, and E. P. Shkurman, Russ. J . Inorg. Chem., 1972, 17. 1008. S. C. Chan and S. F. Chan, J. Inorg. Nuclear Chem., 1973,35, 1247. M. D. Alexander and H. G. Kilcrease, J. Inorg. Nuclear Chem., 1973,35, 1583. K. W. Larson, A, A. Ryan, and J. G. Brushmiller, Inorg. Nuclear Chem. Letters, 1972,8, 991. R. D. Gillard, J. R. Lyons, and P. R. Mitchell, J.C.S. Dalton, 1973, 233. M. Kojima, Y. Yoshikawa, a n d K. Yamasaki, Znorg. Nuclear Chem. Letters, 1973,9, 689. S. Niketic a n d F. Woldbye, Acta Chem. Scand., 1973,27,621. H. E. LeMay and D. L. Aalbers, Inorg. Nuclear Chem. Letters, 1973,9, 469. R. A. Haines a n d A. A, Smith, Inorg. Chem., 1973,12, 1426. H. V. F. Schousboe-Jensen, Acta Chem. Scand., 1972,26,3413. M. Parris, L. J. DeHeyes, a n d D. H. Busch, Canad. J. Chem.. 1972, SO, 3569.

256

Inorganic Chemistry of the Transition Elements

respect to the amino groups adjacent to the ( R ) and ( S ) carbon atoms.451 The has been determined. The structure of ( +)546-[Co(RR)-(2,4-ptn)3]C13,H,0 six-membered chelate rings are in the twisted-boat form, the conformation of the chelate rings being h and the absolute configuration A.452Tris-complexes of cyclopentane- 1,2-diamine (cptn) have been prepared. The complexes of (-)-trans-cptn were separated into lel, and ob, isomers, and the complexes of cis-cptn were resolved into isomers of C, and C, symmetry.453The structure of the ob-isomer, ( +)589-[Co(chn),]C1,,H,0 [chn = ( -)-trans-l,2-diaminocyclohexane] has been reported. The distortion away from true octahedral symmetry is slightly more marked than in the lel isomer and the absolute configuration is A(hhh).454 Poly-amine complexes. A structural study of ( -),,,-u-fac-[Co(dien),][Co(CN),],2H20 (dien = diethylenetriamine) shows there to be two isomeric complex cations in an assymmetric structural unit. Both have a two-fold axis of symmetry and can be designated as skew chelate pairs (AAA). The conformation of the chelate rings formed by the dien molecules in one complex is 6h, while those of the other are hh.455P,P’,P”-Triaminotriethylamine(tren) forms the complexes [Co(tren)X,]A (X = NO,, NCS, or N,; A = anion), [Co(tren)XY]A (X = NO, or NCS, Y = F, C1 or Br; X = C1, Y = Br; A = anion), and [ C o ( t r e n ) o ~ ] A . ~The ~ ~ complex cations [CoX,((3S,8S)-Me2trien)l+ ( X = C1 or NO,; Me,trien = dimethyltriethylenetetramine) have been prepared, the isolated cis-a- and cis-p-isomers having the absolute configurations A and A, respectively.457 The structure of ( +),,,-cis-~-[Co(N0,),(R)-(5Metrien)]CI has been determined, the quadridentate ligands being co-ordinated in a cis-P-arrangement. The absolute configuration of the complex is described as a skew chelate pair, A, the conformation of the ligand being h. The absolute configurations about the two secondary nitrogen atoms are both S.458 The optically active quadridentate ligands NN-bis-(y-aminopropy1)-(R)1,2-diaminopropane (Rappn), NN’-bis-(y-aminopropy1)-(R)-1,2-diaminocyclohexane (Rapchn), and NN’-bis-(y-aminopropyl)-(R)-2,3-diaminobutane (Rapbn) have been prepared and used to synthesize the respective trans-dichloro- and oxalato-cobalt(II1) complexes. The ion ( - ),-[trans-Co(3,2,3-tet)Cl,] +(3,2,3tet = 1,1O-diamino-4,7-diazadecane) was determined to have SS absolute configuration with respect to the co-ordinated secondary nitrogen atoms, based on the similarity of its c.d. spectrum to that of the Rappn and Rapchn complexes, the absolute configuration of which was based on the stereospecificity expected for these ligands. The topology of the oxalato-complexes of 3,2,3-tet 451

452 453 454

455 456 45’

05’

F. Mizukami, H. Ito, J. Fujito, and K. Saito, Bull. Chern. SOC. Japan, 1972,45, 2129. A. Kobaynshi, F. Marumo, and Y. Saito. Acta Cryst., 1972, B28, 3591. H. Tofflund and E. Pedersen, Acta chem. Scand., 1972,26,4019. A. Kobayashi, F. Marumo, and Y. Saito, Acta Cryst., 1972, B28,2709. M. Konno, F. Marumo, and Y. Saito, Acta Cryst., 1973, B29, 739. K.-W. Kno, W. V. Miller, and S . K. Maden, J. Inorg. Nuclear Chem., 1973,35,957. M. Saburi, T. Sawai, and S. Yoshikawa, Bull. Chem. SOC. Japan, 1972,45, 1086; M. Saburi and S. Yoshikawa, Bull. Chem. Sac. Japan, 1972,45,806. K. Tanaka. F. Marumo, and Y. Saito, Acta Cryst., 1973, B29, 733.

Elements of the First Transitional Period

257

and its derivatives was determined to be cis+ from n.m.r. s t u d i e ~ . ~ ”The ligand 2,10-diamino-4,8-diazaundecane (diMe-2,3,2-tet) has been prepared as an isomeric mixture containing the (RS)-(meso)-isomer and the ( R R , SS)racemate. The pure (SS)-isomer has also been isolated. cis- and trans-[CoCl,(diMe-2,3,2-tet)]+ were prepared and both cis- and trans-complexes were obtained containing the optically active ligand, but the trans-isomer was obtained containing the meso-ligand. The optically active ligand co-ordinates stereospecifically in both cis- and trans-forms such that the (SS)-ligand co-ordinates with the secondary nitrogen atoms exhibiting the (RR)-configuration. The (RS)-ligand co-ordinates in the trans-complex with the secondary nitrogen atoms in the (SR)-c~nfiguration.~~* The structure of (-),,,-[transCoC1,(3,2,3-tet)]NO, has been determined: the two six-membered rings adopt the chair conformation, while the five-membered ring is gauche with absolute configuration 6. Both secondary nitrogen atoms have the @)-config~ration.~~ Chiral recognition of prochiral (rneso-carbon) centres is a general feature of enzymatic reactions, but has not been firmly established in model systems. However, Job and Bruice have now reported achieving 100% chiral differentiation of prochiral carboxyl-groups and 65 % steric induction in the reaction sequence shown in Scheme 6.462Meso-l,8-diamino-3,6-diaza-2,7-dimethyloctane (L) forms the complex ions [Co(N0J2L]+ and [ C O C I , L ] + . ~ ~ ~

’

70; Me - C-NH,

+

I

co,

65

x

NH,-N-N-NH,

35 ”/, = ~ ~ - 2 ,diamino--4,7-.diazadecane 9-

Scheme 6 459 460

461 462

463

M. Saburi, C. Hattori, and S. Yoshikawa, Znorg. Chim. Acta, 1972,6,427. P. C. Harrington, S. Linke, and M. D. Alexander, Znorg. Chern., 1973,12, 168. N. C. Payne, Znorg. Chem., 1973,12, 1151. R. Job and T. C. Bruice, J.C.S. Chem. Comm., 1973, 332. M. Saburi and S. Yosjikawa, Bull. Chem. SOC.Japan. 1972,45, 1443.

258

Inorganic Chemistry of the Transition Elements

Strain energy minimization calculations have been performed on several of the possible s-cis- and uns-cis-isomers of the complex ions diacido- and oxalato-NN'-bis-(2-picolyl)-l,2(S)-propanediamine cobalt(m) in order to establish the reason for stereospecific co-ordination of the ligand. The strain energy of A-uns-cis-isomers is at least 3 kcal mol-' less than that of the A isomers. Valence angle deformation and rotation about the propanediamine C - C bond provide the largest contributions to the strain energy!64 A structural study on the diastereoisomeric pair (c$R)- and (apS)-[Co(tetraen)C1](C1O4), (tetraen = tetramethylenepentamine) shows the cations to differ by an inversion at the secondary nitrogen atom. Calculations confirm the experimental observation that the (apS)-isomer is more stable than the (apR)-form by approximately 2 kcal molThe structure of [CoC1(N,)](C104), [N, = 4-(2-aminoethyl)7-methyl-l,4,7,10-tetra-azadecane]has been determined and the core-configuration is shown in (98).466

,

Macrocyclic N-donor ligands and vitamin B analogues. Ligand configurational and cis-trans isomerism have been investigated for several Col"N,X, complexes (N4 = a range of Curtis-type macrocyclics). Ligand configurational isomers result from changes in configuration of atoms around the asymmetric co-ordinated nitrogen atoms. Several new isomers were detected and their structures tentatively assigned. Interconversion between isomers was found to be relatively rapid in dilute acid and several ligand configurations of trans[CO(N,)(OH,),]~+ appear to have about the same energy as the most stable isomer of ci~-[Co(N,)(0H,),]~+, whereas cis-[Co(N,)CI,]+ is far less stable than the trans-i~omer.~~' The complex cations [RCoLX]"+ [L = (99); R = Me or PhCH,, X = C1, Br, or I, n = 1; R = Me, X = MeCN, n = 21 have been prepared from the corresponding cobalt(]) complexes, [CoLX] and by direct reaction of [Co"LX]+ with alkyl halides. The latter method gives only a 50% yield and this has been rationalized in terms of the free-radical-like .natureof Co11(d7).468 The complexes of(99), (loo),and (101)(L), trans-[CoLX,]Y ( X = halide or NO,; Y = halide, ClO,, PF,) have been isolated. Spectro4h4 465 466

467 468

G. R. Brubaker and R. A. Euler, Inorg. Chem., 1972,11,2357. M. R . Snow. J.C.S. Dalton, 1972, 1627. D. A. Buckingham, M. Dwyer, A. M. Sargeson, and K. J. Watson, Acta Chem. Scnnd., 1972,26, 2813. N. A. P. Kane-Maguire, J. F. Endicott, and D. P. Rillema,Inorg. Chim. Acta. 1972,6,443. K . Farmery and D. H. Busch, Inorg. Chem.. 1 9 7 2 , l l . 2901.

Elements of the First Transitional Period

259

chemical studies show the ligand field strength of the macrocyclic increases as the degree of ligand unsaturation increases, and voltammetric data show that the lower oxidation states of cobalt are stabilized to greater degrees with

A correlation has been observed between increasing ligand un~aturation.~~’ the chemical shifts of the methyl groups and the ligand field strengths of X in the complexes [Co(MAC)X2]C10, ( X = Br, C1, N,, NCO, SCN, AcO, NO,, or CN; MAC = meso- and rac-2,3-dimethyl-1,4,8,1l-tetra-azacyclotetradecane, meso-5,5,7,12,12,14-hexamethy1-1,4,8,11 -tetra-azacyclotetradecane, and 5,7,7,12,14,14-hexamethyl-1,4,8,1l-tetra-azacyclotetradeca-4,1 1-diene).470 Complexes of (102) and (103), trans-[Co(102)X2]C104 (X = C1, Br, or OAc), trans-[Co( 102)(NCS),] CNS,H,O, cis-[Co( 102)en](C104),, cis-[Co( 102)(acac)][Co(l02)(NH,),](C10,),, [Co(102)(H,0)(NH,)]C10,,3H20, cis[Co(l03)(acac)](C10,),, cis-[Co( 103)en](C1O4),C1, and [Co(103)(NH3),](ClO,), have been rep~rted.~’’ (c104)29

It has been suggested in the past that the stabilization of cobalt(u1)-alkyl bonds requires the presence of unsaturated ligands bound to the metal atom; however, such a complex with the ligand (104) has now been prepared by the following route. [CO(NH,),OAC)~+(a photochemical source of methyl radicals) was irradiated (254 nm) together with two moles of [Co(L)]’+ [L = (104)] in 0.1 M perchloric acid under nitrogen and yielded [Co(L)469

470 471

S. C. Jackels. K. Farmery. E. K. Barefield, N. J. Rose, and D. H. Busch, Inorg. Chem., 1972, 11, 2893. E. S. Gore, J. C . Dabrowiak, and D. H. Busch, J.C.S. Chem. Comm., 1972,923. N. F. Curtis. J.C.S. Dalton, 1973, 1212.

260

Inorganic Chemistry of the Transition Elements

(H,O)Me](ClO,),. The analogous complex of (103) was prepared in a similar manner and contains the N-meso-isomer of the ligand. [Co{N-dl-(103)](H,O)Me]'+ cations can also be prepared. Chromium(I1) reduction of such complexes yields methane.472Reductive Co-C bond cleavage of alkylcorrins and vitamin B,, model compounds by alkaline CO, S,O;-, or stannite ions proceeds in analogous fashion to similar reactions involving thiols (see under oximato-complexes) and involves t r ~ n s - a t t a c k . 4Reaction ~~ of [MeCo(tn)H,O)ClO, (tn = 2,3,9,10-tetramethyl-1,4,8,11-tetra-azaundeca- 1,3,8,1O-tetraen- 11-01-1-olato anion) with amino-acids and simple oligopeptides gives replacement of the water molecule not the methyl The inhibition of catalase-like activity of cobalt(r1)-hematoporphyrin by amino-acids, adenine, and related ligands has been Oximato-complexes. Deprotonation constants for some trans-bis(dimethy1glyoximato)cobalt(IrI) complexes have been reported.476 Protonation of [EtCo(dmg),H,O] in 6N-HC1 and methanol at 60"C, followed by cooling to 0 "C, gives orange crystals of [EtCo(dmg)(dmgH)Cl]. This complex dissociates in water, yielding [EtCo(dmg),H,O), HCl, and H 3 0 + ions, and structural studies show the site of protonation to be one of the dimethylglyoximato oxygen atoms.477 The anions [RCo(dmg),CN] - (R = alkyl, alkenyl, or alkynyl) have been prepared, and the related dimeric ions with two organocobalt units bridged by one cyanide group were also isolated or characterized in solution. A trimeric compound contained two cyanide bridges and similar monomeric and dimeric azide and thiocyanato-complexes have also been prepared; however, with the cyanato-ligand, only monomeric complexes are formed.478 The trans-effect in [MeCo(dmg)(py)] has been the subject of a detailed investigation by means of n.m.r.,'' The degradation of [RCo(dmg),(py)] by treatment with acetic anhydride in pyridine to yield compounds of the type (105) has been reported. Thus when R = CH,CH(OH)Me reaction for 24 h gives [Co(dmg),(py)(CH,CHOAcMe)], whereas reaction for 9 days at room temperature or 2 days at 60 "C gives only (105) [X = N(OAc), R1 = H), the structure of which has been established by X-ray methods. The production of compounds of the type (105)is probably a general reaction of alkyl-pyridinec o b a l o ~ i m e s The . ~ ~ ~Co-C bond in alkyl-cobaloximes and -cobalamines is reductively cleaved by thiols and dithiols, the best results being obtained in neutral or slightly acidic solutions under anaerobic conditions. The reactions involve trans attack by the thiol on the metal atom as the first step, the initial products being carbanions which react with H + to yield alkanes. The car472

41 3 474

475 476

477 478

479

T. S. Roche and J. F. Endicott, J . Amer. Chem. Soc., 1972, 94, 8622. G. N. Schrauzer, J. A. Seck, and T. M. Beckham, Bioinorg. Chem., 1973,2,211. G. Pellizer, G. R. Tauszik, and G. Costa, J.C.S. Dalton, 1973, 317. P. Waldmeier and H. Sigel, J. Znorg. Nuclear Chem., 1973,35, 1741. V. R. Vijayaraghavanand M. Sanatappa, J. Inorg. Nuclear Chem., 1973,35,3035. A. L. Crumbliss, J. T.Bowman, P. L. Gaus. and A. T. McPhail, J.C.S. Chem. Comm., 1973,415. D. Dodd and M. R. Johnson, J.C.S. Dalton, 1973,1218. J. P. Fox, R. Banninger, R. T. Profitt, and L. L. Ingraham, Inorg. Chem., 1972,11,2379. N. W. Alcock. B. T. Golding. D. R. Hall. and U. Horn, J. Amer. Chem. Soc., 1972,94. X610.

Elements of the First Transitional Period

26 1

banions formed from methyl-cobaloxime and -cobinamide can be trapped by CO, to yield acetate, and this is a plausible model for the terminal step in acetate biosynthesis from methylcobalamin and C0,.481 Insertion of 0, into

R

the C o x bond of optically active alkyl-pyridine cobaloximes proceeds with complete loss of configuration at the asymmetric carbon centre. These results are in accord with generation of an alkyl radical at some stage of the insertion process.48 Oxidation of cobalt(I1) salts in the presence of dmgH and L(L = 0- and m-phenylenediamine, 2-methyl- and 4-amino-p-phenylenediamine)yields the complexes tran~-[Co(dmg),L,].~~~ Sulphanilcyanamide (sim) forms the complexes [Co(dmg),X(sim)] (X = C1, Br, or I) and [Co(dmg),L(sim)]NO, (L = aniline, sulphanilamide, or sulphanilacetamide). 1.r. evidence suggests Semicarbazide (scrab) and that sim co-ordinates via the nitrile adipoin selenosemicarbazone (HL) form the complexes [Co(dmg),(scrab),]X ( X = C1 or NO,), [Co(dmg),X(scrab)] ( X = C1, Br, I, or [CoCl(dmg),HL],24H2O and [C0(dmg),(HL),]C1,3H,0.~~~ Methylglyoximate (MH) forms the complexes [Co(MH),(tu),]Cl, [Co(MH),(tu)X], and [Co(MH),(tu)H,O]X (X = halogen, tu = thiourea). In contrast to the corresponding dimethylglyoximato-complexes,both thiourea molecules in the bis-complex can be replaced by water.487 The complexes trans-[Co(Hdf),L,]X (Hdf = a-benzildioximate; L = cyclohexylcyanide;X = ClO,, C1, Br, NO,, or 10,) have been reported. Treatment of the perchlorate complex with strong base in methanol gives [C0(Hdf)(df)L,]H,0.~~~ Other N-donor ligands. The cation of [Co(py),C03]C10,,H20 has been found to have a distorted octahedral structure, the distortion being due to strain in the four-membered chelate ring (0-C-0 angle = 69.3') and steric hinder481

482

483 484

485 486

487 488

G. N. Schrauzer, J. A. Seck, R. J. Holland, T. M. Beckham, E. M. Rubin, and J. W. Sibert, Bioinorg. Chem., 1973, 2, 93. F. R. Jensen and R. C. Kiskis, J. Organometallic Chem., 1973,49, C46. I. Ganescu, C. Varhelyi and A. Man, Monatsh., 1973,104,676. V. N. Shafranskii and I. L. Fusu, Russ. J . Inorg. Chem., 1972,17, 1144; 1493. N. M. Samus, 0. N. Damaskina, and A. V. Ablov, Russ. J. Inorq. Chem., 1972.17. 713. N. V. Gerbeleu, and V. G. Bodyu, Russ. J . Inorg. Chem., 1972,17, 857. G. P. Syrtsova, Russ. J. Inorg. Chem., 1972,17,1005. A. V. Ablov. D. G. Batyr. and M. P. Starysh, Russ. J. Inorg. Chem., 1972,17, 925.

262

Inorganic Chemistry of the Transition Elements

ance between the pyridine molecules!89 The reaction of [C~(bipy),]~+ and [Co(terpy),13+ with hydrated electrons yields transient species whose reactivities are consistent with the view that they are radical anions of the pyridyl ligands.,” Reaction of [Co(phen),C1,]C1,3H20 with X - in ethanol yields [Co(phen),C1X]Cl,nH20 ( X = NO,, n = 5; X = NCS, n = 2; X = Br, n = 4). The complexes [Co(phen),X(NO,)]Y,nH,O ( X = NCS, Y = C1, n = 2; X = NCS, Y = NCS, n = 1; X = NO,, Y = NCS, n = 2) have also been reported.491 The thermal stabilities of the complexes cis-[Co(phen),(H,O),]X,,H,O (X = C1, n = 5 ; X = Br, n = 4; X = NO,, n = 2) and [Co(phen),X,]Y (X = Cl, Y = C1, Br, NO,, or C10,; X = Br, Y = Br, NO,, or CIO,) have been in~estigated.~” A refined X-ray structural study of Co(PhN=NNPh), has confirmed the earlier reports that the compound has a trigonal distortion, the chelating ligands having a short ‘bite’.493A range of high-spin cobalt(rI1) complexes of the ligands HNCO*NH*CONH2 -(bi), HNCO*NPh-CONH2- (Phbi), HNCO*NPr*CONH2-(3-Prbi) H,NCO*NHCONHPr (1-PrbiH,), and o-phen(bi), and en(bi), have been prepared. They are M[Co(bi),] (M = K or Bu,N), K[Co(3-Prbi),( 1-PrbiH,),], K[Co(3-Prbi),], 2DMS0, K[Co(3-Prbi),], 2H,O, K[Co(Phbi),] ,2DMSO, Bu,N[ Coen(bi),], K[ Co-o-phen(bi),] and Bu,N[Co-o-phen(bi),], CHCl,. They are high-spin in the range 6.4-293 K and react with amines to give diamagnetic 0-Donor, S-donor, Se-donor, and As-donor ligands. [Co(acac),] is oxidized by hydrogen peroxide in the presence of azide ions to form trans-[Co(acac),(N3),]-, and in the presence of donor ligands (L), trans-[Co(acac),(N,)L] (L = py or NH,) are formed. These complexes undergo ready isomerization to cis-[Co(acac)(N,)L]”- (L = py or NH,, n = 0; L = N,, n = 1) at 34 C.,” show stereoTris-a-isopropenyl- and tris-a-isopropyl-tropolonatocobalt(n1) chemical non-rigidity, two distinct processes being observable. The lowtemperature process is one of inversion of absolute configuration (A + A) which proceeds via a trigonal-twist mechanism, the inversion rate being about lo1’ times greater than that of [Co(acac),]. The high-temperature process is geometric isomerism (cis + trans); however, no mechanistic information could be obtained for this process. This is the first report of fluxional behaviour of cobalt(m) complexes.496 In a photochemical study on trans-[Co(CN),(SO,)X]”- (X = SO,,n = 5 ; X = OH, n = 4; X = H,O, n = 3), the principal photoreactions were found to be SO:- substitution to give aquated products. Photo-reduction to cobalt(I1) is only a minor process.497 489 490 491 492 493 494

495 496

497

K. Kaas and A. M. Sorensen, Acta Cryst.,1973, B29, 113. J. H. Baxendale and M. Fiti, J.C.S. Dalton, 1972, 1995. D. M. Palade, T. N. Volokh, and Y. L. Popov, Russ. J. Inorg. Chem., 1972,17,866. D. M. Palade and Y. L. Popov, Russ. J. Inorg. Chem., 1972,17,862; ibid, 1973,18. 141. W. R. Krigbaum,and B. Rubin, Acta Cryst., 1973, B29, 749. P. J. M. W. L. Birker, J. J. Bour, and J. J. Steggerda, Inorg. Chem.. 1973,12, 1254. L. J. Boucher, and D. R. Herrington, Inorg. Chem., 1972,11, 1772. S. S. Eaton, J. R. Hutchinson, R. H. Holm, and E. L. Muetterties, J. Amer. Chem. SOC., 1972,94, 641 1. M . w righton, . H. B. Gray, G. S. Hammond, and V. Miskowski, Inorg. Chem., 1973.12. 740.

Elements of the First Transitional Period

263

An n.m.r. study on { Co[S,CN(benzyl),],} shows that stereochemical nonrigidity arises viu inversion about the metal centre (A + A).498Similar studies have been reported for [ColS,CNR,),] (R = Et, Pr", Pri, or B U ' ) .The ~ ~ octa~ hedral complex [Co(Se,COEt),] has been reported.259 The structure of trans-[Co(diars),Cl,]Cl [diars = o-C,H,(AsMe,),] has been determined and compared with that of the analogous nickel (111) complex (see p. 297).500 Amino-acid complexes. The complexes, K[Co(baen)aa],nH,O (baen = NN'ethylenebisacetylacetoniminate; aaH = Gly, P-Ala, I, -Ala, D-Ala, DL-Ala, L-Val, D-Val, DL-Val, L-L~u, L-Ile, or L-Phe) have been prepared and the aminoacid anions are found to co-ordinate via the amino-group, N.m.r. spectra of the DL-amino-acidato-complexes are consistent with the presence of a 1:2: 1 ) ] and [Co(baen)mixture of [Co(baen)(~ - a a ) ]- , [Co(baen)(~ - a a ) ( ~ - a a -, ( ~ - a a ) , ] ~ - . ~Ten " complexes were obtained from the reaction of [Co(Gly),CO,]- and L-glutamate (L-GluH)in the presence of active charcoal. They are mer-[ Co(G1y)(L-G~uH)](two isomers), mer-[Co(Gly)(L-G~uH),],mer-A-[ Co(L-GluH),], fuc-A- and -A-[Co(Gly),(~-GluH)l, fuc-A- and -A-[Co(Gly)(L-GluH),] and fac-A- and -h-[Co(~-GluH),]. The A:A ratios for the facisomers of bis-Gly, bis-L-G1uH and tris-L-GluH are 60:40, 68:32, and 75:25, respectively. No appreciable stereoselectivity was observed for the merisomers.502Equilibrium constants have k e n reported5', for the reaction :

Four diastereoisomeric pairs of complexes of the type [Co(acac),(s-aa)] [s-aaH = (S)-Ala, @)-Val, N-methyl-(S)-Ala, or N-methyl-(S)-Val) have been separated by column chromatography on alumina. The (+),-isomers were assigned the absolute configuration A, on the basis of n.m.r. evidence.504The mer-(cis-diammine), mer-(trans-diammine) and fac-isomers of [Co(CO,)(aa)(NH,),] (aaH = a-Ala, P-Ala, or Val) have been obtained. They undergo reaction with oxalate to give three isomers of [Co(ox)(aa)(NH,),], and three isomers of [CO(G~~)(NH,),(H,O),]~+ have also been prepared.'05 The preparation and structural assignment of N-methyl-(S)-Ala complexes of cobalt(ii1) have been described. Thus the A-P,-(SSR)-isomer of { Co[S(R)Metrien] [N-Me-(S)-Ala])2+was obtained and isomers of (Co[S(S)-Metrien)[N-Me-(S)-Ala])2 + were observed under equilibrium conditions at pH 7. These were assigned the A-P,-(RRS)- and A-P,-(RRR)- configuration^.^^^ 498 499

500 501

502

503 504 505 506

L. H. Pignolet, D. J. Duffy, and L. Que, J. 4mer. Chem. SOC., 1973, 95, 295. R. M. Golding, P. C. Healy, P. W. G. Newman, E. Sinn, and A. H. White, Znorg. Chem., 1972,11, 2435. P. K. Bernstein, G. A. Rodley, R. Marsh, and H. B. Gray, Inorg. Chem., 1972, 11, 3040. Y. Fujii, Bull. Chem. SOC.Japan, 1972,45, 3084, K. Kawasaki and M. Shibata, Bull. Chem. SOC. Japan, 1972.45.3100. M. A. Bernard and N. Decker, Bull. SOC.chim. France, 1973,838; ibid, 1972, 3721. D. J. Seematter and J. G . Brushmiller, J.C.S. Chem. Comm., 1972, 1277. K. Nakai, S. Kanazawa, and M. Shibata, Bull. Chem. SOC.Japan, 1972,45, 3544. M. Saburi, M. Homma, and S. Yoshikawa, Inorg. Chem., 1973,12, 1250.

Inorganic Chemistry of the Transition Elements

264

Fourteen new trans(N)- and cis(N)-(NN-P-alaninatediacetato),(a-aminocarboxylato)cobalt(iri)ions have been prepared and isolated as their. potassium salts (a-aminocarboxylate = glycinate, (S)-alaninate, or (S)-prolinate]. Isomerism arises with respect to the arrangement of the three feet of the tripodlike NN-P-alaninatediacetate ligand, and the isomers have been separated by optical resolution, fractional crystallization, or i~n-exchange.~"Three isomers of Li[co(~-Asp)(ida)][ida = NH(CH,CO,),] have been prepared and separated by ion-exchange chromatography. They were identified as the cis(N)trans(O,O,)-, cis(N)-trans(O,O,)- and trans(N)-f~rms.~'~ Treatment of trans[CoCl,(en),]+ with L-aspartic acid (L-AspH,) gives [CO(L-AspH),en] and [CO(L-Asp)(en),]+.Six stereoisomers of the former were separated by chromatography and assigned the A- and A-trans(0)-, A- and A-cis(O)cis(N)- and A- and A-trans(N)-configurations.The two previously reported diastereoisomers of the latter were also obtained.509 Reaction of rac-a-Ala with the reaction mixture obtained from treating [CO(CO),]~- with L - A s ~ Hin the presence of active charcoal gives stereoselective formation of [CO(L-AS~H),(Ala),-"]"- (n = 0-3). Three stereoisomers of the complex with n = 2 were obtained."' The c.d. and n.m.r. spectra of a range of L-histidinato-cobalt(ii1)complexes have been measured and a new complex, rac-all-cis-[Co(~-His)(~-His)]Br, was obtained."' The structure of ( +)-[Co(NO2),(~-Arg)]NO3,2H2Ohas been determined: the NO, ligands occupy cis positions and the configuration of the complex cation is R 5 I 2 The preparation of [Co(en),(S)-(Glu)]' from [Co(en),CO,]+ and ( +)-(S)-glutamic acid has been previously reported to show kinetic selectivity in isomer formation; however, a recent has shown that there is no substantial preference, either kinetically or thermodynamically, for one isomer relative to the other. cis(0)- and trans(0)-complexes of [Co(en)(~-Ser),]+ have been prepared and separated into the six possible isomers. These are assigned the A-trans-(0)-, A-trans(0)-, A-C,-cis(0)-, A-C,-cis(0)-, A-C,-cis(O)-, and A-C,-cis(0)- structures. truns(0)- and C,cis(0)-[Co(en)(Gly),] have been resolved into optically active forms and trans(0)-[Co(en)(~-Ala),] separated into two configurationally active isomers. l4 The yellow compound potassium ( +)tris-(~-cysteine-~uIphinato(2 - )-SN)cobalt(ii1) is very easily prepared by a rapid stereoselective synthesis from L-cysteine, and has proved a very good resolving agent for tripositive cation~.~ The ' ~ anions [CO(L-Pro-N-prop),] -, [CO(L-Pro-N-ac)(ida)]-, [Co+

+

+

507

'08

510

511 '12 513

'41'

N. Koine, N. Sakota, J. Hidaka, and Y. Shimura, Znorg. Chem., 1973,12, 859. J. Hidaka, S. Yamada, and B. E. Douglas, J. Coordination Chem., 1972,2, 123. Y. Kojima and M. Shibata, Inorg. Chem., 1973,12, 1009. T. Matsudo, T. Okumoto, and M. Shibata, Bull. Chem. SOC.Japan, 1972,45,802. S . Bagger, K. Gibson, and C . S. Sorensen, Acta Chem. Scand., 1972,26, 2503. W. H. Watson, D. R. Johnson, M. B. Celap, and B. Kamberi, Inorg. Chem. Acta, 1972,6,591. D. A. Buckingham J. J. Deckers, A. M. Sargeson, and L. G. Marzilli, Znorg. Chem., 1972,11, 1207. N. Matsuoka, J. Hidaka, and Y. Shimura, Bull. Chern. SOC.Japan, 1972 45,2491. L. S. Dollimore, and R. D. Gillard, J.C.S. Dalton, 1973, 933.

Elements of the First Transitional Period

265

(L-Pro-N-prop)(ida)]-, and [CO(L-Pro-N-ac)(~-Pro-N-prop)]- (L-Pro-Nprop = L-prolinato-N-monopropionate; L-Pro-N-ac = L-prolinate-N-monoacetate; ida = iminodiacetate) have been prepared and all the anions have either the trans(N)-(RR) or trans(N)-(R)-configurations. Two geometrical were also reported.s isomers of [Co(~-Pro-N-prop)(NH~)~]ClO, [C0(trien)(OH)H,0]~+ promotes the hydrolysis of the dipeptides G ~ Y - L Asp and Gly-L-glutamic acid to form the free amino-acids and [Co(trien)GlyI2+,but contrary to previous reports of the simpler dipeptides with Gly at the N-terminal position an intermediate of considerable stability is f ~ r m e dl 6. ~ The cations [Co(NH,),(a a,)] and [Co(dien)(a, a,)] (a,a2 = dipeptide) have been isolated and it is proposed that the dipeptide is terdentate and planar, having lost the amide proton. Protonation of [Co(dien)(Gly-Gly)] and [Co(NH,),(Gly-Gly)] cations in conc. HClO, yields complexes in which the amide oxygen atom has been protonated. In hot conc. HCl or HBr. [Co(NH3),( Gly-Gly)] C10, yields crystalline [Co(NH,),(Gly-GlyH ,)]X2 (X = C1 or Br) which contain a bidentate peptide. Concentrated solutions of this product precipitate crystalline [Co(NH,),(Gly-GlyH)X] X in which the peptide is also bidentate. Dilute aqueous solutions of [Co(NH3),(Gly-GlyH,)C1]C1, undergo aquation as well as deprotonation, and addition of base produces ring-closure yielding [Co(NH,),(Gly-Gly)] +. The disproportionation of [Co(NH,),(a,a,)]+ and [Co(dien)(a, a,)]’ in alkaline solution and basecatalysed exchange at the methylene group of the C-terminal amino-acid have also been reported, together with some preliminary studies on the activation of the peptide towards condensation with aldehydes at the C-terminal residue.s Schiff-base ligands. The complexes cis-p-[Co(L)Y], cis-p-[Co(L)Z]ClO,, and trans-[ Co(L)A2]C10, (L = baen [INN’-ethylenebis(acetylacetoimine)]or salen ; Y = acac, benzoylacetonate, or 8-hydroxyquinolinate; Z = en, bipy, or phen; A = NH,, MeNH,, py, or PhNH,} have been isolated.518 Malonitrile (mnH) reacts with a variety of cobalt(ii1)compounds of Schiff-base ligands to produce cobalt alkyls of the type [(mn)Co(quad)L] [L = a unidentate ligand; quad = salen, salpn, salbn, saloph, 3-methoxy-salen, 3-methyl-salen, or (dmg),] in a reaction which appears to involve carbanion attack at the metal centre.”’ The influence of ligand structure on the redox pair Co3+-Co2+ in the chelates (106) has been examined, A linear correlation was found between E , values and o m values for substituents, suggesting that electronic exchange takes place between the substituents on the aromatic rings and the metal atom, occurring mainly via the azomethine

,

+

+

+

+

515

516 ’17

519 520

K. Okamoto, J. Hidaka, and Y. Shimura, BuIl. Chem. SOC.Japan, 1973,46,475. A. Y. Girgis and J. I . Legg, J. Amer. Chem. SOC., 1972,94, 8420. I. G. Browning, R. D. Gillard, J. R. Lyons, P. R. Mitchell, and D. A. Phipps, J.C.S. Dalton, 1972, 1815. Y. Fujii, A. 0sawa;Y. Furukawa, F. Ebina, and S. Takahashi, Bull. Chem. SOC. Japan, 1972, 45, 2549. D. Cummins, B. M. Higson. and E. D. McKenzie, J.C.S. Dalton, 1973,414. H. P. Fritz and L. W. G. Vite, Z. anorg. Chem., 1972,392, 271.

Inorganic Chemistry of the Transition Elements

266

Other mixed donor ligands. The complexes [Co(edda)(H,O)(amine)]ClO,, a-cis-[Co(edda)(amine),]C1O4, p-cis-[Co(edda)(NH,),]ClO,, 0-cis-[Co(edda)(en)ClO,]’ and complexes of edda, NN’-Me,edda, and NN’-Et,edda with

I

R3

diamine-, diammine-, and dinitro-cobalt(ll1) species522 have been reported. The structure of roc-K[Co(NO,)(edtria)],l .5H,O (edtria = ethylenediaminetriacetate) has been determined. The nitro-group occupies an equatorial position, as do the en chelate ring and the glycinate chelate ring. The other acetate groups are Direct and [R~(bipy),]~+-sensitizedphotodecomposition of [Co(Hedta)X]- (X = C1, Br, or NO,) has been studied. The principal products were Co2+ and CO, in each case.524 One geometrical isomer of the cobalt (111) complex of ethylenediamine-NN‘diacetate-NN’-dipropionate (edda) has been prepared by oxidation of CoCl, with H,O, in the presence of edda. It has been resolved into optical isomers and spectral evidence suggests that its structure is (107).525 The structure of K[cis-Co(ida),],2.5H20 (ida = iminodiacetate) has been determined.’ 26 Cobalt(ii1) complexes of (S)-azetH (108) have been prepared. One isomer of CO,H

I

CH- CH,

I

I

NH-CH,

0 0 (107)

0

represents a

carbon atom

522

523 524 525 526

K. Kuroda, Bull. Chrm. SOC.Japan, 1973,46, 2176. W. T. Jordan and B. E. Douglas, Inorg. Chem., 1973,12,403. J. D. Bell and G. L. Blackmer, Inorg. Chern., 1973, 12, 836, P. Natarajan and J. F. Endicott, J. Amer. Chem. Soc., 1973,95, 2470. W. Byers and B. E. Douglas, Inorj. Chern., 1972,11, 1470. M. Nardelli, M. A. Pellinghelli, and M. E. V. Tani, J.C.S. Dalton, 1973, 655.

Elements of the First Transitional Period

267

[Co(S)-(azet),] was isolated and assigned the fac-configuration. Both optical isomers of [Co(en),(S)-(azet)]I, were prepared and their absolute configurations assigned; the two isomers, A-( +)-P,-(SS)- and A-( -)-P,-(RR)-[Co(trien)(S)-(azet)]I, were also obtained. The complexes are closely related to those of (S)-pr~line.~~' Treatment of l,2,6-[Co(OC2H,NH,),] with mineral acids yields [Co(OC,H,NH,),(HOC,H,NH2)]X,~H20 ( X = C1, n = 2; X = NO,, n = 2; X = Br, n = l), [Co(OC,H,NH,)(HOC,H,NH2)2]X,nH,0 ( X = SO,, n = 3; X = Br,, n = 1)and l,2,6-[Co(HOC,H,NH,)3]Br3.s28 [Co(LO),] (LOH = l-amino-3,3,3-trifluoropropan-2-ol) has been obtained.529The free hydroxygroups in CoL, (L = N-2-hydrox yethyl- or N-2-hydroxypropyl-ethylenediamine) undergo acylation reactions.s30 NN-Dialkyl-ethylenediamine N-oxides (alkyl = methyl, ethyl, or propyl) act as bidentate donors in the complex cation [ C O ( R , ~ ~ N O ) , ] ~ Pyruvic + . ~ ~ ~ acid-amide-thiosemicarbazone and pyruvic acid-diethylamide-thiosemicarbazone(LH) form the complex2s [Coand the thiosemicarbazone of benzoylL,]X ( X = CI, Br, NO,, or c10,)401 formic acid also acts as a terdentate donor towards ~ o b a l t ( i i i ) . ~ ~ ~ 3+

5+

H

I

I OQc ' 0 -Co(NH,),

OQc 'OH

(110) X

(109)

=

OH or NH,

6-t

/x\

(NH,) ,CO -0 - CO(NH,),

\ * I

O'YO

(NH,),Co \NH( (111) X = OH or NH, 527 528

529 530

531

\Co (NH,) ,

(112) X = OH or NH,

C. Y. Lin and B. E. Douglas, J. Coordination Chem., 1972,Z. 117. V. V. Udovenko, 0. N. Stepanenko. and B. G. Eroshok, Russ. J. Inorg. Chem., 1972,17, 1409. I. Yashida and H. Kobayashi, Bull. Chem. SOC.Japan, 1972,45, 2448. E. I, Karpeiskava, Y. N. Kukushkin, V. A. Trofimov, and I. P. Yakovlev, Rum. J, Inorg. Chem., 1972,17,1140. S. Kida and T. Oniki, Bull. Chem. SOC.Japan, 1972,45, 1078.

268

Inorganic Chemistry of the Transition Elements

Polynuclear anion-bridged complexes. The complex cations [(NH,),Co(pNH2)(p-RC02)Co(NH3)4]4+(R = H or Me) have been prepared from the corresponding p-amido-p-chloro-dimer.s32 The dinuclear cation (109) and its deprotonated analogue have been isolated, as have the related cations [(NH,),CO(~-NH,)(C~-OX)CO(NH,),~~+, [(NH3)4Co(p-OH)(C1-NH2)(p-ox)Co(NH,),12+, and [(NH3),Co(p-OH),(p-ox)Co(NH3)4]2 +.The tri- and tetra-nuclear species (110)-(112) have also been reported.s33 Cobalt(1v) and (”).-Chemical and magnetic evidence has been presented for the formation of COO:- when molten sodium nitrite is electrolysed between cobalt electrodes, or when cobalt salts are added to molten nitrite solutions of Na,O,. The reflectance spectrum of COO:- has been reported.265The new 0x0-cobaltates(iv), K,(Co,O,) and Li,Co04, have been reported.534 Oxides.-The structure of Co,04 has been re-examined and new values for the structural parameters have been reported. It was shown that the Co-0 distance in low-spin Co,O, differs only slightly from that found in high-spin L~COO,.~~’ Cobalt-Oxygen Compounds.-The structure of [Co(acacen)O,(py)] has been bond is bent.536 determined. The Co-0 bond length is 1.95 A and Co-0-0 X-Ray photoelectron measurements on the oxygen adduct of [Co(benzacen)] indicate that the formulation CO~~’-(O;)is correct, in accord with previous structural studies.299 The reversible addition of oxygen to Na,[Co(Pc)] reported by Abel et al. (Pc = phthalocyanine-4,4’,4’,4”-tetrasulphonate) (see Vol. 1 p. 202) has been confirmed. The visible absorption spectra of the monomeric and dimeric species and the oxygenyl adduct have been reported and the adduct is found to predominate in alkaline solution.’ 37 Thermodynamic data have been determined for the binding of a series of bases (L) to [Co(P)] [P = protoporphyrin(IX)dimethylester] and these have been compared with similar data for the reversible binding of 0, to [Co(P)L]. Enhanced 0, binding is found for L = imidazole, 1-methylimidazole, and DMF.538A dramatic solvent,effect has been observed for oxygen uptake by [Co(P)L] (L = l-methylimidazole) which has been studied in CHCl,, MeCN, and DMF. This appears O,) by the more to result from the stabilization of the polar C O ~ ’ ~ - ( species aprotic solvent^.^ 39 Details of the preparation of quinquedentate ligands containing an unsaturated quadridentate unit and a heterocyclic base have been published. The complex of such a ligand, [Co” LjEtOH {L = aa-[2(2-pyridyl)ethyl]ethylenebis(salicylideniminate)}, shows distorted trigonal532 533

s34 535

536

s37

”*

s39

K. L. Scott and A. G Sykes, J.C.S. Dalton, 1972, 2364. K. Wieghardt, Z . annrg. Chem., 1972,391, 142; K. L. Scott, K. Wieghardt and A. G. Sykes, Inorg. Chem., 1973,12,655. M. Jansen and R. Hoppe, Naturwiss., 1973,60, 104. W. L. Smith and A. D. Hobson, Acta Cryst., 1973, B29,362. M. Calligaris, G. Nardin, L. Randaccio, and G. Tauzher, Inorg. Nuclear Chem. Letters, 1973, 9, 419. L. C . Gruen and R. J. Blagrove, Austral. J. Chem., 1973.26, 319. D. V. Stynes, H. C. Stynes, B. R. James. and J. A. Ibers, J. Amer. Chem. SOC., 1973,95, 1796. H. C. Stynes and J. A. Ibers, J. Amer. Chem. SOC., 1972.94, 5125.

Elements of the First Transitional Period

269

bipyramidal co-ordination of the metal atom and forms an adduct with oxygen.540 COX, ( X = MeCO, or PhCO,) dissolves in amines (MeNH, or PrNH,) to form the paramagnetic complexes [CoX,(amine),]. When these complexes are dissolved in excess amine under oxygen, followed by removal of the amine, the hygroscopic powders, [X,(amine),Co,O,] can be isolated. These compounds are diamagnetic, indicating the presence of a peroxo-bridge, but on heating in D M F the paramagnetism is restored although no oxygen is liberated. By adding trapping agents, it has been shown that radicals are formed in this reaction, presumably by 0-0 bond cleavage. The residue from these reactions dissolves in fresh amine and takes up more oxygen.541 The p-peroxo-cation, [(NH3)(en),C~0,C~(en),(NH,)]4+ undergoes oxidation by NO, in acidic solution yielding the superoxo-complex [(NH,)(~~),COO,CO(~~),(NH,)]~ +. Reaction of the peroxo-species with NO; or NCS- in neutral solution gives ligand replacement forming [X(en),C00,Co(en),X]~+ ( X = NO, or NCS) and further reaction of the nitro-complex with cyanide yields [Co,(CN),(en),0,I2-. Reaction of [(en),C~(p-NH,)(p-O,)Co(en),]~+with NO; leads to replacement of the superoxo-bridge of a bridging N' group; however, [NH,(en),Co0,Co(en),NH3]s + is unaffected by NO, ,'. The structure of the per ox o-bridged complex [(en), Co(p-NH,) (p-O,)Co(en),] (NCS), ,H ,O has been reported. The Co-0-0-Co-NH, ring is considerably puckered and the 0-0 bond length is 1.46 A.543 The peroxo-complexes [L(tren)CoO,Co(tren)L]X,,nH,O (L = NH,, X = Cl, n = 2; L = NH,, X = Br, I, NO,, or ClO,, n = 0; L = py, X = I, n = 1) have been prepared by aeration of stoicheiometric quantities of tren, L, and the appropriate cobalt(I1) salts in aqueous solution. The cations are somewhat unstable in aqueous solution and are gradually transformed intc [(tren)Co(0,,0H)Co(tren)13+. The analogous complexes [(tren)Co(O,,NH,)Co(tren)]X,,nH,O ( X = I, n = 0; X = ClO,, n = 1) have been obtained by ligand replacement reactions, and the corresponding superoxo-complexes [NH,(tren)Co0,Co(tren)NH,1(C104)s,2H,0 and [(tren)Co(O,,NH,)Co(tren)] (C10,),,2H20 were prepared by oxidation of the peroxo-~pecies.'~~ When the peroxo-compound [(~-His),Co0,Co(~-His),]is treated with 1SM-HNO, at - 10 "C, the superoxo-compound, [(~-His),Co0,Co(~-His),](N0,), is formed.s45 Spectral studies on these complex cations have been reported.546 Oxidation of Co2+ in the presence of diethylenetriaminepenta-acetic acid (dptah,) with H,O, gives a dinuclear peroxo-bridged species with a Co:dpta ratio of 1 : 1. 5 4 7 540

s41

542 543

544

54s

546 547

J. P. Colleman, H. Takaya, B. Winkler, L. Libit, S. S. Koon, G. A. Rodley, and W. T. Robinson, J. Amer. Chem. Soc., 1913. 95, 1656; G. A. Rodley and W. T. Robinson, Nature, 1972. 235, 438. G. Henrici-Olive and S. Olive, J . Organometallic Chem.. 1973, 52, C49. T. Shibahara and M. Mori, Bull. Chem. Soc. Japan, 1972,45, 1433. H. Thewalt, Z . anorg. Chem., 1972,393, 1 . C. H. Young and M. W. Grieb, Inorg. Chem., 1973,12,663. M . Woods, J. A. Weil, and J. K. Kinnaird, Inorg. Chem., 1972,11, 1713. S. Bagger and K . Gibson, Acta Chem. Scand., 1972,26, 3788. A. Bandoli and V. Carunchio, J. Inorg. Nuclear Chem., 1972.34. 3491.

210

Inorganic Chemistry of the Transition Elements

4 Nickel Carbonyl, Nitrosyl, Nitrogenyl, and Oxygenyl Compounds.-[(Me,Sn)Ni( C 0 ) (x-Cp)] has been prepared by the new methods of treating [(n-Cp)Ni(CO)], with either (Me,Sn),O or (Me,Sn),N.', The complexes [Ni(CO),L,,,] [L = (CF,)PH, or (CF,),PH; rn = 1, n = 3; rn = 2, n = 2) have been isolated, and [{ (CF,),PH}Ni(CO),] undergoes decomposition to form the polymeric compound [{(CF3)2PH}Ni(C0)2]n, which contains both bridging and terminal carbonyl groups. The reaction of (CF3),P2 with Ni(CO), yields [(P,(CF3),}Ni(C0),]2 . 2 9 5 The complex [Ni(CO),{P(CH,SiMe,),}] has also been reported.',, Shifts in the CO stretching frequencies of [(n-Cp),Ni,(CO),] on treatment with R,A1 (R = Et or Bu') indicate a stepwise interaction of the Lewis acid with the bridging carbonyl groups; however, only one of the bridging carbonyls of [(n-Cp)Ni(CO)], interacts with B u ~ A ~ . ' ~ ~ The reaction of bis(cyclo-0ctadiene)nickel with NOCl in the presence of Ph,P(CH,),PPh, yields [NiCl(NO){Ph,P(CH,),PPh,]] ( n = 1, 2, or 3); however, no reaction is observed between NOCl and [Ni{Ph,P(CH,),PPh2)2].548Nickel(I1) halides react with nitrite ions in ethanol in the presence of phosphines to form [NiL(NO)]X [L = MeC(CH2PPh,), or MeC(CH,PEt,),; X = C1, Br, I, BF,, or BPh,]. An X-ray structural study on one of the ethylphosphine compounds shows the cation to be tetrahedral and the NO group to be linear.549 [(n-Cp)Ni(NO)] reacts with LiR (R = Ph or But) in THF or diethyl ether to form the compounds [(n-Cp),Ni,NR], in which the organo-imide group bridges the three metal atoms. Side-reactions also occur which lead to substitution of the C5H5ring; however, these can be suppressed by performing the reaction at -40°C.550 The product of photolysis of [(x-Cp)Ni(NO)] in an argon matrix at 20K (230nm < A < 280nm) has been examined by i.r. spectroscopy, and production of the ion-pair [(n-Cp)Ni] (NO)- is p ~ s t u l a t e d . ~ ~ ' The binary compounds [Ni(N,),] ( n = 1-4) have been identified by i.r. studies on low-temperature matrices,' 5 2 and similar studies on the species [(N2)Ni(02)] and [(N,),Ni(O,)] produced by matrix condensation suggest that both contain 'side-on' bonded 0, and 'end-on' bonded N2.5s3'Side-on' bonding is also postulated for Ni(0,) and Ni(O,),, produced in a similar manner.' 5 4 +

Halides and Pseudoha1ides.-A method has been reported for the preparation of NiCl, in very high The compounds MNiF, (M = Na, K, Rb, or Cs) have been prepared by four different routes. These are the reaction of MC1 with NiF,, the reaction of M F with NiCl,, the reaction of M F with NiF,, 548 549 55"

55'

'" 553 554

H. Hidai, M. Kokura, and Y . Ushida, Bull. Chem. SOC.Japan. 1973.46. 686. D. Bergland and D. W Meek, Inorg. Chem., 1972,11, 1493. J. Mdller. H. Dorner. a i d F. H. Kohler, Chem. Ber.. 1973. 106. 1122. 0.Crichton and A. J. Rest, J.C.S. Chem. Comm., 1973,407. J. K. Burdett, M. A. Graham, and J. J. Turner, J.C.S. Dalton, 1972, 1620; H. Huber, E. P. Kiindig, M. Moskovits, and G. A. Ozin, J. Amer. Chem. SOC.,1973,95, 332. W. E. Klotzbiicher and G. A. Ozin, J. Amer. Chem. SOC.,1973.95, 3790. H. Huber and G. A. Ozin, Canad. J. Chem., 1972,50, 3746.

Elements of the First Transitional Period

27 1

and treatment of MC1 and NiC1, with HF.17, 1.r. data have been presented for MNiC1, (M = T1, K, Cs, or Rb), and Cs,ZnX, (X = C1 or Br) doped with Ni2+ shows a band at ca. 2000cm-l which is assigned to the transition A , E, B2(T2),the two electronic components being unresolved. This is the first report of a d d transition within the ,T,(F) ground state of tetrahedral nicke1(11).~ Thermochemical data have been reported for the formation of CsNiClx (x = 3, 4,or 5 ) in a lithium-potassium chloride e~tectic.~' The structure of [Cu(NH3),Ni(CN),],2C6H6 has been determined. The copper and nickel atoms are cross-linked by cyanide groups to form a polymeric two-dimensional network, the benzene molecules being trapped between layers.556 Nickel (O).-[Ni(P(OPh),},] has been prepared by the new method of treating anhydrous [Ni(acac),] with NaBH, in the presence of P(OPh), in refluxing petr01.~ ' The preparations of [Ni{ P(OPh), - xFx}4] and [Ni{ PPh, - rFx)4] (x = 0-3) have also been reported.558 Protonation of NiL, [L = PMe,, PPh(OEt),, P(OEt),, P(OCH,CH,Cl),, P(OMe),, P(0-p-tolyl),, or P(0-pC,H,OMe),; L, = Ph,P(CH,),PPh,] yields [HNiL,] ', and a correlation has been found between the formation constants for [HNiL,]' and the basicity of L.559 The structure of [(C,F,)Ni{ MeC(CH,PPh,),)] has been determined in an effort to find out why the compound is unreactive towards excess C,F,. The geometry can be viewed as distorted tetrahedral, if the n-bonded fluorocarbon is taken to occupy one co-ordination position, and its lack of reactivity is probably due to the lack of a vacant co-ordination site.560 Electrocheniical studies have been reported on [Ni(bipy),], [Ni(bipy)(NCCH=CH,),] and [Ni(bipy)(NCCH=CHCN),].561 X-Ray photoelectron spectroscopy of [Ni(S,C,R,),]"(R = Ph, n = 0, - 1, or -2; R = CN, n = - 1 or -2) shows the binding energies of nickel to be very similar in all the compounds and very similar to that of metallic nickel and nickel(0) compounds. The binding energies are lower than those of nickel(I1) and nickel(1) compounds, and these together with the sulphur binding energies indicate that such compounds are best classed as nickel(0) with the additional charge residing on the dithiolate l i g a n d ~ . ~ ~ , Nickel (I ).-Treatment of [NiCl,(PPh,),] with LiN(SiMe,), yields [Ni(PPh,),(N(SiMe,),}], which is a pale-yellow air-sensitive solid heff = 1.91 BM). Structural studies show the complex to be a three-co-ordinate monomer (Ni-N = 1.88, Ni-P = 2.313 and 2.200& LNNiP = 122.5 and 130.4", LPNiP = 107.0'). The compounds [NiL,(N(SiMe,),}] [L = PMe,Ph, 555 556

557 558 559

5h0 561

562

A. Mooney, R. H. Nuttall, and W. E. Smith, J.C.S. Chem. Comm., 1972, 1290. T. Misyoshi, T. Iwamoto, and Y. Sasaki, Inorg. Chim. Acta, 1973,7. 97. J. R. McLaughlin, Inorg. Nuclear Chem. Letters, 1973,9, 565. M. H. Micoud, J. M. Savariault, and P. Cassoux, Bull. SOC. chim. France, 1972, 3774. C . A, Tolman, Inorg. Chem., 1972,11,3128. J. Browning and B. R. Penfold, J.C.S. Chem. Comm., 1973, 198. A. Misono, Y. Uchida, T. Yamagishi, and H. Kageyama, Bull. Chem. SOC.Japan, 1972,45, 1438. S. 0. Grim. L. J. Matienzo, and W. E. Swartz, J. Amer. Chem. Soc., 1972.94, 5116.

272

Inorganic Chemistry of the Transition Elements

PMePh,, PEtPh,, PEt,Ph, or PEt,; L, = Ph,P(CH,),PPh,] were also ~ b t a i n e d . ~ ’[Ni(bipy),]+ and [Ni(bipy),]- have been obtained by polarographic methods and studied by e.s.r. spectroscopy. The latter appears to have the extra electron located in an MO which is primarily of ligand character.563 The structure of the distorted tetrahedral complex [NiI{ MeC(CH,PPh,),}] has been reported564 and the compounds [NIX{ MeC(CH,AsPh,),}], which are also pseudo-tetrahedral, have been prepared by reactions of anhydrous nickel@)salts with the ligand in butanol, followed by the addition o ~ N ~ B H , . ’ ~ ’ [Ni(S,C,(CN),},] 3 - has been generated electrochemically by reduction of the dianion, but could not be isolated. Spectral measurements are reported to favour the formal representation [Nil{ [S,C,(CN),]2-},]3-, which is clearly in conflict with the photoelectron data on related anions discussed under nickel(O), but which is consistent with the now generally accepted formalism for the dianion of [Ni”( [S,C,(CN),] -} ,] - .5 6 6 [(n-Cp)Ni(PBu,),]Cl reacts with RC(S)S- (R = Ph, Et, or PhCH,) to form [(n-Cp)Ni(PBu,),(SC(S)R}], which on treatment with HC1 yields [(n-Cp)Ni{S,CR}]. The latter reaction can be reversed by treatment with Bu,P in h e ~ a n e . ~ ,The ’ compounds [(n-Cp)Ni(CNR)], (R = CH,, CD,, or CHMe,) have been prepared and in all cases the dinuclear molecules exist solely in their bridged forms.568 Compounds of the type [(n-Cp)NiL(MR,)] (R = halide, alkyl, or aryl; R = Si, Ge, or Sn; L = R,P, R,As, or C6Hl,NC) have been reported. Most are air-stable in the solid state, but oxidize in solution. Treatment with excess R,P gives [(n-Cp)NiL,]MX, (M = Ge or Sn; X = halide).569 Nickel (1,5).-Treatment of one mole of anhydrous NIX, (X = halide) with two moles of naphthapyridine (napy) and NaBPh, in butanol gives the green high-spin complex [Ni(napy),X]BPh,. However, if the reaction mixture is heated without isolation of the green product, the solution darkens and black crystals of [Ni,(napy),X,]BPh, are formed. The corresponding compounds with X = NO, or NCS have also been prepared and PF; salts can be isolated if NaPF, and NaBH, are used instead of NaBPh,. The magnetic moments of the compounds are equal to 2.91-3.04 BM per nickel, but are in the range 4 . 1 9 4 . 3 4BM per dimer, which is consistent with the presence of three unpaired electrons per two nickel atoms. The structure of the bromo-complex has been reported and shows the nickel atoms to be in a square-planar array of nitrogen atoms (113), the [NiN 3 lanes being almost half-way between the staggered 4. and eclipsed configurations (Ni-Ni = 2.421 I$, Ni-Br = 2.635 A).57G 563 564 565 5b6 567

568 569 570

N. Tanaka. T. Ogata, and S. Niizuma, Inorg. Nuclear Chem. Letters, 1972, 8, 965. P. Dapporto, G. Fallani, S. Midollini, and L. Sacconi, J.C.S. Chem. Comm., 1972, 1161. S. Midollini and F. Cecconi, J.C.S. Dalton, 1973, 681. T. E. Mines and W. E. Geiger, Inorg. Chem., 1973,12, 1189. F. Sato and M. Sato. J. Organometallic Chem., 1973.50, C49. R. D. Adams and F. A. Cotton, Synth. Inorg. Organometaflic Chem., 1972,2,277. F. Glockling and A. McGregor, J. Inorg. Nuclear Chem., 1973,35, 1481. D. Gatteschi, C . Mealli, and L Sacconi, J. Amer. Chem. SOC., 1973,952736.

Elements of the First Transitional Period

27 3

Nickel( 11) Complexes.-Ammine, Amine, and ReZated Ligands. [Ni(NH3)J(1,), has been prepared by dissolving a nickel(I1) salt in aqueous ammonia and adding iodine and a five-fold excess of KI.571The reaction of hydrazine hydrate with Br

Br (1 13)

nickel(I1) salts gives amorphous compounds of indefinite composition which are contaminated with hydroxides. However, reactions with hydrazine salts in neutral or weakly acidic solutions give the crystalline compounds [INi(N,H,),X,],nH,O (X = *SO4, NO,, I, +ox, or OAc, n = 2; X = C1, n = 0; X = Br or NCS, n = 1; X = F, n = 3) and [Ni(N,H,)3(H,0)]C03.53 Both [Ni(en)2(H, O)BF4] BF, and [Ni(en)2(H O),]( BF,), can be obtained from aqueous solutions. Electronic spectroscopy of the latter indicates a trans-structure, while an X-ray structural study of the former shows the en ligands to be in a cis-arrangement, the two remaining octahedral positions being filled by H,O and a co-ordinated BF, ion (Ni-F = 2.12 A). There is strong hydrogen-bonding between the water molecule and both co-ordinated and free BF, ions. Electronic spectroscopy shows that BF, lies slightly higher than H,O in the spectrochemical series.572 The octahedral complexes [Ni(NNEt,en),Br,],nH,O have been found to adopt square-planar structures upon thermal deaquation in the solid phase, whereas the analogous chloride is transformed into the dichloro-complex under similar conditions. No such transformations were observed when X = NO, or I.573Enthalpy and entropy changes for the formation of nickel(x1) complexes of C-substituted ethylenediamines have been r e p ~ r t e d74. ~Magnetic susceptibilities of aqueous solutions of Ni2 and NW-diglycylethylenediamine dihydrochloride (H,L2 +) (1 : 1 molar ratio) have been measured as a function of the amount of added base. They indicate a stoicheiometric conversion of paramagnetic [NiL], + into diamagnetic [Ni(L - 2H)] without the formation of any paramagnetic +

intermediate^.^'^ [Ni(NH,CH,CHMeNH,),]'+ cations react with acetone to give the biscomplex of the P-amino-ketone NH,CHMeCH,NHCMe,CH,COMe, which acts as a terdentate ligand. In pyridine this complex is converted into the 571 572

573 574 575

J. Breckenridge, W. Warzecha, and T. Surles, Inorg. Nuclear Chem. Letters, 1973, 9,431. A. A. G. Tomlinson, M. Bonamico, G. Dessy, V. Fares, and L. Scaramuzzo, J.C.S. Dalton, 1972, 1671. R. Tsuchiya, S. Job% A. Uehara, and E. Kyuno, Bull. Chem. SOC.Japan, 1973,46, 1454. H. K. J. Powell and N. F. Curtis, Austral. J. Chem., 1973, 26, 977. K. S. Bai and A. E. Martell, J. Inorg. Nuclear Chem., 1973, 35, 1313.

Inorganic Chemistry of the Transition Elements

274

nickel(@ complex of the macrocycle C-meso-3,5,7,7,~0,12,14,14-octamethyl1,4,8,1l-tetra-azacyclotetradeca-4,1l-diene (L).The bis-complex of (R)-propane1,2-diamine undergoes an analogous sequence of reactions yielding the (RR)-enantiomorphic C-rac-L complex. Similar treatment of the tris-complex of propane-1,2-diamine with acetone gives a mixture of the C-rac- and C-mesocomplexe~.~ 7 6 The reaction of [Ni( 1,3-pn),I3+ salts with acetone gives the bis-isopropylideneamino-complex cation (114), ClO, and BF, salts of which are low-spin, whereas the acido-complexes with NO,, NCS-, and C1- are high-spin. In the presence of a third mole of 1,3-pn the reaction continues, to give salts of the cation (115), and the reaction can be taken further to yield (116) as the final product. When the reaction is carried out in the presence of NO,, the intermediate cation (117) can be isolated.577 The structure of [Ni,(tren), (NCO),](BPh,), has been determined and the metal atoms are linked by ‘end-to-end’ cyanato-bridges. 78

bN02 (1 17)

(1 161

The positively charged ligand (8) (LH +) forms the trigonal-bipyramidal complexes [NiX,(LH+),]X (X = C1 or Br)54 and the related ligand (118) (L+CH,Cl) forms the pseudo-tetrahedral monomer [NiCl,(L+CH,CI)], the five-co-ordinate chloro-bridged dimer Ni,Cl,(L+CH,Cl),, the trigonalbipyramidal cationic salts [NiCl,(L+CH,Cl),]X (X = C1 or ClO,), and the L CH,Cl)]. In solution these trigonal-bipyramidal complex [INiCl 3( H 0)( +

576

577 578

N. F. Curtis, J.C.S. Dalton, 1973, 863. D. F. Cook and N. F. Curtis, J.C.S. Dalton, 1973, 1076. D. M. Duggen and D. N. Hendrickson, J.C.S. Chern. Cornrn., 1973,411.

Elements of the First Transitional Period

275

complexes give rise to equilibria involving four-, five-, and six-co-ordinate species.s79 (-)-Spartein (73) forms the complexes [Ni(spartein)X,] (X = C1, Br, or I),318 and the benzodiazepines (119) form the square-planar complexes [Ni(ll9),X,] (X = ClO,, Br, or I) and the five-co-ordinate complex [Ni(ll9),Cl]C1.580

(119)

= Me, R2 = R3 = H (meaz) R 1 = R2 = Me, R3 = H (dmaz)

R’ R’

=

R2

=

R3 = Me(tmaz)

Pyridine and Related Ligands. The structure of [Ni(py),(H,O),(OAc),] has been determined: the pairs of ligands occupy mutually trans-positions in the octahedral co-ordination sphere.s The structure of the Fquare-planar complex [Ni(4-Mepy),](C104), has also been reported.”’ Atactic poly-4-vinylpyridine reacts with nickel@) salts in ethanol to form [NiI2(P-4VP),] and [NiX2(P4VP),] ( P 4 V P = a poly-4-vinylpyridine monomer unit; X = C1, salicylaldehydate, o-NO,C,H,O, or acac).’ 84 The pseudo-octahedral complexes [Ni(pdaep)X,] (X = Br, I, or NCS) and [Ni(Me-pdaep)I,] [pdaep = (76a), Me-pdaep = (76b)l have been prepared.,,’ The structure of [(FB(ONCHC,H,N),P)Ni]BF, has been determined and the six N-donor ligands define a slightly tapered trigonal prism.s83 The complexes NiLX, (L = bipy or phen; X = C1or Br) have been prepareds7 and [Ni(phen),](xanthate), has been isolated from the reaction of potassium xanthate with NiCl, and phen in aqueous solution.” D.t.a. studies on optically active [Ni(phen),]X, complexes show specific endothermic peaks in the cases of X = I or ClO, which are attributed to the racemization process,189 and [Ni(phen),X,] complexes have been isolated from the thermal decomposition of [Ni(phen),X,] (X = C1, Br, I, or SCN).19’ The eight-co-ordinate complex [Ni(napy),](ClO,), (napy = naphthapyridine) has been reported and its structure discussed in terms of distortion away from true dodecahedra1 stereo~hemistry.~~The octahedral complex [Ni(napy),(NO,),] has also been ~ r e p a r e d . ’ ~ Imidazole and Pyrazole Ligands. The square-planar complexes [NiL,X,] (X = ClO,, BF,, or NO,) and the pseudo-tetrahedral complexes [NiLmX2]

’’

579

580

L. M. Vallarino, V. L. Goedkin, and J. V. Quagliano, Inorg. Chem., 1973,12, 102. P. W. W. Hunter and G. A. Webb, J.C.S. Dalton, 1973, 26. J. Drew, M. B. Hursthouse, and P. Thornton, J.C.S. Dalton, 1972, 1658. N. Bose and H. Lynton, Canad. J. Chem., 1973,51, 1952. M. R. Churchill and A. H. Reis, Inorg. Chern.. 1972,11, 1811.

’*’

582 583

Inorganic Chemistry of the Transition Elements

276

(X = Cl, Br, I, or NCS; n = 3 or 4) of 1,2-dimethylimidazole have been prepared.60.6 1 The tetrahedral complexes [NiL,Br,] (L = methylthio-2methylimidazole or 1,3-dimethylimidazole-2-thione,325 [Ni(abi),Br,], Et,N[Ni(abi)Br 3], [Ni(a bi), Cl,] ,2H 0, and [Ni(abi), I2],3H,O, the square-planar complexes [Ni(abi)Br,],H,O and [Ni(abi),X,] (X = C1, Br, I, NO,, ClO,, or +SO,), and the distorted octahedral complexes [Ni(abi),(NCS),], [Ni(abi),have also (NCS),], and [Ni(abi),(OAc),] (abi = 2-aminoben~imidazole)~~~ been prepared. [Ni(abi),](BF,), appears to have metal atoms in both squareplanar and tetrahedral environments. 2-Benzenesulphonamido-methylbenzimidazole (HL) forms the complexes [NiL,] and [ N ~ L , ( P Y ) , ] . ~ ~ ~ The substituted pyrazole 2-aminothiazole (atm) forms the complexes [Ni(atm),X,] (X = Cl, Br, or NCS) and [Ni(atm)Cl,], both of which are octahedral, the latter being polymeric.327 Several new terdentate N-donor ligands containing pyrazole, pyrrole, and indene residues, which were designed to present their donor atoms at positions very close to the normal octahedral sites, have been synthesized. They form complexes with nickel(I1) which can undergo ligand deprotonation. However, there is no change in either colour or magnetic moments of the complexes on deprot~nation.'~' MacvocycEic N-donor Ligands. A new synthesis of cyclam (120) has been reported and is outlined in Scheme 7.584The macrocyclic complex cation (121)

,

n

n

(120) Cyclam (20 % yield) Reagents: i, HCO. CHO, H,O; ii, H,, Raiiey nickel; iii, CN-

Scheme 7 584

E. K. Barefield. Inorg. Chem., 1972. 11. 2273.

n

Elements of the First Transitional Period

277

has been synthesized from 1,3-pn and methyl vinyl ketone in the presence of both Ni2+ and H + ions. Several derivatives of this cation have been described including two in which the macrocyclic ligand must be present in a folded configuration in the six-co-ordinate complex. These are cis-[NiL(acac)]PF, and cis-[(NiL),(ox)](PF,),. Evidence is also presented that suggests that the cation (121) has a greater tendency to accept fifth and sixth ligands than either (116) or (122). A detailed description is given of the separation of isomers of [NiL](PF,), and it is proposed that these are the meso- and r a c - f o r m ~ . ~ ~ ~ Metal-ion-promoted oxidative dehydrogenation provides a unique method of synthesizing ligands that are otherwise difficult to prepare. Oxidation of chelate rings that are formed by deprotonation of P-di-imines produces a pattern of unsaturation that has not otherwise been possible. This pattern places a localized olefin bond in a six-membered ring and extends unsaturation into the adjacent chelate ring. Such reactions, which are effected by bromine oxidation, are the conversion of (123) and (124) into (125) and (126), respectively. Two isomers of each product were obtained.586Nickel(1r) complexes of the ligands (L), prepared by the reaction of en with benzylideneacetone, have been isolated. Stereochemical evidence favours assignment of structure (127) for L

rather than (128). Compounds with two configurations of the cation [NiLI2+, arising from chiral co-ordination of the secondary amino-groups, have been isolated. The 0-(N-meso)-configurationis the best one for the bcde-co-ordinated square-planar complexes [Ni(p-L)]X, (X = ClO,, BF,, I, or iZnC1,) and for the trans-octahedral complexes [Ni(p-L)X,] (X = C1, NCS, OAc, or NO,) 585

J. F.Myers and N.J. Rose, Inorg. Chem., 1973,12,1238. C. J. Hipp, L. F. Linday, and D. H. Busch, I n o r g . Chem., 1972,11, 1988,

278

Inorganic Chemistry of the Transition Elements

and trans-[Ni(P-L)(NH,) (H20)] (C1O4),. The a-(N-rac)-configuration is best for the folded abcd-co-ordinated high-spin complexes with chelates in the ef-positions, i.e. [Ni(a-L)(~hel)](ClO,)~(chel = en, n = 2; chel = acac, n = 1) and { [Ni(a-L)]2(ox)}(C10,),. Treatment of these complexes with acid removed the chelate by protonation, whilst maintaining the a-configuration in the resulting square-planar complexes, [Ni(a-L)]X, (X = C10, or kZnC1,); however, these are unstable with respect to the b - i ~ o r n e r s . ~ ~ ~ The structure of macrocyclic (129) has been reported.588 The mono-, di-, and tri-cyclic complexes (54), ( 5 9 , and (56) have been reported (see Scheme 3).

(129)

The first is low-spin and square-planar, as is the second; however, the preferred chair conformation of the six-membered chelate rings may bring oxygen atoms close enough to the metal in axial positions to give the transient fluctuations between singlet and triplet ground states in solution that are indicated by n.m.r. data. In the solid the complex is diamagnetic. The reaction of butane-2,3dione dihydrazone and formaldehyde in the presence of Ni(C104), and molecular oxygen gives the 16.~-system(130). Two isomers of (130), namely (131) and (132), have also been obtained. The former is prepared by oxidation of (54) with 0, in acetonitrile solution containing the added base N2H,, and the latter is prepared in a similar manner except that N,H, must be the last reagent to be added.lg5 The electrochemical behaviour of (77; M = Ni) has been studied and four polarographic reduction steps involving one, one, two,

NAN I

587

D. F. Cook, N. F. Curtis, and R. W. Hay, J.C.S. Dalton, 1973. 1160. F. Hanii, M. Handlovic. and 0. indgren. Coll. Czech. Chern. Cornrn., 1972,37,2119,

I

Elements of the First Transitional Period

279

and one electrons, in turn, and one one-electron oxidation step were observed. It has been suggested that reduction involves only MO's of primarily ligand ~ h a r a c t e r3.3~Reduction of nickel(@ phthalocyanine with sodium in THF or by electrochemical means gives four distinct anions, which involve the addition of electrons, again in MO's of essentially ring ~haracter.~, Other N -donor Ligands. [Ni(diphos)(N,),] reacts with NOBF, or Et,OBF, in CH,Cl, to yield (133), which in turn reacts with CO (5 atm) in CH,Cl, at 20 "C to form [(diphos)Ni(NCO),] [diphos = Ph2P(CH2)2PPh2].589The complexes [NiL,]X, (L = PhCN, n = 6, X- = SbCl,, FeCl,, or InCl,) N

II

N

II

' N

(diphos) Ni

\Ni

(diphos)

\N' N

II

N

have been reported.62 The structure of the pseudo-tetrahedral complex (134) has been determined.590 The square-planar complexes [Ni(Hbptu)]X [X = Br, BPh,, PF,, or SCN; H,bptu = (135)] have been prepared and have

Me 3C- N

\ ,Ni/

N-CMe3

%

H

N (cH,), NH (cH,)

A2 H

J~

(135)

(1 34)

anomalous magnetic moments in the range 0.54.9BM [which may be due to the presence of paramagnetic impurities-Reporter]. The complexes appear to be polymeric in nitromethane and acetonitrile. The ligand is quadridentate in the solid state, but in solution it is terdentate.5g' The complexes [Ni(btat)] and [Ni(bhat)] [btatH, = bis(trifluoroacety1acetone)triethylenetetramine; bhatH, = bis(hexafluoroacetylacetone)triethylenetetramine] have been pre589

590

s91

K. Werner and W. Beck, Chem. Ber., 1972,105,3209. C . H. Wei and J. R. Einstein, Acta Cryst., 1972, B28, 2591. L. E. Heyman, R. Cheney, and E. L. Blinn, J. Inorg. Nuclear Chem., 1973,35, 2217.

280

Inorganic Chemistry of the Transition Elements

pared and are pseudo-octahedral. The reactions proceed stereospecifically, in both cases only the s-cis-isomer being formed.,,* The structure of bis-ethylmethylglyoximatonickel(II)has been redetermined. The complex is square-planar and the bond lengths in the ligands indicate considerable d e l o c a l i ~ a t i o n . The ~ ~ ~ oxime complexes [Ni(aox)Cl,] and [Ni(cy),Cl,] (aox = acetaldoxime; cy = cyclohexanone oxime) have been prepared and both are octahedral,s93 [Ni(HPPK),](NO,), [HPPK = syn-PhC(NOH)C,H,N] has also been prepared.,, ODonor Ligands. The electronic absorption spectrum of Ni2+ in a lithiumpotassium nitrate eutectic has been reported. The nickel ions are in an octahedral environment and the ligand-field parameters have been evaluated.594 Treatment of the nickel sulphite with DMSO in the presence of SO, yields the pyrosulphate Ni(DMSO),S20,. This compound undergoes thermal decomposition to give a mixture of anhydrous NiS,O, and anhydrous NiS0,.362 Anhydrous Ni(ClO,), can be prepared by dehydrating the hexahydrate by means of carefully controlled heating under high vacuum or treating the hexahydrate with a large excess of dimeth~xypropane.~~' Thermal dehydration of Ni(C10,),,6H2O yields the tetra- and di-hydrates as well as the anhydrous compound.594 Ni(IO,),,xH,O (x = 2 or 4) have been isolated as simple crystalline compounds and their heats of formation and stabilities reported.363 It has been shown that the first stage of reduction of nickel@)by hypophosphite is the formation of a 1 : 1 complex.365 The octahedral complexes (RCO,),NiL,xH,O (R = C,F,, p-MeOC,F,, or p-EtOC,F,; L = bipy, x = 2; L = phen, x = 1)have been prepared by treating NiCO, with the respective carboxylic acid and L in aqueous ethanol. Decomposition of these complexes in boiling toluene or benzene in the presence of benzoyl peroxide gives [R,NiL'] (R = p-MeOC,F, or p-EtOC,F,, L' = 2-(p-alkoxytetrafluorophenyl)-1,lO-phen or [(p-MeOC,F,)NiL"] [L" = 2,9bis(p-methoxytetrafluorophenyl)-l,10-phen]}.sg6The complexes [Ni(ox)L,] (L = MeNH,, EtNH,, Pr'NH,, Bu"NH,, Me,NH, or CH,=CHCH,NH,) have been isolated.597 The octahedral complexes Na,[Ni(cat)(A)L,],nH,O (cat = catecholate; L = py or y- or P-picoline; A = thioglycollate, n = 2; A = thiolactate, n = 0) have been prepared.598 Attempted preparation of trialkylamine complexes by the reaction of [Ni(R10HnX2] (X = C10, or BF,; R' = Me, Et, or n-C,H,,; n = 6-9) with R;N (R2 = Me or Et) did not give the expected products, but instead gave [Ni(R:NH),(R:N)m(R'O),X,] (n = 1-8, rn = 0-3).76 The metal complexes [NiL,](SbC1,)2 [L = p-MeC,H,CHO, o-ClC,H,CHO, p-ClC,H,CHO, Me,CO, Ph,CO, PhCHO, 592

593 594 595 596

59'

598

R. H. Bowers, C. V. Banks. and R. A. Jacobson, Acta Cryst., 1972, B28, 2318. M. E. Stone and K. E. Johnson, Canad. J . Chem., 1973,51,1260. S. V. Volkov and N. I. Buryak, Russ. J . Inorg. Chem., 1972.17. 543. G. Le Borgne and D. Weigel, Bull. SOC.chim. France. 1972, 3081. P. G. Cookson, and G. B. Deacon, Austral. J . Chem., 1972,25,2095. G. P. Singh, L. N. Srivastava, and S. V. Chandra, J. Inorg. Nuclear Chem. 1973,35,2104. C . R. Jejurkar and P. K. Bhattacharya, J. Inorg. Nuclear Chem.. 1973,35,2100.

28 1

Elements of the First Transitional Period

HCO,Me, EtOAc, or CH,(CO,Et),] have been isolated75 and the reaction of anhydrous Ni(OAc), with excess benzoin in methanol yields [Ni(benzoin H),], which is a tetrahedral monomer.34o The octahedral complex [NiBr,(acacH),] has been prepared by direct addition of acacH to the anhydrous nickel bromide or by reaction of the trisacetylacetonato-complex with dry HBr in dichloromethane containing free acacH. The ketonic acetylacetone ligands are bonded in a bidentate manner.73 The number-average molecular weight of anhydrous [Ni(acac),] in CCl, indicates the complex to be trimeric, and on this basis the previously reported value for the weight-average molecular weight of 2220 has been questioned.599 [Ni(acac),] shows two bands in its U.V. spectrum when examined in CH,Cl, solution. It is suggested that trimeric [Ni(acac),] shows only one band in pure CH,Cl, and that the other is due to a hydrolysis product formed when even minute traces of water are present. Even with a concentration of water in CH,Cl, of 4 x l o v 3moll-', acacH is liberated in 34% yield from the nickel complex in 48 h, and on the basis of a minute amount of residue isolated from this solution, the reaction: [Ni,(acac),]

+ 3nH,O + [Ni(acac)(OH)(H,O),-

+ 3acacH

is proposed.600The thermal stability of [Ni(acac),] has been studied.69 The structure of [Ni(acac),(H,O),]H,O has been determined by X-ray methods,601 as has that of square-planar [Ni(acac)Me{P(cyclohexyl),)].602 [Ni(acac),] reacts with picric acid in benzene-ethanol to form [(acac),Ni(H,O),](picrate); however, no reaction was observed with 2,4-dinitrophenol or 0-,m-, or p-N02C,H,0H.72 The adducts [Ni(P-dik),]B, (B = piperidine, piperazine, methylpiperazine, or morphine; P-dik = acac, benzoylacetonate, or dibenzoylmethanate)and [Ni(P-dik)]B, (B = methylpiperazineor morphine) have been reported. The two extra B molecules in the latter are not coordinated.,03 The cis-octahedral adducts [Ni(acac),E] (E = en, N-Eten, NN-Me,en, NN-Et,en, or NN-Bu",n) have also been prepared,604 as have the adducts [Ni(acac),(diamine)], (diamine = 4,4'-bipy or pyrazine)." The complexes [Ni(P-dik),]B, (P-dik = 3-phenyl, 3-p-tolyl-, 3-o-toly1, or 3-chloro-acac; B = H,O or heterocyclic bases) and [(3-o-tolylacac),Ni] have been isolated. The last-named compound is a high-spin octahedral trimer, showing that 3-substitution does not necessarily produce low-spin monomers with square-planar stereochemi~try.~~~" The related complexes [Ni(P-dik),(NH,),] (P-dik = 3-allyl- or 3-propylidene-acac) have also been prepared from reactions of metal salts with the appropriate P-diketones; however, the reaction with 3-ethylidene-acacH gave [Ni(aca~),].~~' [Ni(P-dik),(H,O)] F. A. Cotton and C. M. Lukehart, J. Coordination Chem., 1973,2,243. K. Isobe, Y. Nakamura, and S. Kawaguchi, Bull. Chem. SOC.Japan, 1973,46, 166. 601 R. L. Harlow and C. E. Pfluger, J. Coordination Chem., 1973,2,289. 6 0 2 B. L. Barnett and C. Kruger, J. Organometallic Chem., 1972,42,169. '03 G . Marcotrigiano, R. Battistuzzi, and G. C. Pellocani, Canad. J. Chem., 1972, 50,2557. 604 R. H. Balundgi and A. Chakravorty, J. Inorg. Nuclear Chem., 1973,35,2078. 604rr D. P. Graddon and K. B. Heng, Austral. J. Chem., 1972,25, 2247. 599

6oo

Inorganic Chemistry of the Transition Elements

282

complexes (P-dik = heptane-3,5-dionate, nonane-4,6-dionate, 2,6-dimethylor tridecane-6,g-dionate) heptane-3,5-dionate, 2,8-dimethylnonane-4,6-dionate, have been prepared, and dimeric octahedral structures are proposed in all cases. The complexes are stable in the solid state, but disproportionate in solution giving [Ni,( B-dik),],H,O and [Ni( p-dik),],2H,0.605 Chelates of heptane-2,4,6-trione (H,daa), [Ni(Hdaa),],2H20 and [Ni,(daa),],4L (L = H,O or py) have been isolated and they are all octahedral.350 1,7-Diphenylheptane-1,3,5,7-tetraone(LH) forms the complexes [NiL,(H,O),], which has a structure analogous to (Sl), and [Ni,(LH),(H,O),]H,O, which probably has structure (136).349 The structure of [(Ni(H,O)(trop)),(trop),] (trop = tropolonate) has been determined as (137) and shows both bridging and bidentate troponolate ligands

,,/I, I .

w

2

(136) Water molecules omitted for clarity

to be co-ordinated to the octahedral metal atoms.60saThe reactions of nickel@) complexes of acac, salicylaldehydate, and methyl-salicylaldehydate with oxygen, bromine, and SO,C1, have been studied.206 Salicylamide forms the high-spin tetrahedral complex Ni(OC,H4CONH,),f53 and the complexes of acetamide (acm) and caprolactam (cap), [Ni(acm)(H,O),]Cl, and [Ni(cap),]Cl, have been reported.5932,6-Butidene N-oxide (L) forms the five-co-ordinate dimer [L,(SCN)Ni(SCN)2Ni(NCS)L2]79 and 2-picolinic acid N-oxide (HL) forms [NiL,],2H20.80 The complex [Ni(pyzNO),](C10,),2H20 (pyzNO = pyrazine N-oxide) has been prepared and, like the manganese and iron complexes (see above, pp. 194 and 219), it shows a change of co-ordinated ligands upon the application of pressure in preparing a KBr disc of the complex. However, in this case there is a change from oxygento nitrogen-bonded pyzNO, rather than production of free ligand when the '05

6"5n

I. Yoshida, H. Kobayashi, and K. Ueno, Bull. Chem. SOC.Japan. 1972,45, 1411. R. J. Irving, M. L. Post, and D. C. Povey, J.C.S. Dalton, 1973, 697.

Elements of the First Transitional Period

283

perchlorate groups become co-ordinated.8 Nickel complexes of triazine 1oxide have also been reported., 51 The free radical 2,2,6,6-tetramethylpiperidine-nitroxide (tmpNO) (62) reacts with nickel perchlorate in the presence of triethyl orthoformate to form [Ni(trnpNO)](ClO,),, which is probably polynuclear with terminal tmpNO ligands and both bidentate and bridging perchlorate groups.208The related complex of (138), [Ni(L - H),],2H20, has also been reported.352

I

0'

Electronic spectral, magnetic, and spin-echo n.m.r. studies on nickel nitrate complexes of Bu,PO, (BuO),PO, and Bu,(BuO)PO have been reported.353 The trimorpholinephosphine oxide (morPO) complexes [Ni(morPO),]X, (n = i-4, X = BF,, NO,, NCS, C1, Br, or I) have been prepared and a comparative study has been carried out with related complexes of other phosphine oxides. It was concluded that steric factors of ligand size and the size of the anion control the co-ordination number.82 Ph,P(O)CH,P(O)Ph, (dpmo) forms the complexes [Ni(dpmo),]NiX, (X = C1, Br, or I) in which the cation is octahedral and the anion tetrahedral., 5 6 The homologous compound Ph,P(O)CH,CH,P(O)Ph, (dpeo) forms complexes of similar geometry, e.g. [Ni(dpeo),]NiX, (X = C1, Br, or I),356 the octahedral complex [Ni(dpeo),(H,0),](C10,),,354~ 606 five-co-ordinate[Ni(dpe~),](ClO,),,~~~ [Ni(dpeo)]X, (X = C1, Br, or and [Ni(dpe~),.,]Br,.~~~ Ph,P(O)(CH,),P(O)Ph, (dppo) forms [Ni(dppo)]X, (X = Cl, Br, or which is pseudotetrahedral, and Ph,P(O)(CH,),P(O)Ph, (dpbo) forms [Ni(dpbo),](ClO,),,2H20.606The related complex [Ni(dasbo),](C10,),,2H20 [dasbo = Ph,As(O)(CH,),As(O)Ph,] has also been reported.606The complexes [NiL,(NO,),] (L = hexamethylphosphoramide or nonamethylimidodiphosphoramide)have been reported, the NO, groups being co-ordinated in both cases,83 and (Me,N),P(O)NMeP(O)(NMe,)NMeP(O)(NMe,), (L) acts as a terdentate 0,-donor in the complexes [NiL,]X2 (n = 1 or 2; X = BF,, BPh,, NO,, or 3559606

~11.84

The octahedral complex [NiX2,2H,O],, has been isolated by extraction of nickel(Ix7cations from H,SO, solutions with di-(2-ethylhexyl)phosphoricacid (HX).359[Ni(O,SR),(py),] (R = Ph or p-MeC,H,) has been prepared by the reaction of pyridine with [Ni(O,SR)(H,O),]. No linkage isomers of the sulphinate ligands were detected.851,3-Dithian monosulphoxide and its 2-phenyl 606

S . S. Sandhu and R. S. Sandhu, Inorg. Chim. Acta, 1972,6, 383.

Inorganic Chemistry of the Transition Elements

284

analogue (L) form the complexes [NiL,]X, (X = C10, or BF,),86 and [Ni(dx),(H20),](C10,), and [Ni(dme),(H2O),](C10,), have been reported (dx = dioxan, dme = 1,2-dimethoxyethane)," Ni(CO), undergoes direct thermal reaction with 9,lO-phenanthraquinone (quonH)to form [Ni(quon),]? 5 4 N-Allylurea (nau) forms the octahedral complexes [Ni(nau),X,] (X = C1, Br, or C10,) and [Ni(na~),](ClO,),.~~~ SDonor and Se-donor Ligands. Treatment of Ni(N0,),,6H20 with C,Cl,SH in acidic aqueous solution yields [Ni(SC,C1,),I2-, which was isolated as its Ph,As+ [(n-Cp)Ni(PBu,)(SEt)] undergoes an insertion reaction with PhNCS to form [(x-Cp)Ni(PBu,){ SC(=NPh)SEt)], which undergoes reversible dissociation to the starting material in solution.608 The structures of [Ni(S,CNR,),](R, = MePh609 or Pra 6 1 0 ) have been reported. The latter shows Ni-S bond lengths that are shorter than those reported previously for Me,CHCH,H,C,

/s\

s-- s

,Ni, .I

,!CC,H,CHMe2

any related dithiocarbamate complexes. Temperature-dependent n.m.r. studies on [Ni(S,CNR,),] (R = Et, Pr", Pr', Bu', or PhCH,) have been carried produces Photochemical reaction of sulphur with [Ni(S,CC,H,CHMe,),] the square-planar complex (139), the crystal structure of which has been reported. Treatment of (139) with Ph,P gives specific removal of the sulphur atom adjacent to the carbon in the Ni-S-S-C linkage.," The squareplanar complex [Ni(Se,COEt),] has been prepared., 5 9 The planar compounds [Ni(S2PX,),] (X = Me, Ph, OEt, or F) have been isolated and the substituents were found to show the spectrochemical order OEt "N F > Me x Ph. When X = Me, the complex showed two polarographic reduction waves and one oxidation wave in acetonitrile solution.612 Treatment of [Ni(S,PPh,),] with dimethylglyoxime (dmgH) in methanol gave the green octahedral complex. [Ni(S,PPh,),(dmgH)].613 The related complex [Ni(S,AsMe,),] has been prepared from the reaction of nickel salts with Me2As(S)SNa,2H,O. The bispyridine adduct was also isolated.371 The compound [Ni(CS,)(NH,),] has been re-examined and it should be formulated as [Ni(NH,),][Ni(CSJ)2].614 Ph,P(S)CH,P(S)Ph, (sps) forms the stable tetrahedral complexes [Ni(sps),]and X,,$ (X = Br, S = THF; X = I, S = CH,Cl,) and [Ni(~ps),](ClO,$,,~~~ the tetrahedral complex [Ni { Ph, P(S)CH,CH ,P( S)Ph,) Br,] has also been 607

608 609 610 611 612

613 614

C. R. Lucas, M. E. Peach and K. K. Ramaswamy, J . Inorg. Nuclear Chem., 1972,34,?267. F. Sat0 and M. Sato. J. Organometallic Chem., 1972.46, C63. J. M. Martin, P. W. G. Newman, B. W. Robinson, and A. M. White, J.C.S. Dalton, 1972, 2233. P. W. G. Newman and A. H. White, J.C.S. Dalton, 1972,2239. J. P. Fackler, J. A. Fetchin, and D. C. Fries, J. Amer. Chem. SOC..1972,94, 7323. R. G. Cavell, W. Byers, E. D. Day, and P. M. Watkins, Inorg. Chem., 1972,11, 1598. R. N. Makherjee and M. D. Zingde, J. Inorg. Nuclear Chem., 1973,35, 1696. J. M.Burke and J. P. Fackler, Inorg. Chem., 1 9 7 2 , l l . 2744.

Elements of the First Transitional Period

285

r e p ~ r t e d . ~Pyridine-2” and -4-thiol, and 2 methylpyridine-6-thiol form complexes of nickel@) containing the square-planar [NiS,] c h r ~ m o p h o r e . ~ ~ Diamagnetic square-planar complexes [Ni(dtma),], [Ni(dpma),], [Ni(Hdtma),]X, (X = C1, Br, I, or NO,), and [Ni(Hdpma),]X, (X = I or C10,) and the paramagnetic octahedral complexes [Ni(Hdpma),]X, (X = C1, Br, or C10,) (Hdtma = dithiomalonamide, Hdpma = NN-diphenyldithiomalonamide) have been prepared1615and the structure of the trans-octahedral complex [NiCl,(thioacetarnide),] has been reported.616 The structure of bis(2,4-dithiobiureto)nickel(11)glycol has been determined.617 P-Donor and As-donor Ligands. The trans-square-planar compounds [Ni(PMe,),X,] (X = CN, NO,, NCS, C1, Br, or I) have been studied in detail by a range of physical techniques and the authors suggest that electronic spectroscopy provides a meaningful criterion for distinguishing between five- and fourco-ordinate low-spin nickel@) complexes.61* The reaction of anhydrous NiBr, with BuiPF in benzene gives the trans-square-planar complex [NiBr,(PFBu‘,)~],the structure of which has been reported.61s [NiBr2(PPh,CH,Ph),] exists with both tetrahedral and square-planar geometry in its green crystalline form. Application of high pressure (20 kbar) to this solid converts it into the all-square-planar form. This is the first report of spin-pairing of nickel(@ being brought about by the application of pressure.620The complexes [Nix,(phos),] (phos = PR,, PR,Ph, or PRPh,; R = cyclohexyl or propyl) have been prepared and used to examine the importance of steric and electronic effects of the phosphine on the tetrahedral + square-planar equilibrium in such compounds. Results of n.m.r. and magnetic studies in solution show that steric factors are relatively unimportant in affecting the thermodynamics of the structural equilibrium; however, electronic effects are extremely important, and these were interpreted in terms of Ni-P 7c-bonding.621The complex trans-[NiBr,(P(CH,SiMe,),),] has been reported.622 The complex [(x-Cp)Ni(PPh,)Cl] reversibly disproportionates in aqueous acetone yielding [(x-Cp)Ni(PPh,),] + C1- and a cation which is probably [(x-Cp)Ni(Me,CO),] +. The reversible nature of this reaction permits ready substitution of the chloroligand and the compounds [(x-Cp)Ni(PPh,)X] (X = SnMe,, GePh,, SnPh,, PbPh,, CN, NCS, NO,, or NCO) have been isolated. The triphenylstannyl complex reacts with iodine to form [(n-Cp)Ni(PPh,)I]. [(x-Cp),NiFe(CO),(PPh,)] has also been prepared and probably has structure (140).623[(Et,P),NiCl,] reacts with HgCl, to give a dinuclear complex, which probably has the structure (141) based on spectral and magnetic evidence.379The reaction of ‘15 616

617

6*8

619 620 621

622 623

G. Peyronel, G. C. Pellacani, G . Benetti, and G. Pallacci, J.C.S. Dalton, 1973, 879. R. L. Girling. J. E. O’Connor, and E. L. Amma, Acta Cryst., 1972, B28, 2640. A. Pignedoli, G. Peyronel, and L. Antolini. Gazzetta, 1972,103, 679. A. Merle, M. Dartiguenave. and Y. Dartiguenave, J. Mol. Structure, 1972, 13, 413. W. S. Sheldrick and 0. Stelzer, J.C.S.Dalton, 1973, 926. J. Ferraro, K. Nakamoto, J. T. Wang, and L. Lauer, J.C.S. Chem. Comm., 1973, 266. L. Que and L. M. Pignolet, Znorg. Chem., 1973,12, 156. A. T. T. Hsieh, J. D. Ruddick, and G. Wilkinson, J.C.S. Dalton, 1972, 1966. J. Thomson and M. C. Baird, Znorg. Chim. Acta, 1973,7, 105.

286

Inorganic Chemistry of the Transition Elements

Ni(NCS) with (RO),P in benzene gives [Ni(NCS),{(RO),P},] (R = Et, Pr", Pr', Bun, or X-Ray structural studies on trans-[NiCl,L,] (L = 4,4dimethoxy-1-phenylphosphorinan or 9-phenyl-9-phosphabicyclo[3,3,l]nonane) have been p ~ b l i s h e d6.2 6~ ~ ~ ~

The complexes of Me,P(CH,),PMe, (dmp), [Ni(dmp),X] (X = C1, Br, I, or NCS) (five-co-ordinate) and [Ni(dmp)X,] (X = C1, Br, I, or NCS) (squareplanar), have been isolated. The five-co-ordinate complexes with X = Br and I have trigonal-bipyramidal geometry whereas the other two have distorted structures. The only product that could be isolated from the reaction of dmp and Ni(CN), was [Ni,(dmp),(CN),], which also contains five-co-ordinate nickel@) and has a bridging dmp ligand.282 The complexes [Ni(dpp)X,] [dpp = PhP(CH,CH,PPh,),; X = C1, Br, I, NCS, or CN] have been prepared and all except the cyano-complexes are 1 : 1 electrolytes in MeCN and are therefore formulated as [Ni(dpp)X]X. The BPh, salts of these cations have also been prepared and all are square-planar. The cyano-complex is fiveco-ordinate both in solution and in the solid state.627Complexes of the ligands o-C6F,(PPh,), (fdp) and PhP(o-C,H,PPh,), (ftp) have been prepared. In contrast to the non-fluorinated ligands, which readily give five-co-ordinate [Ni(bidentate),X]+ cations, fdp forms only the four-co-ordinate complexes [Ni(fdp)X,] (X = C1, Br, I, or NCS) and [Ni(fdp),](ClO,),. However, both planar [Ni(ftp)Cl]BPh, and distorted square-pyramidal [Ni(ftp)X,] (X = C1, Br, or I) were isolated.628 The tripod ligand MeC(CH,AsMe,), (L) forms the complexes [NiL,X,] (X = Cl, Br, I, NCS, ClO,, BF,, or BPh,), the geometries and co-ordination numbers of which depend on X.565The related ligands MeAs(CH,CH,CH,AsMe,), (tas) and PhP(CH,CH,CH,AsMe2), (dap) form the distorted squarepyramidal complexes Ni(tas)X, (X = Br, I, NCS, or CN) and Ni(dap)X, (X = C1, Br, I, NCS, or CN) and the four-co-ordinate complexes [Ni(dap)X]Y (X = C1, Y = C10,; X = Y = NO,). The polynuclear complexes [Ni2L2(H,O)](ClO,), (L = dap and tas) and [Ni,(dap),I,]BPh, were also isolated.629 624 625

626

627

628 629

A. D. Troitskaya. V. V. Sentemov. and G. D. Ginsburg, Russ. J. Inorg. Chem., 1973,18, 143. A. T. McPhail and J. C. H. Steele, J.C.S. Dalton, 1972, 2680. A. E. Smith, Inorg. Chem., 1972,11,3017. J. C. Lloyd and D. W. Meek, Inorg. Chim. Acta, 1972,6, 607. P. G . Eller and D. W. Meek, Inorg. Chem., 1972,11,2518. C. A . McAuliffe, M. 0. Workman, and D. W. Meek, J . Coordination Chem., 1972,2, 137.

Elements of the First Transitional Period

28 7

The low-spin five-co-ordinate complexes [NiLX,] (X = Br or I) and [Ni,L,(H,O)](ClO,), [L = PhAs(o-C,H,AsPh,), and PhP(o-C,H,AsPh,),] have been prepared and the complexing ability of these particular ligands has been compared with that of similar ligands with aliphatic substituents on the arsenic atoms., 8 3 The ligands cis-(2-phenylarsinovinyl)diphenylphosphine (vasp) and 9,10-bis(diphenylphosphino)phenanthrene (dpph) have been prepared. The four-co-ordinate complexes [NiL,](ClO,), and [NiL,X,] (L = vasp or dpph; X = C1, Br, I, or NCS) and the square-pyramidal complexes [Ni(vasp),X]Y (X = C1, Br, I, or NCS; Y = C10, or BPh,) and [Ni(dpph)NO,]BPh, were isolated and the effect of the chelate back-bone on the complexing abilities of the ligand and the stereochemistry and spectrochemical properties of the complexes has been discussed.630 Mixed Donor Ligands. Di-2-pyridyl ketone (L) forms the octahedral complexes [NiL,X,] (X = Br or I), [NiL,(OAc),],xH,O (x = 2 or 3), and [NiL,SO,], Pyridine-2,6-dicarboxylic acid (dpcH,) reacts with xH,O (x = 6-Q6,’ nickel carbonate or hydroxide in hot water to form [Ni(dpcH),].3H20 and [Ni(dpc)],3H20. The latter is six-co-ordinate, dpc acting as a terdentate donor.387The structure of the former has been determined and the metal atom was found to be in a highly distorted octahedral environment, the dpcH ligands also being terdentate.632 Ethoxy-6-methylpyridine-2-phosphonate (E6MPP) reacts with nickel chloride to form the five-co-ordinate dimer [Ni(E6MPP),],, which contains both bridging and terminal ligands.” Pyridine-2,6-dithiocarbomethylamide(66) forms the complexes [Ni(L - 2H),]~ l structure of C1,,2H20, [Ni(L - 2H),](N0,),,1.5H20, and [ N i L ( ~ y ) ] . ~The bis-{2-[(2-pyridylmethyl)amino]ethyl)disulphidochloro-nickel(11) perchlorate has been determined and the cation is in an octahedral [N,SCl] environment. The pyridine nitrogen atoms and the amino-nitrogen atoms both form mutually cis pairs.6 2-py-CH=NN=C(SMe),(L) forms the six-co-ordinate compounds [NiL,(NO,)]NO,, [NiLX,] (X = C1, Br, I, or NCS), and [NiL,](C1O,),.’OO Spinacine (LH) forms the complexes [HNiLI2 +,[NiL]’, and NiL, in which the ligand probably acts as chelate similar to g l y ~ i n e . ~ ~ ~ [Ni(salen)] forms an orange adduct with NaBPh, [Ni(salen)],NaBPh,, 2THF, when the reagents are mixed in T H F solution. The complex is isomorphous with the cobalt compound (see above, p. 247) and thus contains a sodium atom octahedrally co-ordinated by six oxygen atoms. The related compound [Ni(salen)],NH,SCN has also been reported.388 [Ni(salen)] reacts with NO in organic solvents in the presence of air to form [Ni{5,5’(NO,),salen)] in an almost quantitative yield.635Polarographic studies have been made on nickel(r1)complexes of NN‘-ethylenediamine-bis(acety1aceton630

631 632 633 634

635

K. K. Chow, M. T. Halfpenny, and C . A. McAuliffe, J.C.S. Dalton, 1973, 147. J. D. Ortego and D. L. Perry, J. Inorg. Nuclear Chem., 1973,35, 3031. P. Quaglieri, H. Loiseleur, and G. Thomas, Acta Cryst., 1972, B28,2583. P. E. Riley and K. Seff, Znorg. Chem., 1972,1I, 2993. A. Braibanti, F. Dallavalle, E. Leporti, and G. Mori, J.C.S. Dalton. 1973, 323. M. Tamaki, I. Masudo, and K. Shinra. Bull. Chem. Soc. Japan, 1972.45, 1400.

Inorganic Chemistry of the Transition Elements

288

iminate) and -bis(salicylaldehydeiminate) in DMF solution.390 The complex [NiL(acac)(H,O)] (L = terdentate-[N,O]-Schiff base formed from salicylaldehyde and NN-Et,en) has been isolated. The complex is suggested as having an octahedral structure in which the Schiff base occupies three equatorial sites and the H,O molecule is in an axial position. Dehydration can be effected by heating to 80°C in vacuum and the resulting complex [NiL(acac)] is thought to have a square-pyramidal configuration, one of the oxygen atoms of acacoccupying the axial position.636 The reaction of bis-(salicyla1dehydato)nickel(I1) with aea and apa (142) gives neutral Schiff-base complexes (143). However, the reaction of Ni(OAc), with salicylaldehyde and aea gives [Ni(salen)], which can also be prepared by treating (143a) with acetic

(142) a : n b; n

= =

=2 b;n= 3

2 (aea) 3 (apa)

(143)a ; n

N.m.r. and electronic spectral studies on mixtures of Ni(N-Me-sal), and Zn(N-Me-sal), (N-Me-sal = N-methylsalicylaldiminate) in CDCl, show that ligand exchange is fast on the n.m.r. time scale at room temperature and also provide evidence for the formation of paramagnetic mixed-metal oligomers in the exchange reaction.638 Redistribution reactions of the type NiL;

+ NiL;’ -+ 2NiL’L”

have also been studied by n.m.r. (L’ and L” = salicylaldimine or P-keto-imine residues).639 Condensation reactions of o-aminophenol, N-substituted oaminophenols, and 8-amino- 1-naphthol with cc-diketones have been compared. The basis for the lack of reactivity of the products in forming Schiff-base chelates in cases where the parent diketone is different from glyoxal have been examined and it was found that steric factors alone did not appear to inhibit complex formation.640 The donor atoms of the ligands (144) when co-ordinated to nickel@) could not be unequivocally assigned (see Volume 2 of this series of Reports). However, the complexes (145)have now been prepared by the reaction of butane-2,3-dione monohydrazone or t-butylglyoxal monohydrazone with acetone in the presence 636 637 638 639 640

R. H. Balundgi and A. Chakravorty, Inorg. Nuclear Chem. Letters, 1973,9, 167. C. .A. Root, B. A Rising. M. C. van Der Veer, and C. F. Hellmuth, Inorg. Chem., 1972,11, 1489. M. N. S. Hill, S. Karunaratne, and J. C. Lockhart, J.C.S. Chem. Comm., 1973, 50. J. C. Lockhart and W. J. Mossop, J.C.S. Dalton, 1973, 19. A. Malek and J. M. Fresco, Canad. J. Chem., 1973.51, 1981.

Elements of the First Transitional Period

289

of Ni2+. The co-ordination has been confirmed by n.m.r. and the reaction of (145) with anhydrous en gives the orange-red complex (145a). On this basis similar co-ordination is proposed for the phenyl compounds.641 The paramagnetic octahedral complexes [Ni(doe),X,] [X = C1, Br, or NO,; doe = (146)l have been isolated.642 The barrier to rotation about the amide bond in bis-[2,2'-iminobis(acetamidoximato)]nickel dinitrate has been found to be about 1 kcal mol-l higher than that in the free ligand.643

R'

R2

H

Ph

Ph

I

R2

(144)R'

= Me;R2 = Me, Et, Pr", Bu", or Ph R' = R2 = Et

\

'hT

A *y;

Me-C Me-C II

=NOH

I = NCH,CH,OH (146)

The potentially sexidentate ligand (9 1) forms a five-co-ordinate complex with nickel@) in which one of the ethereal oxygen atoms is ~ n c o - o r d i n a t e d . ~ ' ~ Complexes of the type (147) have been isolated and react with en or 1,3-pn to form (148), which in turn react with additional nickel@) to form the bimetallic complexes f149).644The ligands (150) react with Ni(OAc),,4H20 in methanol to form [LNi,
644

G. A. Melson and D. B. Bonfoey, Znorg. Nuclear Chern. Letters, 1973, 9, 875. A. V. Ablov. N. I. Belichuk, and M. S . Pereligina, Russ. J. Inorg. Chem., 1972,17, 534. R. E. Cramer and R. De Ryke, Canad. J. Chem., 1973,51,892. H.Okawa and S . Kida, Bull. Che;. SOC.Japan, 1972,45, 1759.

Inorganic Chemistry of the Transition Elements

290

also form the complexes [LNi,X] [L = (150b)or (151); X - = OH-, $O", RO-, RS-, NH;, NHR-, NR;, N;, NCO-, C1-,or p y r a ~ o l a t e ] . ~ ~ ~ 2-(o-Hydroxyphenyl)-benzothiazolinereacts with Ni2+ in a 1 : 1 mole ratio

(147)m

=

(148) rn m

2 or 3

(140)m m

= =

= =

n = 2 or 3 2,n = 3

n = 2 or 3 2,n = 3

to form chelates of 2-salicylideneaminothiophenol; however, 2-phenylthiazoline forms the complex bis(benzylideneaminothiophenolato)nickel(II), which has an [NiN,S,O,] core.4o3 The ligand acacenH, reacts with Et,OfBF, in chloromethane, followed by NaHS in ethanol, to form dithioacacenH, (64).

(150)a:X = 0 b:X= S 645

W. D. McFadyen, R . Robson, and H.Schaap, Inorg. Ch&, 1972,11,1777.

Elements of the First Transitional Period

29 1

Nickel complexes of this ligand have been prepared.,” The complexes (152) have been prepared. When R = But, the complex is paramagnetic and tetrahedral, the others being square-planar.,,, Schiff bases derived from hydrazineS-methyl-dithiocarboxylate and substituted benzaldehydes or heterocyclic aldehydes react with NiCl, and Ni(OAc), to produce the neutral square-planar complexes [(RCH=NN=C(SMe)S},Ni] (R = Ph, p-MeOC,H,,p-NO,C,H,,

(152) R = Me, Bun, Pr ‘,

But, or C,H,

o-NO,C,H,, p-HOC,H,, C,H,O, C,H,S, or C,H,N) which possess the [NiN,S,] c h r o m ~ p h o r eThe . ~ ~reaction ~~ of (153) with formaldehyde in the presence of Ni(ClO,), yields the planar complex ( 154).647 Treatment of the complex (155) with acetone in methanol gives (156). In the

n

h40 647

L. El-Sayed, M. F. Iskander, A. El-Tonkhy, and S. E. Zayan, Inorg. Chim. Acta, 1972, 6, 663. N. W. Alcock and P.A. Tasker, J.C.S. Chem. Comm., 1972. 1239.

292

Inorganic Chemistry of the Transition Elements

solid state and in aqueous or methanolic solution, the perchlorate is squareplanar, whereas the halide complexes are high-spin and five-co-ordinate in the solid state or in methanol solution and square-planar in aqueous solution. The isothiocyanate complex is high-spin and six-co-ordinate in the solid state.648 The ligand dta (157) forms the complexes [Ni(dta)X,] (X = C1 or Br) in which the ligand is co-ordinated in a bidentate fashion by nitrogen and sulphur atoms. The related ligand dtpp (158) forms [Ni(dtpp)X]Y (X = C1 or Br; Y = C1, Br, CIO,, or BF,) in which the ligand is quinquedentate, being coordinated by a sulphur and four nitrogen atoms. [Ni(dtpp)Br]Br can also be obtained by treating [Ni(dta)Br,] with pyridine-2-carbaldehyde. Under certain conditions dtpp is reduced in the presence of Ni2+ to produce complexes of

pabtH (159). [Ni(pabt)Cl] was isolated in two forms, one of which was the red-brown square-planar complex [Ni(pabt)Cl], the other the green paramagnetic octahedral complex [Ni(pabt),NiCl,] which may have a thio-bridged s t r u ~ t u r eThe . ~ ~complexes (160)and (161) have been reported6,' and polymeric complexes of (87) and (88) have been prepared and compared with their monomeric analogues of the ligands (89) and The reaction of (5,8-diaza-4,9-dimethyldodeca-3,9-diene-2,1l-dionato)nickel(11) with either N O or organic nitrite, or the reaction of acacH, en, Ni2+,and nitrous acid in aqueous solution gives the two isomers (162)and (163), which can be separated by c h r o m a t ~ g r a p h y The . ~ ~ ~complexes (164;R1 = Me, Et, 648

649 650

F. L. Urbach and D. H. Busch, Inory. Chem., 1973,12,408. W. W. Fee, J. D. Pulsford, and P. D. Vowles, Austral. J. Chem., 1973,26,675. M. J. Lacey, C. G. Macdonald, and J. S. Shannon, Austral. J. Chem., 1973,26,263.

Elements of the First Transitional Period

293

R2 R2

R2

/

\

R4

R' RZ R 3 R4 (160)L = DMSO;

L=py;

H H H H H H C l H H C l H H H H MeH H HOMe H H OMe H H H H benzo C1H H H H H H H

R2 R3 R4 (161)

H H H H OMe H H

C1 H H H Me H OMeH H H N02H benzo

or Pr'; R2 = Me) react with NH3 to form (164; R' = H, R2 = Me) and the appropriate primary amine. A similar reaction of (164; R' = Me, Pr", or Pr'; R2 = Me) with EtNH, gives a good yield of (164; R' = Et, R2 = Me).651The related complexes (164; R' = Me, Et, Pr", Bu", or C,H,OH; R2 = OEt) have also been reported.652 MeCO,

FOMe

(1 62)

(1 63)

(1 64)

Nickel@) complexes of L-amino-acids have been studied by spectral methods and the results interpreted in terms of the chelate ring conformation^.^^^ The reactions of LH'C1- with NiCl, and LH'ClO, wjth NiCO, yielg [NiLCI,] 651

K. S. Bose, J. Inorg. Nuclear Chem., 1972.34, 3593; K. S. Bose, B. C. Sharma, and C. C. Patel,

652

Inorq. Cham.. 1973. 12. 120. R. R. Iyenger, K. S. Bose, and C. C. Patel, Inorg. Chim. Actu. 1973,7,3. C. Ibarra, R. Soto, L. Adam, A. Decinti, and S. Bunel, Inorg. Chim. Acta, 1972,6, 601.

653

294

Inorganic Chemistry of the Transition Elements

and [NiL,](ClO,),, respectively, [LH’ = Me,SCH,CH,CH(NH,)CO;1, and neutralization of LH+ solutions with lithium hydroxide followed by the addition of NiCl, in the appropriate molar ratios yields [Ni(L - H)Cl], [Ni(L - H),], and Li[Ni(L - H)J all of which are high-spin octahedral compounds. This facile deprotonation of the ligand, DL-methylsulphoniummethionine, contrasts sharply with the drastic conditions required for similar reactions of g l y ~ i n e54. ~ The blue octahedral complexes [NiL(H,O),] react with alkali to give yellow square-planar NiL (LH, = Gly-Gly-Gly or Gly-Gly-Gly-Gly).655 The formation of nickel@) complexes of Schiff bases derived from salicylaldehyde and the dipeptides Gly-Gly, Gly-P-Ala, and p-Ala-Gly has been In alkaline media in the presence of Ni2 +,condensation takes place between salicylaldehyde thiosemicarbazone or selenosemicarbazone and salicylaldehyde to give complexes of (165) in which the ligands do not co-ordinate via the X atom.6 The structures of both cis- and trans-bis(dithiosemicarbazido)bis(dinitrat0)-nickel@) have been determined. The Ni-S bond lengths are longer in the trans-isomer than in the c i s - f ~ r r n . ~The ’ ~ structures of the

’’

‘

-N-NH-C-N(165)X

=

;Hm

Sor Se

acetone thiosemicarbazone (L) complexes [NiL,X]X,H,O (X = C1 or NO,) have been determined and the chloro-complex is trigonal-bipyramidal, while the nitrate can be classed as octahedral, although these are only small geometric differences compared with the chloro-compound.659Complexes of adipoinselenosemicarbazone and the thiosemicarbazone of benzoylformic acid have been r e p ~ r t e d . ~ ~ , , ~ ~ ~ A complex of NN-bis- [2-(diethy1amino)eth yl] -2-(dipheny1arsino)ethylamine (L), [NiL(NCS)]BPh,, has been studied by X-ray methods. It is squareplanar with an [NiN,] chromophore, the arsenic atom not being coordinated.660 A complex of a related ligand, [NiI((Ph,PCH,CH,),N(CH,CH,NH,)}]I, is low-spin, and structural studies show it to have trigonalbipyramidal co-ordination that is distorted towards an elongated square pyramid. This is a different distortion from that observed for the analogous high-spin cobalt(I1)compound and it is suggested that the structural differences 654

655 656

657

6s8 659

660

C . A. McAuliffe, L. M. Vallerino, and J. V. Quagliano, Inorg. Nuclear Chem Letters, 1973,9,625. F. Karczynski, C. Varhelyi, and F. Manok, Roczniki Chem., 1972,46, 1223. Y. Nakao and A. Nakahara, Bull. Chem. SOC.Japan, 1973,46, 187. N . V. Gerbeleu and M. D. Revenko, Russ. J. Inorg. Chem., 1972,17,1132. R. G. Hazell, Acta Chem. Scand., 1972,26, 1365. M. Mathew, G. J. Palenik, and G. R. Clark, Inorg. Chem., 1973,12,446. M . Di Vaira and A. Bianchi-Orlandini, J.C.S. Dalton, 1972, 1704.

Elements of the First Transitional Period

295

are a consequence of the different spin states.407 The open-chain ligand Ph,As(CH,),NMe(CH,),NMe(CH,),AsPh, (AsNNAs) forms the four-coordinate complexes [Ni(AsNNAs)]X, (X = ClO,, BPh,, or BF,) and [Ni(AsNNAs)I]X(X = I or BPh,)and the octahedral complexesNi(AsNNAs)X, (X = Br, I, NCS, or OAc) and [Ni(AsNNAs)X]Y [X = OAc or NO, (both bidentate); Y = BPh,].661 The similar ligand Ph,As(CH,),N=CMeCMe=N(CH,),AsPh, (L) forms the square-planar complex [NiL](ClO,), and the five-co-ordinate ligand-bridged complexes [NiLX],(ClO,), (X = C1, Br, or I). The polymers are thought to have square-pyramidal geometry.662 The complexes [NiLX,] [X = halide, NCS, or NO,; L = (95), (96), or (97)] have been prepared. The halides are thought to be five-co-ordinate, but the geometries of the nitrato- and thiocyanato-compounds were ~ncertain.~"The ligands (166) and (167) form a range of nickel(1r) complexes of various geometries. Several mercapto-complexes were isolated by demethylation of these comp l e x e ~6 .3~

Fo-pp FoPPh2 F

F

1

F \

\

SMe

Diethanolamine (deaH) and N-methyldiethanolamine (MedeaH) form the complexes [Ni(deaH),]X,,H,O (X = C1 or Br), [Ni(deaH),]Br,, [Ni(deaH),]C1,,2H20, [Ni(dea)(H,O)]X (X = C1 or Br), [Ni(dea)(deaH)]X,H,O (X = Br or I), [Ni(deaH),(dea)]X,H,O (X = NO, or I), and [Ni(MedeaH),]X, (X = C1, Br, I, or and l-amino-3,3,3-trifluoropropan-2-ol (LOH) forms the polymeric compound [Ni(L0),].529 Ethylenediaminedisuccinic acid (ss-edds), an isomer of edta, forms the octahedral complex (Me,N),[Ni(ss-edds - H,)] in which the ligand is ~exidentate.~~, 1,5-Diazacyclooctane-NN'-diacetate (dacoda) forms the five-co-ordinate complex [Ni(dacoda)(H,O)], the sixth co-ordination site being blocked by an alkyl proton. The complex is square-pyramidal with the water molecule occupying the axial position.398 The NN-dialkyl-ethylenediamine N-oxides (alkyl = Me, Et, or Pr) act as bidentate ligands in the green octahedral complexes [NiL,](C10,)2 and the red square-planar complexes [NiL,](ClO,), . 3 1 2,2'-Bipyridyl N-oxide forms the related complex [Ni(bipyNO),](C104)2.go (o-Aminopheny1)thioacetic acid forms the octahedral complex [Ni(H,O),[NH2C6H4C0,),] which has a [NiO,N,] core." The thiocarbazic acids 661

662 663 664

L. Sacconi and D. Gatteschi, J. Coordination Chem., 1972,2, 107. T. D. DuBois and F. T. Smith, Inorg. Chem., 1973,12,735. P. G. Eller, M. Riker, and D. W. Meek, J. Amer. Chem. SOC., 1973,95,3540. J. A . Neal and N. J. Rose, Inorg. Chem., 1973.12,1226.

Inorganic Chemistry of the Transition Elements

296

NH,NHCOSH and Me,NNHCOSH (LH) in the form of their sodium salts react with NiCl, in a 2 : 1 molar ratio to form low-spin NiL,; however, treatment of NiCl, with a hundred-fold excess of NH,NHCOSNa gives Na[NiL3].665 o-Mercapto-N-methylbenzanilide and o-mercapto-N-benzylN-methylbenzamide (LH) form the complexes NiL, .,06 The 4-(arylazo) thiopyrazol-5-ones (93) (HL) form the complexes NiL,. Magnetic measurements indicate that the complexes are mixtures of square-planar and octahedral polymeric forms in the solid state, but are entirely square-planar in solution.404 The related ligand 3-(4-pyridyl)triazoline-5-thione (94) (L) forms the octahedral complex [Ni(L - H),(py),].405 Pyrazine-3,4,5-trithiol (TH,) forms the complex [Ni(TH)] , P-Furfuraldoxime (11) forms [Ni(ffdox),Cl,], which is ~ c t a h e d r a l , ~and , the complex [LNi(H,O)] (LH, = 8-hydroxy-7-nitrosoquinoline-5-sulphonic acid) has also been reported.97 Other Compounds. [(Et,N),NiCl,] reacts with MeNC in ethanol to form [Ni(CNMe),I2+, which has been isolated as its PF; salt. It is much less stable than the corresponding palladium and platinum complex cations in solution.666 The complexes [NiCl(CNR)L,]X (R = MeOC,H,, MeC,H,, or C,H5 ; L = PPh,, PEt,, PMe,Ph, or PMePh,; X = C1, PF,, or SbF,) have also been reported.

'

Nickel( 111).-The complexes [NiLX,](ClO,) (X = Br, C1, NCO, NO,, or $0,; L = 2,3-dimethyl-1,4,8,1l-tetra-azacyclotetradecane)have been prepared by oxidation of the corresponding nickel@) complexes with aqueous persulphate or concentrated nitric acid. They are all very stable in dry air in the solid state and have low-spin magnetic moments (1.56-2.05 BM) consistent with tetragonally distorted octahedral nickel(m).668 The complex formed between nickel@) and dimethylglyoxime in the presence of oxidizing agents in alkaline solutions has been investigated by pulse radiolysis and this suggests The complexes Ni(bpo), the assignment of the + 3 oxidation state to and Ni(ppo), [bpoH = (168); ppoH = (169)l have been isolated and their formation supports a model proposed earlier to account for the stability of a nickel(1v)complex of 2,6-diacetylpyridinedioxime (see Vol. 2, p. 3 13).6' O Dq and B values have been obtained for the complex tris(rac-serinatoj-

Ph

NOH

669

A. Monaci and F. Tarli, Inorg. Nuclear Chem. Letters, 1972,9,443. J. S. Miller and A. L. Balch, Inorg. Chem., 1972,11, 2069. W. J. Cherwinski, H. C. Clark, and L. E. Manzer, Inorg. Chem., 1972,11, 1511. E. S. Gore and D. H. Busch, Inorg. Chern., 1973.12, 1. J. Lati and D. Meyerstein, Israel. J. Chem., 1972, 10, 735.

670

R. S. Drago and E. I. Baucom. Znorg. Chem., 1972,11,2064.

665

666

667 668

Elements of the First Transitional Period

297

nickel(rII),and e.s.r. measurements indicate that the Ni-0 bonds have covalent character.671 The structure of [Ni(diars),Cl,]Cl [diars = o-C,H,(AsMe,),] has been determined and compared with that of the cobalt(II1) analogue (see above, p. 263). As with the cobalt complex, the cation has a slightly distorted octahedral geometry with trans-chloro-ligands. The Ni-As and Co-As bond lengths are very similar (2.342 and 2.334 A, respectively); however, the Ni-Cl bond lengths (2.425 A) are noticeably longer than those in the cobalt complex (2.256A) and this is probably due to the presence of an unpaired electron in the dz2 orbital of the nickel compound.500 Nickel( IV ).-Oxidation of [Ni(S,CNBu,),] with the 3,5-bis-(NN-dialkyliminium)-1,2,4-trithiolan cation yields the complexes [Ni(S,CNBu,),]X (X- = C1-, Br-, or FeC1;),672 and oxidation of Ni(S,CNR2), with either ferric chloride or ferric perchlorate yields [Ni(S,CNR,),]X (X- = ClO, or FeCl; ; R, = Et, or EtPh, or R,N = piper id in^).,^," Magnetic measurements on these complexes are consistent with the presence of low-spin nickel(1v). The structure of [N~(S,CNBU;)~]B~ has been reported and consists of bromide ions arranged in a trigonal-antiprismatic manner about columns composed of discrete [Ni(S,CNBu;),]+ cations, which are of approximate D, symmetry, the [NiS,] core being twisted by 45.4" from a true trigonal-prism (Ni-S = 2.261 The reaction of [(Ph,P),Ni] with R,SnCl (R = Ph or Me) in toluene yields the colourless air-stable complexes [Ni'VC1,(PPh,),(SnR,),]. The compounds are diamagnetic and can be considered as low-spin nickel(1v) products formed by a double oxidative addition. They are non-electrolytes, and preliminary n.m.r. and X-ray crystallographic evidence indicates the trans-trans-transstructure (170).674 SnR3

SnR3

Oxides.-The new oxonickelate Li,NiO, has been identified. It is isostructural with L ~ , C U O , . , ~The ~ structure of Ni,,,,Pt,O, is best described as a filled p-tungsten structure where the 'filling' oxygen atoms are in a square-planar array around the platinum atoms. Non-intersecting chains of platinum atoms 671 672

673 674

675

B. Angelov and K. Manolo\. Monar rh., 1973,104, 746. J. Willemse and J. A. Cras, R e ( . Trnv. chim.. 1972,91. 1309. J. P. Fackler, A. Avdeef, and R. G. Fischer, J. A m r r . Chem., SOC.,1973,95,774. P. E. Garrou and G. E. Hartwell, J.C.S. Chem. Comm., 1972, 881. H. Rieck and R. Hoppe. Z . anorg. chem., 1972,392, 193.

298

Inorganic Chemistry of the Transit ion Elements

run parallel to the cubic axis and the nickel atoms are situated in channels, each nickel being very weakly bound to eight o x p e n atoms.676 5 Copper Copper(I).-Halides. A method for the preparation of high purity CuCl has been reported.z25I.r., Raman, and n.q.r. data for CuX, (X = C1 or Br) indicate that both are best described in terms of linear structures with ds hybridization of the Complexes. CuCl reacts with K[HB(pz),] (pz = pyrazlyl) in the presence of carbon monoxide to form [(HB(pz),}Cu(CO)] as a white crystalline solid of high stability [v(CO) = 2083 cm- 'I. The complex undergoes decarbonylation at 165°C to form [Cu,{HB(pz),},], which is dimeric in both the solid and the gas phase. The compound also reacts with donor ligands (L) to form [(HB(pz),}CuL] [L = PR,, P(OR),, AsR,, SbR,, RNC, acetylenes, or olefins]. The carbony1 complex is of much higher stability than [(IT-Cp)Cu(CO)] and it is suggested that the increased stability results from strengthening of the Cu-CO bond by back-bonding from the electron-rich metal atom, such a situation arising in consequence of the strong o-donor power of the [HB(pz),] ligand., 7 8 [(Ph,P)CuCl], reacts with Na[BH(OMe),] in D M F to form the thermally stable complex [H,Cu,(PPh,),],DMF. An X-ray study on this cluster compound indicates that the metal atoms are arranged in a slightly distorted octahedron [Cu-Cu = 2.494(6)-2.674(5) A], each copper atom being apically bonded to a phosphine molecule. The hydrogen atoms were not located, but possible sites have been discussed.679Treatment of copper(1) phenylacetylide with [IrCl(CO)(PPh,),] in refluxing benzene for 36 h gives a 60% yield of [CU,I~,(PP~,),(C=CP~)~]together with small amounts of Ph,PO and [Cu,Cl,(PPh,),]. A structural study of the cluster compound shows the six metal atoms also to be in an octahedral array, the ((Ph,P)Ir} moieties being arranged in trans-positions. Four C E C P h units are 0-bonded to each iridium atom and two of these (one bonded to each of the iridium atoms) are n-bonded to each of the four equatorial copper atoms [Ir-Cu = 2.871 8, (average), Cu-Cu = 2.740A (average)]. The formal oxidation states of the metals can be classed as Cuo and Tr'V.680 N-Donor and 0-donor ligands. Hendricker and Bodner68 have previously reported the preparation of Cu(ClO,), complexes of 2,7-dimethyl-l,8-naphthapyridine (Me,napy); however, it has now been found6*, that this reaction and an analogous reaction of 1,s-naphthapyridine (napy) with Cu(ClO,), yields 676

677

679

682

D. Cahen, J. A. Ibers, and R. D. Shannon, Inorg. Chem., 1972.11,2311. G. A. Bowmaker, L. D. Brockliss, and R.Whiting, Austral. J . Chem., 1973,26, 29. M. I. Bruce and A. P. P. Ostazewski, J.C.S. Chem. Comm., 1972,1124. M. R. Churchill, S. A. Bexman, J. A. Osborn, and J. Wormald, Inorg. Chem., 1972,11, 1818. 0.M. Abu Salah, M. I. Bruce, M. R. Churchill, and S. A. Bezman, J.C.S. Chem. Comm., 1972,858. D. G . Hendricker and R. L. Bodner, Inorg. Chem., 1970,9,273. A. Emad and K. Emerson, Inorg. Chem., 1972,11, 2288.

Elements of the First Transitional Period

299

the copper(1) complexes [Cu(Me,napy),]ClO, and [Cu(napy)]ClO,. The dimethyl compound is identical with that reported earlier but clearly contains copper@).The reductant appears to be some impurity present in the dimethoxypropane used for drying. The compounds [Cu,(napy)Cl,] and [Cu,(Me,napy)C12] were also isolated. The distinction between octahedral, tetragonal, trigonal-bipyramidal, tetrahedral, pseudo-tetrahedral, and square-planar stereochemistriesfor bipy and phen complexesof Cu' and Cu" is reported to be possible on the basis of i.r. differences.683 Freshly prepared Cu,O reacts with Me,SO, to form the beige watersensitive compound Cu,SO,. X-Ray powder data and thermal stability studies for the compound have been reported.684Two groups have reported the crystal structure of copper(1) acetate. Crystals were obtained by reducing a solution of Cu(OAc), in pyridine with metallic copper, evaporating off the solvent, subliming the product at 120 "C, and recrystallizing from acetonitrile. The structure consists of a polymeric planar chain in which each copper atom is in a distorted square-planar configuration, being bonded to three oxygen atoms and a neighbouring copper atom [Cu-Cu reported as 2.56 and 2.544(4) A]. The square-planar co-ordination of copper(1) is unusual, as tetrahedral geometry is usually observed.685[MeCu(PPh,),],Et,O reacts with CO, at -40°C in THF to form [(MeCO,)Cu(PPh,),]. When the methyl compound is treated with CO, at room temperature for a somewhat longer period, the acetate is formed and then redissolves to give [(M~CO,)CU(CO,}(PP~,)~].~~~ The complexes of copper(1)trifluoroacetate, [(Ph,P),Cu(O,CCF,)] (n = 1,2, or 3), [(MePh,P),Cu(O,CCF,)], [{ Ph,P(CH2),PPh,: ,CU(O,CCF,)], [( L 5 - d ) Cu(O,CCF,)], [( 1,5-cod)Cu2(O,CCF,), J, and [(cot)Cu,(O,CCF,), J (cod = cyclo-octadiene, cot = cyclo-octatetraene) have also been reported,68 S-Donor and Se-donor ligands. The structure of [CuCl(SPMe,)] has been reported. It consists of a six-membered ring of copper and sulphur atoms which is puckered into a chair conformation with equatorial Me,P units. The copper atoms thus show approximately trigonal-planar co-ordination, being bonded to two bridging sulphur atoms and one terminal chlorine atom. The related compounds CuLX (X = C1, Br, I, or SCN; L = tertiary phosphine sulphide) where also prepared by adding L to CuX or treating CuLl with X - in a nonaqueous solvent.688The ligand Me,P(S)OP(S)Me, (L) forms the complex [CU*L,][CU*B~,].~~~ Crystallographic studies on [(ettu),Cu],SO, and [(Me,tu),Cu]BF, (ettu = ethylenethiourea, Me,tu = tetramethylthiourea) show both cations to have trigonal planar co-ordination via three sulphur atoms.

684

685

686 688

689

G. C. Percy and D. A. Thornton, J. Mol. Structure, 1972,14, 313. K. V. Van and F. Habashi, Ganad. J. Chem., 1972,50,3872. M. G. B. Drew, D. A. Edwards, and R. Richards, J.C.S. Chem. Comm., 1973, 124; T. Ogura, R. D. Mounts, and Q. Fernando, J. Amer. Chem. SOC.,1973,95,949. A. Miyashita and A. Yamamoto, J. Organometallic Chem., 1973,49, C57. M. B. Dines. Znorg. Chern., 1972.11, 2949. J. A. Tiethof, J. H. Stalick, and D. W. Meek, Znorg. Chern., 1973, 12, 1170; J. A. Tiethof, J. H. Stalick, P. W. Corfield, and D. W. Meek, J.C.S. Chem. Comm., 1972, 1141. D. A. Wheatland, C. H. Clapp, and R. W. Waldron, Znorg. Chem., 1972,11,2340.

Inorganic Chemistry of the Transition Elements

300

However, comparison of [Cu(tu),]BF, (tu = thiourea) and [Cu(Me,tu),]BF, (Me,tu = NN'-dimethylthiourea), which contain sulphur-bridged dimers with tetrahedral copper(1) atoms, [Cu(tu),Cl], which contains trigonal planar copper(r), and [Cu(Me,tu),Cl], which contains tetrahedral copper(1) with a [CuS,Cl] core, emphasizes the difficulty of predicting the stereochemistry of soft ligand complexes.690 The reaction of [Cu(tu),I] with phen under various conditions yield [Cu(tu),(phen)]I, [Cu(tu)(phen)]I, and [ C ~ ( p h e n ) , ] I . ~ ~ ~ N.q.r. data have been reported for a range of copper(1) complexes of thiourea and some substituted t h i o u r e a ~ . ~The ~ , structure of [Cu,(SC(NH,),) (SiF6),,H20 has been determined and the complex consists of six-membered rings of alternating copper and sulphur atoms connected by sulphur bridges to form chains which are in turn interconnected via a four-membered Cu,S, ring to form a three-dimensional polymer.693 Copper powder reacts with (Et,NCSe),Se under an inert atmosphere to form [Cu(Se,CNEt,)]. When a solution of this compound in CH,Cl, is exposed to air, it darkens rapidly, and spectral measurements indicate the formation of [Cu(Se,CNEt,),]. Molecular weight measurements of the copper(1) compound in benzene show it to be monomeric, in contrast to the dithiocarbamates which are formulated as the polymers [Cu(S,CNR,)}, (n = 2.9-4.6) in various solvents.694 The thermal decomposition of Cu(SC,X,) (X = F or C1) has been studied.695 Substituted 1,2-dithiole-3-thiones (63) react with copper(I1) salts to produce complexes of two types, [CuL,X] (X = C1, Br, or NO,) and [CuL,]X (X = C1, Br, or C10,). The former probably have dimeric structures., l4 The complex [CuLCl] (L = trithiodiacetylacetone) has been reported.696 The structure of the copper(1) complex of 2,5-dithiahexane-1,6dicarboxylic acid has been reported and shows the metal atoms to be surrounded by four sulphur donors from two ligand P-Donor ligands. Oxidation of Et,P by CuC1, at temperatures above -45 C occurs in the following manner :697 Et,P

+ 2CuC1, + [Et,PCl] + [Cu,CI,]+ 2CuC1, Et,PCl, + 2(CuCI-nPEt3)

(2n + l)Et,P

--t

(n = 1 or 3)

(Me,SiCH,),P (siphos) reacts with either CuCl or CuCl, to form [CuCl(siphos)] ;however, in the presence of excess ligand, [CuCl(siphos),] is forrnedP2, X-Ray structural studies on [CuBr(PPh,),],+C,H, show the complex to be M. S. Weininger, G. W. Hunt, and E. L. Amma, J.C.S. Chem. Comm., 1972, 1140. M. M. Khan and A. U. Malik, J. Inorg. Nuclear Chem., 1972,34, 3591. 6 9 2 J. D. Graybeal and S. D. I n g Znorg. Chem., 1972,1l, 3104. 6 9 3 A. G. Gash, E. H. Griffiths, W. A. Spofford, and E. L. Amma, J.C.S. Chem. Comm.. 1973,256. 694 J. G. M. van der Linden and P. J. M. Geurts, Inorg. Nuclear Chem. Letters, 1972,8.903. 695 M. E. Peach, J. Inorg. Nuclear Chem., 1973,35, 1046. h 9 6 A, Furuhashi, M. Kawano, N. Tashiro, and A. Ouchi. J. Znorg. Nuclear Chem., 1972,34,2960. 696a H. van der Meer, J.C.S. Dalton, 1973, 1. 6 9 7 D. D. Axtell and J. T. Yoke, Inorg. Chem., 1973,12, 1265. 6yo

691

Elements of the First Transitional Period

30 1

monomeric and to have essentially trigonal-planar geometry.698 Similar studies on [Cu2Cl,(dppe),],2Me,CO (dppe = Ph,PCH,CH,PPh,) show the metal atoms to be in tetrahedral environments, each being co-ordinated to one terminal chlorine atom, one bidentate dppe molecule, and one bridging dppe m~lecule.~ Mixed donor ligands. Pyridine-2.6-dithiocarbomethylamide[L,(66)] reacts with copper@) compounds to form [CUL,]CI,~~'and the copper(x) complex of o-mercapto-N-methylbenzanilide has also been reported.406 The flavoguinone (12) forms copper(1) complexes in which chelation occurs via N-5 and 0-6.697 Other Copper(1) Compounds. The compounds [CuX(CN-p-C,H,OMe)J (X = C1, Br, or I, n = 1 ; X = C1 or Br, n = 2), [CuX(CNR)L] (X = C1 or Br, R = p-MeOC,H,, L = py, PPh,, AsPh,, phen, or diphos; X = C1, R = Et, L = PPh,) and the cations [(RNC),CUL,-~I+ have been isolated. It is suggested that the [CuX(CNR)] complexes are probably two-co-ordinate and those of formula [(RNC),CuX] and [(RNC)CuLX] (L = unidentate ligand) are probably dimeric in the solid state, with bridging halogeno-groups, and threeco-ordinate in solution. When L = diphos or phen, the complexes are most probably four-co-ordinate in the solid state and partially ionized in solution. The cations are all f o u r - c o - ~ r d i n a t e . ~ ~ ~ Copper(II).--Halides. A synthetic method has been reported for the preparation of very pure CUC~,.,,~An X-ray structural study shows [(Et,NH),CuCl,] to contain anions with a squashed-tetrahedralgeometry (CI-Cu-C1 angles = 135 and 98").'01 The average Cl-Cu-C1 angle in Cs,CuCl, is 129.2", and three independent Cu-Cl distances of 2.244,2.235, and 2.220 A were observed. After correction had been made for crystal forces and thermal motions affecting these bond-lengths, the Cu-Cl distance was calculated to be 2.283A in an isolated anion, and from this a charge distribution of was e~tirnated.~"A structural study on CsCuBr, shows it to consist of facially bridged Cu,Brz- dimers which share corners with six other dimer units to form a three-dimensional network.703 The compound of stoicheiometry (Me,NH),[Cu,Cl,] has been shown by X-ray methods to contain CuCl, chains and CuC1;- tetrahedra. The distortion in the tetrahedra is different from that usually found for such anions in that their symmetry approximates to C," rather than D2d.704 Controlled addition of NNN'N'-tetraethylethylenediamine (teed) to concentrated solutions ot CuCI, in ethanol yields yellow (teedH,)[CuCl,], red (teedH,),(Cu,OCl, o}, and [CuCl,(teed)]. The tetramethyl analogue (tmed) 698

699 700

701 '02

703 '04

P. H. Davis, R. L. Belford, and I. C. Paul, Inorg. Chem., 1973,12,213. V. G. Albano, P. L. Bellon, and G. Ciani, J.C.S. Dalton, 1972, 1938. J. Bailey and M. J. Mays, J. Organometallic Chem., 1973,41, 217. J. Lamotte-Brasseur, L. Dupont, and 0. Diderberg, Acta Cryst., 1973, B29,241. J. A. McGinnety, J. Amer. Chem. SOC., 1972,94, 8406. Ting-I Li and G. D. Stuckey, Inorg. Chem., 1973,12,441. R. M. Clay, P. Murray-Rust, and J. Murray-Rust, J.C.S. Dalton, 1973, 595.

302

Inorganic Chemistry of the Transition Elements

€orms yellow (tmedH,)[CuCl,], [CuCl,(tmed)], and an ill-defined red product. Similar reactions with CuBr, give (teedH,)[CuBr,] (purple), [(teedH)CuBr,] (pale violet), and [CuBr,(teed)]. On heating, [(teed)CuX,] (X = C1 or Br) forms [(Et,en)CuX,] and MeCH0.705 The structure of the [CU,OC~,,]~7 0 6 and is shown as (171). The therml decomposition ion has been reported705>

c1 I

c1

Cl- cu-

I

c1 (171)

of a number of trihalogeno-phenoxo-complexes of copper(rI), [L,Cu(OC,H,X,),] (X = C1 or Br; L = py, PhNH,, Ph,PO, NH,, Me,NCHO, or Me,SO), yields the compounds L,Cu,X,O. The yields of the 0x0-species are higher when the solvent has the ability to autoxidize the reaction and are increased by the addition of hydro peroxide^.^'^ Substituted 1,s-benzodiazepinium (bzdiaz) cations react with CuCl, to form [2,4,8-Me3bzdiaz][CuC1,], [2,4,7,8Similar reacMe,bzdiaz][CuCl,], and [(2-Me-4-Ph-bzdiaz),][C~,Cl,].~~~ tions between 3-bromo-2,4-dimethyl- and 3-bromo-2,4-diphenyl- 1,s-benzodiazepinium cations and CuBr, yield salts of the anions [CuBr,]- and [Cu,Br,]-. 1.r. data indicate the presence of non-brominated cations in both compounds. Copper@) acetate dissolves in HCl, the following equilibria being achieved : Cu,(OAc),

+ 2HC1+

2CuCl(OAc) + 2HOAc

Cu,(OAc),

+ 4HC1

2CuC1,

f

+ 4HOAc

and the reaction of CuC1, with LiCl in acetic acid follows the equations:710 CuCl,

+ LiCl s LiCuC1, + LiCl + LiCuC1,

LiCuC1,

1.r. data have been published for C S C U C ~ ,and , ~ ~thermochemical data for the

'05

706 707

708 '09 'lo

R. Bedford, D. E. Fenton, and M. R. Truter, J.C.S. Dalton, 1972,2345. J. .IDe . Boer, D. Bright, and J. N. Helle, Acta Cryst., 1972, B28, 3436. B. Carr and J. F. Harrod, Canad. J. Chem., 1972,50,2972. P. W. W. Hunter and G. A. Webb, Inorg. Nuclear Chem. Letters, 1973,9,271. P. W. W. Hunter and G. A. Webb, J. inorg. Nuclear Chem., 1973,35, 1457. K. Sawada, H. Ohtaki, and M. Tanaka, J. Inorg. Nuclear Chem., 1972,34,3455.

Elements of the First Transitional Period

303

formation of CsCuCl ,( x = 3,4, or 5) in a lithium-potassium chloride eutectic have been reported. Complexes. N -Donor ligands, When copper salts are dissolved in aqueous ammonia in the presence of iodine and a five-fold excess of KI, [Cu(NH,),](I,), is formed.' 7 1 The structure of the square-planar complex [Cu(NH,),(isocyanurate),] [isocyanurate = (172)] has been determined and the anions are N - b ~ n d e d . ~ "The complexes [Cu(NCO),L,] (L = PhNH,; p-C1-, p-Br-, or

'

p-I-C6H4NH2;0-,m-, or p-toluidi-) have been isolated and all have transsquare-planar structures except the o-toluidine complex, which is polymeric with bridging NCO The reaction of cyclohexylamine (L) with the appropriate copper(I1) salts in ethanol-toluene yields [CuL,Cl,], [CuL,(OH)Cl], [CuL,Cl,], [Cu,OBr,L,], [CuL,(OH)Br], [CuL,Br,], [CuL,(OH)(NO),], [CuL,(NO,),], [CuL,(OH)(ClO,)], and [CuL,(OH)(C104)]. The hydroxy-compounds are dimeric with bridging hydroxy-groups. [CuL,(NH,),]Cl, was also i~olated.~' The new compounds [CuL(SCN),](ClO,),-, [ x = 0, 1, or 2; L = (en),, (Et,en),, (Me,en),, (1,2-pn),, dien, Me,dien, N(CH,CH,NH,),, or N(CH,CH,NMe,),] have been prepared and it was found that the presence of perchlorate ions in the complexes favours Cu-N bonding of the thiocyanate groups only in the case of unusual stereochemistries. Steric factors appear to have a generally predominant influence over electronic effects in determining the mode of bonding of thiocyanate groups.714 The structure of one of the complexes, [Cu(en),(NCS)]ClO,, has been determined,71 as has that of the related compound [ C U ( N C S ~ ) , ( M ~ , ~ ~ Standard ) , ] . ~ ~ ~ thermodynamic functions have been evaluated for the reaction:

'

cuLq+ + x- =2 CUL,X+

(L = en, Meen, NN'-Me,en, or NN-Me,en; X = C1, Br, I, or SCN) and these, together with spectrochemical parameters, show regular trends for each series of anions considered. This indicates that the five-co-ordinate cations with a

'" P. G. Slade, M. Raupach, and E. W. Rndoslovich, Acta Cryst., 1973, B29, 279. 'I2 713 714 715 716

M. Questlerova-Hvastijova, J. Kohout. and J. Gazo, 2.anorg. Chem., 1973,396, 341. G. Ondrejovic, L. Macaskova, and J. Gazo, Z. anorg. Chem., 1972, 393, 173; L. Macaskova, M. Melnik, M. Kabesova, G. Ondrejovic, and J. Gazo, Suomen Kern., 1973,46, 106. A. Cristini and G. Ponticelli, J. Znorg. Nuclear Chem., 1973,35, 2691. M. Cannas, G. Carta, and G. Marongiu, J.C.S. Dalton, 1973,251. A. Pajunen and J. Korverranta, Suomen Kem., 1973,46, 139.

Inorganic Chemistry of the Transition Elements

304

given chelate have the same stereochemistry which is probably square-pyramidal. [CuI(NN'-Me,en),]+ is anomalous in these trends and this is probably ' reacdue to a large distortion towards trigonal-bipyramidal g e ~ m e t r y . ~The tion of Cu(N03),,3H,0 with Et,en in methanol yields [Cu(NO,),(Et,en)]. Magnetic evidence for this compound suggests that the monomer units are held together by weakly bridging nitrate groups.718When CuI, is treated with [Cu(N03),(2-Me- 1,2-pn),] in aqueous solution, [Cu12(2-Me-1,2-pn),] is precipitated. Magnetic measurements on this complex suggest a trans-tetragonal structure.719A re-investigation of the c.d. spectrum of [Cu(R-pn),I2+ has shown previously reported c.d. data to be in error. New values are quoted for this cation and for [ C ~ ( R - p n ) l ~ +The . ~ ~crystal ' structure of [Cu(l,3-pn),(p-ClC,H,CO,),] has been reported.721 Structural studies on [Cu(N,)Br(HN(CH,CH,NEt,)}], show the metal atom to be in a distorted trigonalbipyramidal environment, the bromine atom being situated in the equatorial plane and the azide group in the apical position. The distortions away from idealized trigonal-bipyramidal geometry are attributed to steric repulsions between the co-ordinated anions and the triamine ligand.721" The related consists of polymeric complex [Cu(OAc){HN(CH,CH,CH2NH2)2]]C104 cations, the metal atom being in a primarily square-planar environment ([CuN,O] core) with two weakly bound acetate groups occupying the tetragonal positions. 7 2 + The trigonal-bipyramidal complexes [CuX,(LH),]X [X = C1 or Br, L H + = Hk(CH,CH,),N] have been reported.', The substituted benzodiazepines (119) form complexes with Cu(ClO,), which are predominantly square-planar, but as the amount of methyl substitution is decreased, five-co-ordinate complexes are formed with methanol occupying the fifth co-ordination site.'*' (-)Spartein (73) forms the complexes [Cu(spartein)X,] (X = C1, Br, or I).318 [CuIL2],I(C10,) (L = 2,2'-bipyridylamine) has been found to have trigonalbipyramidal co-ordination, the iodo-ligand occupying an equatorial The structure of [Cu(py),(NO,),] has been determined and the overall molecular geometry is very similar to that of the Co" and Zn" analogues. The nitrate groups are co-ordinated in an asymmetric bidentate manner in all three compounds, and the large distortions observed in the case of copper are due to a static Jahn-Teller effect.320 The structure of [Cu,Br,O(py),] is very similar to that of [CU,OC~,,]~- shown in (171), the pyridine ligands occupying terminal positions on each metal atom.7 24 Structural studies have

,

717

'18 '19 72"

'210

722

'23 lZ4

R. Barbucci, P. Paoletti, and L. Fabrizzi, J.C.S. Dalton, 1972, 2593. R. Nasanen, M. Nasakkala, and H. Hero, Suornen Kern., 1973,46, 100. R. Nasanen, M. Nasakkala, and L. Jokisalo, Suornen Kern., 1973,46,48. R, A. Haines and E. W. Crews, Canad. J. Chern., 1972, 50, 3390. R. Uggla, 0. Orama, and M. Klinga. Suomen Kern., 1973.46,43. 8. F. Ziolo, M. Allan, D. D. Titus. H. B. Gray. and Z . Dori. Inorg. Chem., 1972. 11. 3044. B. W. Skelton, T. W. Waters. and N. F. Curtis, J.C.S. Dalton, 1972, 2133. J. E. Johnson and R. A. Jacobson. J.C.S. Dalton, 1973, 580. D. D. Swank, D. 0. Nielson. and R. D. Willett, Inorg. Chim. Acta. 1973, 7,91.

305

Elements of the First Transitional Period

also been reported for the polymeric compounds [C~Br,(2-Mepy),],~~~ [CuX,(2-NH,CH,CH2py)] (X = C1 or Br),726the dinuclear, hydroxy-bridged comand the square-pyramidal plex [Cu,(OH),(2-NH,CH,CH,py)2](C104)~,7~7 complex [CUC~(~-~~CH,NH(CH,),NHCH,-~-~~)~C~.~~~ Earlier spectroscopic studies have indicated that [Cu(bipy),]’ may exhibit a dynamic Jahn-Teller effect and have six equal Cu-N bond lengths at room temperature; however, an X-ray structural study on the perchlorate salt has shown this not to be the case, the axial Cu-N bonds being distorted by unequal amounts.729[Cu(phen),](ClO,), also shows distorted octahedral coordination with equal axial distortion^.^^' Photo-reduction of [Cu(2,9-Me2phen)]’+ in methanol yields the corresponding copper(r) and photoredox reactions of bis-(3,3’-dimethylene-4,4‘-dimethyl-2,2’-diquinolyl)copper(11) have also been The complexes [CuLX,] (L = bipy or phen; X = C1 or Br or X, = S0,)57*733 and [ C ~ ( b i p y ) ( o x )have ] ~ ~ ~been isolated. The photo-redox behaviour of such compounds has been examined both in the solid state and in solution.735 The eight-co-ordinate complex [Cu(napy),J(ClO,), (napy = naphthapyridine) has been isolated and its geometry discussed in terms of dodecahedra1 stereochemi~try.~~ The related compound [Cu(napy),(NO,),] is probably polymeric with bridging nitrate groupss9 and complexes [Cu(napy),X,] (X = C1 or Br) are both dimeric in the solid state, the metal atom probably having square-pyramidal co-ordination.’ The complexes [CuL,(NO,),], [CuL,(H,O)(NO,),], [CuL,X,] (X = C1, Br, or I; n = 1or 2),and [CuL,(NCS),] (n = 3 or 4)(L = 1,2-dimethylimidazole) have been reported.60. 2-Benzylbenzimidazole (L) forms the complexes [CuX,L,] (X = C1, Br, NO,, or $0,)and (LH),[CuX,] (X = C1 or Br).737 Structural studies have been reported for tetragonal pyramidal [ C U L , C ~ , ] , ~ ~ ~ distorted octahedral [CUL,SO,],~~~ [CUL,(L-H)C~],~~~ and [Cu,L,(L - H),(C104)4]741(L = imidazole). The 2-substituted pyrazoles, 2-aminothiazole (atm) and 2-bromothiazole (brt), form the octahedral complexes [Cu(atm),X,] +

725

72h 727 728 729

730 731 732

733 734

735

73h 137

738

739 740 741

L

P. Singh, D. Y. Jeter, W. E. Hatfield, and D. J. Hodgson, Inorg. Chem., 1972, 11, 1657. V. C. Copeland, P. Singh, W. E. Hatfield, and D. J. Hodgson, Znorg. Chem., 1972, 11, 1826; V. C. Copeland, W. E. Hatfield, and D. J. Hodgson, Znorg. Chem., 1973, 12, 1340. D. L. Lewis, W. E. Hatfield, and D. J. Hodgson, Inorg. Chem., 1972, 11, 2216. N. A. Bailey, E. D. McKenzie, and J. M. Worthington, J.C.S. Dalton, 1973, 1227. 0. P. Anderson, J.C.S. Dalton, 1972, 2597. 0. P. Anderson, J.C.S. Dalton, 1973, 1237. S. Sundararajan and E. L. Wehry, J . Inorg. Nuclear Chem., 1972, 34, 3699. P. Thomas, H. Spmdler, and D. Rehorek, Z . Chem., 1973. 13,188. P. Thomas, D. Rehorek, and H. Spindler, Z . anorg. Chem., 1973,397, 138. F. A. Walker, H. Sigel, and D. B. McCormick, Inorg. Chem., 1972, 11,2756. P. Birner, R. Held, and U. Ziegler, Z . Chem., 1973, 13, 190; 0. Gurtler, K. P. Dietz, and P. Thomas, 2. anorg. Chem., 1973,396, 227. K. Emerson, A. Emad, R. W. Brookes, and R . L. Martin, Inorg. Chem., 1973, 12,978. M. V. Artemenko, K. F. Slyusarenko, P. A. Suprunenko, G . I. Kal’naya, and A. G . Mazurenko. Russ. J . Inorg. Chem., 1972, 17, 847. B. K. S. Lundberg, Acta Chem. Scand., 1972, 26, 3977. G. Fransson and B. K. S . Lundberg, Acta Chem. Scand.,1972,26, 3969. B. K. S . Lundberg, Acta Chem. Scand., 1972,26, 3902. G. Ivarsson, B. K . S. Lundberg, and N. Ingri, Acta Chem. Scand., 1972,26, 3005.

306

Inorganic Chemistry of the Transition Elements

(X = C1 or Br), [Cu(atm),Cl,], and [Cu(brt),X,] (X = C1 or Br).’,’ The complexes [CuL,(NO,),] (L = 2-methylbenzimidazole, 2-methylbenzoxazole, 2methylbenzothiazole, 2-hydroxymethylbenzothiazole, 2-hydroxyethylbenzothiazole, or 2-methylbenzoselenazole) have been prepared and are probably polymeric with bridging L l i g a n d ~ . ~N-Benzothiazol-2-yl-2-pyridylmethylene~’ amine reacts with copper(I1) to give [Cu(H,O)(pic)L]ClO, [pic = picolinate, L = (173)], the structure of which has been determined. The metal atom was found to be five-co-ordinate, the bidentate (NO)-picolinate ion and L occupying the basal plane and the water molecule occupying the apical position. It appears that the picolinate ion could be formed by hydrolysis of (173) followed by oxidation of the pyridine-2-carbaldehyde produced by the ligand itseIf, both processes being catalysed by the copper complex.743 Structural studies on [CuBr,(adeH),]Br, show the adeninium ligands to be unidentate and coordinated via N-9, protonation having occurred at N-1 ;744 however, the dimer H

[Cu,( ade),( H, O),](C104),,2H 2O contains bridging adenine ligands.745 Cu, C18(adeH),,4H,0 was obtained in an attempt to crystallize Cu(ade)Cl, from HCI solution. The adeninium ions bridge metal atoms via N-3 and N-9.746 The reaction of copper(11)ions with (CONHNH,), and MeCHO gives a greenbrown solution which becomes purple in the presence of oxygen. This has previously been thought to be due to a copper-oxygenyl compound; however, in the presence of ClO; ions, the compound (NH,)2[C,6H,,N806CuH,0), NH,C10,,6H20 was isolated, the structure ofwhich is shown as (174).There is no evidence for the presence of molecular oxygen in the complex,which is formed by a series of condensations of (CONHNH,), with acetaldehyde in the presence of copper, The oxygen is probably required to oxidize a copper(1) intermediate in this reaction.747 Copper(I1) salts react with (175) (L) in basic solution to yield a blue complex which readily converts into a more stable red form. This conversion can be prevented by the addition of acid a few seconds after mixing the reagents, and in the presence of both chloride and perchlorate ions the complex [CuL],Cl(ClO,), was isolated. X-Ray structural studies show this complex to have 742

743 144

745

14‘ 747

M. V. Artemenko, G. I. Kal’naya, S. M. Karal’nik, A. V. Kokal, and P. A. Suprunenko, Russ. J . Inorg. Chem., 1972, 17, 523. A. Mangia, M. Nardelli, C. Pelizzi, and G. Pelizzi, J.C.S. Dalton, 1972,2483. P. de Meester and A. C. Skapski, J.C.S. Dalton, 1973, 424. A. Terzis, A . L. Beauchamp, and R. Rivest, Znorg. Chem., 1973, 12, 1166. P. de Meester and A . C. Skapski, J.C.S. Dalton, 1972,2400. G. R. Clark, B. W. Skelton, and T. N. Waters, J.C.S. Chem. Comm., 1972, 1163.

Elements of the First Transitional Period

307

structure (176), the perchlorate ions being hydrogen-bonded to the macrocyclic ligands. When bromide or iodide were used instead of chloride, [CuLXIC10, (X = Br or I) were isolated.748 Thermodynamic data have been reported for the formation of copper(I1) ClO

I

74M

R. A. Bauer, W. R. Robinson, and D. W. Margerum, J . C . S . Chem. Comm., 1973, 289.

308

Inorganic Chemistry of the Transition Elements

complexes of 3,2,3-tet.749The macrocyclic ligand (127) forms the complexes [CuLIX, (X = ClO,, NO,, or NCS) and [ C U L ] C ~ , , ~ H , OStructural .~~~ studies on (177) show the tetramethylene bridge to be in the half-boat form, the metal atom being in a planar e n ~ i r o n m e n t . ~The ~ ' complex (77; M = Cu)

shows three electrochemical reduction steps involving one, one, and three electrons in turn, and does not undergo electrochemical oxidation. It has been suggested that the first reduction step involves a MO of primarily metal character, whereas the remainder involve orbitals of primarily ligand character.333 It has been found that a zinc porphyrin can form a covalent link to a copper prophyrin uia a peptide linkage containing either a C2H, or a p-C,H, unit. Energy transfer within the linked systems has been studied.330 The reaction of porphyrins with certain copper(I1)P-diketonates to form copper(11) porphyrins has been found to be accelerated by light.751 The thermodynamics of dimerization of copper(I1) phthalocyanine-4,4',4",4'"-tetrasulphonate have been Magnetic measurements on ([Cu(dmgH)Cl](p-Cl,)[Cu(dmgH)Cl]]show the complex to have a triplet ground state and this is the first chloro-bridged Cu" dimer of this type, although several such hydroxy-bridged compounds have been reported.753 Benzonitrile forms the complexes [CU(P~CN)~X,] (X = SbCl, or InCl,, n = 6 ; X = FeCl,, n = 4)62 and the compounds CuL, (LH = 2,2',4,4',6,6'-hexachlorotriazene or 2',4,6'-tribromo-2,4,6trichlorotriazene) have been reported.754The structures of both triclinic and tetragonal forms of the bis-complex of (178) have been determined and are very

749

75Q 751 752 753

754

G. R. Hedwig and H. K. J. Powell, J.C.S.Dalton, 1973, 793. D. Losman, L. M. Engelhardt, and M. Green, Inorg. Nuclear Chem. Letters, 1973, 9, 791. A. Bluestein and J. M. Sugihara, J . Inorg. Nuclear Chem.. 1973, 35, 1048. R. J. Blagrove and L. C. Gruen, Austral. J . Chem., 1973, 26, 225. N. T. Watkins, E. E. Dixon, V. H. Crawford, K. T. McGregor, and W. E. Hatfield, J.C.S. Chem. Comm., 1973, 133. B. E. Zaitsev, V. A. Zaitseva, B. N. Ivanov-Emin, E. S. Lisitsyana, and A. I. Ezhov, Russ. J . Inorg. Chem., 1973, 18, 30.

Elements of the First Transitional Period

309

similar, the co-ordination around the metal atoms being distorted tetrahedral? An n.m.r. study of the interaction of Cu2 with thyroxine, 3,5,3'-tri-iodothyroxine, 3,5-di-iodothyronine, and 3,5-di-iodotyrosine has been +

0-Donor ligands. Benzene solutions of copper@) complexes of ( - )-ephedrine, $-ephedrine, N-ethylnorephedrine, and N-n-butylnorephedrine take up CO,. When iso-octane or cyclohexane are used as solvents, crystalline products which are stable under an atmosphere of CO, are formed. Analytical data are indicative of 1 :1 CO, adducts. It has been shown that the copper(x1)chelates of these ligands are trimeric and it is suggested that adduct formation requires prior dissociation of these species to monomeric forms.757 Solute structuring of aqueous CuC1, solutions has been studied by X-ray diffraction. Copper ions have six nearest neighbours and extensive sharing of chloride ions by adjacent copper@)units is observed. The mean species present are Cu,Cl,(H,O), and Cu5Cllo(H20),, at 3.18 and 4.35 moll- ', respectively. For each species the average Cu-0 distance is 1.93A and the average Cu-C1 distance is 2.43A. The oxygen atoms appear to occupy equatorial sites, the chlorine atoms being axial.7 Thermodynamic functions have been evaluated for copper(1x) ions in aqueous solution759and for the interaction of copper(r1) ions with sulphate ions in aqueous solution.68 The structure of anhydrous Na,Cu(CO,), has been reported. The copper atoms are co-ordinated to four oxygen atoms of four bridging carbonate groups, such that each metal atom is in a square-planar environment (Cum - - Cu = 4.89 A).760 Tl,[Cu(SO,),], however, contains distorted octahedral copper surrounded by six oxygen atoms from six different sulphite Thermal dehydration of Cs2Cu(S0,),,6H,O yields the dihydrate, Cs,Cu,(OH)(SO,),, (2 - x)H,O and two forms of the anhydrous compound.762It has been suggested that the product of reaction of copper(I1) salts with HIO, or alkaline iodates is Cu(I03),,H,0. The mineral bellingerite has the formula 3Cu(IO3),, 2H,O and X-ray and thermochemical studies have established that the synthetic product has the same composition.763X-Ray and magnetic studies have been reported for Cu,(OH),H,IO,,H,O and its dehydrated analogue.764 Structural studies on CuLi(PO,), show that six PO, tetrahedra are linked to LiO, and CuO, octahedra to form a three-dimensional network.765 The structure of CuNa(PO,), has also been reported.766 When a stoicheiometric mixture of CuO and WO, is ground together in a vibrating mill, CuWO, is C. H. Wci, Inorg. Chem., 1972, 11, 2315. W. R. Walker, V. H. L. Shaw, and N. C . Li, J . Amer. Chem. SOC.,1973,95, 3015. 757 J. Vlckova and J. Barton, J.C.S. Chem. Comm., 1973,306. 7 5 8 J. R. Bell, J. R. Tyvoll, and D. L. Wertz, J . Amer. Chem. SOC.,1973, 95, 1456. 7 5 9 V. P. Vasil'ev and B. T. Kunnin, Russ. J . Znorg. Chem., 1972, 17, 1129. 7 h 0 P. C. Healy and A. H. White, J.C.S. Dalton, 1972, 1913. 7 6 1 I. Hjerten and B. Nyberg, Acta Chem. Scand., 1973,27, 345. 7 6 2 M. Tardy, J.-M. Bregeault, and G. Pannetier, Bull. SOC.chim. France, 1972, 2658. 763 K. Nassau and J. W. Shiever, Znorg. Chem., 1972, 11, 2552. 764 R. Uggla, 0. Orama, M. Klinga, C. Harjulin, and P. Pusa, Suomen Kem., 1873,46, 148. 7 6 5 M. Laugt, I. Tordjman, J. C. Guitel, and M. Roudant, Acta Cryst., 1972, B28, 2352. "' M. Laugt, I. Tordjman, J. C . Guitel, and G. Bassi, Acta Cryst., 1972, B28, 2721.

755

756

310

Inorganic Chemistry of' the Transition Elements

formed.' O2 Thermal decomposition studies on CuCr,O, have been CO, undergoes a facile insertion reaction into the Cu-0 bond of Cu(OMe), in pyridine at room temperature to produce Cu(OCOOMe),, which is a square-planar monomer. The CO, is labile, in that heating this complex to 80°C in pyridine-DMF reverses the reaction. The reaction of [(acac)Cu(OMe),Cu(acac)] with CO, under similar conditions yields [(acac)Cu(OCOOMe)(py)], which is also ~quare-planar.,~~ N.m.r. measurements on a range of carboxylates in the presence of copper(@ have been used to locate the binding sites in aqueous solution. 2- and 3-hydroxy- and 2-alkoxy-carboxylates are predominantly bidentate, whereas 4-hydroxy- and 3-alkoxy-carboxylates are mainly unidentate. Malonate, succinate, 2-methylmalate, and diglycollate are all bidentate.769 [CuL(CH,CH,CO,),] (L = p-toluidine) has a structure composed of well-separated one-dimensional chains in which the copper atoms are bound in a square-pyramidal configuration to four carboxylate oxygen atoms and the nitrogen atom of L. Two of the four independent carboxylate groups function as bidentate ligands and form triatomic bridges between copper atoms. The remaining two carboxylate groups form monatomic centrosymmetricbridges between pairs o f m e t a l a t ~ r n s[C~(H,O)(O-B~C~H,CO,)~] .~~~ is a centrosymmetric dimer with the four benzoate groups forming syn-syn bridges between metal atoms (Cu-Cu = 2.624 Na,[Cu(dl-tartrate)], 5H,O contains centrosymmetric [Cu,(d-tartrate)(I-tartrate)14- anions, the metal atom being in a square-planar environment.',, The square-planar compounds [Cu(ox)],O.SH,O, [Cu(ox)L] (L = py or phen), and [Cu(ox)L,] Structural (L = PhNH,, en, MeNH,, or EtNH,) have been studies on [Cu(ox)(NH3),],2H,0 show the metal atoms to be six-co-ordinate as shown in (179).774Thermal decomposition studies on copper oxalate have been reported.113

Attempts to prepare trialkylamine complexes of copper(I1)by the reaction of [CU(R'OH)~X,] with R:N (R' = Me, Et, or n-C,H, 2 ; n = 6-9; R2 = Me or Et; X = C10, or BF,) did not yield the expected products but [Cu(R;NH),,7h7

768 769

770

77'

772 773 7'4

N. E. Konyukhora, I. I . Kalinichenko, and A. 1. Puttov, Russ. J . Inorg. Chem., 1972, 17, 935. T. Tsuda and T. Saegusa, Inorg. Chem., 1972,11,2560. K. B. Dillon and F. J. C. Rossotti, J.C.S. Dalton, 1973, 1005. D. B. Yawney, J. A. Moreland, and R. J. Doedens, J. Amer. Chem., SOC., 1973,95, 1164. W. Harrison, S. Rettig, and J. Trotter, J.C.S. Dalton, 1972, 1852. R. J. Missavage, R. L. Belford, and I. C. Paul, J . Coordination Chem., 1972, 2, 145. J. Malaviya, P. R. Shukla, and L. N. Srivastava, J. Inorg. Nucleuv C k m . , 1973, 35, 1706. J. Garaj, H. Langfelderova, G . Lundgren, and J. Gazo, Coll. Czech. Chem. Comm., 1972,37,3181.

Elements of the First Transirional Period

31 1

(RiN),(RIO)nX,] (n = 1-8; m = 0-3).76. The structure of the octahedral complex [Cu(HOCH,CH,OH),]SO, has been reported.775 The complexes [CuL,(SbCl,),] [L = p-MeC,H,CHO, o-C1C6H4CH0, p-ClC,H,CHO, PhCHO, Ph,CO, Me,CO, HCO,Me, or EtOAc, n = 4 ; L = CH,(CO,Et),, n = 31 have been i~olated.~’ The thermal decomposition of [Cu(acac),] has been studied6’ and the crystal structure of cis-[Cu(py),(hfac),] r e p ~ r t e d . ” ~ The reaction of [Cu(hfac),],H,O with 1,bdiazabicyclo[2,2,2]octane (ted) in 1: 1 and 1:2 mole ratios yields [Cu(hfac),(ted)] and [Cu(hfac),],2ted, respectively. The reaction of [Cu(hfac),] with ted (1:1 mole ratio) in the presence of hfacH yields [Cu(hfac),],(ted). The structure of the 1: 1 complex has been reported, the metal atom being co-ordinated to four equatorial oxygen atoms, the axial positions being filled by nitrogen atoms of bridging ted l i g a n d ~ .Structural ~~~ studies on [(acac)Cu(p-PhCH,O),Cu(acac)] show the molecule to be tetrameric, two units being joined by four apical Cu-0 bonds involving one benzoxy-oxygen atom and one acac oxygen atom of each dimer The chelate Cu(Me,C,H,COCHCONHMe), has been prepared,250and the compounds Cu(3-R-acac), (R = ally1 or propenyl) have been isolated from the respective P-diketone and copper(r1) salts. However, a similar reaction of 3-ethylidene-acacHgave [C~(acac),].~’ Heptane-2,4,6-trioneand its 3-methyl, 3,5-dimethyl,and 2-methoxy-derivatives (LH,) form the complexes [Cu(LH),], and the unsubstituted and 3-methyl compounds also form Cu,L,. Transformation of Cu(LH), into Cu,L, is fairly easy for heptane-2,4,6-trionebut more difficult for the 3-methyl derivative and this is interpreted as a steric effect of the methyl The reaction of l77-dipheny1heptane-l,3,5,7-tetraone (LH,) with copper(1r) salts in methanolwater or acetone-water solutions in the presence of either NaOH or NaOAc as added base yields [Cu,L,(H,O),] and [Cu,L,],H,O. The former probably has a structure similar to the cobalt analogue shown in (81), whereas the latter probably has structure (180).349 [Cu(bipyO,)Br,] shows antiferromagnetic interactions, whereas [Cu(bipyO,)X,] (bipyO, = 2,2’-bipyridyl 1,l’-dioxide,X = C1 or NO,) and [Cu-

B. M. Antti, B. K. S. Lundberg, and N. Ingri, Acta Chem. Scand., 1972, 26, 3984. J. Pradilla-Sorzano and J. P. Fackler, Znorg. Chem., 1973, 12, 1174. 777 R. C. E. Belford, D. E. Fenton, and M. R. Truter, J.C.S. Dalton, 1972, 2208. 777a J. E. Andrew and A. B. Blake, J.C.S. Dalton, 1973, 1102. 7 7 8 F. Sagara, H. Kobayashi, and K. Ueno. Bull. Chem. Soc. Japan, 1972. 45. 794.

’15

776

312

Inorganic Chemistry of the Transition Elements

(pheno)X,] (pheno = 1,lO-phenanthroline 1-oxide; X = C1 or Br) are magnetically n 0 r m a 1 . l ~2,6-Lutidine ~~ N-oxide (L) forms the planar complex [CuL,(ONO,),] and the six-co-ordinate polymer [CuL,(NCS),], which contains bridging thiocyanate groups.79 The free-radical ligands (181) and (182) form the complexes CuLk and CuL;Cl, [L’H = (181); L2 = (182)].352 The complexes [Cu(morPO),X,] (morPO = trimorpholinophosphine oxide; n = 0.5-4; X = C1, Br, I, BF,, NCS, or NO,) have been prepared, and comparison with other phosphine oxide complexes shows that steric factors of ligand size and anion size control the co-ordination numbers.82 Ph,P(O)CH,CH,P(O)Ph, (depo) forms the complexes [Cu(depo)X,] (X = C1, Br, or NO,) and [C~(depo),](ClO,),.~~~ The complexes [Cu(HMPA),(NO,),] and [Cu(NIPA)(NO,),] (HMPA = hexamethylphosphoramide, NIPA = nonamethylimidodiphosphoramide) have been prepared and both contain co-ordinated n i t r o - g r ~ u p sThe . ~ ~ structure of [Cu((Me,N),P(O)CH,P(O)(NMe,),),l(ClO,), has been determined and the [CuO,] octahedra are slightly d i ~ t o r t e d . ~ The same group have also determined the structure of [Cu((Me,CHO),P(O)CH,P(O)(OCHMe,)},](C10,),, which has a similar co-ordination geometry, indicating no appreciable static Jahn-Teller effect. These authors investigated a wide range of previously rqported structures of copper(r1) octahedral complexes and found that there is negligible static Jahn-Teller distortion in such complexes with equivalent donor sites.780 The complexes n = 1 or [CuLnX2] [L = (Me,N),P(0)NMeP(O)(NMe2)NMe,),; 2; X = BF,, BPh,, NO,, or Cl] have also been prepared.84 Di-(2-ethylhexyl)phosphonic acid (HX) forms the complex (CuX,),, which is ~quare-planar.~~’ It has been found that hydrolysis of ATP is considerably reduced when the complex [Cu(bipy)(ATP - H,)] is formed in which the metal atom is bonded to two of the phosphate groups of ATP.781The reaction of (RSO,),Cu(OH,), with bipy in acetone yields [(RS(O)O),Cu(bipy)] and [(RS(O)O),Cu(bipy),] whereas the reaction in pyridine gives [{RS(O),),, monosulphoxide and its 2Cu(bipy),] (R = P - M ~ C , H , ) . ~ ~1,3-Dithiane phenyl-analogue (L) form the complexes [CuLnX2] (n = 4 or 6 ; X = C10, or BF4),86and the complex [CuL,](ClO,), [L = (183)l has been isolated in both red and orange forms which both have the same gross tetrahedral geometry;

’’

779

781 782

P. T. Miller, P. G. Lenhert, and M . D. Joesten, Inorq. (%em., 1972, 1 1 , 2211 P. T. Miller, P. G. Lenhert, and M. D. Joesten, Znorg. Chem., 1973, 12, 218. D. H. Buisson and H. Sigel, Angew. Chem. Znternar. Edn., 1972, 11, 1025. E. Linder, I . P. Lorenz, and D. Langer, Chem. Ber., 1973, 106. 404

Elements of the First Transitional Period

313

however, the red form is less distorted than the orange.783Dioxan (dx)and 1,2dimethoxyethane (dme) form the complexes [(dx),Cu(dx),Cu(dx),](ClO,), and [Cu(dme),J(C10,),.87 S- and Se-donor ligands. Na,S,CC,H,, which can be prepared from sodium cyclopentadienide and CS, in THF, reacts with CuBr, in acetonitrile at -30°C to form [Cu(C,H,CS,),I2-, which was isolated as its Et,N+ salt. Spectral studies indicate the presence of very covalent out-of-plane Cu-S bonds.^^, The complex [Cu(S,CNPr",),] is dimeric in the solid state, with metal atoms in tetragonal-pyramidal en~ironrnents,~~, whereas [Cu(S,CNMePh),] is isostructural with the analogous nickel(I1) complex and is monomeric.609The reaction of [Cu(S,CNBu,),],MBr, (M = Zn, Cd, or Hg) and bromine in stoicheiometric quantities or the reaction of M(S,CNBu,), and [Bu,bitt][Cu,Br,] [Bu,bitt = 3,5-bis-(NN-dialkyliminium)-1,2,4-trithiolan) yields [CU,(S,CNBU,),][MB~,]~. The structure of the cadmium complex has been determinedand the cation contains one copper atom with distorted octahedral geometry, the other two being square-pyramidal. The anion is Cd,Brz-. E.s.r. measurements suggest that the unpaired electron is localized on one copper atom and that the cation can be best described as [{CU~~'(S,CNBU),),{ C U " ( S ~ C N B U , ) ~ ) ][Cu(S,CNEt,),] +.~~~ forms 1: 1 adducts with py, 3picoline, 4-picoline, and 3 , 4 - l ~ t i d i n e . ~ ~ ~ The complexes (184) have been prepared by the reaction of the appropriate substituted biuret with anhydrous CuCl, in alcohol. The golden-yellow compounds have unusual magnetic moments (1.1 1-1.35 BM).788Six new mixed thiourea (tu) complexes, in which the +2 oxidation state is stabilized by the choice of suitable ligands,have been obtained. They are [Cu(bipy),(tu)](ClO,),, [Cu(~hen),(tu)](C10,),, [Cu(salenHtu)], [Cu(pibHtu)](C10,),, [cu(tac)(tu)], iH,O, and [Cu2(pid),(tu)],2H,O [pib = NN-tetramethylene-bis-(2-pyridinaldimine); tac = bis(acetv1acetone)trimethylenediamine. pid = pyridine-2,6R'HN

NHR'

H N)=s,

)=s' R'HN

c 2+/s4NH u

2c1-

's=( VHR'

(184) K' = R2 = Ph or p-tolyl R' = Ph, R2 = 0- or p-tolyl R' = Me, RZ = p-tolyl 783

784 785 786

787 788

G. L. Seebach, D. K. Johnson, H. J. Stoklosa, and J. R. Wasson, Itrorg. NuiIcur Chem. Lrrlers. 1973, 9, 295. P. C. Savino and R. D. Bereman, Inorg. Chern., 1973, 12, 173. G. Peyronel, A. Pignedoli, and L. Antoline, Actu Cryst., 1972, B28, 3596. J. A. Cras, J. Willemse, A. W. Gal, and B. G. M. C. Hummelink-Peters, Rec. Truu. chirn., 1973, 92, 641. J. B. Farmer, F. G. Herring, and R. L. Topping, Cunud. J . Chern., 1973, 51, 1530. K. P. Srivastava and N. K. Agarwal, 2.anorg. Chern., 1972,393, 168.

3 14

Inorganic Chemistry of the Transition Elements

d i ~ a r b o x y l a t e ] .The ~ ~ ~structure of Cu,PSe, has been r e p ~ r t e d . ~Thioxan ” (tx) forms the complex, [(tx)3(03C10)Cu(tx),Cu(OC103)(tx),](C104)2.87 Mixed donor ligands. CuC1, reacts with 6-methylpyridine-2-phosphonate (E6MPP)to form the tetrahedral complex [Cu(E6MPP),].” The related ligands 2-py-P(O)(OEt), and its 4-methyl analogue (L) form the square-planar complexes [CuL,]X, (X = C10, or BF,) and the five-co-ordinate complex [CUL,ONO,]NO,?~~The structure of [Cu{py-2,6-(C02),} (py-2,6-(C02H), >I, 3H,O has bCen reported by two groups and the metal atom is in a distorted octahedral environment.792 Copper(r1) hydroxide or chloride react with 2pyridinol to form [Cu(2-pyO),],pyOH, magnetic measurements on which suggest a dinuclear structure.7932-Benzenesulphonamidomethylbenzimidazole (LH) forms the complexes [CuL,] and [ C U L , ] , H , O , ~ and ~ ~ spinacine forms the complexes [HCu(spin)I2+,[H,Cu(spin),12+, and [HCu(spin),] in which the ligand is probably bidentate, co-ordinating in a similar manner to glycineP3, [CuL,X,] (L = benzoxazole; X = C1, Br, or NO,) complexes have been isolated. The magnetic moments of the chloride and bromide are different from those previously reported for these compounds and although the same preparative conditions were used, the authors suggest they may have isolated new stereochemical forms of the complexes.794 The structure of the transsquare-planar complex bis(pyrazine-2-carboxamido)copper(11)diperchlorate has been reported.795 Cu(C10,),,6H20 reacts with L-arginine in water to form [Cu(ArgH),(ClO,),], which contains two bidentate perchlorate groups and N-bonded arginine molecules. Recrystallization of this compound from water over 24 h yields [Cu(ArgH),(H20),](C10,),, in which the arginine molecules are bidentate and the water molecules occupy axial sites. Pressing the dihydrate into a KBr disc leads to the anhydrous compound being re-formed.796 The structure of [Cu”(~-tyrosinate),] has been reported.797Spectrophotometry, polarography, and potentiometric titrations show [CU(L-bzopro)(~-bzopro)]to be more Structural stable than [CU(L-bzopro),] (bzopro = N-benz~ylprolinate).~~~ studies show trans-[CU(L-bzpro)(~-bzpro)](bzpro = benzylprolinate) to have both benzyl groups directed towards apical positions, whereas trans-[Cu(Lbzpro),] has one benzyl group twisted in the opposite direction, distorting the chelate ring to which it is attached away from planarity.799Electronic spectra A. Montenero and C. Pellizzi, Inorg. chem. Acta, 1972,6, 644. R. Ott, W. Klingen, and H. Hahn, Naturwiss., 1972, 59, 364. 7 9 1 A. N. Speca, L. L. Pytlewski, and N. M. Karayannis, J . Inorg. Nuclear Chem., 1972, 34, 3671. 792 M. Biagini-Cingi, A. Chiesi-Villa, C. Guastini, and M. Nardelli, Gazzettu, 1972, 102, 1026; C. Sarchet and H. Loiseleur, Acta Cryst., 1973, B29, 1345. 7 9 3 S. Emori, I. Okano, and Y. Muto, Bull. Chem. SOC.Japan, 1972, 45, 3717. 7 9 4 G. J. Hamilton and E. Kokot, Austral. J . Chem., 1972, 25, 2235. M. Sekizaki, Acta Cryst., 1973, B29, 327. 796 S. T. Chow and C. A. McAuliffe, Znorg. Nuclear Chem. Letters, 1972,8, 913. 7 9 7 D . Ven Der Helm and C. E. Tatsch, Acta Cryst., 1972, B28, 2307. 7 y 8 V. A. Davankov, S. V. Rogozhin, and A. A. Kurganov, Russ. J . Inorg. Chem., 1972,17, 1126. lYy G. G. Aleksandrov, Yu. T. Struchkov, A. A. Kurganov, S. V. Rogozhin, and V. A. Davanko.. J.C.S. Chem. Comm., 1972, 1328. 789

790

’”

Elements of the First Transitional Period

315

and optical properties of Cu2+ complexes of L-amino-acids have been interpreted in terms of the conformations adopted by the chelate r i n g ~ . ~ ~ ~ A study of the Cu2+-G1y-~-His-Gly(L) system shows [CuL] to be formed at pH 3.0, [CuL], [CuL2], [Cu2L], and [Cu,,L,,] to be formed at pH 4.5, [CuLJ, [Cu,L,], and possibly [Cu,,L,,] to be formed at pH 7.0, and [CuL2], [Cu3L,], [Cu,,L,,], and possibly [Cu15L3,] to be formed at pH 10.0 A structural study on [Cu(L - H)],xH,O (x 12) shows the a-amino-peptide and imidazole nitrogen atoms to be co-ordinated to the metal, pairs of chelates being held together by carboxylate bridges. Each dimer unit is surrounded by four others forming a three-dimensional network with water molecules occupying channels therein. Small-angle X-ray scattering indicates that a similar structure exists in solution.800 The soluble copper(r1) complexes of poly-L-histidine (plh) formed in the pH range 5-14 with a Cu:histidine ratio of 1:4 have been investigated. Four protons per copper are released at pH 3.0-4.5 and a fifth is released in the range pH 4.5-6.5. On the basis of e.s.r. and spectral evidence it was concluded that the complex formed at pH 5 has the copper atom co-ordinated to one peptide and three imidazole nitrogen atoms, and at pH 14 four consecutive peptide nitrogen atoms occupy a distorted square-planar co-ordination sphere, an imidazole nitrogen atom occupying the axial site.801The reactions of copper(I1) complexes of triglycine, tetraglycine, and trialanine with edta are catalysed by the presence of amino-acids. Steric hindrance prevents edta from acting as an effective nucleophile to the copper-oligopeptide complexes, and the postulated role of the amino- acids is the formation of a species with only one Cu-N(peptide) bond. This complex, [Cu(L - H)(aa)]- (L = oligopeptide), allows nucleophilic attack by a tertiary nitrogen atom of edta on a planar copper site.802 Treatment of Cu(S-serinate), with formaldehyde at pH 7-9 yields the biscomplex of (1 85)in 80 7;yield. This complex is optically inactive but the optically active intermediate (186) can be isolated. No reaction occurs between serine and formaldehyde in the absence of Cu2+ions. An X-ray structural study on the final product showed the complex molecules to be linked by a bridging oxygen atom to an adjacent unit, giving square-pyramidal co-ordination of the metal Spectral studies on the copper(I1) complex of (S)-!3-(2-pyridylethyl)-

R. Osterberg, B. Sjobcrg, and R. Soderquist, J.C.S. Chem. Comm., 1972, 983. A. Levitzki, I. Pecht, and A. Berger, J . Amer. Chem. SOC., 1972, 94, 6844. G. R. Dukes and D. W. Margerum, Znorg. Chem., 1972,11,2952. J. R. Brush, R. J. Magee, M. J. O'Connor, S. M. Teo, R. J. Gene, and M. R. Snow, J . Amer. Chem. SOC.,1973,952034.

Inorganic Chemistry of the Transition Elements

316

L-cysteine (1 87) show that co-ordination occurs by chelation of amino- and carboxy-groupsin a glycine-likefashion in both the solid state and solution.804

The dipeptides Gly-Gly,Gly-P- Ala, and 9-Ala-Gly react with salicylaldehydeto form square-planar quadridentate complexes; however, N-sal=P-Ala-p-Ala does not form complexes of this type. The stability of the products increases in the order 6.5.5 [Cu(sal=Gly-Gly)] 2 6.5.6 [Cu(sal=Gly-P-Ala)] 2 6.6.5 6.6.6 [C~(sal=P-Ala-P-Ala)].~s6 The complexes [Cu(sal=P-Ala-Gly)] [Cu(ONO)] and [Cu(ONO)(H,O)] have been prepared, where O N 0 represents a terdentate dibasic anion derived from salicylaldehyde or 2-hydroxynaphthaldehyde and the amino-acids L-Val, L-Phe, and L-Leu. Molecular weight measurements on [Cu(sal=~-Val)] showed it to be tetrameric in CHCl,; however, lack of solubility precluded such measurements on the other compounds.8os The complexes[Cu(salen)],NH,SCN and [Cu(salen)]LiSCN,THFhave been reported.388The reaction of Cu(sa1en) with NO in organic solvents in the presence of air gives [Cu{ 5,5’-(NO,),-salen)] in almost quantitative yield.63 Polarographic studies have been carried out on copper(r1) complexes of N N ’ ethylene-bis(acety1acetoniminate) and -bis(salicylaldehydeiminate) in DMF solution.390The reaction of the bis-salicylaldehyde complex of copper(i1) with H , N ( C H , ) , N m H , or H2N(CH,),N-H2 yields the complexes (188);however, the reaction of Cu(OAc), with salicylaldehyde and H,N(CH2),$ +

(CH,), - N q

I

(188)

(189)

R,

=

Me,, Et,, or EtH

e C H , yields [ C ~ ( s a l e n ) ] New . ~ ~ ~methods have been reported for the preparation of [Cu(PrOHsal)X], and [Cu(PrOsal)], (PrOHsal = N-3-hydroxypropyl-salicylaldimine; X = C1 or ON0,).806 The reaction of [Cu(sal),] *04 *05

*Ofi

R. H. Fish, J. J. Windle, W. Gaffield, and J. R. Scherer, Znorg. Chem., 1973, 12, 855. G. 0. Carlisle, A. Syamal, K.K. Ganguli, and L. J. Theriot, J . Inorg. Nuclear Chem., 1972, 34, 2761. J . 0. Milner and E. Sinn, Synth. f m r y . Orguriornetallic Chem., 1972, 2, 231.

Elements of the First Transitional Period

317

with NN-R,en (R, = Me,, Et,, or HEt) in toluene yields the compounds [Cu(sal)(salNR,)] [salH = salicylaldehyde; salNR, = (1 89)]. It is suggested that the mixed ligand complexes are five-co-ordinate, and when they are treated with HX, the planar complexes [CuX(salNR,)] (X = C1 or Br) are formed.807 A similar reaction of [Cu(sal),] with NN-Me,en yields the complex [Cu(sal)(salNMe,)], the structure of which has been determined. The metal atom is co-ordinated in a distorted square-pyramidal manner.8o8 The dinuclear complexes [Cu(X-salNR)Cl], [X-salNR = (190)] have been prepared and spectral and magnetic evidence indicates three types of structures : brown

(190) R = alkyl, substituted phenyl, or (CH,),OH X = H, C1, Me, or NO,

pseudo-tetrahedral, yellow-green square-pyramidal, and yellow trigonalbipyramidal.809 Cu(OAc),H,O reacts with X-salNR [190; X = H or Br; R = (CH,),OH] in refluxing methanol to give [Cu(X-salNR)H,O], which is tetrameric in CHC1,.810 The related compounds (191)-(194) have also been reported.649 R1

(191) R’ R2 R3 H H H H C1 H C1 H H H Me H H OMe H H benzo

‘09

”*

R. H. Balundgi and A. Chakravorty, Inorg. Chem., 1973, 12,98 I . R. Tewari, R. C. Srivastava, R. H. Balundgi, and A..Chakravorty, Inorg. Nuclear Chem. Letters, 1973, 9, 583. M. Kato, K. Imai, Y. Muto, and T. Tokii, J . Inorg. Nuclear Chem., 1973, 35, 109. A. Syamat and L. J. Theriot, J . Coordination Chem., 1973, 2, 241.

Inorganic Chemistry of the Transition Elements

318

F' @ o \ C / o D R2 \ \N-

-N/

R3

(194) R' H H

R'

w

'

R2

R3

RZ R3 C1 H H

H

H OMe Me H OMe H H H NO,H H benzo

In a study of the role of ketimine species and their tautomerization reactions in transamination reactions of model biological systems, the complexes [Cu(hbaka)] (195) and [Cu(mhbaka)] (196) were isolated, and the rate of the process [Cu(hbaka)] -,[Cu(sal-aa)] (aa = amino-acidato) was determined.*' ' The complexes (197) have been isolated. The mcthyl compound was

(195) R1 = Me; R2 = Me or Pr'

(196) R'

=

H; R2

=

Me or Pr'

obtained in two forms, one of which has a dimeric five-co-ordinate structure, the other being planar. The octyl complex is also planar four-co-ordinate, while the benzyl and 2-phenylethyl compounds have distorted tetrahedral structures.*

(197) R = Me, n-octyl, PhCH,, or PhCH,CH2

Treatment of acacenH, with Et30fBF, in CH,CI,, followed by NaHS in ethanol, yields (64), which forms copper(I1) complexes on reaction with Cu(OAc), in ethanol.219 Structural studies of [CuC1,(1,7,10,16-tetraoxo4,13-diazacyclo-octadiene)] show the metal atom to be in a trans-distorted octahedral environment.* The Schiff base formed from 2,6-diformyl-4-

'13

G. N. Weinstein and R. H. Holm, Znorg. Chem., 1972, 11, 2553. R. M. Kirchner, G. D. Andretti, D. Barnhart, F. D. Thomas, D. Walsh, and E. C. Lingafelter, Znory. Chim. Acta, 1973,7, 17. M. Herceg and R. Weiss, Acta Cryst., 1973, B29, 542.

Elements of the First Transitional Period

319

methylphenol and either glycine or alanine forms the dinuclear complexes (198).8

(198) R R

= =

H, X = OH, C1, or Br; Me,X = C1

(199) R = Me or Et; X = C1, Br, or OH

The related compounds (199) have also been isolated and their stabilities follow the order OH >> Br > Cl.815 The dinucleating ligands L3- (150b) and Q3- (15 1) have been prepared and form the complexes LCu,X and QCu,X (X- = OH-, to2-,RO-,RS-, NH,, NHR-, NR;, N;, NCO-,C1-, or the pyrazolate anion).645The complexes (200) react with en or 1,3-pn to form the complexes (201), which in turn react with additional copper(I1) ions to yield (202).644The compounds (203)-(205) have also been reported.8f6The

(200) rn = 2 or 3

(201) m = 2, n = 2 or 3

m = 3,n

=

3

Schiff base (206) reacts with copper(I1) to form bis-(heptane-2,4,6-trionato)dicopper(u) and (207).8 N-3-Hydroxy-n-propylsalicylaldimineforms two types of dimeric copper(r1) complexes. One type has copper atoms bridged by pairs of deprotonated alcoholic oxygen atoms of the ligand, the other type has '14 '15

*I7

H. Okawa, S. Kida, Y. Muto, and T. Tokii, Bull. Chem. SOC.Japan, 1972, 45, 2480. H. Okawa, T. Tokii, Y. Nonaka, Y. Muto, and S. Kida, Bull. Chem. SOC.Japan, 1973,46, 1462. T. Tanaka, Bull. Chem. SOC.Japan, 1972,45,2113. T. Yano, T. Ushijima, M. Sasaka, H. Kobayashi, and K. Ueno, Bull. Chem. SOC.Japan, 1972, -15,2452.

320

Inorganic Chemistry of the Transition Elements

-

(CH,), C O ,

-

0 , C (CH,).

(203)X = Br, n = 1; X = Me or C1, n = 2

H (204)X = Br, n = 1 ; X = Me or C1, n = 2

H

(205)X = Br, n = 1; X = Me or C1, n = 2

either one chloride or one nitrate ion per copper atom, and bridging occurs via the phenolic oxygen atoms. In this latter type, the alcoholic hydroxy-groups are not deprotonated but are either co-ordinated to the metal, giving rise to five-co-ordinatemetals in discrete dimeric units, or participate in intermolecular hydrogen-bonding, linking dimeric units in which the metal is four-co-ordi-

nate. In the presence of py, NH,, or mild inorganic base a rearrangement reaction occurs in which the phenolic bridged dimer (five-co-ordinate Cu) is converted into the alcoholic bridged dimer (four-co-ordinate Cu).'

'

J. 0.Miners and E. Sinn, Bull. Chem. SOC.Japan, 1973,46, 1457.

Elements of the First Transitional Period

32 1

(208) n = 6, 8, or 10

The ligands (208) form copper(I1) complexes which are probably t r i m e r i ~l9, ~ and the potentially sexidentate ligand (91) forms a copper(ir) complex which is probably four-co-ordinate, Polymeric copper(I1) complexes of the ligands (87) and (88) have been prepared and compared with the monomeric analogues of the ligands (89) and The ligands (209)form a range of copper complexes which are monomeric in the solid state and probably mostly have square-planar structures; however, the possibility of weak co-ordination of the middle donor atom cannot be

(209) Y Y Y Y

= S, n = 2, X = H, 5-Br, 5-Me, or 3-Me0 = S, n = 3, X = H or 5-Br = NH, n = 2, X = H or 5-Br = 0, n = 3, X = 5-Br

ruled out in some cases.82o The reaction of [Cu(l,3-pn),12+ with acetone yields a mixture of the C-meso- and C-rac-copper@)complexes of 3,5,7,7,10,12,0'

I

0'

I

P

aoH ("

@OH (210) *19 820

(211)

K. Tobinaga, M. Mukaino, T. Inazu, and T. Yoshino, Bull. Chem. SOC.Japan, 1972,445, 3485. L. W. Lane and L. T. Taylor, J. Coordination Chem., 1973,2,295.

322

Inorganic Chemistry of the Transition Elements

14,14-octamethyl-1,4,8,1l-tetra-azacyclotetradeca-4,1 1-diene.576 The paramagnetic Schiff bases L'H (210) and L2H (211) form the complexes-[CuL:] (pLeff = 2.98 BM, p,igand = 1.67 BM) and [CuL2] (diamagnetic, pligand = 1.73 BM).*,' The structures of [CU(NH,CH,CH,CH,CO,)~] and [Cu(NH,CH,CH,CH2C0,),],2H,O have been reported. The former consists of infinite onedimensional chains in which two y-aminobutyrate ligands connect two metal atoms by trans-double bridges and the latter has an infinite two-dimensional network structure, the water molecules not being co-ordinated.822Structural studies on [C~(6-aminohexanoate)~],2H,Oshow that the molecule contains a planar [CuO,N,] core formed by four 6-aminohexanoate ligands, two of which are co-ordinated by oxygen and two by nitrogen. The second oxygen atoms of two carboxylate groups are co-ordinated in axial positions.823 1,5-Diazacyclo-octane-NN'-diacetate (dacoda) forms the square-pyramidal complex [Cu(dacoda)], the sixth co-ordination site being blocked by an alkyl proton. The properties of this complex have been compared with those of edda.398 H,NC6H,SCH2C0,H (HL) forms the compound [CUL,],~~ and diethanolamine (deaH) forms [C~(deaH),](N0,),.~~~ Copper(I1) complexes of tris(hydroxymethy1)aminomethane and l-amino-3,3,3-trifluoropropan-2-01 have also be reported.95*5 2 9 The ligand (66)(L) forms the complexes [CuL(H,O)Cl]Cl, [CuL,](NO,),,2H,O and [Cu(L - 2 H ) ( ~ y ) ] . ~2-pyCH=NN=C(SMe), ~' (NNSMe) forms the complexes [Cu(NNSMe)X,] (X = NO, or NCS), [Cu(NNSMe),](BF,),, [Cu(NNSMe),](C10,),,4H20,and [Cu(NNSMe),I]BF,, all of which contain the ligand co-ordinated in a bidentate-(NN) manner; however, the structure of [Cu,(NNSMe)Cl,] could not be unequivocally assigned.'" 3-(4-Pyridyl)triazoline [L, (94)] forms the octahedral complex [Cu(L -H),(py)(H,O)], which is possibly and 3,4,5-pyrazine (tH,) forms [ C U ~ ( ~ ) , ( ~ H ) ~ ] , 10H20.262 The complexes, [CuLICl, and [CuL,](ClO,), (L = dithiooxamide, "'-dimethyl-, NN'-dihydroxyethyl-, NN-dicyclohexyl-, or NN'dibenzyl-dithio-oxamide) have been prepared.824 dithioThe antitumour agent Cu(kts) (kts = 3-ethoxy-2-oxobutyraldehyde semicarbazonate) has an extremely large apparent formation constant at pH 7.4 and has a one-electron reduction potential of - 120mV at pH 6.6. Thus the complex can take part in reactions with redox-active groups in the cell. Cu(kts) also undergoes stepwise protonation in aqueous acid, but is relatively unreactive to ligand substitution. It slowly oxidizes thiols, but in the presence of excess thiol dissociation of the complex Salicylaldehyde thiosemicarbazone (H,thsa) forms the complexes [Cu(thsa)] and [Cu(thsa)L],2H20 (L = bipy or phen), and salicylaldehyde selenosemicarbazone (H,sesa) reacts with 82' 822

823

825

Y . G. Mamedova, A. A. Medzhidov, and L. N . Kolomma, Russ. J . Znorg. Chern., 1972,17, 1548. A. Takenaka, E. Oshima, S. Yamada, and T. Watanabel, A m Cryst., 1973, B29, 503. B. Sjoberg, R. Osterberg, and R. Soderquist, Acta Cr)rst.,1973, B29. I 136. G. C. Pellaconi, G. Peyronal, and A. Pignedoli, Gazzettu, 1972,102,835. D. H. Pickering, Bioinorg. Chern., 1972, 1, 255, 273.

Elements of the First Transitional Period

323

Cu(N0,),,6H20 in methanol acidified with HNO, to form [Cu(Hsesa)(NO,)],H,O. Under similar conditions H,sesa reduces CuCl2,6H,O to a copper(r) species, but the reaction in aqueous pyridine yields [Cu(sesa)(py)], In alkaline which in turn reacts with bipy to form [Cu(~esa)(bipy)],2H,O.~~~ solution in the presence of Cu2+ ions, condensation occurs at the amide nitrogen of salicylaldehyde t hiosemicarbazone or selenosemicarbazone with salicylaldehyde to give complexes of the ligands (165), in which the S or Se atoms are not ~o-ordinated.~~' CuX,,nH,O (X = C1, Br, or CF,CO,) reacts with 2-hydroxycyclohexanone thiosemicarbazone (H,thad) to form [CuX,(H,thad)],nH,O. With copper trichloroacetate. [Cu(CCl,CO,XHthad)], $H,O is formed, and with Cu2(OAc),,2H,O the dimer [Cu(thadEH,O], is obtained. Complexes of the corresponding selenosemicarbazone[CuX,(H,sesad)] (X = C1 or Br) were also prepared.827The thiosemicarbazone of benzoylformic acid also forms copper(1r) complexes,223and the complexes (212) have been prepared.828

(212)R' = R2 = MeCO R1 = Me, R2 = C5H,,

The NN-dialkylethylenediamine N-oxide (alkyl = Me, Et, or Pr) (L) form the complexes [CUL,](C~O,),,*~~ and the related complex of 2,2'-bipyridyl N-oxide (bipyNO), [Cu(bipyNO),](ClO,),, has been rep~rted.~' P-Furfuraldoxime (1 1) forms the octahedral complex [Cu(ffd~x),Cl,]~~ and the Schiff base derived from diacetylmonoxime and monoethanolamine [doe,(146)] reacts with copper(11)halides to give [CuX,(doe)] (X = C1 or Br).642The lack of concordance between studies on the 1:1 complex of Cu2+ and pyridine-2carbaldehyde-oxime(LH) has prompted a re-investigation of the relationship between pH of the solution containing Cu2+:LH in a 1:1 ratio and the composition of the products isolated. The compound Cu3L,(OH)S0,,2H,O was isolated at pH 5.5 and this has structure (213). It is suggested that the compound previously formulated as [CuL(OH)],H,O should be re-formulated as [Cu,L,(OH),],3H20, which is probably polymeric rather than trimeric. [Cu(HL)826

828

M. D. Revenko and N. V. Gerbeleu, Russ. J . Znorg. Chem., 1972,17,529; N. V. Gerbeleu, M. D. Revenko, and A. V. Ablov, Russ. J . Znorg. Chem., 1972, 17, 709. V. G. Bodyu and N. V. Gerbeleu, Russ.J . Znorg. Chem., 1972,17,1123. L. E. Warren, S. M. Horner, and W. E. Hatfield, J. Amer. Chem. SOC.,1972,94, 6392.

324

Inorganic Chemistry of the Transition Elements 2 t

so;-

Cl,],H,O was also obtained at low pH and high chloride ion concentration; however, the nature of the co-ordination in this complex could not be ascertained. [Cu3L3(OH),]C10,,2H,0 was obtained at pH 8.5 and this is also probably polymeric. Both polymers have bridging hydroxy-groups.' 2 9 The disodium salt of 7-nitroso-8-hydroxyquinoline-5-sulphonic acid (Na,L) reacts with Cu2+ to form C U L , H , O . ~Cu(ClO,), ~~ reacts with 10-methylisoalloxazine (L) and aqueous formic acid to form [CUL~](C~O,)~,~H,O, the structure of which is shown as (214). The complex serves as a model compound for metal-flavin enzymes and controverts earlier suggestions that

quinonoid flavins only form complexes with metals capable of a one-electron oxidation, e.g. Cu', Fe", and Ag1.830The related flavoquinone (12) also forms a copper(I1) c~mplex.~'The dissociation of copper(I1)-protein complexes in human serum has been studied.831 829

831

B. F. Hoskins and D. G . Vince, Austral. J . Chem., 1972,25, 2039. C. J. Fritchie, J.C.S. Chem. Comm., 1972, 1220. E. L. Gironx and R. 1. Henkin, Bioinorg. Chem., 1973, 2 , 125.

Elements of the First Transitional Period 325 Copper(~r~).--The reaction of Cu(S,CNR,), with either FeCl, or Fe(ClO$, yields [Cu(S,CNR,),]X (X- = Cloy or FeC1, ; R, = Et, or EtPh), magnetic studies on which are consistent with low-spin C U " ' . ~ ~When ~ ' a solution of [Cu(Se,CNEt,),] is oxidized with iodine, purple diamagnetic [Cu(Se,CNEt,),](I3)is formed.694 [CU~~'(IO,),]~oxidizes the alcohols MeOH, EtOH, Pr'OH, PhCH,OH, and CH,=CHOH. Kinetic results indicate that the copper-containing reactive intermediate is a deprotonated monoperiodato-copper(II1)ion.832 Oxides and Hydroxides. M,[Cu(OH),] (M = Ba or Sr) can be crystallized from a solution of Cu2+ and M 2 + in 50% sodium hydroxide under nitrogen at 120 "C. Its structure has been reported.833 Structural studies have also been reported on CuTeO, and C ~ T e , 0 , 8 ~8 3~5 * When purified kaolin is treated with CuO at 1ooO"C under an oxygen atmosphere, the brown spinel CuAl,O, is formed as the principal A new form of Cu,V,08 has been prepared at 900°C and 30 kbar and its structure determined.837 6 Ligands The synthesis of Mn", Fe", Co", Ni", and Zn" complexes of l,l,l-tris(pyridine2-aldiminomethy1)ethane (py3tpn) has now been reported in detail. The structures of [M(py,tpn)](ClO,), (M = Fe or Zn) and that of [Ni(py,tach)](ClO,), [py,tach = cis,cis-1,3,5-tris(pyridine-2-aldimino)cyclohexane] have been determined and all three complexes are considerably distorted from octahedral geometry, the angle of twist being 32" for the Zn complex, 28" for the Ni complex, and 17" for the Fe complex.838 Electronic properties of the complexes M(L-L),, which have structures described in part by a twist angle (41have been investigated over the range 4 = 0" [trigonal-prismatic (TP)] to 4 = 60" [trigonal-antiprismatic (TAP)]. One-electron d-orbital energies have been calculated as a function of the angular parameters and energy-level schemes for d7- and d8-TP and d8-TP to @-TAP geometries have been calculated. Relationships between 4 and structural parameters of the co-ordination sphere have been derived and these have been applied to a series of complexes. The nbserved structural trends within a range of complexes suggest that within any series where the ligand is kept constant and the metal atom changed, the results may be rationalized in terms of destabilization of the d6 to d8 configurations in TP compared with TAP geometry. Low-spin Fe" is the most unstable and a displacement towards TAP geometry was found as the ionic radius decreased, other structural factors being constant. Electronic spectra 832 833 834

835 836

837 838

W. G . Movius, Znorg. Chem., 1973, 12, 31. E. Dubler, P. Korber, and H. R. Oswald, Nafurwiss., 1972, 59,467. 0. Lindquist, Acta Chem. Scand., 1972,26, 1423. K. Hanke, V. Kupcik, and 0. Lindquist, Acta Cryst., 1973, B29, 963. M. Hassanein, Z . anorg. Chem., 1972,392, 188. R. D. Shannon and C . Calvo, Cunucl. J . Chem., 1972, 50, 3944. E. B. Fleischer, A. E. Gebala, D. R . Swift, and P. A. Tasker, Inorg. Chem., 1972, 11, 2775.

326

Inorganic Chemistry of the Transition Elements

(for Co" and Ni"), n.m.r. spectra (for Ni"), polarographic redox potentials (for Co" and Fe"), and Mossbauer spectra (for Fe") of a series of complexes with different ligands all show a progressive, though not necessarily monotonic, change with changing twist angle. Proton linewidths are particularly sensitive to stereochemistry in the case of Ni". These results have been applied to complexes of the new sexidentate ligands (215) and (216), of unknown geometry, and similar properties have been measured. The Ni" and Co" complexes are proposed as having intermediate geometry in solution with the latter being nearer the TP limit. The Fen complexes are estimated to approach or perhaps achieve TAP stereochemistry in solution and in the solid state.839 Calculation of ligand-ligand repulsion energies for complexes of the type

(215) M

=

Fe. Co, or Ni

(216) M = Fe,'Co, or Ni

[M(L-L),]"+ shows that a continuous change can be expected from octahedral to trigonal-prismatic stereochemistry as the 'bite' of the ligand is decreased, This is borne out experimentally in dithiolato-complexes.840 The influence of bidentate ligands on the stereochemistry of eight-coordinate compounds has also been examined by calculation of ligand-ligand repulsion energies. Potential-energy surfaces are critically dependent upon the 'bite' of the ligand, which is defined as the distance between the two donor atoms of the same ligand divided by the metaldonor distance. For ligands having small bites and for complexes of the type [M(unidentate),(bidentate),] or [M(bidentate),], a single minimum is observed in each case corresponding to a dodecahedron of D,, symmetry, which is the experimentally observed geometry. For [M(bidentate),], calculations predict significant distortions from D,, symmetry, and this agrees with experiment. As the bite of the ligand is increased, a change of D,, dodecahedra1 to D , square-antiprismatic stereochemistry is predicted.841 Geometries of di- and poly-nuclear metal complexes having bridging halide, OR, SR, NR,, PR,, H, alkyl, and aryl groups have been discussed, and rationales of their stereochemistries based on the concepts of symmetry of MO's and their electron occupancy are proposed. The authors are pessimistic 839 840 841

E. Larsen, G. N. LaMar, B. E. Wagner, J. E. Parks, and R. H. Holm, Inorg. Chem., 1972,11,2652. D. L. Kepert, Inorg. Chem., 1972, 11, 1561. D. G. Blight and D. L. Kepert, Inorg. Chem., 1972, 11, 1556.

Elements of the First Transitional Period

327

at present of being able to carry out realistic MO calculations designed to comment on the extent of involvement of individual ligand orbitals in the bridging M O ’ S . A ~ ~nomenclature ~ symbolism for chiral and achiral isomers of bridged complexes has been described.843 A general bonding model for linear and bent M-N-0 linkages has been proposed based on WolfsbergHelmholtz orbital energy calculations for the cation [Co(NH,),N0I2 with the angle Co-N-0 varied between 90 and 180°.844 Types of rearrangement for octahedral complexes have been examined in the light of recent n.m.r. studies on tris-chelates. It was noted that the experiments cannot distinguish between a mechanism which involves racemization and one that does not.845 Further reports have appeared on the use of metal complexes as ligands. Thus, tris(mercaptoethylamine)cobalt(mj reacts with FeC1,,6H20 in acetone to form the low-spin complex [(Co(NH2CH,CH,S),],Fe]C1,,2H,O, in which the six mercapto-groups are co-ordinated to the iron atom.258The reaction of Cu2+with both 1,2,3- and 1,2,6-isomers of [Co(NH,CH,CH,O),] gives the red complex cation (217) and the green complex cation (218j, respect i ~ e l y[(x-Cp),Nb(SMe),] .~~~ reacts with NiCl, to form the cation [((x-Cp),Nb+

2+

(317)

(SMe),}2Ni]2f, in which the nickel atom is tetrahedral and can be classified as formally zerovalent, together with two zerovalent niobium atoms.847 Addition of Na[M(CO),(x-Cp)] (M = W or Mo) to CuCl in diglyme in the presence of Me4NC1 gives the yellow complexes Me,N[Cu( M(CO),(nC P ) } , ] . ~The ~ ~ compounds [(py)4Mn(M(CO),(n-Cp)),] (M = Cr, Mo, or W) have also been r e p ~ r t e d . ~ ’ The interaction of M2+ cations (M = Ni, Co, Mn, or Cu) with polyriboadenylic acid (poly-a) has been investigated. In the presence of 5 x 10- moles of NaCl, 2 moles of Ni2+ or C o 2 +per mole of poly-a stabilize the single helical 842 843

844

845 846

847 848

R. Mason and D. M. P. Mingos, J . Organometallic Chem., 1973,50,53. U. Thewalt, K. A. Jensen, and C. E. Schaffer, Inorg. Chem., 1972, 11, 2129. D. M. P. Mingos, Inorg. Chem., 1973,12, 1209. J. I. Musher, Inorg. Chem., 1972, 11, 2335. A. N. Gerasenkova and V. V. Udovenko, Russ. J . Inorg. Chem., 1972, 17, 1138. W. E. Douglas and M. L. H . Green, J.C.S. Dalton, 1972, 1796. P. Hackett and A. R. Manning, J.C.S. Chem. Comm., 1973, 71.

Inorganic Chemistry of the Transition Elements

328

structure, whereas the same amount of Mn2+ gives a mixture of single and double helices and Cu2+ gives rise to a random-coil structure. The amount of added NaCl is an important factor in the role of the

7 Formation and Stability Constants Formation and stability constants are not presented in detail; however, the systems studied and the relevant references are given in Table 2. Table 2 Formation and stability constants Manganese (n)

R ef:

Pyridine Disubstituted purines Ethylenediamine and edta Sulphate Acetate, chloride, bromide, chlorate, nitrate, and thiocyanate Heptane-3,5-dione 0-Hydroxybutyrophenones Oxinate Aryl- and alkyl-thioacetic and selenoacetic acids Glutaminate and serinate Aminomethyl-8-h ydrox yquinoline Riboflavin and its monophosphate ester

850 851 852 853 854 855 856 857 858 859 860 861 861a

Iron@) Hydrazine Pyridine 2,4,6-Tri-(2-pyridyl)-1,3,5-triazine Formate Oxinate Phen ylalaninate Glutaminate and serinate Thioglycollic acid

862 850 863 864 857 865 860 866

I-glut amhe

Iron(i 11) Phen and bipy Tetraphenylporphin and imidazole Acetoacet-ortho-toluidide, acetoacet-ortho-anisidide, and acetoacetortho-chloroanilide 2-Hydroxynaphthoic acid Oxinate Phenylalaninate Glutaminate and serinate Thioglycollic acid Triethanolamine Nitrilotriacetate and various carboxylates Methyl- and ethyl-carbamide 849

Y . A. Shin, J. M. Heim, and G . L. Eichhorn, Bioinorg. Chem., 1972,1,149.

867 868 869 870 857 865 860 866 871 872 873

Elements of the First Transitional Period Cobalt(n) Chloride Thiocyanate Acetate, bromide, chlorate, and nitrate Aniline and derivatives Pyridine Dimethylglyoxime and pyridine Ethylenediamine and edta N-Benzyl- and N N ’ - dibenzyl-ethylenediamine Disubstituted purines a,P,y.&Tetra-(p-methoxypheny1)porphyrin Lactate P-Hydroxypr opionate Citrate Cyclopropane- 1,l-dicarboxylic acid, cyclopentane- 1,l-dicarbox ylic acid, and cyclohexane-1,l-dicarboxylic acid Heptane-3,5-dione Substituted acylpivaloylmethanes 1-Phenyl-3-methyl-4-benzoylpyrazolonate and N-heterocycles Aminomethyl-8-h ydrox yquinoline Riboflavin and its monophosphate Aryl- and alkyl-thioacetic and selenoacetic acids Pyridine-2-carboxamide and pyridine-2-carboxylic acid NN’-Ethylenediaminedisuccinic acid

329 Ref 874,875,854 875,876,854 854 877 850 878 852 879 851 880 881, 882 882 883

Glutaminate and serinate Phen ylalaninate

884 855 885 886 86 1 861a 858 887 888 889 890 89 1 892 859 860 865

Cobalt(II1) Ethylenediamine-NN’-dimalonic, -disuccinic, and -diglutaric acids Hydroxycobalamine and Fe(CN):-

893 894

NN’-Bis-(2-hydroxyethyl)ethylenediamine Gly, Ala, a-aminobutyric acid, norVal, Ser, Thr, Phe, Tyr, and norLeu L-Tyrosine L-Proline and L-hydroxyproline L-glut amhe

Nickel(I1) Acetate, chloride, bromide, chlorate, nitrate, and thiocyanate Pyridine Amines and aminocarboxylates Ethylenediamine or 1,2-propylenediamine and phen or bipy C-Alkyl-ethylenediamines N-Benzyl- and NN’-dibenzyl-ethylenediamines Ethylenediamine and edta 2,2-DiaIkylpropane- 1,3-diamines Disubstituted purines 1,4,8-Triazaoctane Pyrazine Imidazole, picolinamide, and picolinate Formate Lactate and P-hydroxypropionate Citrate Cyclopropane-1,l-dicarboxylic acid, cyclopentane-1,l-dicarboxylic acid, and cyclohexane-1,l -dicarboxylic acid Acac and dibenzoylmethanate

854 850,895 896 897 898 879 852 899 851 900 901 902 903 882 883 884 904

*,

330

Inorganic Chemistry of the Transition Elements

Acylpivaloylmethanes Heptane-3,S-dione 0-Hydroxybutyrophenones Salicylaldehyde Catechol and substituted catechols Dithiocarbamates Oxinate NN’-Ethylenediaminedimalonicacid NN’-Ethylenediaminedisuccinic acid NN‘-Ethylenediaminediglutaricacid Aspartates with Gly, P-Ala, Val, or Leu Gly, Ala, cr-aminobutyric acid, norVal, Ser. Thr. Phe, Tyr, and norLeu L-Ala, DL-Ala, L-Val, DL-Val, L-Leu, DL-Leu, L-His, and DL-His Cysteine L-Tyr L-Pro and L-hydroxy-Pro I-Glutamine Glutaminate and serinate Phen ylalanine L-LYS-G~Y-L-L~S and G~Y-L-LYs Cysteine and penicillamine Methyl-substituted o-hydroxyphenoneoximes Triethanolamine Hydroxy- or mercapto-acids and bipy 2-Aminoethanethiol 3-Mercaptopropane- 12-diol and 2-mercaptoethanol Aryl- and alkyl-thioacetates and -selenoacetates Riboflavin and its monophosphate Aminomethyl-8-hydroxyquinoline Copper(11) Acetate, chloride, bromide, chlorate, nitrate, and thiocyanate Hydroxide P yridine Amino-pyridines Bipy, phen, or pyrocatecholate En or 1,2-pn with bipy or phen 2,2-Dialkylpropane- 1,3-diamines N-Benzyl- and NN’-dibenzylethylenediamine Dimethylglyoxime and pyridine 1,4,8-Triazaoctane Disubstituted purines Lactate and P-hydroxypropionate Glycollate Fulvate Cyclopropane- 1,l-dicarboxylic acid, cyclopentane- 1,l-dicarboxylic acid, and cyclohexane-1,l-dicarboxylicacid Protocatechuic acid 0-Hydroxybutyrophenone Heptane-3,5-dione Salicy laldehyde Catechol and substituted catechols Ponceu-3R Substituted acylpivaloylmethanes

Ref 885 855 Q56 905 906 907 857 908,909 888,909 909 910 890 91 1 912 89 1 892 859 860 865 913 914 915 916 917 918 919 858 861a 861

854 920 850 92 1 922 897 899 879 923

900 851 882 924 925 884 926 856 855 905 906 927 885

Elements of the First Transitional Period

33 1 R eJ:

Gly, Ala, a-aminobutyric acid, norVal, Ser, Thr, Phe, Tyr, norLeu and Val L- Ala, DL-Aia, L-Val, DL-Val, L-Leu, DL-Leu, L-His, and DL-His Aspartates with Gly, a-Ala, Val, or Leu Phenylalanine Glutaminate and serinate l-Glutamine L-Pro and L-hydroxy-Pro L-Tyr N-Carboxymeth yl-amino-acids d,l-tartaric acid, aspartic acid, and Gly with ortho- and pyro-phosphate or sulphate L-LYSand its dipeptides L-Phe-L-Leu-L-Phe, D-Phe-L-Leu-L-Phe, L-Phe-L-Leu-D-Phe, and D-Phe-L-Leu-D-Phe Gly-Gly and Gly-Sar and their methyl esters NN’-Ethylenediaminedisuccinic acid NN’-Ethylenediaminedimalonicacid Nitrilotriacetate 6-Aminohexanoic acid Pyridine-2-carboxylic acid Pyridine-2-carboxamide Pyridyl-2,6-dimethanol Thioether carboxylates and derivatives of sulphoxides and sulphones with bipy 2-Dimethylaminoethanethiol Aryl- and alkyl-thioacetic and -selenoacetic acids Aminomethyl-8-hydroxyquinoline Alizarin sulphonate Riboflavin and its monophosphate AMP

890,928 91 1 910 865 860 859 892 891 929 930 93 1 932 933 888 908 934,935 936 937, 887 887 938 939 940 858 861 941 861a 942

J. Bjerrum, Acta Chem. Scand., 1973,27,970. M. M. Taqui-Khan and C. R. Krishnamoorthy, J. Znorg. Nuclear Chem., 1973,35, 1285. N. N. Barkhanova, A. Y. Fridman, and N. M . Dyatlova, Russ. J . Znorg. Chem., 1972, 17, 1569. M. Ruzinsky and L. Treindl, CON.Czech. Chem. Comm., 1973,38, 1008. 8 5 4 M. H. Hutchinson and W. C. E. Higginson, J.C.S. Dalton, 1973, 1247. J. L. Ault, H. J. Harries, and J. Burgess, J.C.S. Dalton, 1973, 1095. 8 5 6 J. R. Shah and R. P. Patel, J . Znorg. Nuclear Chem.. 1973,35,2589. H. F. Steger and A. Corsini, J . Znorg. Nuclear Chem., 1973,35, 1621, 1637. G. J. Ford, P.Gans, L. D. Pettit, and C. Sherrington, J.C.S. Dalton, 1972, 1763. R. C. Tewari and M. N. Srivastava, J . Znorg. Nuclear Chem., 1973, 35, 2441. D. R. Williams, J.C.S. Dalton, 1973, 1064. 861 T. Hata and T. Uno, Bull, Chem. SOC. Japan, 1972,45,2497. 861a M. M. T. Khan and M. S . Mohan, J . Znorg. Nuclear Chem., 1973,35, 1749. 8 6 2 R. Y. Aliev and A. D. Kuliev, Russ. J . inorg. Chem., 1972, 17, 1639. F. H. Frazer, P. Epstein, and D. J. Macero, Znorg. Chem., 1972, 11, 2031. 8 6 4 V. I. Paramonova, V. Y. Zamanskii, and V. B. Kolychev, Russ. J . Znorg. Chem., 1972, 17, 542. 86s D. R. Williams and P. A. Yeo, J.C.S. Dalton, 1972, 1988. A. Napoli, Gazzetta, 1972,102,273. 8 6 7 A. A. Anashkina, Y. I. Rutkovskii, and V. E. Mironov, Russ. J. Znorg. Chem., 1972, 17, 1209. 868 J. M. Duclos, Bioinorg. Chem., 1973,2, 263. 8 6 9 A. D. Taneja and K.P. Srivastava, J. Znorg. Nuclear Chem., 1972,34,2946. 8 7 0 A. N. Pant, R. N. Soni, and S. L. Gupta, J. Znorg. Nuclear Chem., 1972, 34, 2951. M. Kunaszewska, Roczniki Chem., 1973,47,691. 8 7 2 S. Ramamoorthy and P. G. Manning, J. Znorg. Nuclear Chem., 1973, 35, 1571. 873 K. Kurzelna-Cedzynska and J. Maslowska, Roczniki Chem., 1973, 46. 1222. 850

851

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Inorganic Chemistry of the Transition Elements

E. A. Belousov, V. V. Bocharov, and V. E. Mironov, Russ. J . Inorg. Chem., 1972,17, 1717. K. R. Magnell and W. L. Reynolds, Znorg. Chim. Acta, 1972,6, 571. 876 A. Schriver, Bull. SOC.chim. France, 1973, 1 1 . 8 7 7 T. V. Zhurba and V. I . Dulova, Russ. J . Inorg. Chem., 1972, 17, 1203. 8 7 8 A. Rockenbauer, E. Budo-Zahonyi, and L. I. Simandi, J . Coordination Chem., 1972,2,53. D. E. Goldberg and K. C. Patel, J . Inorg. Nuclear Chem., 1972, 34, 3583. F. A. Walker, J . Amer. Chem. Soc., 1973,95, 1150, 1154. R. Larsson and G. Nunziata, Acta Chem. Scand., 1972, 26, 1971. Z. Warnke and E. Kwiatkowski, Roczniki Chem., 1973, 47, 476; J. Savic, M. Savic, and I. Filipovic, Croat. Chem. Acta, 1972, 44, 305. 883 A. S. Kereichuk and I. M . Churikova, Russ. J . Inorg. Chem., 1972, 17, 1300. 884 E. Roletto, A. Vanni, and G . Ostacoli, J . Inorg. Nuclear Chem., 1972, 34, 2817. 8 R 5 E. Uhlemann and F. Dietzer, Z. anorg. Chem., 1972, 393, 215. ''' N. S. Al-Niaimi, A. R. Al-Karaghouli, and S. M. Aliwi, J . Inorg. Nuclear Chem., 1973, 35, 577. x 8 7 S. C. Chang, J. K. H. Ma, J. T. Wang, a n d N . C. Li, J . Coordination Chem., 1972, 2, 31. 0. P. Sunar and C. P. Triredi, J. Inorg. Nuclear Chem., 1972, 34, 3286. 8 8 9 A. Milczarska and S . Petri, Roczniki Chem., 1972, 46, 1487. 890 A. Gergely, I. Sovago, I. Nagypal, and R. Kiraby, Inorg. Chim. Acta, 1972, 6, 435. 8 9 1 M. L. Barr, E. Baumgartner, and K. Kustin, J . Coordination Chem., 1973, 2, 263. 8 9 2 K. Kustin and S.-T. Liu, J.C.S. Dalton, 1973, 278. 8 9 3 A. P. Samsonov and 1. P. Gorelov, Russ. J . Znorg. Chem., 1973, 18, 96. 894 Y. Popova and K. Manolov, Monatsh., 1973, 104,640. 8 9 5 S. Y. Rakhmatova and A. G. Maftakhov, Russ. J . Inorg. Chem., 1972, 17, 1429. 896 M. Tanaka, J . Inorg. Nuclear Chem., 1973,35,965. 897 G. Sharma and J. P. Tandon, Bull. Acad. Polon. Sci., 1972, 20, 369. 8 9 8 N. F. Curtis, G. R. Hedwig, and H. K . J. Powell, Austral. J . Chem., 1972, 25, 2025. 899 M. S. Newman, D. H. Busch, G. E. Cheney, a n d C . R. Gustafson, Inorg. Chem., 1972,11,2890, 900 R. Barbucci, L. Fabrizzi, and P. Paoletti, Inorg. Chim. Acta. 1973, 7, 157. J. M. Malin and R. E. Shepherd, J . Inorg. Nuclear Chem., 1972,34, 3203. 902 J. K. H . Ma, J. T. Wang, and N. C. Li, J . Coordination Chem., 1973, 2, 281. 903 P. H. Tedesco, V. B. De Rumi, and J. A. Gonzalez-Quintana, J . Inorg. Nuclear Chem., 1973, 35, 285. 904 A. Choplin and R. Hugel, J . Inorg. Nuclear Chem., 1972, 34, 3739. 9 0 5 J. Gomez-Lara, R. Cetina, and J. A. Duran, Inorg. Nuclear Chem. Letters, 1973, 9, 141. ' 0 6 R. F. Jameson and M. F. Wilson, J.C.S. Dalton, 1972, 2614,2617. 907 G. S. Vigee and C. L. Watkins, J . Inorg. Nuclear Chem., 1972, 34, 3936. 908 M. Mashihara, T. Ando, and I . Murase, Bull. Chem. SOC.Japan, 1973, 46, 844. , 909 A. P. Sansonov and I . P. Gorelov, Russ. J . Inorg. Chem., 1972, 17, 1148. 9 1 0 M. K. Singh and M. N. Srivastava, J . Inorg. Nuclear Chem., 1973, 35, 2433. 9 1 1 F. Karczynski and M. Puscasiu, Roczniki Chem., 1972, 46, 1489. 9 1 2 S. K. Srivastava, E. V. Raju, and H. B. Mathur. J . Znorq. Nuclear Chem , 1973, 35, 253. 'I3 M. Kaczmarek, F. Karczynski, and G. Kupryszewski, Roczniki Chem., 1973,47, 249. 9 1 4 J. H. Ritsma and F . Jellinek, Rec. Trav. chim.,1972, 91, 923. 'I5 M. N. Patel and R. P. Patel, J. Inorg. Nuclear Chem., 1973, 35, 3023. 'I6 G. A. Bhat and R. S. Subrahmanya, Inorg. Chim. Acta, 1972,6,403. 9 1 7 J. D. Joshi, B. R. Panchal, and P. K. Bhattacharya, J. Inorg. Nuclear Chem., 1973, 35, 1685. 9 1 8 S. A. Grachev, L. I. Shchelkunova, and Y. A. Makashev, Russ. J . Inorg. Chem.. 1972, 17, 706. 9 1 9 H. F. De Brabander, L. C. Van Poncke, and Z. Eeckhaut, Inorg. Chim. Acta, 1972, 6,459. 920 H . Ohkati and T. Kawai, Bull. Chem. SOC.Japan, 1972,45, 1735. 9 2 1 Y . Couturier and C. Pettitfaux, Bull. SOC.chim. France, 1973, 439, 445. 9 2 2 H. Sigel, P. R. Huber, R. Griesser, and B. Prigs, Inorg. Chem., 1973, 12, 1198. 923 D. Dryssen, K. E. Falk, and E. K. Ivanova, Acta Chem. Scand., 1972, 26, 3865. 9 2 4 E. Bottari and M. Vicedomini, Gazzetta, 1972,102,902. 9 2 5 P. G. Manning and S. Ramamoorthy, J . Inorq. Nuclear Chcm.. 1973, 35, 1577. 9 2 6 V. A. Tvanov and P. K. Migal, Russ. J . Inorg. Chem., 1972, 17,553. 9 2 7 E. J. Hakoila and P. Kiilholma, Suomen Kem., 1973, 46, 143. 9 2 8 Ting Po I and G. H. Nancollar, Inorg. Chem., 1972, 11,2414. 929 R. V. Snyder and R. J. Angelici, J . Inorg. Nuclear Chem., 1973, 35, 523. 9 3 0 S. Ramamoorthy and P. G. Manning, J . Inorg. Nuclear Chem., 1973,354 1279. 9 3 I M. Kaczmarek, F. Karczynski, and G . Kupryszewski, Roczniki Chem., 1973, 46, 780. 932 B. Tomicka, F. Karczynski, and G. Kupryszewski, Roczniki Chem., 1972, 46, 1721. 9 3 3 R. Nakon and R. J. Angelici, Znorg. Chem., 1973, 12, 1269. 874

875

Elements of the First Transitional Period

333

W. A. E. McBryde and V. Cheam, Znorg. Nuclear Chem. Letters, 1973, 9, 95. S. Ramamoorthy, P. G. Manning, and G. Guamaschelli, J. Inorg. Nuclear Chem., 1972,34,3443, 9 3 h R. Osterberg and B. Toftgard, Bioinorg. Chem., 1972, 1, 295. 937 N. V. Arkhipova. A. G . Muftakhov. and K . R. Rakhimov. Rum. J . Innorq. Chem.. 1972. 17. 1551 ”’ J. Pinart, C. Petitfaux, and J. Faucherre, Bull. Soc. chirn. Frunce, 1972,4534. 939 H. Sigle, R. Griesser, and D. B. McCormick, Znorg. Chim. Acta, 1972, 6 , 559. 940 M. L. Mittal, R. S. Saxena, and A. V. Pandey, J . Inorg. Nuclear Chem., 1973,35, 1691. 9 4 1 P. K. Govil, C. D. Dwivedi, and S. K. Banerji, Israel J. Chem., 1972, 10, 685. 9 4 2 P. R. Huber and H. Sigel, 2. Naturforsch., 1972, 27b, 1319. 934

935

8 Bibliography As the list of reviews relevant to the field was omitted from Volume 2, a complete list covering the period October 1971 to September 1973 is given below. The plenary lectures of the XIIIth International Conference on Co-ordination Chemistry have been published in Pure Appl. Chem., 1971,27. They include the following papers of relevance. Development of transition-metal chemistry in the U.S.A. (J. Bailar) p. 1. Co-ordination and redox properties in solution (V. Guttmann) p. 73. Theory and importance of oxygen-bridge bonding (B. Jezowska-Trzebiatowska) p. 89. Synthesis, structure, and reactions of chelate metal olefin complexes (R. Nyholm) p. 127. Orbital symmetry rules and mechanisms of inorganic reactior? ?. G. Pearson) p. 145. Conformational and spin state interconversions in transition-metal complexes (L. Sacconi) p. 167. The development of co-ordination chemistry in the Soviet Union (V. I. Spitsyn) p. 193. Absorption lines in transition-metal complexes (I. Tsujikawa) p. 227. The role of co-ordination in catalytic redox processes (K. B. Yatsimirskii) p. 251. The proceedings of the International Conference on Co-ordination Chemistry held at Bressanone in 1971 have also been published (Coordination Chem. Rev., 1972, 8) and include the following papers of relevance. Mixed cluster carbonyl anions containing nickel and cobalt (P. Chini, A. Cavalieri, and S. Martinengo) p. 3. Reaction of metal carbonyls with Lewis acids: carbon- and oxygen-bonded CO (D. F. Shriver and S. A. Alich) p. 15. How to distinguish between inner- and outer-sphere complexes in aqueous solution thermodynamics and other criteria. (S. Ahrland) p. 21. Progress in the thermodynamics of copper(r1) polyamine complexes (R. Barbucci, L. Fabbrizzi, and P. Paoletti) p. 31. Two problems involved in solving complex formation equilibria : the selection of species and the calculation of stability constants (A. Vacca, A. Sabatini, and M. Gristina) p. 45. Partial hydrolysis of a Schiff base ligand co-ordinated to copper(1r). (E. C. Lingafelter, L. C . Andrews, R. M. Kirchner, N. J. Rose, and L. J. Wilson) p. 55. High-spin behaviour and chemical properties of organometallic derivatives of iron(1rr) (C. Floriani and F. Calderazzo) p. 57. Recent developments in the field of organometallic derivatives of cobalt chelates (G. Costa) p. 63. New cationic hydrido- and hydrido-dinitrogen-complexes of iron(m) (P. Giannoccaro, M. Rossi, and A. Sacco) p. 77. Recent kinetic studies of metal-metal bonded carbonyls (D. DeWitt, J. P. Fawcett, A. J. Poe, and M. V. Twigg) p. 81. The mechanism of oxidation of some d‘ low-spin metal complexes by two peroxoanions (J. 0. Edwards) p. 87. The hydrolysis of some carboxylato-bis-(ethylenediamine)cobalt(rrr)complexes (M. E. Farago, M. A. R. Smith, and I. M. Keefe) p. 95.

334

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The role of the carboxylate group in octahedral substitution (T. P. Dasgupta and M. L. Tobe) p. 103. Mechanisms of the chromium(I1) reduction of binuclear and quadrinuclear cobalt(rI1) complexes and the formation of cobalt(IrI)-chromium(III) intermediates (M. R. Hyde, K. L. Scott, and A. G. Sykes) p. 121. HCN as a ligand in phosphino-complexes of nickel@) (B. Corrain) p. 159. Some aspects of the chemistry of cobalt(1) cyanide and related complexes (J. Halpern, G. Guastalla, and J. Bercaw) p. 167. Some aspects of the chemistry of phosphino-cyanide complexes of transition metals (P. Rig0 and A. Turco) p. 175. The following reviews have been published. Alfred Werner's research on polynuclear co-ordination compounds (G. B. Kaufman, Coordination Chem. Rev., 1973, 9,339). Valence in transition-metal complexes (R. Mason, Chem. SOC.Rev., 1972, 1, 431). The 16- and 18-electron rules in organometallic chemistry and homogeneous catalysis (C. A. Tolman, Chem. SOC.Rev., 1972, 1, 337). M.O. Theory of transition-metal complexes (D. A. Brown, W. J. Chambers, and N. J. Fitzpatrick, Inorg. Chim. Acta, Rev., 1972, 6, 7). The trans influence, its measurement and significance (T. G. Appleton, H. C. Clark, and L. E. Manzer, Coordination Chem. Rev., 1973, 10, 335). The cis- and trans-effects of ligands (F. R. Hartley, Chem. SOC.Rev., 1973, 2, 163). Geometry of pentaco-ordinate complexes (B. F. Hoskins and F. D. Williams, Coordination Chem. Rev., 1973, 9, 365). Stereochemical and electronic structural aspects of five-co-ordination (J. S . Wood, Progr. Inorg. Chem., 1972, 16, 227). Trigonal-prismatic us. octahedral stereochemistry in complexes derived from innocent ligands (R. A. D. Wentworth, Coordination Chem. Rev., 1972,9, 171). Spin-forbidden electronic excitations in transition-metal complexes (L. L. Lohr, Coordination Chem. Rev., 1972, 8, 241). Application of ligand-field spectroscopy to problems of chemical bonding in solids (D. Reinen, Angew. Chem. Internat. Edn., 1971, 10, 901). Ligand design and synthesis (D. St. C . Black and A. J. Hartshorn, Coordination Chem. Rev., 1973, 9, 219). The photochemistry of transition-metal co-ordination compounds - a survey (W. L. Waltz and R. G. Sutherland, Chem. SOC.Rev., 1972, 1, 241). Photopolarographic studies on first-row metals (D. R. Crow and S . L. Ling, J.C.S. Dalton, 1972, 698). Inorganic electrosynthesis in non- aqueous solvents (B. L. Laube and C. D. Schmulback, Progr. Inorg. Chem., 1971, 14, 65). Organometallic electrochemistry (R. E. Dessy and L. A. Bares, Accounts Chem. Res., 1972, 5, 415). High pressure, electronic structure, and chemistry in solids (H. G. Drickamer, Chem. in Britain, 1973, 9, 353). Low-temperature condensation of high-temperature species as a synthetic method (P. L. Timms, Adv. Inorg. Chem. Radiochem., 1972, 14, 121). Preparation and properties of high-valent first-row transition-metal oxides and halides. (C. Rosenblum and S. L. Holt, Transition Metal Chem., 1972, 7, 87). Metal-metal interactions in transition-metal complexes containing infinite chains of metal atoms. (T. W. Thomas and A. E. Underhill, Chem. SOC.Rev., 1972, 1, 99). New bonding patterns for the carbonyl ligand. (D. F. Shriver, Chem. in Britain, 1972, 8, 419). Dinitrogen complexes of the transition metals. (A. D. Allen, R. 0. Harris, B. R. Loescher, J. R. Stevens, and R. N. Whiteley, Chem. Rev., 1973, 73, 11). Nitrogen fixation. (J. Chatt and G. J. Leigh, Chem. SOC.Rev., 1972, 1, 121).

Elements of the First Transitional Period

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Some aspects of the biology and chemistry of nitrogen fixation. ( J . Chatt, Bull. SOC. chim. France, 1972, 431). Transition-metal nitrido-complexes. (W. P. Griffith, Coordination Chem. Rev., 1972, 8, 369). Recent developments in transition-metal nitrosyl chemistry. (N. G. Connelly, Inorg. Chim. Acta, Rev., 1972,6, 47). Metal alkoxides and dialkylamides. (D. C. Bradley, Adv. Znorg. Chem. Radiochem., 1972,15, 259). Hydride complexes of the transition metals. (H. D. Kaesz and R. B. Saillant, Chem. Rev., 1972, 72, 231). Hydrido transition-metal cluster complexes. (H. D. Kaesz, Chem. in Britain, 1973, 9, 344). Transition metal hydrides. ( J . P. McCue, Coordination Chem. Rev., 1973, 10, 265). Transition-metal cluster compounds. (R. B. King, Progr. Inorg. Chem., 1972, 15,287). Stereochemistry of bis-chelate metal@) complexes. (R. H. Holm and M. J . O'Connor, Progr. Inorg. Chem., 1972, 14, 241). Kinetics and mechanisms of substitution reactions of octahedral macrocyclic amine complexes. (C. K . Poon, Coordination Chem. Rev., 1973, 10, 1). Conformational analysis on tris-ethylenediamine complexes. ( J . K . Beattie, Accounts Chem. Rev., 1971,4, 253). The co-ordination chemistry of pyrazole-derived ligands. ( S . Trofimenko, Chem. Rev., 1972, 72, 497). Synthesis of heterocyclic compounds via transition-metal intermediates. (C. W. Bird, J . Organometallic Chem., 1973, 47, 281). Synthesis and properties of polymeric phthalocyanines and their metal derivatives. (A. A. Berlin and A. I. Sherle, Inorg. Macromol. Rev., 1571, 1, 235). Transition-metal complexes containing bidentate phosphine ligands. (W. Levason and C. A. McAuliffe, Adv. Inorg. Chern. Radiochem., 1972, 14, 173). Some recent studies on poly(tertiary phosphines) and their metal complexes. (R. B. King, Accounts Chem. Res., 1972, 5, 177). Spectroscopic studies on metal-phosphorus bonding in co-ordination complexes. (J. K. Verkade, Accounts Chem. Res., 1972,9, 1). NN-Ethylenebis(salicy1ideneiminato) transition metal ion chelates. (M. D. Hobday and T. D. Smith, Coordination Chem. Rev., 1973, 9, 311). Structural aspects of metal complexes with some tetradentate Schiff bases. (M. Calligaris, G. Nardin, and L. Randaccio, Coordination Chem. Rev., 1972, 7, 385). Binuclear complexes of transition metals with a common unsaturated ligand. (A. N. Nesmeyanov, M. I. Rybinskaya, L. V. Rybin, and V. S. Kaganovich, J . Organometallic Chem., 1973, 47, 1). Carbamoyl and alkoxycarbonyl complexes of transition metals. (R. Angelici, Accounts Chem. Rex, 1972, 5, 335). Isocyanide insertion and related reactions. (Y. Yamamoto and H . Yamazaki, Coordination Chem. Rev., 1972, 8, 225). SO, insertion reactions of transition-metal alkyls and related complexes. (A. Wojcicki, Accounts Chem. Res., 1971, 4, 353). Metalhlefin and -acetylene bonding in complexes. ( F . R. Hartley, Angew. Chem. Znternat. Edn., 1972, 11, 596). Fluoroalicyclic derivatives of metals and metalloids. (W. R. Cullen, Adv. Inorg. Chem. Radiochem., 1972, 15, 323). Metal complexes of sulphur-containing amino-acids. (C. A. McAuliffe and S. G. Murray, Inorg. Chim. Acta, Rev., 1972, 6 , 103). Metals, ligands, and cancer. (D. R. Williams, Chem. Rev., 1972, 72, 203). Anticancer drug design involving complexes of amino-acids and metal ions. (D. R. Williams, Znorg. Chim. Acta, Rev., 1972, 6, 123). '

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Metal isotope effects on metal-ligand vibrations. (K. Nakamoto, Angew. Chem. Internat. Edn., 19712, 11, 666). G.C. of metal chelates. (P. Jacquelot and G. Thomas, Bull. SOC.chim. France, 1973, 1261). X-Ray absorption edge spectrometry as applied to co-ordination chemistry. (U. C. Srivastava and H. L. Nigam, Coordinatiori Chem. Rev., 1973,9,275). Mossbauer spectra of inorganic compounds - bonding and structure. (G. M. Bancroft and R. H. Platt, Adv. Inorg. Chem. Radiochem., 1972, 15, 59). Application of Mossbauer spectroscopy to the study of mixed ligand complexes. (K. Burger, Inorg. Chim. Acta, Rev., 1972,6, 31). Magnetically perturbed Mossbauer spectra of iron and tin co-ordination compounds. (W. M. Reiff, Coordination Chem. Rev., 1973, 10, 37). Magnetic resonance methods in the study of the electronic structures of transition metal complexes. (D. R. Eaton and K. Saw, Coordination Chem. Rev., 1971, 7, 197). Magnetic anisotropy. (S. Mitra, Transition Metal Chem., 1972, 7, 183). Magnetic exchange in transition-metal complexes, Part V I . (A. P. Ginsberg, Znorg. Chim. Acta, Ret.., 1971, 5, 45). Recent studies on complexes of transition metals having anomalous magnetic behaviour. (D. M. L. Goodgame, Bull. SOC.chim. France, 1972, 3). Manganese porphyrin complexes. (L. J. Boucher, Coordination Chem. Rev., 1972, 7, 283). Higher oxidation state chemistry of manganese. (W. Levason and C. A. McAuliffe, Coordination Chem. Rev., 1972, 7, 353). Some aspects of the co-ordination chemistry of iron(Ir1). (S. A. Cotton, Coordination Chem. Rev., 1972, 8, 185). Structure and function of ferritin. (R. R. Crichton, Angew. Chem. Internat. Edn., 1973, 12, 57). Iron-sulphur proteins : structural Chemistry of their chromophores and related compounds. (R. Mason and J. A. Zubieta, Angew. Chem. Internat. Edn., 1973, 12, 390). Bonding effects in circularly dichroic cobalt(n1) complexes. (L. I. Katzin and I. Eliezer, Coordination Chem. Rev., 1972, 7, 331). Complexes of cobalt(m) with flexible tetradentate ligands. (G. R. Brubaker, D. P. Schaeffer, J. H. Worrell, and J. I. Legg, Coordination Chem. Ret.., 1971, 7, 161). Effect of the nature of the ligands on the reactivity of the metal-carbon bond in cobalt chelates. (G. Costa, Pure Appl. Chem., 1972, 30, 335). Recent developments in the bio-inorganic chemistry of Vitamin BIZ,Part I. (R. H. Prince and D. A. Stotter, J. Inorg. Nuclear Chem., 1973, 35, 321) Part 11. (J. Lewis, R. H. Prince, and D. A. Stotter, ibid., p. 341). The organic compounds of cobalt(rr1).(D. Dodd and M. D. Johnson, J . Organometallic Chem., 1973, 52, 1). The influence of geometry and donor atom set on the spin state of five-co-ordinate cobalt(I1) and nickel(I1) complexes. (L. Sacconi, Coordination Chem. Rev., 1972, 8, 35 1). Steric and electronic factors influencing the structure of nickel@) complexes. (E. Uhlig, Coordination Chem. Rev., 1973, 10, 227). Chelating dioxygen compounds of the platinum metals. (V. J. Choy and C. J. O’Connor, Coordination Chem. Rev., 1972, 9, 145). Kinetics of nickel, palladium, and platinum complexes. (A. Peloso, Coordination Chem. Rev., 1973, 10, 123). Carbonyl chemistry of the group IB metals. (M. I. Bruce, J. Organometallic Chem., 1972, 44, 209). Catalysis by metallo-enzymes. (R. J. P. Williams, Inorg. Chim. Acta, Rev., 1971,5, 137). Metal-ion function in carbonic anhydrase. (R. H. Prince and P. R. Woolley, Angew. Chem. Internat. Edn., 1972, 11, 408). Volume 17 (1972) of ‘Progress in Inorganic Chemistry’ is devoted to reviews on aspects of inorganic reaction mechanisms.

3 The Noble Metals BY L. A. P. KANE-MAGUIRE

1 Ruthenium Cluster Compounds,-A study of the reaction of Ru,.(CO) with the cyclic diazepines (1)and (2) has shown that, whereas (1) yields a yellow monomer of the type [L,Ru(CO),], i.r. and X-ray data indicate that the cluster arrangement is retained with (2) giving the interesting complex (3).' Ph

Ph \ N-N

Ph

Ph

Following a preliminary report,, details have been given of the preparation of mixed clusters of the type [RuPt,(CO),L,J [L = PPh,, PPh2Me, PPhMe,, PPh(OMe),, or AsPh,] and [Ru,Pt(CO),L,] (L = PPhMe,), oia the action of [PtL,] on Ru,(CO),,. The product mixture depends on the nature of L, and can be separated by chromatography. In addition to the above compounds, new clusters of the type [Ru,Pt(CO),(diphos)] and [RuPt,(CO),L,] [L = PPh(OMe), or P(OPh),] were isolated. These latter complexes were assigned structures (4) and (5), respectively, on the basis of is-. and 'H n.m.r. D. P. Madden, A. J. Carty, and T. Birchall, Znorg. Chem., 1972, 11, 1453 M. I. Bruce, G. Shaw, and F. G. A. Stone, Chem. Comm., 1971, 1288.

337 M

Inorganic Chemistry of the Transition Elements

338

evidence. Such reactions are also a good source for compounds of general formula [Ru,(CO),,-~L,] ( n = 1,2, or 3)., The alternative synthetic route to [RuJCO) - ,L,] complexes (L = phosphines or arsines) via the direct action of L on Ru,(CO),, has been re-investigated, confirming the isolation of monoand di-substituted species (n = 1 or 2) as well as [Ru,(CO),L,] compounds. Furthermore, a tetra-substituted complex was obtained when L = PPh(OMe),, for which the structure (6) was suggested. Pyrolysis of a number of the arylphosphine complexes [Ru,(CO),L,] yielded products containing bridging

,

phosphide ligands and o-metallated phenyl rings., Related investigations5 of the pyrolysis of [Ru3(C0),{ P(OPh),),] in decalin also yielded o-metallated products of the type [Ru(CO),( P(OC,H,) (OPh),),] (two isomers) and [HRu,(CO),{ P(OC,H,) (OPh),),( OP(OPh,)] (7, as well as the hydridocluster [H,Ru,(CO),{ P(OPh),),]. The presence of the o-metallated phosphite ligands was indicated from 'H n.m.r. data, and confirmed by an X-ray crystal structure determination for (7) (Table 1). The synthesis of the novel ruthenium-nitrosyl clusters (8) and (9) uia the reduction of a benzene solution of [RuClJNO) (PMePh,),] and HPPh, has been reported., The structures were calculated from X-ray crystal data (Table l), which also showed that the mode of nitrosyl co-ordination changed from linear in (8), to slightly bent in (9) ( L RuNO = 160.3'). A re-investigation of the compound previously reported7 to be [Ru,(O,CMe),(PPh,), J has shown M. I. Bruce. G. Shaw, and F. G. A. Stone, J . C. S. Dalton, 1972, 1781. M. I. Bruce, G. Shaw, and F. G. A. Stone, J.C.S. Dalton, 1972, 2094. M. I. Bruce, 3. Howard, I. W. Nowell, G. Shaw, and P. Woodward, J . C. S. Chem. Cornm., 1972 1041. R. Eisenberg A. P. Gaughan, C. G. Pierpont, J. Reed, and A. J. Schultz J . Amer. Chem. Soc., 1972, 94, 6240. P. Legzdins. R. W. Mitchell, G. L. Rempel, J. D. Ruddick and G. Wilkinson. J . Chem. SOC.(A). 1970,3322.

The Noble Metals

339

it (Table 1) to have a basic acetate-type structure of the type [Ru,O(O,CMe),(PPh,),]. The identity of its solid and solution i.r. spectra indicated that the same structure is retained in solution. Rationalization of the non-integral

Ph,MeP,

/NO

,p,

Ru

Ru

oxidation state (2%) for ruthenium, and the diamagnetism of the compound, was made in terms of a qualitative MO treatment of the Ru,OP, 7c-electron system.8 An interesting alternative method for determining the hydride positions in transition-metal hydrides has been reported for [H,Ru,(CO),C(CH,)], involving 'H n.m.r. measurements of the complex dissolved in the nematic phase of a liquid crystal (Vari-light VL-3268-N).' Ruthenium(0) and Ruthenium(I).-Apart from the ruthenium clusters discussed above and some X-ray structural studies (Table l), few ruthenium(0) complexes have been reported. The synthesis of the cationic nitrosyl complexes [Ru(CO),(NO)L,]Y (L = PPh, or PCy,; Y = BPh, or PF,) has been reported in detail," following a preliminary account. Replacement of CO and L led to the isolation of the species [Ru(CO)(NO)L,]+ (10) [L, = (PPh,), or (PPh,) (dppe)] and [Ru(NO) (dppe),] +. An alternative route to (10) and [Ru(CO),(NO) (PPh,),] was found via treatment of [Ru(CO) (NO) (PPh,),Cl] with AgPF,, followed by addition of the ligands (CO, PPh,, or dppe). The new cations [Ru(CO),(NO)L,] are subject to oxidative addition by chlorine yielding cis-[Ru(CO),L,Cl,] and [Ru(NO)L,Cl,], and reaction with halide ions (X-)causes substitution to give [Ru(CO)(NO)L,X]. A complex of formula [Ru(CO),L] [L = MeC(CH,PPh&,] has been isolated from the reaction of the terdentate phosphine L with either Ru3(CO)12 or [Ru(CO),(PPh,),]. Its i.r. spectrum and steric arguments indicate the cis structure shown in Scheme 1 . 1 2 +

+

* lo

l1

F. A. Cotton and J. G. Norman. Znorg. Chim. Acta, 1972,6,411. A. D. Buckingham, J. P. Yesinowski, A. J. Canty, and A. J. Rest, J. Amer. Chem. Soc., 1973, 95, 2732. B. F. G. Johnson and J. A. Segal, J.C.S.Dalton, 1973. 478. B. F. G. Johnson and J. A. Segal, J . Organometallic Chem., 1971,31, C79. W. 0. Siegl, S. J. Lapporte, and J. P. Collman, Inorg. Chem., 1973, 12, 674.

c;u-co

Inorganic Chemistry of the Transition Elements

340

P.

.. I

xz

,

[Ru X ( CO),L] X

(X = Clor Br)

CO

-c*l HCl __f

[RuX,(CO)L]

Scheme 1

During a comprehensive study of the preparation of tertiary mono- and di-t-butylphosphine complexes of ruthenium(@, it was found l 3 that certain highly sterically hindered phosphines reacted with RuCl, in boiling 2-methoxyethanol to give diamagnetic dimers of the type [RuX(CO),L], {X = C1, Br, I, or OAc; L = PBu',Ph or PBu',(p-tolyl)). Their dimeric structures were confirmed by molecular weight determinations, and X-ray data', for the complex with X = CI, L = PBu',(p-tolyl). They are readily oxidized with chlorine to yield [Ru,Cl,(CO),L,], which in turn undergo bridge-splitting reactions with ligands Q, producing mononuclear [RuCl,(CO),QL] (Q = py or PMe,Ph). An e.s.r. study has been carried out on y-irradiated f°Co source) [Ru(CN),I4ions doped in alkali-metal halide lattices. The main complexes formed are a Ru' species (low-spin d') assigned as [Ru(CN),(CN')(H,O)l4-, [Ru(CN),(CN'),]5-, [Ru(CN),(CN')Hal15-, and [Ru(CN),(Hal),15- (where CN' = cyanide ligand tilted off the z-axis).15 Other authors have independently studied the species produced from both X - and y-irradiation of solid K,[Ru(CN),],3H20. l 6

Ruthenium(1I).-Group VII Donors. Halogeno-carbonyl and -phosphine complexes. A comprehensive study has appeared', of the preparation of tertiary mono- and di-t-butylphosphme complexes of the types cis-[RuCl,(CO),(PR,Bu?,] (phosphine trans, CO and Cl cis) (R = Me, Et, Pr", Bu", Ph, or p-tolyl), cis-[RuCl2(CO),(PRBu',),1 (R = Me or P r ) , and trans-[RuCl,(CO),(PR,Bu?,] (R = Et, Pr", or Bun). For the last-mentioned trans-complexes, 31Pn.m.r. spectra showed a linear correlation between the chemical shift of the free phosphine, ofreer and the co-ordination shift, A, on complexation. Conformational effects prevented similar behaviour for the corresponding cis-[RuCl,(CO),L,] complexes, but their n.m.r. spectra revealed a linear correlation between the 13C chemical shift of the CO groups and the force constants for the C - 4 stretching vibrations. A related paper reports" the l3

l4

D. F. Gill, B. E. Mann, and B. L. Shaw, J.C.S. Dalton, 1973, 311. R. Mason, K. M. Thomas, D. F. Gill. and B. L. Shaw. J . Organometallic Chem., 1972, 40, C67 M. C. R. Symons and J. G. Wilkinson, J.C.S. Dalton, 1973. 965. R. S. Eachus and F. G. Herring, Canad. J . Chem., 1972, 50, 162. J. T. Mague and J. P. Mitchener, Inorg. Chem., 1972 11, 2714.

The Noble Metals

341

preparation of the compounds trans-[Ru(L,),Cl,], where L, is a variety of di(tertiary)phosphines and arsines, via the direct attack of L, on ethanolic RuC1,,3H20. However, when L, is bis(diphenylarsino)methane, the product [Ru(L,),Cl,] is obtained instead, which contains both mono and chelating diarsine ligands. In addition, the synthesis of mixed carbonyl and nitrosyl complexes of the type [Ru(L,),(CO),CI,], [Ru(L,)(CO),Cl,], and [Ru(L,)(NO)Cl,] are described. The new terdentate phosphine complex [RuCl,(CO)L) reported above (Scheme l), has been shown to react with CO and SO, according to equations 1 and 2.12 The utility of the complex M[IRuCl,(CO)(C,H,)] as a starting

[RuCI,(CO)L]

+ CO

Ru(CO),CI,

-+

( 1)

P

+so, [RuCl,(CO)L] -so, [RuCI,(CO) (SO,)L]

(2)

material for the preparation of a wide range of ruthenium@) compounds has been described.ls Reaction with excess triphenyl-phosphine or -stibene yielded the complexes M[RuCl,(CO)(APh,),]. On the other hand, the use of smaller amounts of PPh, gave the dimer [RuCI,(CO)(PP~,),]~ whereas monomers of the type M[RuCl,(CO)L,] were obtained with L = AsPh, or SbPh,. The new brown-red dimer [Ru(AsPh,),Cl,], has been isolated from the reaction between AsPh, and RuC1,,3H,O in isobutyl alcoh01.l~Molecular weight measurements, absorption spectral data, its diamagnetism, and X-ray powder data suggest that, unlike its polymeric triphenylphosphine analogue, it has a dimeric square pyramidal structure (11). Ph3As

C1

AsPh,

‘d 2:

Ph3As’l

\c1/ c1

‘AsPh,

Hydridophosphine complexes. Proton abstraction from [RuH,(PPh,),] using trityl hexafluorophosphate in dichloromethane has yielded the new fiveco-ordinate cation [RUH(PP~,),]PF,.~~ Since this cation reacts with smaller phosphines or nitriles to give six-co-ordinate cations [RuHL,]+ and [IRuH(RCN),(PPh,),]+, respectively, the failure to obtain [RuH(PPh,),] is +

Is

l9 2o

L. Ruiz-Ramirez, T. A. Stephenson, and E. S. Switkes, J. Organometallic Chem., 1973, 49, C77. R. K. Poddar and U. Agarwala, J. Jnorg, Nucleai Chem., 1973.35, 56?. J. R. Sanders, J.C.S. Dalton, 1973, 743.

342

Inorganic Chemistry of the Transition Elements

probably due to steric crowding. On standing in ethanol solution the red [RuH(PPh,),]PF, dissociates to give off-white [RuH(PPh,),]PF,, which has been assigned the interesting n-bonded structure (12) on the basis of ‘H n.m.r. data. Stereochemical non-rigidity in the six-co-ordinate hydrides [H,RuL;] (L1 = phosphine, phosphite, phosphinite, or phosphonite) and some related [H2RuLiL2] (L2 = CO or PhCN) complexes has been examined using variable temperature ‘H and 31P n.m.r. spectroscopy.21 The rearrangement

PPPh2 barriers proved relatively insensitive to wide variations in steric and electronic character of the phosphorus ligands. Group I4 Donors. 0-Donor and S-donor 2igands. As part of a systematic study of the synthesis of tertiary phosphine-carboxylate derivatives of the noble metals, a convenient general route has been found to a range of ruthenium(I1) carboxylate complexes via the action of carboxylic acids on hydride and phosphine compounds.22 Among the new complexes reported are the series [RuHand [Ru(OCOCF,),(OCOR)(CO)(PPh,),], [RuC~(OCOR)(CO)(PP~,)~], (CO) (PPh,),]. The i.r. spectrum of the diacetate [Ru(OCOMe),(CO)(PPh,),] confirms the presence of both uni- and bi-dentate acetate ligands. A rei n ~ e s t i g a t i o nof ~ ~the reaction between [RuH,(PPh,),] and carbon dioxide in toluene has shown that the product is the formato-complex [Ru(O,CH)H(PPh,),(PhMe)], rather than the deritative [RuH(CO,)(OMe)(PPh,),] previously reported.24Evidence for the hydrido-formato formulation included Z

PPh 3

Z

PPh 3 (1 3)

” 22

23 24

P. Meakin, E. L. Muetterties, and J. P. Jesson, J . Amer. Chem. SOC.,1973, 95, 75. S. D. Robinson and M. F. Uttley, J.C.S. Chem. Comm., 1972. 1047. S. Komiya and A. Yamamoto, J. Organometallic Chem., 1972,46, C58. M. E. Vol’pin, Plenary Lecture, Vth International Conference on Organometallic Chemistry, Moscow. 197 1.

The Noble Metals

343

i.r. data and the reaction with sulphuric acid releasing CO, and hydrogen gas. The ready release of carbon dioxide ilia reaction with a variety of reagents including RX, H,, N,, and PPh3, is a characteristic of the complex. Reversible oxidation of the o-quinone complexes (13; M = Ru,X, Y = CO, Z = C1 or Br) to give compounds containing co-ordinated semiquinone radicals has been detected using cyclic voltammetry. The oxidations may also be effected chemically with either of the oxidants NiS,C,(CF,), or AgPF,.2s" A new simple synthesis for [RuCl,(DMSO),], involving refluxing RuC1,,3H20 in DMSO for a few minutes, has been described.25bIts i.r. spectrum suggests a mixture of 0-and S-donor sites. The complex has proved to be an extremely useful starting material for the synthesis of other ruthenium(I1) complexes (Scheme 2). Another useful synthetic precursor is the species M[RuCl,(CO)(C,H,)] which, among other reactions, combines with S-donor ligands to produce M[RuCl,(CO)L,] complexes (L = Me,S or Me,S0).18

[RuCl JNO) (DMSO),]

IR~C~,(CO~,~DMSO),I [RuCl,L(DMSO),]

[Ru(S~CI,),(DMSO),] ~R~(E~,NCS,),(DM~~),I [RuCI,L~(DMSO),]

r

~ R U C I ,P ~ (OP ~ )J ,~DMSO)I

[RuCl,L(DMSO),]

(L2= 2-mercapto benzthiazole) scheme 2

Group VDonors. Molecular nitrogen complexes. Interest in Ru" molecular nitrogen complexes has recently shifted from synthetic studies to investigations of their physical properties. Several i.r. spectral studies have appeared including an investigation of the complexes trans-rRuCl(XY)(das),lZ [XU = N,, NO, or CO ; Z = C1, Br, I, or PF, ; das = o-phenylenebis(dimethy1arsine)l over the region 4000-250 cm-1.26 On the basis of a three-body model for force constant calculations, a band of medium intensity near 490 cm- in the dinitrogen complex (assigned by other authors to the Ru-N stretching vibration) has been reassigned to the Ru-N-N bending vibration. In addition, the changes observed in the X-Y force constants upon co-ordination to ruthenium (Ak,,)

'

'' (a)A. L. Balch, J . Amer. Chem. Soc., 15173,95,2723;(b)I. P. Evans, A, Spencer and G. Wilkinson, 2h

J.C.S. Dalton, 1973, 204. M. S. Quinby and R. D. Feltham, lnorg. Chem., 1972,11, 2468.

344

Inorganic Chemistry of the Transition Elements

were shown to bear a direct relationship to the Ru-X force constants (kRud. These observations are consistent with d,p, bonding between ruthenium and the diatomic ligands. Agreement with this x-back-bonding model was also obtained from i.r. intensity measurements on [Ru(NH,),(N,)]X, (X = C1, Br, or I) both as solids and in a variety of solvent^.^' The intensity of the N-N stretching vibration, A("), increased with decreasing frequency, v(NN). A related study showed that for the cation [Ru(NH,)~(N,)]~+the intensity A(") was also dependent on the polarizability of the anion. While A(") was lower for dithiocarbamato and related anions than for halide salts, the frequency v(") showed little variation.,* An ESCA study of a wide range of transition-metal molecular nitrogen complexes gave broad ill-resolved Nls electron spectra for [Ru(NH,),(N,)]X, (X = Cl or Br), because of the presence of ammonia also. However, the charge on the ruthenium was observed to be considerably more positive than in related rhenium and iridium complexes.29 Measurements of the 9 9 Ru quadrupole splittings and centre shifts for the complexes [Ru(NH,),L12+ (L = N,, CO, or MeCN) confirm the belief that dinitrogen is relatively a poor o-donor, but a moderate x-a~ceptor.~' A valuable calorimetric study has measured AH values for the reactions of [TRu(NH,),(H,O)]"+ (n = 2 or 3) with a variety of ligands, including dinitrogen and [Ru(NH,),(N,)]' +.31 It was observed that [Ru(NH,),(H,O)]'+ binds more strongly to a-donors, whereas [Ru(NH,),(H20)]" forms more stable complexes with x-acceptor ligands. Bound dinitrogen in Allen's compound was shown conclusively to be a poorer ligand than free nitrogen towards [RU(NH~),(H,O)]'~.Interestingly, the value of AH = - 18.3 & 0.9 kcal rnol-' found for reaction (3) indicates that an earlier estimate by Taube et ( - 13.2 kcal mol-l) is in considerable error.

The only synthetic report on ruthenium(r1)-dinitrogen complexes is a new route to the complex [Ru(NH3),(N2)(H20)]I,, via the action of nitric acid and excess hydrazine hydrate on K,[Ru(NO)ClJ. The red compound is stable for at least six months in air, but decomposes slowly in water, ammonia, or alkaline solution.33 Nitrosyl complexes. The synthesis of the new series of cis-nitrosyl complexes of the type cis-[Ru(NH,),(NO)X]"+ (X = H,O, OH; C1; Br; or I-) has been achieved by direct stereospecific attack of NO on the corresponding cis[Ru(NH,),X,]"+ complexes. Their i.r. spectra contain more bands than the 27

29 30

B. Folkesson. Acta Chrm. Scand., 1972. 26, 4008. B. Folkesson, Acta Chem. Scand., 1972. 26, 4101. B. Folkesson, Acta Chem. Scand., 1973, 27. 287. G. M. Bancroft, K. D. Butler, and E. T. Libbey, J.C.S. Dalton, 1972, 2643

31

G . D. Watt. J . Amer. Chem. SOC..1972,94, 7351.

32

J. N. Armor and H. Taube, J . Arner. Chern. SOC., 1970,92,6170.

33

V. M. Volkov and T. V. Butenkova, Russ. J. Inorg. Chem., 1972. 17, 460

The Noble Metals

345

known trans series, as expected for the less symmetric isomer. Although cis --+ trans isomerization could not be obtained in the solid state, or in acid or neutral solution, slow isomerization was observed in alkaline solution.34 A careful re-in~estigation~~ of the action of hydroxide ion on [Ru(NH,),(NO)]~+has revealed that it is more complex than previously ~ ~ ~ p o sgiving e d , other ~ ~ (Scheme 3). The complex products as well as tran~-[Ru(NH~),(N0)(0H)]~+ [Ru(NH,),(NO)(NH,)]X, is believed to be 4 rare example of a compound containing a non-bridging amido ligand, the NH, bending mode being assigned to an i.r. band at 1570 cm- The low v(N0) frequency of the amido-complex (1837 cm- ') indicates trans geometry and a high n-electron-donor capacity for the amido ligand.

'.

Scheme 3

Quadrupole parameters for 9 9 R ~have been recorded for a variety of complexes including the nitrosyls [RuX5(NO)12- (X = C1, Br, CN, or NCS), [Ru(NH,),(NO)] and [Ru(CN),(NO)]~-.~'A general bonding model has been developed for linear and bent transition-metal nitrosyl complexes, including [Ru(diphos),(NO)] and [Ru(PPh,),(NO),Cl] + . 3 Other N-donor ligands. The reaction between [Ru(NH&H20)I2+ and hydrazoic acid has been shown to give rapidly one mole of nitrogen and 0.5 moles of both [ R u ( N H ~ ) ~ ]and ~ + [Ru(NH,),(H20)I3 +. The proposed mechanism [equation (4)-(7)] involves Ru-N bond formation prior to N-N cleavage in In contrast to similar ruthenium(II1) n i t r e n e ~the ~ ~species the azide +

[RU(NH,),(H,O)]~+ [(NH,),RuN,H]'+

+ HN, -,[(NH3),RuN3Hl2+ + H 2 0

+ [(NH,),RuNH]'+

+ N,

(4)

(5)

+ H + -+ [(NH,),RuNH,]~+ (6) [(NHj),RuNH,l3+ + [Ru(NH,),(H2O)I2+ + H + -, [Ru(NH3),I3+ + ~ R ~ ~ N H ~ ) , ( H , o ) I ~(7) + [(NH,),RuNHI2+

34 35 36 37 38 39

S. Pel1 and J. N. Armor, Znorg. Chem., 1973, 12, 873. F. Bottomley and J. R. Crawford, J.C.S. Dalton, 1972, 2145. F. Bottomley and J. R. Crawford, Chem. Comm., 1971,200. D. M. P Mingos. Inorq Chew.. 1973.12, 1209. P. S. Sheridan and F. Basolo, Inorg. Chem., 1972, 11, 2721. L. A. P. Kane-Maguire, P. S. Sheridan, F. Basolo, and R. G. Pearson, J . Amer. Chem. SOC.. 1970. 92, 5865.

346

Inorganic Chemistry of the Transition Elements

[(NH,),RuNHI2+ reacts as a nucleophile, suggesting that the co-ordinated NH group acts here as an imido group NH2- rather than as a co-ordinated have established the nitrene NH. In a related oxidation process. Taube et quantitative stoicheiometry [equation (S)] of the action of molecular oxygen on [RU(NH,)~]~+. An analogous reaction occurs with [Ru(en),12 +. 2Ru2+ + 2H+ + O2 ;r 2Ru3+ + H , 0 2

(8)

Convenient routes to arylazo-complexes of the type [RuX,(N,Ar)(PPh,),] (X = C1 or Br) have been found via either the successive addition of ArN,BF, and LiX to [RuX,(PPh,),] in acetone, or reaction of 1,3-diaryltriazenes (ArN=NNHAr) and RuCl, with ethanolic triphenylph~sphine.~' The inert complexes show strong i.r. bands attributable to v(N=NAr), in the region 1850-1900 cm- '. By analogy with the corresponding nitrosyl derivatives, they are formulated as Run species containing linearly co-ordinated (N=NAr +) groups. Several new examples of triazenido-complexes have been reported including [Ru(PPh,),H(N,Ph,)] and [Ru(PPh,),(N,Ph,),], and their bis(p-fluorophenyl)triazene analogues.42 'H and I9F n.m.r. studies indicate that [Ru(PPh,),(N,Ar,),] contains chelating triazenes. The reaction of the useful precursor M[RuCl ,( CO)(C, H ,)I with 2,2'-bipyridine or 1,lO-phenanthroline has been shown to yield the species M[RuCl,(CO)(N--N)], [RuCl,(CO)(N-N)],, or the new [RuCl(CO)(N-N),]Cl, depending on the conditions employed. Routes to the analogous cationic phosphine complexes [RuCl(PPh,)(N-N),]Cl and [RuC~(PP~M~,),(N-N)]CI,H,O were also described. A related investigation of the reaction of (N-N) with [RuO,(py),] has resulted in the isolation of [Ru(0H),(py),(bipy)],3H2O and [Ru(OH),(py),(phen)],1.5H20 in high yields.43 The diamagnetism of these monomeric compounds confirms their spin-paired d6 configuration. Photolysis of [ R u ( N H , ) , ~ ~ ] in ~ +its metal-to-ligand charge transfer region is reported to cause mainly photoaquation of the pyridine and of the cis and trans ammonia l i g a n d ~Quantum .~~ yields for the photoaquation of L in [Ru(NH,),LI2+ (L = py, PhCN, 3-Clpy, 4-Mepy) were found to be pH-dependent, the results being interpreted in terms of mechanisms involving competitive protonation of an excited state or intermediate. In contrast, the irradiation of [Ru(bipy),],' in its charge transfer to ligand (CTTL) bands is known to cause no detectable photochemistry. It is interesting therefore that flash photolysis of both [Ru(NH,),py12+ and [Ru(N.-N),]~ (N-N = 2,2'-bipyridine, or 1,lO-phenanthroline) has been found4, to cause transient bleaching of the characteristic CTTL absorption bands. The low absorbance transient species +

40

41 42

43 44

45

J. R. Pladziewicz, T. J. Meyer, J. A. Broomhead, and H. Taube, J . Amer. Chem. SOC.. 1973, 12, 639. K. R. Lain& S. D. Robinson, and M. F. Uttley, J.C.S. Chem. Comm.. 1973, 176. W. H. Knoth, Inorg. Chem.. 1973, 12, 38. T. Ishiyama and Y. Koda, Inorg. Chem., 1972,11, 2837. D. A. Chaisson, R. E. Hintze, D. H. Stuermer, J. D. Petersen, D. P. McDonald, and P. C. Ford, J . Amer. Chem. SOC.,1972.94, 6665. P. Natarajan and J. F. Endicott, J . Amer. Chem. SOC., 1972,94, 5909.

The Noble Metals

347

were considered to contain Ru"' centres and co-ordinated radical anions (py-,bipy-,phen-). Such radical anions were also postulated as transient species during the reaction of [Ru(bipy),12 and related complexes with hydrated electrons.46 Further photolysis studies (at 410 nm) of [Ru(bipy),12+ in the presence of [Co(NH,),Brl2 have shown .that the first triplet charge-transfer excited state of [Ru(bipy),]' + can function as an electron-transfer reductant, being oxidized in the process to ground-state [R~(bipy),],+.~~ 'H and ''F n.m.r. studies of the isoelectronic complexes [M(NH,),(RCN)]"+ (M = Run or Rh"'; R = Me, Ph, Pr, acrylo, a-methacrylo, or FC,HJ show that, whereas Rh'" co-ordination leads to deshielding of the ligand resonances compared with the free ligand values, Run co-ordination results in shielding of ligand positions remote from the binding site.48These results are interpreted as indicating x-back-bonding from Run to the ligand involving not only the x-symmetry orbitals of the nitrile group, but also those of unsaturated R groups. Sb-donor Zigands. The preparation of the stilbazole complexes [R~(bipy),L,]~ and [Ru(bipy),LCl) (L = cis-4-stilbazole or trans-4-stilbazole) has been reported together with their photochemi~try.~~ These complexes undergo wavelength-independent isomerization of the stiibazole ligands as their only important photoreaction. Two types of excited state may be produced, including metal-oxidized-ligand radical anions similar to those described above for compounds. [Ru(bipy),]' Group IVDonors. Si-Donor and Sn-donor Zigands. As part of an extensive study of the synthesis and properties of complexes of the ligand tris(trimethylsily1methyl)phosphine, P(CH,SiMe,),, the complex [RuCl,(CO),L,] has been isolated from the reaction of L with ethanolic R U C ~ , , X H , OIts . ~ ~i.r. and 'H n.m.r. spectra suggest the trans-structure (14). Interestingly, the polymeric +

+

+

+

+

c1

co

\I

/L

L/Y\C!*

CO

[Ru(CO),Cl,] reacts with L to give the unusual methylphosphine complex [RuCl,(CO), {(Me,SiCH,),PMe} ,]. lr9Sn Mossbauer spectra have been recorded for a wide range of trichlorostannyl metal complexes, including Z[RuCl,(SnCl,),] (Z = Me4N or 46 41

*'

*'

J. H. Baxendale and M. Fiti, J.C.S. Dalton, 1972, 1995. H. D. Gafney and A. W. Adamson, J. Amer. Chem. SOC.,1972,94,8238. R. D. Foust and P. C. Ford, J . Amer. Chem. SOC., 1972,94, 5656. P. P. Zarnegar, C. R. Bock, and D. G. Whitten, J . Amer. Chem. SOC., 1973,954367. A. T. T. Hseih, J. D. Ruddick, and G. Wilkinson, J.C.S. Dalton, 1972, 1966.

Inorganic Chemistry of the Transition Elements

348

Ph3P€Q51 The isomer shifts of all the complexes were correlated with the S n - C l stretching frequencies. Mixed Oxidation State Ruthenium. In view of the growing number of mixed valence state ruthenium complexes reported, especially Ru"."' compounds, all the pertinent references are collected in this section. The new pyrazine-bridged species [(NH 3) ,Ru- P N - R u ( N H , ) , ] " +

u prepared both in solution and as solids.52The

( n = 4, 5, or

9

have been

5 + species (15) was believed to be a mixed valence complex with distinct oxidation states [2 +, 3 +], rather than a [24 ,24+] species. Spectral support for this formulation is the presence not only of the absorption bands found in the 4+ and 6 + species, but also a unique band at 1560 nm. In addition, when the ruthenium atoms are made substitutionally non-equivalent, the shift observed in this band corresponds in energy to the reiative stabilization of one oxidation state caused by the substitutional changes. Unequivocal confirmation of the electronic structure of the mixed valence complex (15) was subsequently obtained from Mossbauer spectra of each of the 4 + , 5 , and 6 + species as their toluene-p-sulphonate salts.53 The 4 + compound exhibits a single broad band with an isomer shift consistent with Rut*,and the 6 + species shows significant quadrupole splitting and an isomer shift typical of Rut" complexes. The mixed valence complex showed both these features in the ratio 1: 1, and is best described as a class I1 bridged species having two distinct ruthenium sites with enough interaction to produce physical properties absent in the reduced and oxidized forms. The synthesis of an extended range of dinuclear complexes [Ru,(RCOJ,X] (R = H, X = C1 or Br; R = Me, X = C1, Br, I, SCN, NO,, or MeCO,; R = Ph, X = C1 or Br) has been reported together with their physical properties.54The compounds appear to be isostructural, and their magnetic moments (2.84-2.96 BM) are significantlyhigher than the spin-only moment for dinuclear Ru"~'" species with a single unpaired electron. Yet another, and perhaps the final, re-investigation of the blue complex formed from the reaction of HC1 on [Ru(NH,),]Cl,, has established the product as the mixed oxidation state complex [Ru,C~,(NH,),]~+.~ The stoicheiometry of equation (9) was sup-

+

+

~ [ R u ( N H , ) , ] ~ ++ 14H+ + 6C1-

-+

2[Ru2C13(NH3)J2+ + H 2 + 12NH:

(9)

ported by measurement of the amount of hydrogen gas released. The blue complex decomposed in the presence of oxygen to give cis-[RuCl,(NH,),), and this fact, together with i.r. evidence, suggests the presence of a triple chloride bridge between the Ru atoms. Titration of the blue cation with Ce'" required only 0.5 51

s2 53 54

s5

R. V. Parish and P. J. Rowbotham, J.C.S. Dalton, 1973, 37. C. Creutz and H. Taube, J . Amer. Chem. SOC., 1973,%, 1086. C. Creutz, M. L. Good, and S. Chandra, lnorg. Nuclear Chem. Letters. 1973, 9. 171 M. Mukaida, T. Nomura,and T. Ishimori, h l l . Chem. SOC.Japnn, 1972,45, 2143. E. E. Mercer and L. W. Gray, J . Amer. Chem. SOC., 1972,94,6426.

The Noble Metals

349

equivalents of oxidant Ru, while its magnetic susceptibility (1420 x l o v 6e.s.u.) was also consistent with one unpaired electron. Several related papers have appeared concerning the facile oxidation of hydroxide ion by ruthenium ‘brown’ viu equation (10). Kinetic results are consistent with a mechanism involving rate-determining attack of OH- on the [(NHJSRu -O-Ru(NHJ,

--O-RU(NH,),]~+

1

+ OH-

I(NH,),RU-O-R~(NH,),-O-R~(NH,),~~~ + HZ0

+ 0,

(10)

central ruthenium atom.56 The analogous ethylenediamine complexes were also investigated. Spectral evidence suggests the presence of a fairly stable intermediate in the reaction which is thought to be a peroxide of the type [ R u ( O O ) R U O R U ] ~ +The . ~ ~unusually facile oxidation of OH- by the mildly oxidizing ruthenium ‘brown‘ is apparently favoured by (i) non-labile, nonacidic ligands occupying all ordinary co-ordination sites of ruthenium and preventing normal OH- co-ordination, (ii) the tendency of ruthenium to form species of co-ordination number seven, and (iii) the low-lying antibonding orbitals of the metal cluster which can accept electron density from the OHion. The significance of these results for photosynthetic oxygen evolution has also been disc~ssed.~’ Ruthenium(I1r). Group VII Donors. Halide donor ligands. The isolation of the salts [N(CH,CH,NH,),][RuX,],HX,nH,O (X = CI. n = 2; X = Br, n = 0) has been reported from the reaction of N(CH2CH,NH,),,3HCl with K,[Ru(ox), J in the presence of excess HX. 5 9 The [RuX,] - anions are stabilized by the large cation and precipitated, rather than yielding the anticipated amine complexes. Similar attempts to prepare [ R u F J - and [RuI,I3- were unsuccessfu!. A low-temperature e.s.r. study of HCl solutions of Na,[RuCl,] and Na,[OsCl,] in the decimetre wavelength range has shown that the hyperfine interaction in ruthenium(rI1) ions is less than in osmium(In).60 Halogenophosphine complexes. Iodine has been reported to add oxidatively trans to [RuCl(NO)(PMePh,),] in benzene solution to form orange crystals of [RuI Cl(NO)(PMePh,) ,]. Recrystallization from dichloromethane causes partial isomerization of this ruthenium(II1) complex.6’ The synthesis of the diphosphine complex [RuL,Cl,]BF, [L = bis(diphenyiphosphino)methane] via the rapid attack of NOBF, on truns-[RuL,Cl,] has been briefly mentioned.” Group I/I Donors. 0-Donor ligands. cis- and trans-isomers of ruthenium(rI1) trifluoroacetylacetonates (1 6) have been sepated by chromatography and

56

57 58 59

6o 61

J. E. Earley and T. Fealey, Znorg. Chem., 1973, 12, 323. J. E. Earley and H. Razani, Inorg. Nuclear Chem. Letters, 1973. 9. 331. J. E. Earley, Inorg. Nuclear Chem. Latters, 1973, 9. 487. J. R. Gaylor and C. V. Senoff, 1nor.q. Chem., 1972, 11, 2551. R. S. Abdrakhmanov, N. S. Garifyanov, and E. I. Semenova, Rum. J . Znorg. Chem., 1972, 17, 613. J. Clemens, M. Green, and F. G. A. Stone, J.C.S. Dalton, 1973, 375.

Inorganic Chemistry of the Transition Elements

3 50

identified by X-ray powder studies.62 'H and 19F n.m.r. spectra have also been recorded for [Ru(tfac),] and some related complexes, including [Ru(( +)-3acetylcamphor},] (17J6, 2H N.m.r. spectra were also measured for some complexes deuteriated in a methyl position, but these showed no significant improvement in resoiution, presumably owing to nuclear quadrupolar relaxation. In a related study, the separation of four diastereoisomers of (17) has been

RZ

Me

WR3

R4

H

(1

achieved via t.1.c. on silica gel.64 cis- and trans-diastereoisomers were distinguished by 'H and 2H n.m.r., and the configurations were assigned on the basis of the isomorphism of two of the diastereoisomers with analogous chromium(n1) complexes, for which absolute configurations are known. An extensive study has been made of the polarographic behaviour of a variety of b-diketonato-complexes of the type [RuL,].~' In generai they exhibit uncomplicated, reversible, one-electron transfer reactions : [Ru(R'COCHCOR'),]

+ e - + [Ru(R1COCHCOR2),]-

in DMF or MeCN solution. Their half-wave potentials are strongly influenced by the nature of the substituents R' and R2, becoming more positive as the number and type of electron-releasing R decrease. The new tropolonato-complex [RUT,] [T = (18)] has been isolated by a

6z 63 64 65

C. Potvin, J. M. Manoli, A. Dereigne, and G. Pannetier, Bull. SOC.ch;m. France, 1972. 3078. G. W. Everett and A. Johnson. J . Amer. Chem. SOC.,1972,94, 6397. G. W. Everett and R. M. King, Znorg. Chem., 1972, 11,2041. G. S. Patterson and R. H. Holm, Inorg. Chem., 1972, 11, 2285.

The Noble Metals

35 1

method similar to that employed to prepare [Ru(acac),]. The shift in the M - 0 stretching frequency is different to that observed for the analogous iron(rn) complex, in accordance with the different spin states of 3d5 Fe"' and 4d5R u " ' . ~ ~ Interestingly, a variable temperature 'H n.m.r. study of some related [Ru(a-RT),] complexes (RT = isopropenyl, or isopropyltropolonato) reveals that they are stereochemically rigid, in contrast to their Al" and Co" analogues.67 S-Donor ligands. Various new complexes of thiourea and substituted thioureas have been prepared.68Whereas RuCl, and methanolic thiourea or allylthiourea yielded black crystals of [RuL,Cl]Cl, phenyl-, naphthyl-, or ditolyl-thiourea gave grey [RuL,Cl,]Cl, and diphenylthiourea produced [RuL,Cl,]. 1.r. spectra indicated Ru-S bonds in all the complexes except the allylthiourea species for which a Ru-N bond was indicated. In view of the paucity of wellcharacterized sulphamato-complexes, the preparation [equation ( 1 111 of a [MX6I3-

+ NH2S03H + KCI

--f

K,[M(NH2S03)C15]

(1 1)

range of complexes of the type K,[M"'(NH,S0,)Cl5] (M = Ru, Os, Rh or Ir) is of some interest6' 1.r. data suggest that the sulphamato ligand is N-bonded. Other new complexes reported are a variety of dialkyl(ary1)phosphinodithioate compounds of formula [Ru(S2PR2),L,] [R = Me, Et, or Ph; L = PPh,, PMePh,, PMe,Ph, or P(OPh),].70 Variable-temperature 'H n.m.r. studies of these complexes show cis-phosphines in all cases and scrambling of the R groups at high temperatures. The scrambling is explained in terms of rapid inversion of configuration between two enantiomorphs (19a and b). Unlike the related [Ru(S,CNR,),L,] (R = Me or Et; L = PPh, or PMe,Ph) complexes, these compounds undergo carbonylation reactions to produce (20a and b).

Similar variable-temperature 'H n.m.r. investigations have been made of the complex [Ru(MeBzdtc),] (MeBzdtc = NN-methylbenzyldithiocarbamato), which reveal that it is the first stereochemically non-rigid tris-chelate compound of r ~ t h e n i u m .A~ ~low-temperature coalescence ( - 13 to + 43 "C) 66 67 68

69 'O 71

L. G. Hulett and D. A. Thornton, Spectroch'm. Acta, 1973,29A, 757. S. S. Eaton, G. R. Eaton, R. H. Holm, and E. L. Muetterties, J . Amer. Chem. Soc., 1973,95, 1116. M. Mahfooz Khan, J . Inorg. Nuclear Chem., 1973,35, 1395. W. P. Grifith and D. Pawson, J.C.S. Dalton, 1973, 524. D. J. Cole-Hamilton,P. W. Armit, and T. A. Stephenson,Inorg. Nuclear Chem Letters, 1972,8,917. L. H. Pignolet, D. J. Duffy, and L. Que, J . Amer. Chem. Soc., 1973,95, 295.

352

Inorganic Chemistry of the Transition Elements PMe,Ph

PMe ,Ph

results from A + A inversion, and the high-temperature coalescence ( 4 3 4 4 ° C ) is due to S,C-N bond rotation. The polarographic behaviour of [Ru(sacsac),] (sacsac = S analogue of acetyiacetonate) has been studied in DMF solution as part of a more extensive (4.2 K) 125TeMossbauer study of P-diketonate c ~ m p l e x e sLow-temperature .~~ spectra have been recorded for the compounds MTe, (M = Fe, Co,or R u ) . ~ ~ Group V Donors. N-donor Eigands. An unusual molecular nitrogen complex of ruthenium(II1) with formula [Ru(NH,)~(N~)(H~O)](NO,)~ has been isolated If the from the nitric acid oxidation of the known [Ru(NH,),(NJ(H,O)]~+.~~ oxidation is carried out by iodine, a compound analysing as [Ru(N,)(NH~)~I(NH,),Ru(N,)]I, is obtained which is believed to contain both Ru" and Ru"'. As expected the ruthenium(II1) dinitrogen complexes are less stable in solution than corresponding ruthenium(@ compounds. Some doubt has been cast on the recent assignment7, of the absorption band at 402 nm in alkaline solutions of [Ru(NH3),l3+ to the conjugate base [Ru(NH3)5NH2]2+.75 The characteristic yellow colour could not be generated at the same pH (= 12) using a HPOi--NaOH buffer. In addition the intensity of the 402 nm band was strongly dependent on the presence of added anions (SO;-, Cl-), suggesting that the band may possibly be due to ion pair formation or some highly absorbing impurity, although the issue remains undecided. Formal redox-potentials (Ef) have been measured for the system

+

[Ru"'(NH,),L] e - + [Ru"(NH,),L] cis- and tr~ns-[Ru"'(NH,)~L~] e - + [Ru"(NH,),L2]

+

(L being a wide variety of ligands)employing cyclic voltammetry, potentiometry, and p ~ l a r o g r a p h y For . ~ ~ x-bonding ligands L, a good correlation was found between E f values and the n-acceptor ability of the ligand. On the other hand, for complexes with non-n-bonding ligands L, anionic ligands (Cl-, Br-, OH-) have more negative E f values than those containing neutral L (H,O, NH,). The low-temperature (4K) e.s.r. spectra of [Ru(en),13+, measured either in [Rh(en),C13~,,NaC1,6H,0 crystals or in [Co(en),]Br3,3H,0 powder, give g1 = 2.640 and gll = '0.330.77Interpretation of these values in terms of the 72

A. Kjekshus and D. G. Nickolson, Acta Chern. Scand., 1972,26, 3241.

73

T. V. Butenkova and V. M. Volkov, Rum. J . Inorg. Chem., 1912,17, 1770. D. Waysbort and G. Navon, Chem. Comm., 1971, 1410. J. N. Armor, J . Inorg. Nuclear Chem., 1973,35,2067. H. S. Lim, D. J. Barclay, and F. C . Anson, Inorg. Chem., 1972,11, 1460. J. A. Stanko, H. J. Peresie, R. A. Bernheim, R. Wang and P. S. Wang Inorg. Chem., 1973,12, 634.

74

75 76 77

353

The Noble Metals

theory of axial distortions for a low-spin d5 configuration shows the ground electronic state to be E1(,A1), and yields a value for the trigonal field splitting parameter K of -413 cm-l. The Hg2+-catalysed aquation of cis-[Ru(en),C12]C1,H20 has been shown to proceed with complete retention of geometric and optical config~ration.'~ This stereochemical result was interpreted in terms of a dissociative mechanism involving a square-pyramidal transition state, which is in accordance with Pearson's theoretical predi~tion'~ that this is the most stable geometry for a five-co-ordination low-spin d5 complex. Group ZVDonors. C-donor ligands. Although the major product from the acidcatalysed aquation of [Ru(NH,),(irnidaz~le)]~+is [Ru(NHJ,H~O]~+,air oxidation of the mixturegave a 107;yield of a solid with composition Ru(NH,),(Im)Cl,.80 'H N.m.r. evidence suggests that in both the Ru" and Ruin states of this ion the Im is bound via C-2 of the ring, i.e. as a C-bound imidazolium ylide (21). H Ru -

(NHJ,-

I

R'

dNX

x

hH

R2

(21) R' = R2 = H, Me, or Ph

R'

=

Me. R 2

=

H

Ruthenium(1V).-Group VII Donors. An investigation of the hydrolysis of the complexes [RuC1,I2- and [Ru,0C1,0]4- in HCl solution shows that hydrolysis of both begins at HCI concentrations less than 6 rno1-l at 0.1-0.3 mol I-' all the chloride ligands are displaced. However, in general, for HCI concentrations less than 6 mol I-', spectral evidence suggests that dinuclear forms of RuN containing the group (21a) with formula [(RuOH),CI,(OH),-

H \

/O\

/

/Ru,o/Ru\

H

(H20), -x-g]6- x - y predonimate in solution. A similar but less detailea study has been made of the chloro-species in equilibrium solutions obtained from the action of HCl (0-12 mol I-') on Ru'" perchlorate." Paper chromatographic methods have been described for the separation of 60 different metal 79

L. A. P. Kane-Maguire, Znorg. Chem., 1972, 11, 2281. R. G. Pearson, J . Amer. Chem. Soc., 1969,91,4941. K. A. Bol'shakov, N. M. Sinitsyn, m d V . V. Borisov, Russ.J : Znorg. Chem., 1972,17,1731. V. I. Shlenskaya, A. A. Biryukov, and V. M. Kadomstseva, Russ. J . Znorg. Chem., 1972,17, 572.

354

Inorganic Chemistry of the Transition Elements

complexes and ions, including [RuC1,I2- for which R , values with various eluents are given. * A re-in~estigation~, of the preparation of [RuH,(PPh,),] has shown that this complex is in fact the tetrahydride [RuH,(PPh,),] previously reported by K n ~ t hThe .~~ new improved synthesis involves reduction of [RuCl,(PPh,),] with sodium borohydride in benzene-methanol. Although the white product decomposes rapidly in air, it is stable indefinitely under argon. It reacts with a variety of small molecules, in particular with carbon disulphide to yield red crystals of [Ru(HCS),(PPh,),], for which 'H n.m.r. and i.r. data suggest the dithioformate structure (22). PPh,

Other Donor Ligands. "Ru Mossbauer spectra have been recorded for the ternary oxides MRu0, (M = Ba, Ca, or Sr) and Y,Ru,O,, and for the quaternary oxides Sr(Ru,-,IrJO, (x = 0.1 or 0.2) and Sr(Ruo.,Mno~,)0,.85Of particular interest, the spectrum of SrRuO, reveals the first example of a hyperfine magnetic field in a ruthenium complex. Also, CaRuO, is not antiferromagnetic as previously reported. New dinuclear nitrido-bridged complexes of RuN with carbon monoxide, cyanide, and chelate ligands have been reported.86 Ruthenium(V I) and Ruthenium (V I1I).-Following a preliminary report,87full details have appeared of the preparation and properties of the new ruthenium(v1) terminal nitride complexes Cs,[Ru(N)X,] and R[Ru(N)X,] (X = C1 or Br; The dipole transition moment has been calculated for R = Ph,As or Bu,N).~~ the lowest energy t, --+ 2e ( l A , -,lT2) transition for RuO,, employing a LCAO-MO treatment.88 2 Osmium Cluster Compounds.-The reaction between Os,(CO) and triphenylphosphine has been investigated in the hope of preparing the three complexes [Os,(CO)12-x(PPh3)x](x = 1, 2, or 3) simultane~usly.~~ However, as well as these compounds, a range of other products was obtained including the unusual new T. Nascutiu, Rev. Roumaine Chim., 1973,18, 161. R. 0.Harris, N. K. Hota, L. Sadavoy, and J. M. C. Yuen,J..Organometallic Chem., 1973,54,259. W. H. Knoth, J . Amer. Chem. SOC.,1972, 94, 104. T. C. Gibb, R. Greatrex, N. N. Greenwood, and P. Kaspi, J . C . S. Dalton, 1973, 1253. 8 6 W. P. Griffith and D. Pawson, J . C . S. Dalton, 1973, 1315. " W. P. Griffith and D. Pawson, Chem. and lnd., 1972,609. " S . P. Tandon and S. S. L. Surana, J . Inorg. Nuclear Chem., 1972,34, 3089. ' 9 C. W. Bradford and R. S. Nyholm, J.C.S. Dalton, 1973, 529.

355

The Noble Metals

Table 1 X-Ray data for ruthenium compounds

violet isomer

R 0.100

Comments Basic acetate-type structure with equilateral triangle of Ru atoms, bridged by 6 acetate groups and the central 0 atom

0.047

Square pyramidal with CO axial. b Ru is 0.34 A above basal plane Square pyramidal with CO b equatorial. Ru is 0.34 A above basal plane Ru octahedrally co-ordinated to 6 c nitrogens. NO; ligand acts as nacceptor and shows strong transeffect d Powder only. Solid solutions of these compounds isomorphous with O ~ 3) ,(NJIC~, H Distorted tetrahedron around Ru e atoms, which are bridged by PPh, groups. Ru-N--O linear. Short Ru-Ru distance (2.629 A) indicates strong bond e Rectangular array of Ru atoms, opposite pairs covalently bonded (Ru -Ru = 2.787 A). RU-RU bonded atoms bridged by PPhz while other Ru's bridged by C1. Ru-N--O slightly bent (160.3O) f Ru has trigonal-bipyramidal geometry with NO equatorial C RuNO = 174" Distorted from D4, towards 9 flattened equatorial RuP, tetrahedron, with axial hydrides. Shape arises from steric effects Confirms presence of o-metallated h phosphite ligands. Ru atoms bridged by the OP(OPh), group, and by one of the metallated aryl groups Both contain octahedrally 1 co-ordinated Ru. The R u 4 e distances (2.48A) are same in both, and consistent with strong n-bonding by GeC1, Similar to Sn analogue. Extensive j overlap between Ru orbitals at the Ru-Ru distance of 2.96 A Slightly distorted octahedron. k Contains bent Ru 4 - 0 bonds ( 154")

0.060 0.025

.-

0.054

0.049

[Ru(N0)(diphos),]BPh4,MezC0

0.074 0.074

0.12

cis- [Ru{CO),(GeCl,) ,]

0.041

trans- [Ru(CO),(GeCI ,),]

0.019

[Ru(CO),(SiMe,)(SiMe3)],

0.050 0.086

c

Re$

a

Inorganic Chemistry of the Transition Elements

356

Table 1- c m t inued Compound

R

Comments

[Ru(CO)(EtOH)(TPP)]

0.075

RUN,portion planar, and

Rej I

R u 4 4 essentially linear (175.8") ( a ) ref. 8. ( b ) I. Bernal, A. Clearfield, E. F. Epstein, J. S. Ricci, A. Balch, and J. S . Miller, J.C.S. Chem. Comm., 1973, 39. ( c ) F. Bottomley, J.C.S. Dalton, 1972, 2148. (d)J. E. Fergusson, J. L. Love, and W. T. Robinson, Znorg. Chern., 1972, 11, 1662. (e) ref. 6. v) C. G. Pierpont and R. Eisenberg, Znorg. Chem., 1973, 12, 199. ( 9 ) L. J. Guggenberger, idid., 1973, 12, 1317. ( h ) ref. 5 . (i) R. Ball and M. J. Bennett, Inorg. Chem., 1972,11, 1806. (i)M. M. Crozat and S. F. Watkins, J.C.S. Dalton, 1972, 2512. ( k ) D. Cullen, E. Meyer, T. S. Srivastava, and M. Tsutsui, ibid., p 584; TPP = tetraphenylporphine. (1) J. J. Bonnett, S. S. Eaton, G. R. Eaton, R. H. Holm, and J. A. Ibers, J . Amer. Chem. SOC.,1973, 95. 2141.

complexes [HOs3(CO)9(PPh3)(PPh2C6H4)11, [HOs3(C0)*(PPh,)(PPh,C,H,)I, [Hos,(Co),(PPh,)(PPh,)(C,H,)I, [Os,(Co),(PPh,>(Ph)(PPhC,H4)], and [Os,(CO),(PPh,),(C,H,)]~ Analogous reactions with triphenylarsine or P(C,H,Me), yielded some similar derivatives. An alternative route to [Os,(CO) - .L,] complexes involves the addition of [Pt(phosphine),] derivatives to OS,(CO),,.~ This latter behaviour contrasts with that of Ru3(CO),, with which mixed Ru-Pt clusters were obtained, and reflects the greater stability of osmium clusters. However, when cis-[OsH,(CO),] was employed as substrate, the mixed clusters [OsPt,(CO),L,] (L = PPh, or PMePh,) and [OS,P~(CO),(PM~P~,)~] were isolated. In a reaction not unlike recent resultsg0 with Ru,(CO),,, the compound [H,Os,S(CO),] has been obtained via the action of H,S on OS,(CO),, in n-octane at 125°C.91Its 'H n.m.r. spectrum shows a single hydride signal at room temperature and - 50°C, and the S is believed to bond to the Os, ring via a single atom. Osmium(0) -The synthesis of the cationic nitrosyl complexes [Os(CO),(NO)L,]Y (L = PPh, or PCy,; Y = BPh, or PF,) has been reported in detai1,'O following a preliminary account." Replacement of CO and L led to the isolation of the species [Os(CO)(NO)L,] (10) [L, = (PPh,),, (PPh,)(dppe), (PPh,Me),, or (PPh,),P(OMe),] and [Os(NO)(dppe),]+. An alternative route to (10) and [Os(CO),(NO)(PPh3),]+ was found via treatment of [Os(CO)(NO)(PPh,),CI] with AgPF,, followed by addition of the ligand (CO, PPh,, or dppe). The new cations [Os(CO),(NO)L,] are subject to oxidative addition by chlorine yielding cis-[0s(C0),L2C~,] and [Os(NO)L,CI,], a n d reaction with halide ions (X-)causes substitution to give [Os(CO)(NO)L,X]. Osmium(I1) -The great majority of references to osmium(I1) complexes concern ligands in which nitrogen is the donor atom of interest. Group V Donors. Molecular nitrogen complexes. As was observed for ruthenium(@-dinitrogen complexes, research emphasis appears to have shifted

,

+

+

90

''

A. J. P. Domingos, B. F. G. Johnston, and J. Lewis, J . Organometallic Chem., 1972,36, C43. A. J. Deeming and M. Underhill, J . Organometallic Chem.. 1972.42, CGO.

The Noble Metals

357

somewhat from preparative studies to investigations of physiochemical properties. However, an interesting paper reports the synthesis of some novel mixed valence dinitrogen complexes.92The green [(H20)(NH,),0sNNOs(NH,),] + and [C1(NH3)40sNNOs(NH3)5]4+were prepared and separated by cation exchange column chromatography, after the reaction sequence : 2[0s(NH3),(N2)I2+ + C ~ S - [ O S ( N H ~ ) ~ ( N , ) , ] ~ + ~-% ~

HZ

'+

In addition, the green symmetrical dimer ([OS(NH,),C~]~N,} was obtained by heating and oxidizing ~is-[0s(NH,),(N~),]~'. The symmetry of the 3 + cation is confirmed by the virtual absence of an NN stretching band in the ix., whereas all three cations show a strong Raman band around 2000 cm- '. The osmium in these mixed valence complexes is unlike normal osmium(n1) since the compounds are stable in acidic aqueous solution. This fact, together with u.v./visible spectral evidence, suggests that electronic coupling between the metal centres in OsNNOs5+ is strong enough to classify the complex as a Robin and Day93 class I11 system. Following an initial report in 1967, full experimental details have appeared for the preparation of [Os(NH,),(NJ]X, (X = C1, Br or ,'.)I Also reported are the syntheses of [0s(NH3),(CO)l2+ and cis-[Os(NH,)(N&CO)l2 (Scheme 4). All the complexes are diamagnetic as expected and, like the ruthenium analogues, are characterized by extreme inertness. +

[OSCI(NH~)~]CI~ + HCOzH

z3 soln Kz [Os(NH3),(CO)]X2 +-

[Os(NH,)4(N2)(C0)]2f

Scheme 4

A more detailed study of the decomposition of osmium(I1) dinitrogen species in aqueous solutions confirms that both [OS(NH,),(N~]~' and [Os(NH3),(N2),I2+ are very stable in neutral water.', However, in both acidic and basic solution the decomposition of the former complex is subject to autocatalysis. Surprisingly, C~S-[OS(NH~),(NJ~]~ is stable between pH 1 and 14, although it was expected to be less stable than the mono-complex on the basis of i.r. frequency positions. These observations can be rationalized if one assumes S,2 attack on osmium by OH-, and that the positive charge on the metal is smaller for [OS(NH~),(NJ,]~+ than for the mono-complex. The formation of adducts of the type M-XY-AIR, between a variety of transition-metal carbonyl and dinitrogen complexes and the Lewis acids AIR, (R = Me, Ph, or CI) has been examined in benzene solution using i.r. and lH n.m.r.96It was concluded that for complexes with low v(NN) frequencies, +

'' R. H. Magnuson and H. Taube, J. Amer. Chem. Soc., 1972,94,7213. y3 y4

" 96

M. B..Robin and P. Day, Ado. Inorg. Chem. Radiochem., 1967, 10, 247. A. D. Allen and J. K . Stevens, Canad. J. Chem., 1972,50, 3093. B. Folkesson, Acta Chem. S c a d . , 1972,26,4157. J. Chatt, R. H. Crabtrec, E. A. Jeffery, and R. L. Richards, J.C.S. Dalton, 1973, 1167.

Inorganic Chemistry of the Transition Elements

358

including mer-[OsCl,(PEt,Ph),(N&] terminal dinitrogen has a basic strength (towards AlMeJ comparable with ether. As part of an ESCA study of a wide range of transition-metal dinitrogen complexes, it was observed that [Os(NH,),(N&]X, (X = CI, Br, or X) gave broad ill-resolved N Is electron spectra, because of the presence of ammonia also.29However, the charge on the osmium was found to be considerably more positive than in related rhenium and iridium complexes. Further information on the bonding and charge distribution in dinitrogen complexes comes from i.r. intensity measurements on [Os(NH,),(N&]X, (X = C1, Br, or I), both in the solid state and in a variety increased of The intensity of the N-N stretching vibration A(") with decreasing frequency v("), in agreement with the (d-p*) n-back-bonding model. Furthermore, the greater A(") value for the osmium complexes compared with analogous ruthenium compounds implied a higher degree of back-bonding in the former. A related study showed that for the cation was also dependent on the polariz[OS(NH,),(N&]~' the intensity A(") was lower for dithiocarbamato and ability of the anion.28 While A(") related anions than for haiide salts, the frequency v(NN) showed little variation. Other N-donor Iigands. Unlike ruthenium chemistry,few osmium nitrosylamines are known. The complexes [Os(NH,),(NO)]I, and [OsI(NH,),(NO)]I, have now been prepared by treating [Os(NH,),I]I, with NO, and their properties compared with analogous ruthenium c~mplexes.~'The reactions of [Os(NH3),(NO)]X,,H,0 (X = C1, Br, or X) are summarized in Scheme 5.

In general, the complexes are unreactive to nucleophilic attack at the NO' upon refluxing. group, except with hydrazine which yields [Os(NH,) ,(NJ] Evidence has been obtained for a further new nitrosyl complex of formula [Os(CO),(NO),], from an i.r. investigation of the photochemical reaction between [Os(CO),] and NO in an argon matrix at 20 K.98 The azide complex cis-[Os(N3),(PMe,Ph),1 has been prepared :99 +

acetone

[OsCi,(PMe,Ph),]

+ NaN,refluxcis-~O~(N~)~(PMe~Ph),]

Attempts to degrade this purple compound to nitrido or dinitrogen species were unsuccessful. A convenient route to the arylazo complexes [OsX,(N,Ar)97

98 99

F. Bottomley and S. B. Tong, J.C.S. Dalton, 1973,217. 0.Crichton, M. Poliakoff, A. J. Rest, and J. J. Turner, J.C.S. Dalton, 19i'3, 1321. B. Bell, J. Chatt, J. R. Dilworth, and G. J. Leigh, Inorg. Chirn. Actn, 1972, 6, 635.

The Noble Metals

359

(PPh,),] (X = C1 or Br) has been reported uia the successive addition of ArN,BF, and LiX to suspensions of [OsX,(PPh3),] in acetone.,' These inert complexes show strong i.r. bands attributable to v(N=NAr) in the region 1850-1900 cm- '. By analogy with the corresponding nitrosyl complexes they were formulated as osmium(I1)derivatives containinglinearly co-ordinated (N=NAr +)groups. Other GroupDonors. A general route to the complexes[OsH,L,] (L = PMePh,, PEtPh,, AsEt,Ph, AsEtPh,, etc.) has been found :loo mer-[OsCl,L,]

+ NaBH:s

[OsH,L,]

These white, air-stable compounds exhibit three v(0s-H) bands in the i.r. between 1850 and 2050cm-l. Many neutral ligands L' displace dihydrogen to yield the new dihydrides [OsH,L,L'] (L' = CO, PR,, or AsR,), which are assigned cis geometry on the basis of their 'H n.m.r. spectra. The cream solid obtained on treating [OS,(CO)~,] with sodium in liquid ammonia has been shownlof to be a useful starting material for the synthesis of complexes of the type [Os(CO),X,] (X = Me, H,Ge, Ph,Sn, Me,Pb, or AuPPh,) and [Os(CO),HX] (X = Me, H,Ge, or Me,Sn). On the other hand, reaction with Me,SnCl, yielded the dimer [Os(CO),(SnMe,)],, and protonation gave [OsH,(CO),]. As part of a systematic study of the synthesis of transition-metal tertiary phosphine carboxylate complexes, the new species [OsH(0COR)(PPh,),] have been isolated from the action of RCO,H on [OSH,(PP~,),].~~ X-Ray powder diffraction data confirm that they are isostructural with the well-known ruthenium analogues. Other carboxylate compounds reported are [OsCl(OCOCF,) (CO)(PPh3)J, [Os(OCOCF,),(CO) (PPh3)J, and [Os(OCOCF3),(CO)2(PPh3)2].In the diacetate [Os(OCOMe),(CO) (PPh,),], i.r. spectral evidence indicates the presence of both uni- and bi-dentate acetates. Osmium(I1 I).-Several new complexes of this relatively uncommon oxidation state have been reported. In view of the paucity of well-characterized transitionmetal sulphamato-complexes,the synthesis of the new K3[Os(NH2S0,)Cl,] is of some intere~t.~' It is obtained in good yield from the action of sulphamic acid on [OSC~,]~-.1.r. data suggest that the sulphamate ligand is N-bonded to the osmium. Osmium(@ dinitrogen complexes can be used as starting materials for the synthesis of hitherto unknown or poorly characterized osmium(rr1) halogenoammine compounds (Scheme @.Io2 The inertness of the [OsX(NH,),]X, (X = C1 or I) isolated here casts doubt on the authenticity of previously reported samp!es which have labile ch10ro'~~ and iodo' O4 ligands. The tendency for cis -+ trans isomerization decreases rapidly in the sequence C1 > Br > I. loo

lo'

B. Bell, J. Chatt, and G. J. Leigh J.C.S. Dalton, 1973, 997. 2.D. George, S. A. R. Knox, and F. G. A. Stone, J.C.S. Dalton, 1913,972. A. D. Allen and J. R. Stevens, Canad. J . Chem., 1973,51,92. F. P. Dwyer and J. W. Hogarth, J . Roy. SOC.New South Wales, 1951,84, 117.

Inorganic Chemistry of the Transition Elements

360

[.OS(NH,),(N,)]~++ 1 , q [Os(NH3)& HX 1reflux [Os(NH,),X}X, (X

=

c~s-[OS(NH,),(N~,]~+ + HX 5 c's-[Os(NH,),X,]X(X

1 trans-[Os(NH,),I,]I

=

C1, Br,

01-

I)

prolonged reflux

tra)ts-[Os(NH,),X,]X

&x

ClorBr)

(X

= C1 or

Br)

Scheme 6

The azido-complex trans-[Os(N,)Cl,(PMe,Ph),] has been prepared by treating the corresponding chloro-complex with NaN,.99 Attempts to degrade this purple complex to nitrido or dinitrogen species were unsuccessful. The co-ordinating ability of the mixed phosphine-diarsine ligand (23) has been Ph

c,H,A~/

/

\Ph

PhP Ph

investigated for a wide range of transition metals.lo5 On reaction with an ethanol-HC1 solution of OsO,, the yeliow-orange complex [OsLCl,] is obtained, containing terdentate L. This compares with the osmium(rv) product [OsLICl,] obtained with the corresponding tritertiary phosphine ligand (Ph,PC,HJ,PPh. During an extensive study of the polarographic behaviour of tris(pdiketonato)ruthenium(m) complexes in DMF solution, it was observed that [Os(acac),] was more difficult to reduce (by 0.52 V) than its Ru"' analogue.65 Also studied was the sulphur derivative [Os(sacsac),]. An e.s.r. investigation6' of the hyperfine splitting in the complex Na,[OsCl,] has confirmed the value of the nuclear spin I = 3 for the odd isotope lS9Os,which was known earlier only from n.m.r. measurements. Osmium(IV).-Brown salts of formula Cs3[Os3(N),X, (NH3),], 2H,O (X = C1 or Br) have been precipitated from the reaction between OsO, and concentrated aqueous ammonia.8 1.r. spectral data and their diamagnetism indicate the Osv-Os'v-Osv structure (24), which is similar to that of ruthenium red, but contains bridging nitrido ligands. The green polymer K,[Os(N)Br,],, lo4 lo5

G. J. Sutton, Austral. J . Chem., 1961, 14, 33. R. B. King and P. N. Kapoor, Znorg. Chim. Acta, 1972,6, 391.

The Noble Metals

361

obtained from the dehydration of the terminal nitrido-complex K[Os(N)Br,(H20)],H20, is similarly believed to contain --Os=N--Os=N-- - chains.

Paper chromatographic methods have been described for the separation of 60 different metal complexes and ions, including [osc16]2-, for which R , values are given with various eluents.82 The Gibbs energy of formation (AG;) of brown OsO, has been determined by an e.m.f. method, and published thermodynamic data for this oxide and OsO, have been reviewed.lo6 Osmium(V).-Following a preliminary report, O7 details have appeared for the synthesis of the arylimido complexes [OsC1,(PPh3),(NC6H,R)] (R = H, C1, or OMe).99The paramagnetism of these pink, air-stable solids is consistent with an osmium(v) centre. Osmium(v I).- The preparation and properties of the new terminal nitridocomplexes R[Os(N)X,] (X = Cl or Br; R = Ph,As or Bu;N) have been described.86A preliminary investigation of the slow hydrolysis of [OsF6] has been carried out, from which the initial product appears to be [ O S O F , ] . ~ ~ ~

Table 2 X-Ray datafor osmium compounds Compound

R

[Os(NH,),(N,)]Cl,

0.039

Comments

Ref

Distorted octahedron about 0 s . a 0s-N, distance = 1.84 A ; N -N distance = 1.12 A. d. OsNN = 179: Unlike corresponding Ru complex, the structure is ordered 0.039 Structure based on central tetrahedron of b four 0 s atoms, with remaining two 0 s atoms bridging. Formal oxidation states of 0 s atoms vary from - 1 to 1. Each 0 s has three terminal CO ligands OS,(CO), 2 preliminary Seven 0 s atoms in a capped octahedral b arrangement (a) J. E. Ferguson, J. L. Love, and W. T. Robinson, Znorg. Chem., 1972, 11, 1662. ( b ) R.Mason,

+

K. M. Thomas, and D. M. P. Mingos, J . Amer. Chem. SOC.,1973, 95, 3802.

3 Rhodium Cluster Compounds.-The reported preparation of the first carbidocarbonyl derivative of the cobalt triad, namely [Rh6(C0)15C]2-, involves the action of lo6

J. I. Franco and H. Kleykamp, Ber. BunsengeseNschuftphys. Chem., 1972,76,691.

lo’

J. Chatt and J. R. Dilworth, J.C.S. Chem. Comm., 1972. 549. R. T. Paine, Inorg. Chem., 1973,12, 1457.

lo*

Inorganic Chemistry of the Tramition Elements

362

NaOH and CO on Rh4(C0)12.'09 An X-ray structure analysis of the [NMe,(CH,Ph)]+ salt (Table 3) shows that it is the first hexanuclear metal atom cluster with a trigonal-prismatic structure (25). A related paper'" reports the synthesis of a wide range of similar complexes : Rh,(CO)16 + X~~[Rh6(CO),,x](X = Cl,Br,I,CN,orSCN)

(12)

Rh6(C0)16+ ROH/Na,CO~~[Rh6(CO)15X](X = CO,Me, CO,Et, or CONHPr')

(13)

oc

oc

Their i.r. spectra and analogy with the known"' [Rh6(CO), J]- indicate that they all maintain the Rh6(C0)16 structure. With KCN and using higher reaction temperatures, the disubstituted cluster [Rh6(CO)14(CN)2]2- was obtained.' l o Further treatment of the above alkoxycarbonyl anions [Rh6(CO),,C02R]- with alkaline ROH yielded the novel cluster [Rh6(CO), 5]2-, which was isolated as its tetrabutyhammoniurn salt.' " This salt is in turn converted partly into the dark-green species [Rh,(C0),J3on prolonged reduction in alcoholic NaOH. Studies of the 13Cn.m.r. spectrum of Rh,(CO),, between room temperature and 50°C has provided direct evidence for intramolecular scrambling of the CO groups in the cluster, via bridge-terminal interconversions.' These preliminary investigations emphasize the impressive power of 3C n.m.r. spectroscopy in exploring this field of fluxional behaviour.

'

Rhodium( - rho the preparation and properties of a large number of [M(NO)L,] complexes have been reported, including [Rh(NO)L,] L = PPh,, log

'lo

'I2

'I3

V. G. Albano, M.Sansoni, P. Chini, and

S. Martinengo, J.C.S. Dalton, 1973, 651. P. Chini, S. Martinengo, and G. Giordano, Gazzetta, 1972,102,330. V. G. Albano, P. L. Bellon, and M. Sansoni, J . Chem. Sac. ( A ) , 1971,678. S. Martinengo and P. Chini, Gazzetta, 1972. 102. 344, F. A. Cotton, L. Kruczynski, and B. L. Shapiro, J . Amer. Chem. SOC., 19729 % 619l. G. Dolcetti, N. W. Hoffman, and J. P. Collman, Inorg. Chim. Acta, 1972.6, 531.

The Noble Metals

363

PMePh,, (p-MeC,H,),P, (p-FC,H,),P].l l4 Their “0) frequencies suggest that they are d10 complexes, while ‘Hn.m.r. data are consistent with t h e , pseudo-tetrahedral structure (26) rather than the alternative bent NO- structure 0

111

N

with square-planar geometry. Oxidative addition reactions with a variety of reagents have been reported. These nitrosyl complexes have been subsequently found to react with toluene-psulphonyl azide in benzene to yield the tetrazene derivatives [Rh(NO)(PPh,)(N,R&] (R = S02C&4Me).11S ‘H N.m.r. soiution data suggest the equilibrium shown in equation (14). The reaction with HCl

R

I

+

ON\

R3P’

M

‘.\N

1

R

R

R

-

ON

I

N-N

I __3L

R3P

:Mi

-N

I

ON

I

N

\M4

R3P’

\N -N=N

I

R

R

(14)

+

is consistent with this ring opening, producing the new nitrosyl species

[Rh(NO)(PPh ,)Cl,]. Rhodium(I).-Group VII Donors. Hydrido-carbonyl and -phosphine complexes. The hydride species [RhH(PPh,),] has been shown to react with CO, in toluene to form the orange adduct [Rh,H,(C02)(PPh,)6(PhMe)].z3 Support for this formulation rather than a formato-complex comes from the fact that sulphuric acid or heat (220°C) treatment yields only CO, gas. During the course of investigations into the co-ordination behaviour of the ligand siphos [P(CH,SiMe&J it was observed that the new complex trans-[RhCl(CO)(siphos),] reacted with NaBH, to produce a rare example of a tetrahydroborate ~ ~ and ‘H n.m.r. measurements complex [Rh(BH,) (CO)( ~ i p h o ~ j , ] .1.r. [v(B-H) bands at 2370 and 2385 cm-’1 indicate the bridged structure (27).

(27) ‘15

G. La Monica, P. Sandrini, F. Zingales, and S . Cenini, J. Organometallic Chem., 1973,%287.

Inorganic Chemistry of the Transition Elements

364

Halogeno-carbonyl and -phosphine complexes. 1.r. spectrai studies at elevated CO pressures have indicated that carbon monoxide, like other Lewis bases, is capable of bridge splitting in rhodium dicarbonyl halides, as in reaction (13.'

'

[Rh(CO),X],

+ 2CO + 2[Rh(CO),X]

(X = C1, Br, or I)

(15)

The equilibrium is established rapidly at room temperature, lying further to the right along the series C1 < Br < I. A related spectroscopic study has been made of halide exchange equilibria in the systems [Rh(CO),12]--C1-, [Rh(PPh,),(CO)I]-CI-, and [Rh(CO)1,l2--X- (X = C1 or Br). In nonaqueous solvents the replacement constants showed that the iight halides are preferred in all cases. This result is highly significant since rhodium was previously regarded as a soft acceptor." Interestingiy, in aqueous solution this preference is inverted for the anionic complexes, but unchanged for the neutral phosphine species.' More recent evidence'lg suggests that the compounds trans-[RhX(CO),(PPh,)] (X = C1, Br, or I) previously made12' from [RhC!(CO),], and PPh, (1 :2) should be reformulated as the dimers trans-[RhX(CO)(PPh,)],. The complexes undergo bridge-splitting reactions with a variety of Lewis bases to give [RhX(CO)(PPh,)L] (L = PPh,, PMePh,, P(C,H,,),, AsPh,, SbPh,, py, Me,& etc.). In the case of SbPh,, the five-co-ordinate complex [RhCl(CO)(PPh,)(SbPh,),] is also formed. An alternative route to the above [RhX(CO)L], (L = PPh, or AsPh,) complexes has been described by other authors:I2'

'

[Rh(acac)(CO)L] + HX

--+

[RhX(CO)L],

They also report similar bridge-splitting reactions with Lewis bases, including P(OPh),, to give mixed RhX(CO)L1L2.The latter comGlexes were assigned a trans geometry on the basis of their v(C0) and v(RhX) frequencies. The terdentate ligand PhP(CH,CH,CH,PPh,), readily forms complexes of the type RhLX (X = C1, Br, or I), which have the advantage of being dissociatively stable in non-aqueous solvents.122 Studies of their activation of small molecules A show that they readily form five-co-ordinate adducts RhLC1,A (A = BF,, CO, SO2, 0,). On the other hand, cationic derivatives can be obtained employing either reaction (16) or reaction (17).

+ A + -+ [RhLCl,A]+ (A = Hf,N O + , N2Ph+,MeCO+) [RhL'Cl] + L2 [RhL'L2]+ + CI- (L2 = MeCN, CO, etc.)

[RhLCI]

-+

(16) (17)

An alternative low-pressure route to the known complex [RhCI(PF,),],

has been reported, via the sealed tube reaction of excess PF, on

'I8 *I9 120

D. E. Morris and H. B. Tinker, J . Organometallic Chem., 1973,49. C53. D. Forster, Inorg. Chem., 1972,11, 1686. E. J. Bounsall and A. J . Poe, J . Chem. SOC.( A ) , 1966, 286. D. F. Steele and T. A. Stephenson, J.C.S. Dalton, 1972, 2161. P. Uguagliati, G. Deganello, L. Busetto, and U. Belluco, Inorg. Chem., 1969, 8. 1625. D. M. Barlex, M. J. Hacker, and R. D. Kemmitt, J . Organometallic Chem., 1972,43, 425. T. E. Nappier, D. W. Meek, R. M. Kirchner, and J. A. Ibers, J. Amer. Chem. SOC., 1973,95, 4194.

The Noble Metals

365

[RhC1(C2H4)2]2.123Whereas [RhCl(PF,),], reacts with CO to yield the carbonyl dimer [RhCl(CO),], quantitatively, triphenylphosphine cleaves the haiogen bridge affording the square-planar [RhCl(PF,)(PPh,),]. I9F N.m.r. analysis of the latter complex establishes a trans geometry. In a closely related paper, the same starting material [RhCl(C,H,),], was mixed with dimethylaminodifluorophosphine to yield either the analogous dimer [RhCl(PF,NMe,),], or monomeric [RhCl(PF,NMe,),], depending on the conditions emp10yed.l~~ As with the PF, complexes above, 19F and 'H n.m.r. data reTeal facile phosphine exchange. In addition, [RhCl(PF,NMe,),], undergoes bridge cleavage with PPh, to yield cis-[RhCl(PPh,)(PF,NMe,),]. Further new halogeno-phosphine complexes reported include the tricyclohexylphosphine derivative [RhCl(CO)(PCy,)2]125 and the useful stereospecific hydrogenation catalyst [RhCI(( -)-diop}(C,H,)] [diop = 2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis(diphenylphosphino)butane], which contains a chiral diphosphine ligand.126While the majority of investigations of catalysis by Rh' complexes are outside the scope of this review, a few studies warrant mention. An in situ i.r. spectral study of the acceleration of [RhCl(CO)(PPh,),] catalysed hydroformylation of olefins caused by the addition of hydroperoxides has shown that this is due to the conversion of the catalyst into the even more In addition, the dimer [RhCl(CO)active species ~is-[RhC1(C0),(PPh~)].'~~ (PPh,)], was isolated from the reaction mixture, and was found to combine readily with CO to yield the above active catalyst. Other investigations128, have shown that [RhCl(PPh,),] is a useful cataiyst for the hydrosilylation of carbonyl compounds. When the reaction was slow a yellow intermediate could be precipitated, which was identified as the oxidative addition product [RhCl(PPh,),(H) (SiEt,)]. Group VI Donors.-O-Donor Eigands. The interaction of a variety of organic acids with [MH(CO)(PPh,),] (M = Rh or Ir) has been investigated, providing, among other results, more convenient routes to [Rh(CF,C02) (CO) (PPh,),] and the cationic [Rh(CO)(PPh3)3Jf,130A related study of the action of carboxylic acids on the substrates [Rh(NO)(PPh,),], [Rh(H)(CO)(PPh,),], and [Rh(H)(PPh,),] has yielded the new carboxylato-species [Rh(NO)(OC OR) (, PPh ), ,I. [Rh(CO) (0COR) (PPh ), ,I1 and [R h(OCOR) (PPh ), 31, respectively (R = alkyl, aryl, or CF,).,, The coinplexes [Rh(LL)(CO),] and [Rh(LL)(PPh,)(CO)] (LL = acac- or 8-quinolino!-) have been shown to undergo oxidative addition reactions with halogens (X3 to give Rh"' comp o u n d ~ . ' ~However, ' addition is often accompanied by removal of LL (acac-) 123 124 125

12' 128

129

131

D. A. Clement and J. F. Nixon, J.C.S. Dalton, 1972,2 5 5 3 . D.A. Clement and J. F. Nixon, J.C.S. Dalton, 1973,195. F.G.Moers, J. A. M. De Jong, and P. M. H. Beaumont, J . Znorg. Nuclear Chem., 1973.35,1915. H. B. Kagan and T. P. Dang, J . Amer. Chem. Soc., 1972,94,6429. H.B.Tinker and D. E. Morris, J . Organometallic Chem.. 1973,52,C55. I. Ojima, M. Nihonyanagi, and Y. Nagai, J.C.S., Chem. Comm., 1972.938. I. Ojirna, M. Nihonyanagi, and Y. Nagai, Berll. Chem. SOC.Japan, 1972,45,3722. C . K.Brown, D. Georgiou, and G. Wilkinson, J.C.S. Dalton. 1973. 929. Yu. S. Varshavskii, T. G. Cherkasova, and N. A. Buzina, Russ. J. Inorg. Chem., 1972, 17, 1150.

Inorganic Chemistry of the Transition Elements

366

or by its extensive halogenation (8-quinolinol-), giving products of the type [Rh(CO),Cl,],, [Rh(PPh,)(CO)X,], (X = C1 or Br) or [Rh(LL)(PPh,)(CO)X,]. The synthesis of a variety of new dioxygen complexes of composition [RhX(O&PPh,),(RNC)] (X = C1, Br, or I, R = But; X = C1, R = cyclohexyl or p MeC, H4),[RhCl(0,)(AsPh ), (, Bu'NC)], and [Rh(0), (PPh 3) (Bu'NC),] has been reported.' 3 2 These thermally stable, diamagnetic adducts are polymeric, and i.r. studies suggest the presence of trans halogen-bridging structures. Meanwhile, a theoretical study has attempted to rationalize the bonding in many trasition-metal-dioxygen adducts including Rh' species.' Another paper of theoretical significance reports rhodium 3d3,2 and 3d,,, binding energies for a range of rhodium complexes, including the Rh' com~~ pounds [RhCl(PPh,),] and [RhCl(CO)(PR,),] (R = Ph or o - t ~ l y l ) . ' In general the 3d binding energies were observed to decrease (by up to 2.8eV) with decrease in oxidation state down the series Rh"', Rh", Rh', provided comparisons were made within related series. S-Donor ligands. The first known sulphurdiimine complex [RhCl(CO),L'] [L1 = (28)] has been prepared via direct reaction between [RhC1(C0),l2

,-

//

S=N

N

'CMe

3

and L2.13' 'H N.m.r. studies indicate that the N-bonded isomer undergoes intramolecular and intermolecular exchange of L1, whereas the S-bonded isomer does not. The corresponding carbodi-imine complexes [RhC1(C0),L2] (L2 = di-t-butyl- or di-isopropyl-carbodi-imine), undergo similar ligand exchange. The new sulphur dioxide derivative [RhH(SO,)(CO)(PPh,),] has been synthesized [reaction (18), M = Rh].13, Its anomalous spectroscopic [MH(CO) (PPh,),]

+ liqd.SO,

-+

[MH(S03 (CO)(PPh,),]

H\

/H

It

0

0 13'

133 134 35 13'

A. Nakamura, Y. Tatsuno, and S. Otsuka, Inorg. Chem., 1972,11,2058. R. D. Harcourt, Inorg. Nuclear Chern. Letters, 1973,9,475. A. D. Hamer, D. G. Tisley, and R. A. Walton, J.C.S. Dalton, 1973, 116. J. Kuyper, K. Vrieze, and A. Oskam, J . Organometallic Chem., 19 72,46,C25. J. J. Levison and S. D. Robinson, J.C.S. Dalton, 1972,2013.

(18)

367

The Noble Metals

features were tentatively interpreted in terms of a tautomeric equilibrium [reaction (19)] involving hydride migration between M and co-ordinated SO,. In the course of a study of rhodium phosphole complexes, the brown complex [RhC:(TPPS)],CH,Cl, was isolated in which the triphenylphosphole sulphide ligand (TPPS) is S-bonded to the Rh.' 37 This co-ordination behaviour contrasts with that of triphenylphosphole oxide and other phosphole ligands which n-bond via the ring. Group V Donors. N-donor ligands. New, more convenient syntheses of the nitrosyl complexes [RhCl,(NO)(PPh,),], [Rh(NOJ(NO)(PPh,),], and [Rh(NO&NO),(PPh,),] have been described involving nitrosation of [RhCl(PPh,),] with KNO, in acidic solution.'38 Replacement of the chloro ligand by nitrite occurs only when excess KNO, is employed. Perhaps more significant is the reported synthesis of the alkoxycarbonyl compound [Rh(PPh,),(NO)(CO,R)(ROH)]BF, (R = Me or Et) and [Rh(PPhJ,(NO),]BF, via the action of NOBF, on alcoholic solutions of trans-[Rh(PPh,),(CO)X] (X = N, or NCO) at 5 and 40°C re~pectively.'~'These complexes undergo the reactions shown in Scheme 7. [Rh(PPh,),(NO)(COOR)(MeOH)]BF, NaN,-Me,CO

I

[Rh(PPh3),(NO)(C0OMe)N3]

YZC0 [Rh(PPh3)2(NO)(COOMe)(Me2CO)]BF,

Scheme 7

Treatment of [RhC!(CO),], with N-methyloctaethylporphyrin in benzene has yielded violet crystals of a new porphyrin complex, for which 'H n.m.r. (220 MHz) and i.r. data suggest an unusual structure based on (29).140 Interest-

13'

138

139

140

D. G. Hoiah, A. N. Hughes, and B. C, Hui, Canad. J . Chem., 1972,50,3714. Yu. N. Kukushkin and L. I. Danilina, Russ. J . Znorg. Chem., 1972,17, 176; Yu. N. Kukushkin aqd L. I. Danilina, Russ. J . Ifiorg. Chem., 1972, 17, 617. W. Beck and K. V. Werner, Chem. Ber., 1973,106,868. H. Ogoshi, T. Omura, and Z. Yoshida, J . Amer. Chem. Soc., 1973,95,1666.

Inorganic Chemistry of the Transition Elements

368

ingly, when heated in chloroform, (29) undergoes methyl migration from a N atom to the rhodium, producing the Rh'" species [(OEP)RhMe] (OEP = octaethylporphyrin). Similar compounds and reactions were observed with the analogous N-ethyloctaethylporphyrin. A further new porphyrin complex is the diamagnetic, air-stable H[Rh(TPP)],2H20 (TPP = tetraphenylporphyrin), which has been obtained from the reduction of the interesting Rh" porphyrin Rh(TPP) with molecular hydrogen in DMF solvent.14' The dimeric compounds [(PPh,),(CO)MN,M(CO)(PPh,),]BF, (M = Rh or lr) have been prepared : [M(PPh,)z(CO)N,]

+ NOBF4-r [(PPh,)z(CO)MN,M(CO)(PPh,),lBF, + N2O + N,

Their i.r. and 14N n.m.r. spectra are consistent with the bridged structure (30).'42 Bridge-splitting reactions occur with ligands (L = polar organic N

Ill

N

solvents or PPh,) to regenerate [M(PPh,),(CO)N,], and produce [M(PPh,),(CO)L]BF4. Protonation and carbonylation of the corresponding isocyanato complexes [M(PPh,),(CO)(NCO)] (M = Rh or Ir) have also been investigated (Scheme 8).14, A wide range of triazenido-complexes has been prepared,

[M(PPh,),(CO)(NCO)]

+ HBF,

Naoxprotonation

[M(PPh,),(CO)(NHCO,Et)]

+ EtOH + NaBF,

[M(PPhJz(C0) z(C02Me)] Scheme 8

142

143

B. R. James and D. V. Stynes, .I. Amer. Chem. SOC.,1972,94,6225. K. V. Werner and W. Beck, Chem. Ber.. 1972,105, 3209. K. V. Werner and W. Beck, Chem. Ber., 1972,105,3947.

369

The Noble Metals

including [Rh(PPh,),(N,Ph,)] and [Rh(CO),(N3Ph,)]2.4 'H N.m.r. and i.r. studies show that, whereas the former complex contains chelating triazene, the dicarbonyl dimer features a bridging N,Ph, group. Oxidative addition products of the type [Rh(PPh3),(N3Ph,)XY] (XU = H,, CO, MeI, or OJ are readily obtained. Reaction of the anion [Rh(CO),X,] (X = C1 or Br) with N-donor ligands has given rise to the compounds [Rh(CO),(L-L)X] (L-L = Nphenylenediamine), [Rh(2-NH ,py), XI, and [Rh(C H NH ), 3X]. '44 No logical trend was observed in the nature of the reaction products, and it seems likely that the controlling factor is the insolubility of the product. In a related study, the yellow products [Rh(CO),XL'] and [Rh(C0),X],L2 (X = C1 or Br) have been obtained by treating [Rh(CO),X], with the cyclic diazepines (1) and (2), respectively.' A recent X-ray crystal structure of the former complex showed'45 that the azine ligand is bonded to the rhodium via a single N atom. However, the L2 = (2) complex was observed to be dimeric in solution, and probably has the structure (3 1) in which the diazepine acts as a bidentate bridging ligand.' Ph

An i n v e ~ t i g a t i o n 'of~ ~the action of NaCN on [Rh(CO),Cl], in methanol has been completed by a stopped-flow spectrophotometric study of the growth and decay of the transient species [Rh(CN),I3- [reactions (20) and (21)].'47 Similar oxidative additions of alkyl halides to [Rh(CN),13 -,[Rh(CN),(C0)I2-, and [Rh(CN),(CO),] - are also reported.

P- and As-donor 2igands. More convenient syntheses have been reported for the diarsine and diphosphine complexes [Rh(L,),]Cl [L, = o-phenylenebis(dimethylarsine), PhMePC,H,PMePh, or Ph,AC,H,APh, (A = P or As)], ilia direct treatment of [RhCl(C,H,,)], with excess L2.'48 The diars cation undergoes a wide variety of oxidative additions yielding [Rh(diars),XY]Z 144

145

14'

1 J8

N

J. V. Kingston, F. T. Mahmoud, and G. R. Scollary, J . Inorg. Nuclear Chem.. 1972.34, 3197 R. A. Smith, D. P. Madden, A. J. Carty, and G. J. Palenik, Chem. Comm., 1971.427. R. A. Jewsbury and J. P. Maher, J . Chem. SOC. (A), 1971,2847. R. A. Jewsbury and J. P. Maher, J.C.S. Dalton, 1972,2089. J. T. Mague, Znorg. Chem., 1972,11,2558.

Inorganic Chemistry of the Transition Elements

370

(XU = HCl, H,, CO, etc.; Z = PF, or BPh,). The preparations of the related cyano-complexes [Rh(CN) (PPh), ,] and [R h(CN) (Ph,PC, H,PPh,),] have also been de~cribed.'~" In general, oxidative addition on the former complex gives [Rh(CN)(PPh,),XY] (XU = CO, 0,, or H,). However, treatment with both CO and PPh, yields [Rh(CN)(PPh,),(CO)]. These studies confirm the ability of cyanide ligands to stabilize five-co-ordination of d8 metal ions, and also to facilitate dioxygen adduct formation. An interesting paper provides 'H n.m.r. evidence for the first example of stereochemical rigidity in an ML, complex, namely [Rh(P(OMe),},]BPh,.' 5 0 The barrier to intramolecular exchange (AG* = 7.4 kcal mol- ') was considerably higher than in other known ML, systems, resulting in some inequivalence of the ligands at temperatures as high as - 50°C. The trigonal-bipyramidal structure (32) was proposed. PA

PA

Group ZV Donors. ""Sn Mossbauer spectra have been recorded for a wide range of trichlorostannyl metal complexes, including [Rh(PPh,),(SnCI,)] and [(Ph,PCH2Ph),Rh,C1,(SnC13)4].51The isomer shifts of all the complexes were correlated with the Sn-Cl stretching frequencies. Rhodium@I).- This relatively rare oxidation state is attracting increasing attention, with the isolation and characterization of several new complexes. Group VI Donors. 0-donor ligands. Rhodium(r1) acetate reacts with pyridine2,6-dicarboxylic acid in boiling water to yield the light-green complex RhL,3H,0.151 An ESCA spectral study confirmed 3d,/, and 3d,/, binding energies characteristic of rhodium(@. Similar ESCA measurements have been made for the Rh" acetate [Rh,(OAc),] and Rh,(OAc),,2L (L = PPh,, tu, DMSO, or py), as part of an extensive study of Rh'," c ~ m p l e x e s . 'The ~ binding energies were insensitive to the nature of L in the adducts Rh2(OAc),,2L, but in general decreased with decrease in metal oxidation state. Raman and i.r. spectral assignments have also been reported for the wider series of Rh" carboxylates, [Rh,(O,CR),] and [Rh2(02CR),],2L (R = Me or Et, L = MeOH, H,O, Me,SO, or PPh,).152 The Rh -Rh stretching frequencies for all these carboxylates fall in the region 288-351 cm- support-

',

14'

G. Favero and P. Rigo, Gazzetta, 1972, 102, 597.

J. P. Jesson and P. Meakin, J . Amer. Chem. SOC., 1973,95, 1344. 15'

R. W. Matthews, A. D. Hamer, D. L. Hoof, D. G. Tisley, and R. A. Walton, J.C.S. Dalton, 1973.

Is2

A. P. Ketteringham and C . Oldham, J.C.S. Dalton, 1973, 1067.

1035.

371

The Noble Metals

ing multiple Rh-Rh bondings, and decrease with increasing donor strength of the attached ligands. Group I/ Donors. The metalloporphyrin [Rh(TPP)] (TPP = tetraphenylporpyrin) has been isolated :

While it exhibits an e.s.r, spectrum typical of Rh" in chloroform at 77 K, its low magnetic moment (peff= 1.2 BM) suggests Rh-Rh interaction^.'^' Further support for the formulation as a Rh" complex comes from the reaction with molecular hydrogen, which yields [HRh'(TPP)J,2H20 via the reversible stoicheiometry :

Treatment of RhX3,3H,O with tricyclohexylphosphine in propan-2-01 at room temperature has yielded the paramagnetic complexes [RhX,(PCy,),] (X = C1 or Br) (peff = 2.2-2.3 BM).125 Similarly, the ligand P(CH,SiMe,), reacts with RhCI, in benzene to give a Rh" compound for which 'H n.m.r. and i.r. data suggest the dimeric bridged structure (33).5 In contrast, the L

'

c1-Rh

Cl /'

I CI''I

L

f. 'Rh-Cl

L

corresponding reaction with RhBr, yielded the monomer trans-[RhBr,L,]. Its magnetic moment (peff = 1.5BM) is rather low compared with the spinonly value expected for one unpaired electron. Rhudium(III).-Group VII Donors. Halogeno-complexes. Paper chromatographic methods have been described for the separation of 60 different metal complexes and ions, including [RhC1,I3-, for which R , values are given with various eluents.82 The polarographic behaviour of [RhCl,] 3 - and the aquospecies trans-[RhCl,(H,O),] + and [RhCl,(H,O), J have also been investigated.' All undergo a two-electron reduction at the dropping mercury electrode. In addition, potential measurements, and voltammetric and chronopotentiometric studies have been carried on the reversible Rh"'/Rh0 couple in fused LiCl-KC1 eutectic at 450 "C.' 5 4

154

A. W. Addison, R. D. Gillard, and D. H. Vaughan, J.C.S. Dalton, 1973.1187. R. A. Bailey, E. N. Balko, and A. A. Nobile, J . lnorg. Nuclear Chern., 1973,35. 701.

372

Inorganic Chemistry of the Transition Elements

Halogeno-carbonyl and -phosphine complexes. In the course of studies on the internal metallation reactions of tertiary phosphine complexes, the new compounds [RhClL,] and [RhCl,(P-C)L,] [L = dimethyl or methylphenyl(1-naphthy1)phosphine;P-C = peri-(or 8-)metallated L] have been isolated.’” The recently reported complex [RhCI(CO)(PPh,)(AsPh,)] (see above) has been shown to undergo ready oxidative addition giving [RhClXY(CO)(PPh3)(AsPh3)J(XY = Cl,, I,, or MeI).’ l 9 The methyl iodide derivative is in equilibrium with its acyl isomer [RhCII(COMe)(PPh3)(AsPh,)],0.5MeI, this type of isomerism being fairly general for such complexes. Group VZ Donors. 0-donor ligands. Orange-brown crystals of Na[Rh(dpc),],2H20 (dpc = pyridine-2,6-dicarboxylate) have been isolated from the reaction of Na,dpc with RhC1,,3H,O in boiling water.’” This formulation is supported by ESCA studies of the tetraphenylarsonium salt showing 3ds,, and 3d,,, binding energies typical of Rh”’. An investigation of the co-ordination behaviour of (SS)-ethylenediaminedisuccinic acid, H,edds (34), includes the synthesis of Na[Rh(edd~)J.’’~From its ‘H n.m.r. O H

/I

I

HO - C - 4 -H

H O

I

1

I

I

I1

HO 4 4 - N H - 4 H , ~ ~ H , - - N H - 4 - - C - - O H

I1

O H

spectrum, and by analogy with the known cobalt(m) analogue, this complex is considered to contain hexadentate edds4- in which both aspartate moieties are in identical environments. Reversible oxidation of the o-quinone complex (13; M = Rh; X = Cl; Y = C O ; Z = C1) to give compounds thought to contain co-ordinated semiquinone radicals has been detected using cyclic ~oltammetry.~’ The oxidation may also be effected chemically with oxidants such as NiS,C,(CF,), or AgPF,. The photochemistry of K,[Rh(C,O,),] has been investigated in the solvents 3.5M-H 3P04,5.5M-H, SO,, 1OM-LiC1, and eth yleneglycol-water mixtures. Formyl (HCO) and H radicals were detected by e.s.r. at low temperatures and their behaviour on warming was followed. Other workers have reported thermal decomposition studies on the solid-state form of K,[Rh(C,O,),],4.5H,O and other transition-metal oxalates.’ Thermogravimetric curves

’’

’*

lSh

15*

J. M. Duff and B. L. Shaw. J.C.S. Dalton, 1972, 2219. J. A. Neal and N. J. Rose, Inorg. Chem., 1973,12, 1226. L. A. Il’yukevich. N. I. Zotov, L. N. Neokladnova. Yu. V. Glazkov, and V. V. Pansevich, Russ. J . Znorg. Chem., 1972,17, 1491. K. Nagase, Bull. Chem. SOC. Japan. 1972,45,2166.

The Noble Metals

373

indicate that the thermal stability of the anhydrous complexes decreases approximately with increase in electron affinity of the central metal ion. Differential scanning calorimetric curves yielded AH values for dehydration and decomposition. Subsequent studies showed carbon dioxide to be the only gaseous product, the decomposition occurring via electron transfer from a C 2 0 i - ligand to the central rhodium.lS9 An extensive study of the polarographic behaviour of Rh'" complexes, including [Rh(ox),I3-, [Rh(H20)6]3+, and [Rh2L8C1202]'+ (L = py or picoline; n = 2 or 3),lS3has shown that all the compounds undergo a two-electron reduction at the dropping mercury electrode, with the superoxo- and peroxo-bridged dirhodium(m) species behaving similarly to the analogous pperoxodicobalt(1u) compounds. S-donor Iigands. As previously foundf60 with Et,S as ligand, four complexes of stoicheiometry RhC1,,3Me2S have been isolated from the room temperature reaction between Na3[RhCl], and dimethyl sulphide.16' The species were distinguished by colour, molecular weight, and ESCA measurements. A yellow product of formula RhC1,,4Me2S was also reported. Similarly,treatment of Na,[RhCl,] with diethylsulphoxide has yielded the complexes Na[Rh(DESO),Cl,] and [Rh(DES0)3C13].1621.r. studies reveal that, whereas the former complex contains only S-bonded diethylsulphoxide, the tris species contains a mixture of S- and 0-bonded DESO ligands. (cysu = cysteinesulphinato(2 -)The yellow anion ( +)-[Co(~-cysu)~]~SN), which is readily obtained in a stereoselective synthesis from L-cysteine, has been shown to be an excellent resolving agent for 3 + cations of the type [ML3I3+ In particular, the complexes [Rh(phen),],+, [Rh(bi~y)~],+, and [Rh(phen),(NH,),l3+ have been resolved for the first time. Other sulphinatocomplexes reported include the tris(organosu1phinato-s) species [Rh(RS02) (H,O),] (R = Me, Ph, or p-MeC,H,).164 These yellow, diamagnetic compounds exhibit i.r. bands which indicate S-co-ordination of the SO, groups. In the course of studies into the co-ordination behaviour of the interesting ligand (PhO),P(S)Se-, the dark-red RhL, has been isolated.16s U.v.-visible spectral studies indicate that the ligand generally forms a chelate structure (35) with

,-

159 160 161

162 163 164

K. Nagase, Bull. Chem. SOC.Japan, 1973,46, 144. A. P. Kochetkova and L. B. Sveshnikova, Russ. J . lnorg. Chem., 1970,15, 1645. A. P. Kochetkova and L. B. Sveshnikova, Russ. J . Inorg. Chem., 1972,17, 1154. Yu. N. Kukushkin and K. A. Klokhryakov, Russ. J . Inorg. Chem.. 1972,17, 136. L. S. Dollimore and R. D. Gillard, J.C.S. Dalton, 1973, 93. E. Lindner and I. P. Lorenz, Inorg. Nuclear Chem. Letters, 1972,8,979. S. V. Larionov, L. A. Il'ina, and T. V. Bulycheva, Russ. J . Inorg. Chem., 1972, 17, 1013.

374

Inorganic Chemistry of the Transition Elements

four-membered rings, and has a position in the spectrochemical series identical with the diethylthioselenophosphate ion (EtO),P(S)(Se)- . The preparation of the yellow complexes CN,H,[RhX( SO,H)(dmg),],nH,O (CN,H, = guanidinium; X = Br or I; n = 1 or 3) has been described:'66

In addition, an i.r. analysis of the related sulphito compounds [C(NH,),],[Rh(SO3),(dmg)],2H2O and [C(NH,),][Rh(SO,)(dmg),(H,O)] indicates that I ~further ~ examthe SO:- ligand is unidentate and S-bonded to the r h 0 d i ~ m . A ple of an S-bonded sulphite species is the compound [Rh(SO,)(CN)(NH,),],2H,0.168 Its co-ordination behaviour was again supported by i.r. evidence, and confirmed from a single-crystal X-ray analysis (Table 3). Rhodium 3d,,, and 3d,,, binding energies have been recorded for a wide variety of rhodium complexes, including trans-[RhX2(dth),]CI04 (dth = MeSC,H,SMe; X = C1 or Br), [RhCI,(PPh,)(otth)], cis-[RhX,(thiox),] (thiox = 1,4-thioxan; X = C1, Br or I), [RhCI,(PhSC,H,SPh)ln, and [RhCl,],1.5(PhSC2H,SPh).134For these Rh"' complexes, the binding energies are very sensitive to the ligand environment. Group V Donors. N-donor ligands. A variety of complexes of the type [Rh(CO)(L-L)HX,] (L-L = 1,lO-phenanthroline or 2,2'-bipyridine; X = C1 or Br) have been isolated from the treatment of solutions of [Rh(CO),X,]- with N-donor ligands. 144 Similarly, with pyridine the species [Rh(py),X,] is obtained. In a related study, re-examination of the synthesis of cis-[Rh(L-L)Cl,] from RhC1, and ethanolic L-L shows it to be a catalytic process.'69 This has led to convenient catalytic preparations for the range of compounds cis[Rh(L-L),X2]"+ (X = I-, CN-, H,O, or NH,), cis-[Rh(L-L),ClY]"+ (Y = NO;, H,O, NH,, or py), and [Rh(L-L)J3+, some of which are new. In compounds via a chromatoaddition, the resolution of the cis-[Rh(L-L),Cl,] graphic technique has been described, which is the first successful resolution reported for the bis-(2,2'-bipyridine) species. The synthesis of the arylazocomplexes [RhX,(N,Ar)(PPh,),] (X = C1 or Br) has been reported:41 +

+

Their i.r. spectra show two bands at 1620 and 1560 cm-I associated with the (N=NAr) group. Thus by analogy with the corresponding nitrosyl complexes they are formulated as rhodium(II1) derivatives of (N=NAr-). In contrast, the absence of appropriate i.r. bands in the previously reported17* complexes Ibb lh7

lh8 16'

G. P. Syrtsova and T. S. Bolgar, Russ. J. lnorg. Chem., 1972, 17, 238. G. P. Syrtsova, Yu. Y. Kharitonov, and T. S. Bolgar, Russ. J. lnorg. Chem., 1972, 17. 142. L. M. Dikareva, I. B. Baranovskii, and Z . G . Mekhtiev, Russ. J . lnorg. Chem., 1972,17, 177. P. M. Gidney. R. D. Gillard, and B. T. Heaton, J.C.S. Dalton, 1972, 2621. M. C . Baird and G. Wilkinson, J. Chem. SOC.( A ) , 1967,865.

The Noble Metals

375

'[RhCl,(N,Ar)(PPh,),]' shows that they should be formulated as aryldiimine derivatives, [RhC1,(NH=NAr)(PPh3),]. The preparation and characterization of a variety of nitrile complexes have been described, including truns-[RhX,(RCN),]+ (X = C1 or Br; R = Me, Et, Pr", Ph, or PhCH,) and [RhCl,(RCN),],(R = Me, Pr', or PhCH2).I7' Interestingly, while the treatment of RhC1, with MeCN is known to give both 1,2,3- and 1,2,6isomers of [RhCl,(RCN)], only the 1,2,4-isomer was observed when R = Et, Pr", Pr', or PhCH,. Structures were assigned unambiguously from the 'H n.m.r. spectra. Other workers have recorded 'H and 19F n.m.r. spectra for the related organonitrile complexes [Rh(NH,)5(RCN)]3+ (R = Me, Pr, Ph, acrylo, a-methacrylo, or 0,m-,or p-FC,H4).48 In every case, co-ordination to the Rh"' centre leads to deshielding of all the ligand protons or F atoms with respect to the free ligand values. Further organonitrile complexes reported are the series [RhXY,(PPh,),(RCN)] (X = C1 or Br; Y = CN or ,':)I

Of greater interest is the observation that if reactions (23) and (24) are carried out under mild conditions in the absence of RCN, then the cyanogen-containing complexes [RhX(CN),(PPh3),],(C2N2)and [RhCII,(PPh,),(C,NJ] are obtained. 1.r. evidence supports the structure -Rh-N=C-C=N-Rh-, containing a bridging cyanogen molecule, for the former complex, while in [RhClI,(PPh3),(C2N2)] the cyanogen is believed to be bonded to the rhodium tiia a lone pair on one nitrogen atom. The syntheses of the new complexes [Rh(NOJ(H,O)(dmg),] and H[Rh(NO,)Cl(dmg),] have been reported, together with the kinetics of their aquati011s.l~~ Another report shows that co-ordinated nitro (NO,) ligands can be oxidized by concentrated nitric acid to yield nitrato-complexes:' 74

Formulation of the brown product as hexanitratorhodiumf III) was supported by i.r. and ESCA measurements. An investigation of the co-ordinating ability of ligand (36) has resulted in the isolation of the species [RhLCI,],H,O, which is

17'

17* 173

174

R. D. Gillard, B. T. Heaton, and H. Shaw, Inorg. Chim. Acta, 1973,7, 102. G. Favero, B. Corain, P. Rigo, and A. Turco, Gazzetta, 1973,103, 297. G. P. Syrtsova and T. S. Bolgar, Russ. J. Inorg. Chem., 1972, 17, 1585. L. K. Shubochkin, V. I. Nefedov, E. F. Shubochkina, M. A. Golubnichay and L. D. Sorokina. Russ. J . Inorg. Chem., 1972, 17, 1496.

376

Inorganic Chemistry of the Transition Elements

believed to be polymeric in view of its high melting point. The reduction of Rh"' bipyridine (1 :2) solutions with NaBH, in methanol has been shown to proceed via labile hydride intermediates, one of which has been trapped by addition of triphenylpho~phine:'~~ Rh"'

+ 2 bipy + PPh,

c10,

- ~-

MeOH

[Rh(bipy)(PPh,),H,]C104

In contrast, addition of RX to the reaction medium yielded the new complexes [Rh(bipy),(R)X]ClO,, which are believed to arise from oxidative addition of RX to a mono-Rh'-bipyridine species. A related study has been published on the reduction of cis-[Rh(bipy),Cl,] + in alkaline aqueous ethanol under dihydrogen.'77 The known [Rh(bipy),] is produced via an autocatalytic process. Following an earlier report,178 the complete resolution of the cations [M1"(en),13 (M"' = Co, Cr, or Rh) has been described, via the novel method of paper electrophoresis using a solution of sodium d-tartrate and AlCl, as a chiral supporting electrolyte.' 79 Tests indicated that separation of the enantiomorphs of [M(en),13 was accomplished by some aluminium d-tartrate complex rather than by the d-tartrate anion alone. Another interesting paper reports the preparation and separation of four of the possible eight conformational and optical isomers of [Rh{( +)-chxn),l3' (chxn = trans-1,2-cyclohexanediamine).' Characterization by u.v.-visible and c.d. spectra showed Jaegar's' 8 1 initial study of this system to be incorrect, since he considered optical rotations rather than absolute configurations. C.d. spectra of [Rh(L-L)3]3+ (L-L = 1,lO-phenanthroline or 2,2'-bipyridine) have also been recorded.' 8 2 A method based largely on these c.d. data was employed to establish the stereochemical configuration of a range of isomers of bis- and tris-(L-L) complexes. A detailed study has been made of the Raman and i.r. spectra (to 40 cm- ') of the solid salt [Rh(en),]Cl,,H,O, and of its Raman spectrum in solution.'83 Also reported are the far4.r. spectra (400-30 cm-') of [M(NH,),X]X, (M = Co, Rh, or Ir ;X = C1, Br, or I), and their deuterium derivatives.lg4 In addition, ESCA measurements provided Nls (NH,), N l s (NO,), and C12p3/, binding energies, which were observed to decrease down the series Ir, Rh, Co. Thus, a good correlation was obtained between the force constant of the M-N and M 4 1 bonds and the N and Cl binding energies. Other authors have recorded Rh 3d,,, and 3d,/, electron binding energies for a very large range of rhodium complexes, including trans- [RhCl,(py),] C1,H ,O cis-[RhCl,(bip y),] C1,2H20, phenH[RhCl,(phen)J, and [RhCl,L,] (L = MeCN or a-picoline).' 34 +

+

+

176 17'

179

lS1

lS4

H. G. Ang, W. E. Kow, and K. F. Mok, Inorg. Nuclear Chem. Letters, 1972,8, 829. I. I. Bhayat and W. R . McWhinnie, J . Organometallic Chem., 1972,46, 159. J. D. Miller and F. D. Oliver, J.C.S. Dalton, 1972, 2473. H. Yoneda and T. Miura, Bull. Chem. SOC.Japan, 1970,43, 574. H. Yoneda and T. Miura, Bull. Chem. SOC.Japan, 1972,45, 2126. G. Galsbsl, P. Steenb~al,and B. Ssndergaard Serrensen, Acta Chem. Scand., 1972,26, 3605. F. M. Gaegar and L. Bijkerk, Z . anorg. Chem., 1973,233,97. S. F. Mason and B. J. Peart, J.C.S. Dalton, 1973, 949. D. W. James and M. J. Nolan, Inorg. Nuclear Chem. Letters, 1973,9, 319. 1. B. Baranovskii and G. Y. Mazo, Russ. J . Inorg. Chem.. 1972. 17, 870.

377

The Noble Metals

The binding energies are sensitive to the ligand environment in these Rh"' species, and in addition generally decrease (by up to 2.8 eV) with decrease in metal oxidation state. The polarographic behaviour of a similar range of com(L = NH,, py, %n, itrien, or substituted pounds of the type trans-[RhL,X,] pyrazines; X, = Cl,, Br,, I,, CIOH, BrOH, etc.), [Rh(L-L),],+ (L-L = en or py), LRh(L-L)Cl,] (L-L = phen or bipy), [Rh(NH,),XI2+ (X = Cl or OH), and [RhX,I3- (X = CN- or NO,) has also been examined.lS3In agreement with preparative observations, the replacement of two ethylenediamine ligands by four pyridines (or other aza-aromatic ligands) increases the E , values appreciably, and thus renders these Rh'" complexes susceptible to ethanol acceleration of their substitution reactions. Several papers have appeared concerning the photochemistry of rhodium(n1) amine complexes. Quantum yields have been recorded for the various products arising from the d-d irradiation of the compounds [Rh(NH3)5C1]2+and trans[RhL,Cl,]+ (L = NH,, h n , or &y~larn).'*~ Chloride aquation was observed to be predominant in all cases, yielding trans-[RhL,Cl(H,0)]2+ as the only observable products for at least 25 % reaction. The results support a mechanism in which photochemistry. originates from the lowest triplet state, which in D,, symmetry is ,E,. Thus the change in electron density relative to the ground state will labilize ligands lying along the z-direction (Cl-Cl axis), resulting in dissociation of a chloride. A more theoretical paper has developed a model for predicting the course of the photoreactions of low-spin d6 complexes including [Rh(NH3),XI2+ and trans-[RhL,X,]+ (X = C1, Br, or I ; L = NH, or +n).lg6 The molecular axis which is photolabilized is predicted by considering bonding changes which occur when the lowest triplet and singlet excited states of the metal complex are populated. Furthermore, the relative quantum yields of solvation of the two ligands on the labilized axis are interpreted from a simple analysis of their donor orbital energies. Photolysis (Hg iamp) of aqueous solutions of [M(NH,),N,I2+ (M = Rh or Ir) in dilute HCl has been shown to yield the chloroamine complexes [M(NH,),(NH,C1)I3 + as the primary product^.'^' Since one molecule of dinitrogen was also produced, even in the presence of added I- or acrylamide scavengers, the involvement of azide radicals was eliminated. Instead the mechanism in Scheme 9 (M = Rh) was proposed, and the formation of such a co-ordinated +

CM~NH,),N,I~+

1

h~ -N,

[(NH,),M--N:I2+

/

[(NH,)s-M-NH]3

+-k!%

[I(NH,),M(NH2C1)]3

Scheme 9

''' C. Kutal and A. W. Adamson, Inorg. Chem., 1973,12, 1454. 186

ls7

J. I. Zink, Inorg. Chem., 1973, 12, 1018. J. L. Reed, F. Wang, and F. Basolo, J. Amer. Chem. SOC.,1972,94. 7173.

+

Inorganic Chemistry of the Transition Elements

378

nitrene (M-NH) intermediate is supported by independent studies of the flash photolysis of [Rh(NH3)5N3]2+.188Transient absorbances were observed which were attributed to species formed by reaction of the nitrene either with itself: 2[(NH3) R hNH]’

+

-+

[(NH,) 5RhNzH]5

+

+H

(25)

+

or with I-. As observed by Basolo et aE.,187less than 10% of the product dinitrogen was scavengeable with I-. However, strong dinitrogen scavenging by I- was observed for the corresponding flash photolysis of [ C O ( N H ~ ) ~ N ~ ] ~ + , indicating the intermediacy of azide radicals.’ 88 P- and As-donor ligands. In the course of investigations of the complexing behaviour of the mixed ligand (Ph,AsC,H,),PPh, the orange complex RhLC1, has been obtained via direct reaction of L with ethanolic RhC1,,3H,0.105

Table 3 X-Ray data for rhodium compounds Compound [NMe,(CH,Ph)], [RhJCO),

$1

R 0.033

Comments Re?: In anion, 6 Rh atoms form trigonal prism, edges associated with symmetrically bridging CO groups. Remaining 6 CO ligands terminally bonded to Rh’s Carbide atom occupies centre of prism [see structure (291 Dimeric. Rh --Rh distance (2.63a) indicates M -M bond. Unsymmetrical CO’s and phosphines Ph,P

\

,:,

,pph3

/Rh,T/R\ Ph,P 0.036

0.025

[RhClL]

188

0.035

0

PPh,

Octahedron of 0 atoms about Rh Distorted octahedron with quinquedentate edta, and H,O co-ordinated to Rh in an equatorial site. Edta bears proton on unbound glycinate arm Octahedral co-ordination with 0 and N atoms mutually trans Confirms trans-geometry, and co-ordination of SO3 ilia S atom. Rh lies above RhN, plane to side of S atom by 0.15 A Monomeric. Square plane about Rh. Molecule has imposed mirror symmetry

G . Ferraudi and J. F. Endicott, J. Amer. Chem. SOC., 1973,95,2371.

The Noble Metals Table ?continued Compound [RhCl(NO)L]PF,

379 R

Comments

0.055

(a) Ref. 109. (b) P. Singh, C. B. Dammann, and

Monomeric. Tetragonal bipyramidal co-ordination about Rh. Bent nitrosyl ( L RhNO = 131")

Rej. B

D. J. Hodgson, Znorg. Chem., 1973, 12, 1335. (c)

J. C. Morrow and E. B. Parker, Actu Cryst., 1973. B29, 1145.(d) G. H. Y . Lm, J. D. Leggett, and

R. M. Wing, Acta Cryst., 1973, B29, 1023. (e) A. E. Bukanova, I. V. Prokofleva, M. A. Porai-Koshits, A. S. Antsyshkina, and L. M. Dikareva, Russ. J . Znorg. Chem., 1972, 17, 396. (j)L. M. Dikareva, 1. B. Baranovskii, and Z. G. Mekhtier, Russ.J . Znorg. Chem., 1972,17, 1772. ( 9 ) Ref. 122; L = PhP(CH2CH2CH,PPh,),.

4 Iridium Cluster Compounds.-The reaction of tetranuclear phosphine-substituted clusters of the type [Ir,(CO~,L,] [L = PPh,, P(p-MeC,H,),, PEt,, or PPr'j] and [Ir4(CO)8L4] (L = PEt,, PPr;,, or PBu';) with CO gas has been investigated by high-pressure i.r. spectrophotometry.' 8 9 The aryl- and isopropyl-phosphine derivatives cleave to dinuclear [Ir,(CO),L,] or [Ir,(CO),L], depending on the conditions. However, breakdown of the tetranuclear cluster occurs less readily for the n-alkylphosphine derivatives, which initially yield [Ir,(CO),L,] and [Ir4(CO)loL2], and only finally give [Ir,(CO),L]. On the other hand, reaction with a mixture of CO and H, causes complete cluster breakdown with all of the above substrates, yielding [HIr(CO),L]. A similar investigation of the unsubstituted cluster Ir4(CO)12 showed no reaction with CO alone, but partial conversion into [HIr(CO),] when treated with CO and H, (l;l, 430 atm, 200°C).1 An improved, more convenient synthesis of Ir4(CO)12 was also found with yields of 70 -80 < : : Na,[IrCl,]

+ Cusponge + CO

2-methoxyethanol 100 atm, 100°C

Ir,(CO) 12

Iridium(-I).-The preparation and properties of a large number of [M(NO)L,] complexes have been reported, including [Ir(NO)(PPh,),].' l4 Their v(N0) frequencies suggest that they are d" complexes, while 'H n.m.r. data are consistent with the C3"pseudo-tetrahedral structure (26 ; M = Ir) rather than the alternative bent NO- structure with square-planar geometry. Oxidative addition reactions with a variety of reagents were reported. These nitrosyl complexes have been found subsequently to react with toluene-p-sulphonyl azide in benzene to yield the tetrazene derivatives [lr(NO)(PPh,)(N,R,)] (R = S02C6H4Me).1'S 'H n.m.r. data suggest an equilibrium (14; M = Ir) in solution between the tetrazene ring stabilized by co-ordination, and open forms. The reaction with HCl is consistent with this ring opening to produce the new nitrosyl species [Ir(NO)(PPh,)Cl,]. The above d10 nitrosyl [Ir(NO)(PPh,),] has been included in a theoretical discussion leading to a general bonding model for linear and bent transition-metal nitrosyl complexes.37 lS9

190

A. J. Drakesmith and R. Whyman, J.C.S. Dalton, 1973,362. R. Whyman, J.C.S. Dalton, 1972,2294.

380

Inorganic Chemistry of the Transition Elements

Iridium(I).---Group VII Donors. Halogeno-carbonyl and -phosphine complexes. During the course of investigations into the co-ordination behaviour of the ligand siphos [P(CH,SiMe,),] it was observed that the new complex trans[IrCl(CO)(siphos),] reacted with NaBH, to produce a rare example of a tetrahydroborate complex [Ir(BH,)(CO)(siph~s),].~~ 1.r. and 'H n.m.r. measurements indicate the hydride bridged structure (27; M = Ir). Another interesting paper reports the first example of oxidative addition of an ortho B-H bond to Ir.Ig1 Whereas addition of the phosphine l-dimethylphosphino-1,2-carbaborane(L = C2BloHl,PMe,)to [Ir(C,H,,),Cl], at room temperature yields yellow [IrClL], on refluxingin cyclohexanea white, air-stablepowder is obtained. Its i.r. spectrum has an Ir-H band, while molecular weight, C-deuteriation, and 'H n.m.r. data indicate the formula [IrHCIL,(C,B,,Hl,PMe,)] with structure (37). L

Md

Refluxing the polymer [Ir(CO),Cl], with benzene solutions of the chelating agents Ph,AC2H,APh, (A'= P or As) has led to the new five-co-ordinate species [Ir(CO),(L-L)Cl] (38).lg2 On the hand, reaction with BEt, (B = S, Se, or Te) yielded [Ir(CO),BCl]. The complexes (38; A = As) were shown to dissociate in solution according to equilibrium (29, and thence to undergo

oxidative addition reactions yielding products (39 ; XY = C1, or MeCOCl) or (40; XY = I, or Ph,SOCl), depending on the nature of XY. X

co

co Adduct formation has been studied between the four-co-ordinate complexes trans-[IrX(CO)(PPh,),] (X = F or Cl), trans-[IrCl(CS)(PPh,),], and trans19' 19*

E. L. Hoe1 and M. F. Hawthorne. J . Amer. Chem. Soc., 1973,95, 2712. P. Piraino, F. Faraone, and R. Pietropaolo, J.C.S. Dalton, 1972, 2319.

The Noble Metals

381

[IrC1(CO)(AsPh3),], and a variety of Lewis acids including cyano-olefins, BX,, 0,, SO,, and SbX,.I9, From changes in v(C0) [or v(CS)] on adduct formation the tentative order of relative basicity [IrCl(CO)(AsPh,),] > [IrCl(CO)(PPh,),] > [IrCl(CS)(PPh,),] was proposed, which parallels the order of decreasing ligand reactivity. In a related study, the reaction of Vaska's compound trans-[Ir(CO)Cl(PPh,),] with MH,X and M,H, (M = Si or Ge; X = H, C1, Br or I) has been shown to involve addition of the silanes and germanes as H- and MH,X-, yielding octahedral adducts such as (41).'94 H Ph,P\I C1'

,co

Ir\PPh

,

A spectroscopic study of halide exchange in the systems Ir(CO),I;-X(X = C1 or Br) and Ir(PPh,),(CO)I-Cl-, indicates that in non-aqueous solvents the lighter halides are preferred.' l 7 This result is quite significant since iridium was previously regarded as a soft acceptor.' Interestingly, in aqueous solution this preference is inverted for the anionic complexes, but unchanged for the neutral phosphine species.ll7 Group V7 Donors. 0-Donor and S-donor ligands. The rate of oxygen uptake by the series of complexes [IrCl(CO)L,] [L = PPh,, PEtPh,, or PEt,Ph, P(pC 1 , p-Br-, or p-Me4,H4),, or P(m-Me or rn-MeO--C,H,),] has been observed to increase with increasing number of alkyl groups on the phosphine.' 9 5 This result, together with Hammett type correlations, provides further evidence for the M-0, bonding model involving back-donation of electrons from metal n-orbitals to antibonding n-orbitals of dioxygen. A theoretical study has also appeared rationalizing the bonding in Ir' 4ioxygen adducts.' Qualitative measurements on the homogeneous oxidation of PPh, and PPh,Me by the related oxygen complex [Ir(CO)(PPh,Me),(0,)]C104 in a variety of solvents show it to be an inefficient catalyst.lg6 The reaction between hydroperoxides and trans-[IrX(CO')L,] (X = Cl or Br) has yielded stable alkylperoxy-compounds, as shown, with the evolution of

'*

trans-[IrX(CO)L,] (R

=

Bu',L

=

+ R O , H toluene r o ~ m p[IrX(O,R),(CO)L,] ,

PPh,, AsPh,, or PPh,Me; R

=

PhMe,C, L

=

PPh,)

oxygen.1 9 7 On the other hand, treatment of [IrH(CO)(PPh,),] with the organic acids p-nitrophenol, pyridine-2-thiol, and trifluoroacetic acid, provides the new R. J. Fitzgerald, N. Y. Sakkab, R. S. Strange, and V. P . Narutis, Inorg. Chem., 1973, 12, 1081 E. A. V. Ebsworth and D. M . Leitch, J.C.S. Dalton, 1973, 1287. E. E Mercer, W. M. Peterson, and B. F. Jordan, J . Inorg. Nuclear Chem., 1972, 34,3290. V . J. Choy and C. J. O'Connor, J.C.S. Dalton, 1972,2017. B. L. Booth, R. N . Haszeldine, and G. R. H. Neuss, J.C.S. Chem. Comm., 1972, 1075.

lY5

19'

Inorganic Chemistry of the Transition Elements

382

complexes [Ir(OC,H,N0,)(CO)(PPh3)2], [IrH(C,H,NS)(PPh,),], and [Ir(CF,CO,)(CO)(PPh,),], respe~tive1y.l~~ The new sulphur dioxide derivative [IrH(SO,)(CO)(PPh,),] has been synthesized [equation (18), M = Ir],136 and its anomalous spectroscopic features were tentatively interpreted in terms of a tautomeric equilibrium [equation (19)] involving hydride migration between M and co-ordinated SO,. Group I/ Donors. N-Donor ligands. The nitrosyl analogue of Vaska's compound, namely [IrCl(NO)(PPh,),] , has been prepared both by chlorination of , and by reaction of [IrHCl(NO)(PPh,)] with non[Ir(NO),(PPh,),] co-ordinating a c i d ~ . This ' ~ ~ reactive complex forms five-co-ordinate addition products with neutral ligands [CO, PPh,, Ph,PC,H,PPh,, Ph2PC,H,PPh,, P(OPh),, etc.], whereas co-ordinating anions X- (NO;, C1-, HS-) form [IrX,(NO)(PPh,),]. An independent study has provided alternative, highyield route to the series [IrX(NO)(PPh,),]+ (Scheme 10; X = C1, Br. or I; +

+

tr~n~-[Irx(CO)(PPh,),1

[IrX(NO)(PPh,),]BF,

Scheme 10

R = p-nitrobenzoyl).' 99 The intermediate dinitrogen complexes were also isolated. All the nitrosyl compounds showed v(N0) in the region 18951902 cm- ',confirming co-ordination as NO'. However, the adduct [IrCl(NO)(PPh,),(tcne)]ClO, formed with tetracyanoethylene has a v(N0) band at 1595 cm- indicating conversion into a bent nitrosyl ligand. In this connection, a theoretical study has appeared giving a general bonding model for linear and bent transition-metal nitrosyl complexes, including [Ir(CO)(NO)X(PPh,),] (X = C1 or Br), [Ir(NO)Cl,(PPh,),], and [Ir(N0)2(PPh3)2]+.37 The aryldiazo-complex [IrCl(ArN,)(PPh,),] +has been isolated in high yield ziia a one-step reaction from Vaska's compound (equation 27).200It reacts with

',

+

[IrCI(CO)(PPh,),]

+ ArCON, iA-

[IrCI(ArN,)(PPh,),]PF,

(27)

a variety of reagents (L = CO, RNC, PR,, AsR,, or SbR,) to give the fiveco-ordinate species [IrCl(ArN,)(PPh,),L]. By analogy with known nitrosyl structures, trigonal-bipyramidal geometries with linear Ir -N-N-Ar were assigned to the L = PPh, and AsPh, compounds, whereas the L = RNC and CO species were given square-pyramidal shapes and bent aryldiazo-ligands. Scheme 11 has been employed to yield the co-ordinatively unsaturated comly8

C. A. Reed and W. R. Roper, J.C.S. Dalton, 1973, 1014. R. J. Fitzgerald and €1. W. Lin, Inorg. Chem., 1972,11, 2270. B. L. Haymore and J. A. Ibers. J . Amer. Chem. SOC.,1973,95, 3052.

lYy *O0

The Noble Metals

383

plexes [Ir(A-A)(CO),]X (A-A = 1,lO-phenanthroline, or 2,2'-bipyridine ; X = PF; or C10;).201 These compounds are very reactive, undergoing oxidative addition with various molecules such as H,, HCl, HgCl,, HgBr,, and I,.

Scheme 11

The dimeric compounds [(PPh,),(CO)MN,M(CO)(PPh,),lBF, (M = Rh or Ir) have been prepared from [M(PPh,),(CO)N,] and NOBF,; their i.r. and 14N n.m.r. spectra are consistent with the bridged structure (30).14, Bridge-splitting reactions occur with ligands L (polar organic solvents or PPh,) to regenerate [Ir(PPh,),(CO)N,], and produce [Ir(PPh,),(CO)L]BF,. Protonation and carbonylation of the corresponding isocyanato-complexes [M(PPh,),(CO)(NCO)] (M = Rh or Ir) have also been investigated (Scheme 8).14, In an interesting attempt to prepare high-temperature superconductors, cyanine dye bases were treated with equimolar amounts of the semiconducting complex cis-[Ir(acac)(CO),]. ,02 However, the products cis-[TrCl(CO), L] surprisingly showed no evidence for intermetallic interactions, having conductivities in the range of organic insulators. Absolute i.r. intensity measurements on a number of dinitrogen complexes, including [IrCl(N,)(PPh,),] and [IrCl(N2)(C8H1204)(PPh3)71, have shown increases with decreasing frequency v(NN).,03 This that the intensity A(") agrees with a model of d,-p,, back-donation for Ir-N, bonding. In addition, calculations suggest that the terminal nitrogen atom in these compounds carries the smallest negative charge (and the inner nitrogen atoms the most). Confirmation of such polarity in the dinitrogen ligand comes from ESCA measurements of the NIs binding energies for [IrC1(N2)(PPh,)2].29 Both nitrogen atoms carry a negative charge, with a total of ca. 0.7-0.9 a.u. From studies on a range of related rhenium complexes, the charge separation on the nitrogen atoms was shown to increase with decreasing v(NN). P-Donor ligands. A series of salts of the type [IrL,]X and [IrL,]X [L = PR,, P(OR),, or AsR,; X = BPh,, PF,, or ClO,] has been prepared from the reaction of L with ethanolic [Ir(C8H12)C1],.204The four-co-ordinate species [Ir(PMe,Ph),]BPh, readily forms an oxygen adduct, but the corresponding arsenic analogue can only be obtained via the cyclo-octane complex (equation 28). Its i.r. and 'H n.m.r. spectra are consistent with structure (42). Other new '01 '02 203

'*'

G . Mestroni and A. Camus, lnorg. Nuclear Chem. Letters, 1973,9, 261 T. Winkler and C. Mayer, Helo. Chim. Acta, 1972, 55, 2351. B. Folkesson, Acta Chem. Scand., 1973, 27, 276. L. M. Haines and E. Singleton, J.C.S.Dalton, 1972, 1891.

Inorganic Chemistry of the Transition Elements

384

compounds reported include the tricyclohexylphosphine derivative [IrCl(CO)(PCyJ,], obtained by passing CO through a boiling alcoholic mixture of PCy, and IrC1,,3H20.'25 In the absence of CO these latter reagents yield the interesting products [IrX,(PCy,),] (X = C1 or Br). Unlike their rhodium analogues [(C8H14),IrCl],

+ AsMe,Ph + 0, %[Ir(O,)(AsMe,Ph),]BPh,

(28)

these complexes are diamagnetic, suggesting low-spin d6 hydrido species [IrHX,(PCy,),], or perhaps an Ir',"' formulation. The purple precipitate obtained in 50% yield from briefly boiling [IrH(CO)(PPh,),] in decalin has Ph

A s MezPh

As Me ,Ph

Ph

/ -\

Ph

Ph

(43)

been shown to have the dimeric structure (43) on the basis of an X-ray analysis (Table 4).,05 To comply with the effective atomic number rule this complex requires four electrons in the Ir--Ir bond, which is consistent with the short Ir-Ir bond length (2.554 A) and the acute angles (67")at the bridging P atoms. Iridium(1 I I). -Group VII Donors. Halogeno-complexes. U.v.-visible spectral studies and ion exchange experiments indicate that the anomalous electrical conductivity of [IrC1,I3- in aqueous solution arises from aquation and ion pair formation as shown.206 [IrC1,I3-

+ H20

[1r(H2O)Cl5]'-

+ C1-

41 { [Ir(H20)C15]Cl)3-

ESCA measurements on the series of complexes K,[IrX,] (X = C1, Br, NO,, CN, or sox) reveal that the ability of ligands to withdraw electron density from lr decreases in the order NO, > CN > $ox > C1 > Br > I.207 Comparison with related Irrv species shows that the Ir 4f7,, binding energies increase with increasing oxidation state. Halogeno-carbony2 and -phosphine complexes. An interesting paper reports that for the equilibrium [Ir(CO),(CI,] --I- in non-aqueous solvents, the iridium(II1) anion exhibits novel ambivalent acceptor properties, i.e. it displays soft acceptor halide preference at two halide positions, but hard behaviour at the other halide positions.'

'

205

'06 '07

R. Mason, I. Sertofte, S. D. Robinson, and M. F. Uttley, J . Organometallic Chem., 1972,46. Cbl. Yu. N. Kukushkin and M. S. Soboleva, Russ. J. lnorg. Chem., 1972,17,619. V. I. Nefedov, I. B. Baranovskii, and M. A. Porai-Koshits, Russ. J. lnorg. Chem., 1972. 17. 11 75.

The Noble Metals 385 The preparations of a wide range of complexes with the ligands dimethyl(1naphthy1)phosphine and methylphenyl(1-naphthyl)phosphine (L), together with their peri-(or 8-) metallated (P-C) derivatives, have been described (Scheme 12).f55 Configurations were assigned on the basis of 'H and/or 31P n.m.r.

HCI

11

base

Scheme 12

spectra. In the course of investigations into the co-ordination behaviour of the ligand P(CH,SiMe,), (siphos), a complex of formula [IrHCl,(CO)(siphos),] was isolated by treating a carbonylated alcoholic solution of chloroiridic acid with excess siphos. The related co-ordinatively unsaturated complexes [IrHCl,(PBu',R),] (R = Me, Et, or P r ) readily take up the small molecules CO and MeNC (Q to give octahedral [IrHCl,Q(PBu',R),), for which 'H n.m.r. and i.r. data indicate geometry On the other hand, while the R = Me substrate similarly adds o-donors such as pyridine, 4-methyIpyridine, or P(OMe), togive adducts of type (44a), with the more bulky R = Et or Prn substrates these &donor ligands displace a phosphine to yield [IrHCl,Q,(PBu',R)] of configuration (44b). Other new phosphine compounds reported B. L. Shaw and R. E. Stainbank, J.C.S. Dalton, 1972, 2108.

Inorganic Chemistry of the Transition Elements

386

include the hydrides [IrXCl,~CO)(PCy,),] (X = H or D), obtained by oxidative addition of XCl to the new [IrC1(CO)(PCy3)z].’25 Group VI Donors. 0-Donor Zigands. Reversible oxidation of the o-quinone complex (45; M = Ir, X = C1, Y = CO) to give compounds thought to contain

co-ordinated semiquinone radicals has been detected using cyclic voltamr n e t r ~ . ,The ~ oxidation may also be effected chemically with oxidants such as NiS4C4(CF3)4or AgPF,. In a systematic study of the synthesis of tertiary phosphine-carboxylate complexes, a convenient route to the new [IrH,(CF,CO,)(CO)(PPh,),] and [IrH(CF,CO,),(CO)( PPh,),] has been found via reaction of low-valent phosphine substrates with trifluoroacetic acid.” This route has been independently described by other authors.’ 30 S-Donor ligands. A series of 4-substituted benzenethiols HSC,H4Y (Y = F, Br, H, Me, or MeO) has been shown to react with [IrCl(APh,),] (A = P or As) to yield dimeric complexes of the type [IrHCl(SC,H4Y)(APh3)z]z (Scheme 13).209 On the other hand, 44trobenzenethiol gives [IrCl,(SC,H,N02)(APh,),],. In view of the paucity of Ir-dithio ligand compounds, the reported L

2

L

‘ /

L,/

Ir

‘c1

+ 2 HSAr

-2

cis

oxid. addit.

dimerize

r

L

2 H-Ir

I

,SAr

I ‘Cl L

Scheme 13

preparation of the series [IrL,] (L = 12-dialkyldithiocarbamates) is of some interest.” All of these yellow-orange complexes sublime under vacuum, while ’09

’lo

J. L. Herde and C. V. Senoff, Canud. J . Chem., 1973,51, 1016. C. G. Sceney and R. J. Magee, lnorg. Nuclear Chem. Letters, 1973,9,595.

The Noble Metals

387

their i.r. spectra [v(CN) values] confirm the presence of chelating L. Related dithiocarbamate and xanthate complexes of the type [IrH,L,(S,CW] (L = PPh, or AsPh, ;X = NEt, or OEt) have also been prepared,211using [IrH,L,] and Na,SCX. Their l H n.m.r. and i.r. spectra are consistent with structure (46).

L

The first examples of transition-metal sulphenato (RS=O) and alkoxysulphenato (ROS=O) complexes, namely [IrCl,(MeSO)(CO)L,] (L = PPh, or PPh,Me) and [IrCl,(ROSO)(CO)L,] (L = PPh,, R = Me or Et; L = PPh,Me, R = Me, Et or Pr'; L = PPhMe,, R = Me), have been synthesized

uiu the oxidative additions shown.212The new sulphinato (R-S

/p

) and thio

*O

complexes [IrC1,(MeS02)(CO)(PPh2Me)2] and [IrCl,(p-MeC,H,S)(CO)L,] (L = PPh, or PPh,Me) were also reported. Interestingly, the alkoxysulphenatocomplexes do not rearrange to sulphinato-compounds even on prolonged refluxing in toluene. During studies of the complexing ability of the interesting ligand (PhO),P(S)Se-, the orange [IrL,] has been is01ated.l~~ U.v.-visible spectral studies indicate that the ligand generally forms a chelate structure (35) with four-membered rings, and has a position in the spectrochemical series identical with that of diethylthio-selenophosphate ion (EtO),P(S)Se-. Group VDonors.Various aryldiazo-complexes of the type [IrClX(p-YC,H,N,)(PPh,),L] (X = C1, Br, I, N,, NO,, or NCO; Y = H, F, or Me; L = CO or EtNC) have been prepared :,O0 [IrCl(PPh,),L]

+ ArN,PF,

--t

[IrClX(ArN,)(PPh,),L]

These six-co-ordinate compounds are undoubtedly 1 8-electron systems, and probably possess bent, reactive ArN; moieties. For example, reaction with 'I'

A. A. Araneo and T. Napoletano, Inorg. Chlm. Acta, 1972,6, 363. T. A. George and D. D. Watkins, Znorg. Chem., 1973,12, 398.

Inorganic Chemistry of the Transition Elements

388

Et,O+BF, or HBF, yielded the derivatives [IrC1,(ArN,R)(PPh3),(CO)]BF4 (R = Et or H).Interestingly, other workers have isolated a number of products from the action of p-FC,H,Nl on Vaska's compound, including a yellow species which X-ray analysis showed to contain an o-metallated aryldi-imide moiety (Table 4).,13 In a related study the yellow, diamagnetic [IrH,(PPh,),(NH=NAr)]BF, were obtained via addition of ArNl to [IrH,(PPh,),], followed by insertion into an Ir-H bond, as Although these species are sensitive to nucleophilic anions (e.g. halides or OH-), the unstable (NH= NAr) ligand is greatly stabilized by coordination to iridium. The synthesis of [TrH,(PPh,),]

+ [ArNrNIBF, [IrH,(PPh,),( NH-NAr)]

+

the triazenido-complex [Ir(PPh,),(CO)(N,Ph,)] has also been reported, in which the triazene acts as a chelating ligand.,, Another paper described the preparation of the white [IrCl(NCF,)(CO)(PPh,Me),] oia direct treatment of trans-[IrCl(CO)(PPh,Me),] with excess hexafluoroazomethane.21 The authors choose to regard this as a nitrene complex in which the Ir-NCF, bonding involves donation of an electron pair from N to Ir, with concomitant backbonding from filled Ir d-orbitals to an empty p-type orbital of nitrogen. Possible pathways for the formation of the product are outlined in Scheme 14. CF,

/

[IrCI(CO)(PPh,Me),]

+ CF,N=NCF,

chHk(PPh,Me),(CO)CIIr

/

+/r -N

\

- NCF 3

[(PPh,Me),(CO)C11r(NCF3)]

-(PPh,Me),(CO)ClIr

N-N

cleavage

CF3 /

N

I

4 3 3

'N - C F ,

Scheme 14

The yellow-green complex K3[Ir(N02)3(N03)3] has been obtained via oxidation of co-ordinated nitrite in K,[Ir(NO,),] by dilute nitric The presence of both NO; and NO; ligands (in 1 :1 ratio) was confirmed by i.r. and ESCA measurements. On the other hand, treatment of K3[Ir(N0&] with concentrated HNO, or the use of prolonged heating, yielded a violet product which was similarly shown to be K3[1r(NO3),]. In the first reported '14

*I5

F. W. B. Einstein and D. Sutton, J.C.S. Dalton, 1973, 434. G. Caglio and M. Angoletta, Gazzetta, 1973. 102,462. J. Ashley-Smith. M. Green, and F. G . A. Stone, J.C.S. Dalton, 1972, 1805.

The Noble Metals

389 CEN /

study of the reaction of sulphur dicyanide (S

\

) with metal complexes,

CEN the compounds [IrCl(CN)(SCN)(CO)L,] (L = PPh, or PPh,Me) have been isolated from treatment with [IrCl(CO)L,].216 Their i.r. spectra indicated S-co-ordination of the thiocyanato-group. However, recrystallization from CH,Cl,-methanol caused isomerization to the N-bonded linkage isomer, for which an X-ray structure analysis has been carried out (Table 4). An investigation of the co-ordinating ability of the ligand 2-pyridyldiphenylphosphine (39 has resulted in the isolation of the species IrLCl,,H,O, which is believed to be polymeric in view of its high melting point.'75 The preparation of the edta complexes K[Ir(HY)C1],2H20 and K[Ir(H,Y)Cl,] has been reported, together with polarographic and conductivity studies.217Their i.r. spectra confirm the presence of both free and co-ordinated carboxylate groups. Investigations of piperidine-stabilized hydrido Ir" complexes continue with the synthesis of the yellow species [HIr(pip)X,] (X = NCO, NCS, and NCSe) trans-[IrClH(pip)]ClO,+ excess X - x [ H I r ( p i p ) X 2 ; l

Spectral studies indicate that all the diamagnetic solids are N-bonded, but that solutions of the thiocyanate complex are mixtures of N- and S-isomers. Another study records absorptiop and emission spectra as well as photoluminescence quantum yields for a series of [IrCl,(L-L),]Cl complexes, including the novel compounds with L-L = 4,7-or 5,6-dimethylphenanthroline, and 4,4'-dimethy1-2,2'-bip~ridine.~'~ The effect of solvent medium on the measured lifetimes of the complexes is interpreted in terms of a model invoking d,, +, , configurational interactions. The resolution of the parent cis[IrCI,(L-L)]+ (L-L = 1,lO-phenanthroline or 2,2'-bipyridine) cations has also been reported for the first time, employing a chromatographic technique.' 69 Following the recent elucidation220of the reaction of HCl with [Ir(NH,),N3I2+to produce [Ir(NH3)5(NH2Cl)]3+,similar studies have been extended to the cis-[lr(en),(N,),]+ species.221With 12M-HCl, two moles of dinitrogen were isoliberated and the bis(ch1oroamine) complex trans- [Ir(en),( NH,Cl),]Cl lated. The presence of the chloroamine ligand was supported by a U.V.peak at 253 nm ( E = 1300), and oxidation experiments with I- which were shown to follow the stoicheiometry of equation (29). [Ir(en),(NH2C1)l3+ + 4 1 - ~ [ I r ( e n ) , ( N H , ) , ] 3 + H+

216 217 218

'I9 220 221

+ 21, + 2C1-

(29)

J. A. Ibers, D. S. Hamilton, and W. H. Baddley, fnorg. Chem., 1973, 12, 229. N. A. Ezerskaya, T. P. Solovykh, and L. K. Shubochkin, Russ. J. Inorg. Chern., 1972, 17, 1160. E. R. Birnbaum, J. Znorg. Nuclear Chem., 1972,34, 3499. R. J. Watts, G. A. Crosby, and J. L. Sansregret, Znorg. Chem., 1972,11, 1474. B. C. Lane, J. M. McDonald, F. Basolo, and R. G. Pearson, J. Amer. Chem. Soc., 197294, 3786. T. R. Weaver, B. C . Lane, and F. Basolo, Znorg. Chem., 1972,11,2277.

390

Inorganic Chemistry of the Transition Elements

In an interesting related paper, photolysis of [Ir(NH3),N3I2+ in dilute HCl solution has been shown to be an alternative route to [Ir(NH3)5(NH2C1)]3+.187 Since one mole of dinitrogen was also produced, even in the presence of added I- or acrylamide scavengers, the involvement of azide radicals was eliminated. Instead the mechanism in Scheme 9 (M = Ir) was proposed, involving the formation of a co-ordinated nitrene (Ir-NH) intermediate. A detailed study has been made of the Raman and i.r. spectra (to 40 cm-') of the solid salt [Ir(en)3]13,H20, and of its Raman spectrum in s01ution.l~~ Also reported are the far i.r. spectra (400-30cm-1) of [M(NH3),X]X2 (M = Co, Rh, or Ir; X = C1, Br, or r) and their deuterium derivati~es.'~, In addition, ESCA measurements provided Nls(NH3), Nls(N03), and C12p3/, binding energies, which were observed to decrease down the series Ir, Rh, Co. Thus, a good correlation was obtained between the force constants of the M -N and M X 1 bonds and the N and C1 binding energies. Other authors have recorded 1r4f7/,, Nls, and C12p electron binding energies for a range of iridium complexes, including cis-[IrClX(en),]NO, (X = C1, I, SCN, or NO,), cis-[IrY,(en),]+ (Y = Br, I, or NO,), [ r I ~ ( e n ) ~ ] and A ~ ,cis-[Ir(NCS),(en),]~~~ N03.,07 The results show that the ability of ligands to attract electrons from Ir increases in the order I Br C1 < S03Na NCS < NO,. On the other hand, the charge on the Ir atom in [Ir(en),]A, is independent of the anion A, which suggests that ESCA studies will prove useful in determining whether a ligand is in the inner or outer co-ordination sphere.222 Group IV Donors. C-Donor and Sn-donor Iigands. A series of new isocyanide complexes [IrH,X(pMeC,H,NC)(AsPh,),] (X = F, C1, Br, I, or N3) has been prepared by treating the corresponding trihydrides with HX.2231.r. and 'H n.m.r. data for the halogeno-species suggest (47) as the most probable

-

-

ASPh3

X (47)

structure. The nature of the bonding in the co-ordination polymers M![Ir(CN),],,xH,O (M = Mn, Fe, Co, Ni, Cu, or Zn) has also been investigated.,,, Compared with K,[Ir(CN),] both the v(C=N) and v(1r-C) stretching bands are shifted to higher *frequencies,which was attributed to a bridging structure Ir--C=N--M for the cyanide ligand. In addition, electronic spectra and magnetic data indicate that MI' is in a high-spin state, while the C-co-ordinated Ir"' is low-spin. "'Sn Mossbauer spectra have been recorded for a wide range of tri222

223 224

V. I. Nefedov and I. B. Baranovskii, Russ. J . lnorg. Chem.. 1972,17, 244. A. Aranco, T. Napoletano, and P. Fantucci, J . Organometallic Chenr.. 1972.42, 471. H. Inoue, N. Wada, and S. Yanagisawa, Inorg. Chim. Acta, 1973,7,129

The Noble Metals

39 1

chlorostannyl metal complexes, including Z,[Ir,Cl,(SnCl,),] (Z = Me,N or Ph,PH).” The isomer shifts of all the complexes were correlated with the Sn 4 1 stretching frequencies. Iridium(IV).-- ESCA studies provide Ir 4f,,, and CI 2p3,, electronic binding energies for the halogeno-salts K2[IrX,] (X = C1 or Br).207Comparison with the corresponding Ir”’ complexes shows that, in agreement with other results, metal 4f energies increase with increase in oxidation state. Paper chromatographic methods have been described for the separation of 60 different metal complexes and ions, including [IrC1,I2-, for which R , values are given with various eluents.*, The Gibbs energy of formation of 11-0,has been determined by electromotive force measurements over the temperature range 9001200 ~ . 2 2 5

The preparation, as shown, of the new oxide nitrate Ir30(N03)lohas been reported. The deep purple powder has a magnetic moment k(22”C) = 1.22 BM] consistent with one unpaired electron, as expected from a MO scheme for trinuclear Ir’V.226Its i.r. spectrum suggests the formulation [Ir,0(N03),]N03 with both bridging and unidentate nitrate, as in structure (48).

The absorption and magnetic c.d. spectra have been recorded for the series [IrC1,L2] (L = PR,, AsR,, SEt,, or py).227Charge transfer transitions from C1 and L to iridium were identified, these transitions giving a good approximation to the energies of the bonding orbitals of L with respect to Ir. The authors suggest that the formation of high-energy orbitals with subsequent low-lying excited states in the case of phosphines and arsines may be responsible for the ‘softness’ of these ligands, especially since little evidence for n-bonding from these can be found experimentally. 225

226 227

H. Kleykamp and L. J. Paneth, J . Inorg. Nuclear Chem.. 1973.35,477. B. Harrison and N. Logan, J.C.S. Dalton, 1972, 1587. M. D. Rowe, A. J. McCaffery, R. Gale, and D. N. Copsey, Inorg. Chem., 1972,11, 3090.

Inorganic Chemistry of the Transition Elements

392

Table 4 X-Ray data for iridium compounds R 0.030

[IriCo),(CS)(PPh,),]PF,,Me,CO

0.098

0.038

0.049

0.058 0.032

Co mnien t s

Ref.

Distorted tetrahedron about Ir. Since nitrosyl bonding is linear ( L IrNO = 174.1"), it is formulated as an NO+ complex of Ir-' Ir at centre of trigonal bipyramid with the phosphines at apices, and CO and CS coplanar with Ir. Ir XCS) = 1.867A Dimeric. Irregular tetrahedron about each Ir, with bridging PPh, groups. Short Ir -1r distance (2.554 A) indicates strong interaction. [See structure (43)] Contains a 1,4-p-fluorophenyltetrazene ring co-ordinated to Ir.

N- 1 -N-2 and N-3 -N-4 are esscntially single bonds (1.400 and 1.350 A) Octahedral Ir: the SCN group is not quite linear (C SCN = 174.2; CIrSC = 109") Essentially octahedral. Thiocyanate is N-bonded to Ir, and N C -S linkage is linear. Disordered Contains an o-metallated aryl di-imide moiety. Ir co-ordination distorted from octahedron by the five-membered ring, which imposes an angle of 77" at 11-

a

b

C

d

e

J'

~

0.032

9

lo::

IrCl(CO)(PPh,),

F

Cubic structure, isomorphous with Rh7Mg44

h

(a) C. P. Brock and J. A. Ibers, Znorg. Chem., 1972, 11, 2812; (b)J. S. Field and P. J. Wheatley, J . C . S .Dalton, 1972, 2269. ( c ) ref. 205. (6)F. W. B. Einstein and D. Sutton, Znorg. Chem., 1972, 11, 2827. ( e ) H. D. Flack and E. Parthe, Acta Cryst., 1973, B29, 1099. v) ref. 216. ( 9 ) ref. 213. (h) L. Westin and L. E. Edshammar, Acta Chem. Scand.. 1972, 26, 3619.

The Noble Metals

393

5 Palladium Palladium(O).-Two related papers228 , 2 2 9 have reported the formation of binary carbonyls [Pd(CO),] ( n = 1-4) via the co-condensation of atomic palladium with dilute CO-argon(or zenon) mixtures at low temperature. Using C l 8 0 isotope enrichment experiments the i.r. bands at 2070,2060,2044, and 2050 cm-' were assigned to the species Pd(CO),, Pd(CO),, Pd(CO),, and Pd(CO), respectively. Diffusion studies indicated that the lower carbonyls readily react with excess CO to yield [Pd(CO),], which is stable in a xenon matrix up to 80 K. An improved synthesis of the mixed complexes [Pd(CO)(PPh,),], [Pd,(CO),(PPh,),], and [Pd,(CO),(PPh,),] has also been described, involving the treatment of methanolic [Pd(PPh3)2C12] with CO and primary or secondary amines.,,' On the other hand, the use of tertiary amines such as Et,N selectively yields the methoxycarbonyl complex [Pd"(PPh,),Cl(CO,Me)]. The carbonyl-phosphine compounds are interconvertible under suitable conditions (Scheme 15).

Scheme 15

In contrast to binary carbonyl studies, co-condensation of Pd atoms with 14N2at 4.2-10°K has been shown by matrix isolation i.r. and Raman spectroscopy to lead to only three species [Pd(N2),] ( n = 1-3).231,232 Structural assignments were made on the basis of I5Nisotope studies, and force constants calculated. Palladium(1I).-Group VII Donors. Halide and hydride donor ligands. An interesting paper describes the absorption of heavy-metal salts, including Na,[PdCl,], from aqueous and alcoholic solution by filtering through cotton (cellulose) fabrics containing polyethylene (and polypropylene) sulphide Absorption arises via complex formation at these polysulphide sites. On the other hand, paper (cellulose) chromatography may be employed to separate and identify numerous metal complexes and ions such as [PdC1,I2-, for which R , values are reported with various eluents.82

'" E. P 229

230 231 232

233

Kundig, M. Moskovits, and G . A. Ozin, Canad. J . Chem., 1972,50. 3587. J. H. Darling and J. S. Ogden, J.C.S. Dalton, 1973, 1079. M. Hidai, M. Kokura, and Y. Uchida, J . Organometallic Chem., 1973, 52, 431. G. 0. Ozin, M. Moskovits, E. P. Kundig, and H. Huber, Canad. J . Chem., 1972,50, 2385. H. Huber, E. P. Kundig, M. Moskovits, and G. A. Ozin, J . Amer. Chem. SOC.,1973,95, 332 Y. Avny, D. Leonov, and A, Zilkha, Israel J . Chem., 1973,11, 53.

Inorganic Chemistry of the Transition Elements

394

Halogeno-phosphine and -phosphite complexes. cis- and trans-isomers of [PdC1,(PMe2-o-toly1),] have been prepared :234 Li,[PdCl,]

+ PMe,R

+

[PdCl,(PMe,R),]

In chloroform solution cis-trans isomerization is slow owing to steric hindrance by the bulky o-tolyl groups. However, isomerization is catalysed by addition of various ligands, via a consecutive displacement mechanism involving ionic intermediates of the type [PdC1L(PMe2-o-tolyl),]C1. Other workers have isolated the analogous cations [PdCIL(AR,),]Z [L = PR,, AsR,, or P(OR),; A = P or As] via treatment of [PdCl,(AR,),] with L in the presence of AgZ.235 Pd-421 stretching frequencies varied with the trans influence of L. Another report describes the reaction of mercury(I1) halides with [MX,(AR,),] (M = Pd or Pt; X = C1, Br or I) to yield adducts of the type [MX,(AR,),HgX,].236 From i.r. studies, and analogy with X-ray data for [PtC1,(PMe,Ph),HgX2],237 the double halide bridged structure (49) is indicated, with square-planar Pd and tetrahedral Hg. Treatment of Na,[PdCl,] with the bulky tertiary phosphine L[ = PBu',(0-EtPh)] has been shown to yield trans-[PdCl,L,], which on heating undergoes internal metallation to give [Pd,Cl,{ CH(M~)C,H,PBU\)].~~'On the other hand, reaction with the even bulkier L1[ = PBu', (0-isopropylphenyl)] produces [Pd,Cl,Li], which fails to undergo metallation. Also reported are the ometallated triarylphosphite derivatives (50 ; M = Pd or Pt ; R = H, C1 or Me ; X = C1, Br or I), obtained by boiling [MX,(P(OAr),),] in d e ~ a l i n . ~The ~' tendency to undergo metallation increases in the order I < Br < C1. Synthesis R

(49)

50)

of the [MX,{P( OAr)3)2]starting materials was achieved via direct treatment of Na,[MCl,] with the appropriate triarylph~sphite.~~' In addition, i.r. and n.m.r. studies indicated that all the complexes occurred with cis-geometries, except for those containing the bulky tri-o-tolylphosphite or iodide ligands. Group F/I Donors. 0-donor ligands. Few complexes of palladium with the soft OH- ligand are known in view of HSAB considerations. However, stable 234

235 236 237

238

239 240

1). G. Cooper and J. Powell, Canad. J . Chem., 1973.95, 1634. W. J. Cherwinski, H. C. Clark, and L. E. Manzer. Znorg. Chem., 1972, 11, 1511. P. R. Brookes and B. L. Shaw, J.C.S. Dalton, 1973, 783. R . W Baker, M. J. Braithwaite, and R. S. Nyholm, J.C.S. Dalton, 1972, 1924. D. F. Gill, B. E. Mann. and B. L. Shaw, J.C.S. Dalton, 1973, 270. N. Ahmad, E. W. Ainscough, T. A. James, and S. D. Robinson,J.C.S. Dalton, 1973,1151. N. Ahmad, E. W. Ainscough, T. A. James, and S. D. Robinson, J.C.S. Dalton. 1973. 1148.

The Noble Metals

395

complexes of the type [M,(OH),(PR,),](BF,), (M = Pd or Pt ; R = Et or Ph) have been isolated from the reaction of AgBF, with [MCl,(PR,),] in moist acetone.241Their i.r. spectra confirm the presence of co-ordinated OH groups [v(OH) = 3500 crn-'], and suggest dimeric structures with double hydroxybridges. Interestingly, excess phosphines do not cleave these bridges, despite the ready cleavage of analogous chloro-bridged species.242Reaction of PdC1, with methanolic heptane-2,4,6-trione has yielded the yellow complex [PdL,] (5 l),

o=cY e \

CH,

Me \C

4

O=C -O\

HC

=O

/

Pd

/ \

CH

\.o-c 4 \

Me

c=O

/

Me

which contains both free and co-ordinate v(C0) bands.,,, A cyclic voltammetric study of the o-quinone complex (45; M = Pd; X, Y = vacant) has revealed reversible one-electron oxidation to give compounds thought to contain co-ordinated semiquinone radicals.25 The oxidation may also be effected chemically with oxidants such as NiS,C,(CF,), or AgPF,. Thermogravimetric curves for solid K,[Pd(C20,),],3H20 and other transition-metal oxalates indicate that the thermal stability of the anhydrous complexes decreases with increase in electron affinity of the central metal ion.' 5 8 AH values were obtained for both dehydration and decomposition. Subsequent studies showed carbon dioxide as the only gaseous product, the decomposition occurring via electron transfer from a C 2 0 $ - ligand to the central palladium.' 5 9 Mixed 0-donor and N-donor ligands. Volatile complexes of the type [ML] [52; M = Pd; R', R 2 = Me, CF,, etc; B = (CHJ,, (CHJ,, CH,CHMe, etc).,

241

242 243

G. W. Bushnell, K. R. Dixon, R. G. Hunter, and J. J. McFarland, Canad. J . Chem., 1972,50,3694. K . R. Dixon and D. J. Hawke, Canad. J . Chem., 1971,49, 3252. F. Sagara, H. Kobayashi, and K . Ueno, Bull. Chem. SOC.Japan, 1973,46,484.

396

Inorganic Chemistry of the Transition Elements

have been prepared via direct reaction between H,L and [MC12(PhCN)2].244 Their high stability permits gas chromatographic measurements at elevated temperatures ( > 250 "C). The 1 :1 complex obtained from mixing solutions of [Pd(8-quinolinol),] and tcnq2(7,7,8,8-tetracyanoquinodimethane)has been shown from diffuse reflectance spectral measurements to be essentially a Z-z charge-transfer complex, in which the metal chelate acts as the electron donor and tcnq, as an acceptor.245 1.r. studies of the newly prepared o- and rn-aminobenzonato-complexes [PdL,] indicate that the ligand is co-ordinated oia both the amino and carboxylate Similar preparative and spectral investigations of the coordination behaviour of isonitrosoacetylacetoneimine ligands have shown that, while in most cases bonding to palladium occurs via nitrogen atoms only, in the N-alkylated derivatives (53) a mixture of N- and 0-bonding occurs.247,248

R ( 5 3 ) R = Pr'. C , H , , , Ph. or p-MeC,H,

S-Donor ligands. Cysteine complexes of formula [PML,] (M = Pd or Pt) have been prepared by treating K2[ MCl,] with excess cysteine h y d r ~ c h l o r i d e . ~ ~ ~ Their i.r. spectra confirm co-ordination uia S and 0 sites, with free amine groups. Similarly the P-ketosulphoxide complex [PdL,] (L = PhCOCH,SOMe) has been shown to have the structure (54; M = Pd).250In an extension of previous

studies on dithio-oxamide complexes, the new compounds [PdLX,] (L = HOC2H,NHCS), or (PhCH,NHCS), ;X = C1, Br or I> have been synthesized, 244 245

246 24' 248 249 250

R. Belcher, K. Blessel, T. Cardwell, M. Pravica, W. 1. Stephen. and P. C. Uden, J. Znorg. Nuclear Chem., 1973.35, 1127. S. Koizumi and Y. Ijda, Bull. Chem. SOC.Japan, 19?3,46,629. T. Inomata and T. Moriwaki, Bull. Chem. SOC.Japan, 1973,46, 1148. B. C. Sharma, K. S. Bose, and C. C. Patel, Znorg. Nuclear Chem. Letters, 1972,8, 805. K. S. Bose, B. C. Sharma, and C. C. Patel, Inorg. Chem., 1973, 12, 120. M. Chandrasekharan, M. R. Udupa, and G. Aravamudan. Znorg. Chlm. Acta, 1973,7,88. E. Boschmann, J . lnorg. Nuclear Chem., 1973,35, 1025.

The Noble Metals

397

as well as [PdL,] {L = (HOC2H4NHCS), ~ n l y ) . ~The ” complexes are diamagnetic and SN-bonded. Other new compounds prepared are the related NN’-dimethyl- and NN’-dicyclohexyl-dithio-oxamide complexes [PdLX,] (X = C1, Br or I) and [PdL2](C104),.252 The positions of their v(CN) and v(CS) bands indicate bidentate SN-co-ordination. I

Compounds of 3-substituted rhodanine RNCOCH,SCS (R bis- or 3,3’-butylenebis-) have been reported :253

=

3,3’-ethylene-

+ L + HCl ~ [ P d L C I , ]

KJPdCl,]

On the other hand, when R = 3-allyl,the product [PdL,Cl,] is obtained, which i.r. studies show to contain an unco-ordinated olefinic group and unidentate bonding via the thiocarbonyl S. Also described is the synthesis of the new ligand H,(sacac),(en), together with the preparation of the stable palladium complex (55).254 Its ‘H n.m.r. spectrum is consistent with this planar structure. Biscomplexes ofligand(56) have been isolatedofformula [ML,] (M = Pd or Pt).,” Me N ‘’

Ph

I

Interestingly, i.r. and ‘H n.m.r. studies suggest SO-bonding in the palladium complex, whereas SN-co-ordination occurs in the platinum compound. New complexes of the methylene-bridged dithiols Ph,P(S)CH,P(S)Ph, and Ph,P(S)CH,P(S)Me, have been prepared :256 PdC1,

+

(L- L)

fm [Pd(L-L)Cl,]

Their i.r. spectra indicate the presence of six-membered ring chelates. However, the corresponding S-bridged ligands R,P( S)SP(S)R, undergo cleavage during complex formation to yield phosphorodithioate compounds with stable fourmembered rings. Similar reactions with the dithiols HS(CH,),SH (n = 2 or 3) have in contrast produced dark-brown solids of empirical formula Pd[S(CH2)nS].257 Their insolubility, high decomposition points and other properties resemble those of the known benzenethiol polymer [Pd(PhS),],, and they were tentatively assigned similar polymeric S-bridged structures. 2s1

2s2 253 254 255

2s6 257

A. C. Fabretti, G. C. Pellacani, and G. Peyronel. Gazzetta, 1973. 103, 397. G. Peyronel, A. C. Fabretti, and G. C. Pellacani. J . Inorg. Nuclear Chem.. 1973. 35, 973. F. G. Moers, J. W. M. Goossens, and J. P. M . Langhout. J . Inorg. Nuclear Chem., 1973,35. 855. R. M. C. Wei and S . C. Cummings, lnorg. Nuclear Cheni. Letters, 1973, 9, 43. A. C. Patel, J. J. Brooks, G. Geoffroy, and T. H . Crawford, J . Inorg. Nuclear Chem., 1973,35, 1855. D. A. Wheatland, C . H. Clapp, and R. W. Waldron, Inorg. Chem., 1972,11, 2340. L. Cattalini, J. S. Coe, S. Degetto, A. Dondoni and A. Vigato, l n o r g . Chem., 1972, 11, 1519.

Inorganic Chemistry of the Transition Elements

398

Also reported are dithiophosphinate complexes of the type (57; M = Pd; R = F, Me, Et, CF, or OEt).258A correlation was observed between the Pd-S stretching frequencies and the first electronic transition, and the substituents

-

- -

fell in the spectrochemical order OEt F > Me Et CF,. The treatment of K2[PdC14] with potassium salts of perthio- and dithio-cumic acids in acidic aqueous solution has led to the isolation and separation of [Pd(p-dtc),] and sulphur-rich [Pd(p-dt~),S].~~’ Abstraction of S from the latter complex occurs readily with triphenylphosphine, which is rationalized in terms of Scheme 16 (M = Pd).

Scheme 16

The red-brown indole complexes [PdZL2X4] (X = Cl or Br) have been synthesized :260 K,[PdX,]

+ H X + L *[Pd2L,X4]

They are assumed to have dimeric halogen-bridged structures. More interesting is the isolation of the related benzothiazole complex [ML,X,] [L = (58)], for

258 259

R. G. Cavell, W. Byers, E. D. Day, and P. M. Watkins, Znnrg. Chem., 1972. 11. 1598. J. P. Fackler, J. A. Fetchin, and D. C. Fries, J . Amer. Chem. SOC., 1972, 94, 7323. V. M. Shul’man, T. V. Zagorskaya, I. M. Cheremisina, G. K. Parygina, and E. A. Kravtsova, Russ. J . Inorg. Chem., 1972, 17, 1306.

The Noble Metals

399

which X-ray spectra confirm unidentate co-ordination via the S atom. This result contradicts earlier opinion that S-heteroatoms are incapable of metal bonding. Following a preliminary account,26 a full description has appeared of the use of the dithio-complexes [Cp,Nb(SR),] (R = Me or Ph) as ligands, giving with [PdCl,(PhCN),] the red-purple derivatives [Pd{ Cp,Nb(SR),),]BF4.262By analogy with the corresponding Ni cation, for which an X-ray analysis has been performed, the structure (59; M = Pd) is suggested with

tetrahedral co-ordination about the Pd. Bridge splitting reactions of the halogen-bridged complexes [Yd,(tu),X,] (X = C1 or Br; tu = thiourea) with thiourea and ethylenediamine have been investigated in DMF solvent.263 Also reported is the reaction of [Pd(SC6C15),] with pyridine to yield P~(SC~C~S),(PY)~-’~~ Treatment of [Pd(SCN),I2 - with cis-Ph,PCH=CHPPh, (vpp) in n-butanol has yielded the novel pink compound [Pd(vpp),(SCN),], for which i.r. data confirm S-bonded thiocyanate groups.265This observation provides further evidence of the subtle nature of the factors controlling the mode of thiocyanate co-ordination, since the analogous Ph,PC,H,PPh, complex contains both Nand S-bonded CNS.266A related paper reports the synthesis of [Pd(Ph,PCH,C(CF,)=CHPPh,)X,] (X = C1 or SCN) via the reaction of Ph,PC=CCF, on [PdX,I2- salts.267Particularly interesting is the unprecedented bond cleavage during attack on Pd, with the formation of a three-carbon chain from two acetylene groups. 1.r. data indicate S-bonding of the thiocyanato-complex, which was confirmed by X-ray analysis (Table 5). In contrast, reaction with the t-butylsubstituted acetylene Ph,PC = CBu’ does not result in bond cleavage : 2 6 8

Whereas the yellow cis-product contains both Pd-N and P d 4 bonds, recrystallization from non-polar solvents gives an orange trans-isomer for which X-ray analysis (Table 5) shows the presence of only S-bonded thiocyanate. 262 263 2h4

26s 266

267

’‘*

W. E. Douglas, M. L. H. Green, C. K. Prout, and G. V. Rees, Chem. Comm., 1971, 896. W. E. Douglas and M. L. H. Green, J.C.S. Dalton, 1972, 1796. R. Battistuzzi and G. Marcotrigiano, Gazzetta, 1972, 102.459. C. R. Lucas, M. E. Peach, and K. K. Ramaswamy, J . lnorg. Nuclear Chem., 1972,34, 3267. K. K. Chow and C. A. McAuliffe, lnorg. Nuclear Chem. Letters, 1972.8, 1031. D. W. Meek, P. E. Nicpon, and V. 1. Meek, J. Amer. Chem. SOC., 1970,92, 5351. R. T. Simpson. S. Jacobson, A. J. Carty, M. Mathew, and G. J. Palenik, J.C.S. Chem. Comm., 1973. 388. G. Beran. A. J. Carty. P. C. Chieh, and H. A. Patel, J.C.S. Dalton, 1973, 488.

400

Inorganic Chemistry of the Transition Elements

The authors are thus led to suggest that, contrary to previous assertions,269 palladium(@ prefers S-bonded CNS - in phosphine complexes. Following a preliminary communication,270 the synthesis of the sulphur dioxide derivatives [M(SO,)(PPh,),](M = Pd or Pt) has been described uia the anaerobic addition of SO, to benzene solutions of [M(PPh3)4].271 These dark-purple species are air-sensitive, being readily oxidized to the sulphatocompounds [M(S04)(PPh,),],H20. Se-Donor ligands. As part of the investigation of the complexing behaviour of the ligand (PhO),P(S)Se-, the red-brown complex [PdL,] has been is01ated.l~~ U.v.-visible spectral studies indicate that the ligand generally forms a chelate structure (35) with four-membered rings, and that the crystal field of Se is weaker than S. However, nephelauxetic parameters indicate that replacement of S by Se leads to a slight increase in the covalent character of the M-chalcogen bond. Another interesting paper describes the synthesis of the first selenocarbamato complexes: 2 72 [PdCI,(PPh,),]

+ [ Bu;NH,

J [OSeCNBu;]

THF

[Pd(PPh,),(OSeCNBu;)]

3h

Molecular weight and i.r. measurements suggest that the selenocarbamato ligand is unidentate in the solid state, but that in solution partial dissociation of PPh, occurs, causing the ligand to become bidentate as in (59a; M = Pd).

159a)

Complexes of the ligands EtOCSe; (sexant) have also been reported, including [ P d ( ~ e x a n t ) , ] . ~U.v.-visible ~~ spectral studies confirm the zoptvalue of ca. 2.5 for Se-containing ligands, and place (sexant)- in the following spectrochemical series, (sexant)- < (dsc)- < (dtc)- for Pd". Group V Donors. N-donor ligands. The first reported molecular nitrogen complexes of Pd" have been synthesized uia the action of hydrazine sulphate on cis[Pd(NO,),(NH,),] (Scheme 17).274 The hydrazine was determined iodometrically while co-ordinated dinitrogen was measured by decomposing the complexes in water. Little other evidence was given to support the structures in Scheme 17, except the medium intensity band at 2100cm- assigned to bridging dinitrogen. 269 270

"'

272 273 274

H. Norbury, J.C.S. Dalton, 1971, 1090; and references therein. J . J. Levison and S. D. Robinson, Chem. Comm.. 1967, 198. J. J. Levison and S. D. Robinson, J.C.S. Dalton, 1972, 2013. K. Tanaka and T. Tanaka, Inorg. Nuclear Chem. Lztters, 1973.9,429. C. Cauletti and E. Cervone, J . Inorg. Nuclear Chem., 1973,35. 593. V. M. Volkov, A. I. Korosteleva, and S. S. Chernikov, Kuss. J. Inorg. Chem., 1972. 17,1061

The Noble Metals

401

Treatment of PdCl, with the ligand LH (60) in alcoholic media has led to the isolation of the yellow complexes [PdL,] and [Pd(LH)L]C1.275 Their diamagnetism supports a square-planar geometry, and i.r. data indicate co-ordination via the pyridine and oxime N atoms. Similar complexes of the dioxime

Scheme 17

LH, (61) have also been reported.276As with the previous compounds, significant H-bonding is evident from the i.r. spectra. Other workers have reported mass spectral fragmentation patterns for related bis-complexes of the a-dioximes HON=C(R)C(R)=NOH (R = Me, Et, or n-C3H,).277

The new stable five-co-ordinate species [PdX(PPh,O)(PPh,OH)(phen)] and [SdX(PR,),(phen)]BF, (X = C1 or Br ; R = Et or Ph) have been isolated from the facile reaction of 1,lO-phenanthroline on acetone solutions of [Pd,X,(PPh,O),(PPh,OH),] and [Pd,X,(PR3),], respectively., Decomposition of 275

276 2’7

278

0

B. Sen and D. Malone, J . Inorg. Nuclear Chem., 1972. 34 3509. A. H. I. Ben-Bassat and F. Kaszirer, Israel J . Chem., 1972, 10, 701. A. V. Ablov, K. S. Khariton, andZ. Y. Vaisbein, Russ. J . Inorg. Chem., 1972, 17, 1722. K. R. Dixon and A. D. Rattray, Canad. J . Chem., 1973,51,618.

402

Inorganic Chemistry of the Transition Elements

[PdX(PR,),(phen)]BF, in hot methanol or CH2C12leads to the square planar complexes [PdX(PR,)(phen)]BF,. A u.v.-visible spectroscopic study of a range of related Pd" and Pt" bipyridine complexes, including [PdCl,(bipy)], has shown large shifts with change in solvent, which may be correlated with the E , parameters of the solvents.279Complexes of the ligand thiazolidine-2-thione (L = S=CNHCH,CH,S) have also been prepared, of general formula [PdL,X,] (n = 2,3, or 4; X = C1, Br, or I).28o

K,[PdCl,]

+ nL + excess HX

Hzo - (IPdL,X,]

Lr., 'H n.m.r. and u.v.-visible spectral dataconfirm that the ligand is N-bonded in these compounds, and conductivity measurements show that they are 1 :2 electrolytes in dilute aqueous solution. P-Donor and As-donor Eigands. In order to evaluate further the effect of fluorine substitution on the properties of aryl phosphine ligands, the complexes [PdL'X,] [L' = (62a; X = Cl, Br, I or SCN], [PdLiIClO,, and [PdLiX,] [L2 = (62b)l have been prepared.281 Physical measurements indicate that these complexes are generally planar, unlike their nickel analogues, while the potentially

terdentate ligand (62b) co-ordinates via only the two S atoms. An interesting feature of fluorine substitution is the facile demethylation observed in solution, leading to corresponding mercaptide complexes, e.g. [Pd(L--Me),]. A related study reports the synthesis of complexes of the ligands Ph,P(A)CH,P(A)Ph, (A = S or Se).282 The co-ordinating ability of the ligand (36) has been investigated with a wide range of metals, resulting in the isolation of the complex [PdL2C12] via direct reaction between L and ethanolic [PdC1,]2-.175 1.r. data indicate Pd-P bonding, and together with solid reflectance spectra support a trans-squareplanar geometry. Similar extensive studies with the mixed phosphine-diarsine ligand (23) have yielded pale yellow [PdLC1].loS However, in contrast to the corresponding tritertiary phosphine (Ph,PC2H4),PPh, it was not possible to prepare bimetallic or trimetallic derivatives with the mixed ligand, owing to the 279

280

281

282

P. M. Gidney, R. D. Gillard, and B. T. Heaton, J.C.S. Dalton, 1973, 132. D. De Filippo, F. Devillanova, E. F. Trogu, G. Verani, C. Preti, and P. Viglino, Cannd. J. Chem., 1973,51, 1172. P. G. Eller, J. M. Riker, and D. W. Meek, J. Amer. Chem. SOC., 1973,95, 3540. W. E. Slinkard and D. W. Meek, J.C.S. Dalton, 1973, 1024.

The Noble Metals

403

lower donor ability of arsenic compared with phosphorus. Other authors have investigated the complexing behaviour of the mixed N -As ligands R,NC2H4AsPh, and (R,NC,HJ,AsPh (R = H, Me or Et) with Pd11.283Reaction with ethanolic PdX, yielded square-planar [PdLX,] (X = C1, Br or I) in both cases, the failure to obtain five-co-ordinate species with the potentially terdentate (R,NC,H,) ,AsPh being ascribed to the destabilizing influence of the strong o-donor amine. In addition, treatment of [PdCl,(R,NC,H,AsPhJ] with NaSCN gave the corresponding thiocyanate complex, which was shown to be S-bonded from i.r. evidence. Since the analogous N-P complex is known284to contain N-bonded thiocyanate, it is suggested that phosphorus is a better n-acceptor towards Pd" than arsenic. Group IV Donors. C-donor ligands. Cationic isocyanide complexes of the type [PdClL,(RNC)]Z (L = PR, or AsR,) have been prepared via the treatment of [PtCl,L,] with isocyanide in the presence of AgZ.285As with analogous Ni" and Pt" complexes, v(N----C) increased on co-ordination compared with free isocyanide, the magnitude of Av(N=C) decreasing down the triad Pt > Pd > Ni. Since this order parallels the relative electronegativities of the metals, a + decreasing contribution of the resonance hybrid - M--C=N -R is indicated. Other new isocyanide compounds reported are the cations [M(CNMe),](PF,), (M = Pd or Pt'? obtained by direct reaction between aqueous K,[MC14] and excess MeNC.286These complexes react with MeNH, to yield the white airstable species [M(C(MeNH),),]' +,which are the first examples of transition metals co-ordinated solely by ligands of the resonance-stabilized carbene type (63). 'H N.m.r. and i.r. data support structure (63) with the ligands in the amphi Me

2 i

I

I

(63)

H

configuration, while the invariance of the 'H n.m.r. spectrum between - 50 and -90°C indicates appreciable multiple bonding in the N-C-N grouping. A related study by Chatt and c o - ~ o r k e r sdescribes ~~~ nucleophilic attack by ethanol on the isocyanides cis-[MC1,(p-NO2C,H,NC),] (M = Pd or Pt) to produce the bis-carbenes cis-[MC1,(C(OEt)NH-p-NO~c6H4},]. 283 284 285

286

2*7

T. L. Morris and R. C. Taylor, J.C.S. Dalton, 1973, 175. D. W. Meek, P. E. Nicpon, and V. I. Meek, J . Amer. Chem. SOC., 1970,92, 5351. W. J. Cherwinski, H. C. Clark and L. E. Manzer, Inorg. Chem., 1972.11, 1511. J. S. Mills and A. L. Balch, Inorg. Chem., 1972,11, 2069. J. Chatt, R. L. Riohards, and G. H. D. Royston, Inorg. Chim. Acta. 1972.6, 669.

Inorganic Chemistry of the Transition Elements

404

Protonation of the isocyanato-complex [Pd(PPh,),(NCO),] with HBF, in ethanol has yielded the new species [Pd(PPh3)2(NH2C02Et)](BF4)2.143 Carboxamido-complexes of the type [MC1L,(CONR’R2)] (L = phosphine or arsine; R = H or alkyl; M = Pd or Pt) have also been synthesized:288 [MCI,L,]

+ C O + R1R2NH -,[MC1L2(CONR’R2)]

Their ‘H n.m.r. spectra indicate trans geometry with a high barrier to rotation about the C-N bond. Analogous thiocarboxamido-compounds [MClL,(CSNMe,)] were obtained by oxidative addition of ClC(S)NMe, to [ML,]. Both series of complexes are air-stable solids which are stable in water, in contrast to similar alkoxycarbonyl derivatives. Sn-Donor and Pb-donor ligands. Tin(nr) adducts of formula (Ph,BzP),[Pd(dto),,nSnX,] (dto = dithio-oxalate; n = 1 or 2) have been isolated via treatment of(Ph,BzP), [Pd(dto),] with SnX,in anhydrous d i c h l ~ r o m e t h a n e . ~ ~ ~ Following the recent preparation2’0 of [M(PEt,),(PbPh,),] (M = Pd or Pt), the analogous triphenylphosphine complexeshave now been synthesizedby the oxidative addition of hexaphenyldilead to [M(PPh3),].29’ The M-Pb bonds are readily cleaved by reagents such as bromine, iodine, or HBr. Palladium( Iv)-Differential-thermogravimetric and X-ray diffraction studies on the thermal decomposition of (NH,),[PdCl,] have revealed the evolution of gaseous chlorine,
Table 5 X- Ray data for palladium compounds Compound Pu,Pd,

R 0.045

trans-[PdHCl(PEt J,]

0.072

0.064

Comments Ref. Pd -Pd = 2.87 -3.69 A. New a structure type The mutually trans P atoms and b the C1 atom are at 3 corners of square about Pd, with H believed to be at fourth site. Long P d 4 1 bond (2.427 A) indicates strong trans-influence of H Square plane of 2 1’s and 2 P’s c about Pd. In addition, octahedral sites of Pd are occupied at long distance (3.18A) by P-H’s from phenyl groups

’” C. R. Green and R. J. Angelici, lnorg. Chem., 1972.11,2095.

’” D. Coucouvanis, N. C. Baenziger, and.% M. Johnson, J. Amer. Chem. Soc., 1973.95, 3875. ’”

G. Deganello, G. Carturan, and U. Belucco, J. Chem. SOC.( A ) , 1968,2873. B. Crociani M. Nicolini, D. A. Clemente, and G. Bandoli, J. Organometallic Chem., 1973,49, 249. Yu. A. Sidorenko, A A. Filippov, E. E. Lukashenko, and V. G. Chumakov, Russ. J. Inorg. Chem., 1972,17, 1165.

405

The Noble Metals Table 5-continued Compound

trans-[Pd(CNS)Z(Ph,PC CBU?,I [Pd(S,C,H,)I

Ruj. d Both thiocyanato-groups Sbonded. Unidentate phosphine e Approximate square plane of S atoms about each Pd. Dimeric with two Pd-dithiolen units in eclipsed relationship joined by Pd-Pd bond (2.790 A) Square-planar co-ordination'of S f and N from amino-acid, and two C1 atoms. Chelate ring has a 1 conformation Distorted cis square-planar co9 ordination about Pd. Both tetrazole rings are N-1 bonded and planar

R 0.069

Coninients

0.059

[PdCI,(SmCH)],H,O

0.049

cis-[Pd(PMe,Ph),L,]

0.042

P

,N-N

I I

'

P-Pd-N, N C"'

I

N-N [Pd(SCN),{ Ph2PCH,C(CF3) = CHPPh,}],CH,Cl,

0.072

I C-N

I cis-square planar structure with S-bonded thiocyanates

h

Ph

SCN 0.1 1

0.024 0.060

0.057

Ph Square plane of 4 N's about Pd. Contains two 7-membered chelate rings in twist-chair conformation, with COO group in quasi-equatorial position Square planar. Monomeric nitrosobenzene ligands N-bonded Bite of bipy causes rectangular distortion of PdN, skeleton, giving mean L NPdN = 80: Mutual twist of two bipy ligands to avoid interligand o-H contacts. Square-planar bonding of three N's and one C1. Wni- and bi-dentate dipyrromethene ligands deviate from planarity.

1

1

406

Inorganic Chemistry of the Transition Elements

Table 5--continued

R

Compound

0.072

Comments

Trigonal co-ordination about each Pd. Dibenzylideneacetone ligands bond via olefin groups rather than carbonyl sites Powder pattern only

Ref.

rn

n

( a ) D. T. Cromer, A. C Larson, and R. B. Roof, Acta Cryst., 1973, B29, 564. (h) M. L. Schneider and H. M. M. Shearer, J . C . S . Dulron, 1973, 354. ( c ) T. Debaerdamaeker, A. Kutoglu, G . Schmid, and L. Weber, Arta Cryst., 1973, B29, 1283.(d)ref. 268. ( e ) K. W. Browall, T. Bursh, L. V. Interrante, and J. S . Kasper, Znorg. Chem., 1972, 11, 1800. U, L. P. Battaglia, A B. Corradi, C. G . Palmieri, M. Nardelli. and M. E. V. Tani, Acta Cryst., 1973, B29, 762; SmCH = MeSCH,CH(NH,)CO,H. ( 9 ) G. B. Ansell, J.C.S. Dalfon, 1973, 371; L = 5-methyltetrazolate. (h) ref. 267. (i) Y. Nakayama, K. Matsumoto, S. Ooi, and H. Kuroya, J.C.S. Chem. Comm., 1973, 170. (i)R. G. Little and R. J. Doedens, Inorg. Chem., 1973, 12, 537. ( k ) P. C. Chieh, J.C.S. Dalton, 1972, 1643. ( I ) F. C. March, J. E. Fergusson, and W. T. Robinson. .t.C.S. Dalton, 1972, 2069; cpmH = 3,4'-bis(ethoxycarbonyl)5-chloro-3~4,5'-trimethyldipyrromethene. ( m ) M. C. Mazza and C. G . Pierpont, J.C.S. Chem. Comm., 1973, 207. (n) R. W. Berg and K. Rasmussen, Spectrochim. Acta, 1973, 29A, 319.

6 Platinum

Cluster Compounds.-An X-ray analysis of the cluster [FePt,(CO),{ P(OPh),)-,] reveals a triangular structure with terminally bonded ligands (Table 8).293This bonding behaviour contrasts with analogous Ru and 0 s complexes which contain bridging CO groups. Another paper reports the preparation of several cationic clusters including [Pt,(PPk,),]Z (Z = NO,, B F , or PF,) :294

Platinum(O).-Studies on complexes of this low oxidation state have decreased appreciably over the last year, However, the syntheses of a range of new polytertiaryphosphine and phosphine-arsine compounds have been described.29 The general procedure employed was direct reaction between 293

294 2y5

V. G. Albano, G. Ciani, M. I. Bruce, G. Shaw, and F. G. A. Stone, J . Organometall'c Chem., 1972, 42, C99. D. M. Blake and L. M. Leung, Inorg. Chem., 1972,11,2879. R. B. King and P. N. Kapoor, Znorg. Chem., 1972,11,1524.

H2O

MeCN

HZO 1M-HC10,

EtOH

C1 or I

Br or C1

Cl or Br C1 or Br

p(oR)3 (R = Et, Pr, Pr‘, Bu, Bu’, or Bus)

n](2-n)+

-

cis + trans

[PdL,]’ [PdL,(H,O),PdL,

,

Composition of complexes forrped on treating,[Pd( SCN),] - with PIOR), determined by equilibrium-displacement and isomolar-series methods. Complex formation occurs in stages variable-temperature In most solvents the cis-isomers are ‘H n.m.r. thermodynamically more stable than trans. Polar solvents favour cis u.v.-visible spectra

u.v.-visible spectra u.v.-visible spectra

u.v.-visible spectra

f

e

Studied replacement equilibria between a [PdC1,I2- and [PdI,]’-. Stability constants decrease in order I > Br > C1, indicating that Pd is soft Evaluated successive equilibrium b constants pi to p4 for replacement of Br by C1. Stability of [PdCl,]’- is greater than [PdBr,12; a dramatic inversion of relative stabilities in water K only C S,(n = 1 4) d

-

u.v.-visible spectra

-J2

( n = 0 4)

[PdClJ,

Ref.

Coniments

Method of Study

Complex

( a ) S. C . Srivastava and L. Newman, Znoyg. Chem., 1972, 11, 2855. ( b )P. Klotz, S. Feldberg, and L. Newman, ibid., 1973, 12, 164. ( c ) A. Gulko and G. Schmuckler, J . Inorg. Nuclear Chem., 1973, 35, 603. (d)L. I. Elding, Znorg. Chim. Acta, 1972, 6, 647. ( e ) G . D. Ginzburg V. V. Sentemov, and A. D. Troitskaya, Russ. J . Znorg. Chem., 1972, 17, 723. (f) D. A. Redfield and J. H . Nelson, Inorg. Chem., 1973, 12, 15.

various organic

Solvent

Table 6 Stability constant data for Pd’ complexes

Ligand

P 0 4 1

2 E rc,

ig$

3

2

Inorganic Chemistry of the Transition Elements

408

Table 7 I.r. structural studies of Pd I' complexes Complex [Pd(Metolen),]CI [Pd(Ettolen), JCl,

Other studies

~P~,x,ISM~),I Pr,N[PdX,(SMe,)] (X = C1 OT BT) P~LX,I, (L = R,SO, R,S, or tu ; X = halides)

Pt H n.m.r.

r

-

Results and conclusions Re$ Two non-co-oidinated OH groups a are trans for Ettolen, but mixture of cis and trans for Metolen Below 800cm- '.Indicate lower b trans-influence for SMe, than PMe, For sulphoxide and sulphide C complexes presence of both bridging and terminal Pd--X frequencies indicates dimeric structure

' X /

'X

Pd

L A' x '

I

rpd(s,c~r),

[Pd(s,CAT) 2 1

[Pd(S,CAr)(S,CAr)] M'[Pd(CSJ,] [Pd(PMePh,),(CS,)] [Pd(PMePh,),(CS,O)] IP~(so,)(NH,),I

Pt X-ray of Pt Ni, Pt

~-

/X

Pd

x'

However, only bridging halides present in tu-type complexes indicating polymeric structures Assigned ligand vibrations and M---S stretches 4000--200 cmAssigned all v(CS) and v(PdS) frequencies, which could be used to distinguish tri- and dithiocarbonate complexes Indicates S-bonding only for sulphite ligand

d e.

f

N

I

N-Pd-N

I O+O 0 Pt

Group vibrations assigned using C-deuteriated ethylenediamine, and various anions. Pd--Pd interactions between cation and anion do not affect vibrational spectra

g

( a ) E. I. Karpeiskaya, Yu. N. Kukushkin, V. A. Trofimov. I. P. Yakovlev, and R. A. Vlasova, Russ. J . Inorg. Chem., 1972, 17, 141 1; Metolen = N-(2-hydroxyethyl)ethylenediamine,Ettolen = N-(2-hydroxypropyl)ethylenediamine.(b) P. L. Goggin, R. J. Goodfellow, S. R. Haddock, F. J. S. Reed, J. G. Smith, and K. M. Thomas, J.C.S. Dalton, 1972, 1904. ( c ) Yu. N. Kukushkin, L. V. Konovalov, E. A. Andronov, and R. A. Vlasova, Russ. J. Inorg. Chem., 1972, 17, 1207. (d) J. M. Burke and J. P. Fackler, Inorg. Chem., 1972, 11, 3000; Ar = benzoate, toluate, or cumate. ( e ) J. M. Burke and J. P. Fackler, ibid.,1972, 11, 2744. v) ref. 365. (9)R. W. Berg and K. Rasmussen, Spectrochim. Acta, 1973,29A, 37. (h) R. W. Berg and K. Rasmussen, ibid., 1973, 29A, 319. (i) A. H. Norbury and A. I. P. Sinha, J. Inorg. Nuclear Chem., 1973, 35, 121 1.

409

The Noble Metals

K,[PtCl,] and the phosphine ligand in aqueous ethanol, in the presence of sodium borohydride. Oxidative addition of carboxylic acids to the related [Pt(PPh,),] has yielded the hydride complexes [PtH(PPh,),]X [X = (CF,C02),H,(CF2ClC02)2H,(C2F5C02)2H,(CF2C02)2H, or (C02)4H3].296That CF,COi is not co-ordinated is confirmed by its replacement in water by NaBPh, to give [PtH(PPh3)3]BPh,. The chemisorption of molecular oxygen on platinum foil at low pressures has been investigated by flash-filament techniques.297 Platinum(II)'.-Group VII Donors. Halogeno-complexes. A number of u.v.visible absorption spectral studies have appeared of halogenoplatinum(r1) compounds. Sharp-line luminescence has been observed for the [PtCl,] ion doped in singlecrystalsof Cs,ZrCl,, and assigned to the transition r5( BIJ -+ r1(1A1J.298 In addition, d-d bands were noted and assigned on the basis of a CF analysis. Another investigationreports the electronicspectrum of K, [PtCl,] dissolved in melts of CsC1, KCl, LiCl, or the eutectics CsCl-LiCl or KClLiC1.299The spectrum remains normal in CsCl at 650-700°C and in the eutectics below 400°C,but it is modified in LiCl at elevated temperatures by a drawing together of the two spin-allowed states. This effect is attributed to polarization of [PtC1,I2- by the outer shell of Li+ ions. The single-crystal polarized absorption spectrum has been recorded for Magnus' green salt [Pt(NH3),][PtCl,J at both 300 and 15 K."' Paper chromatographic methods have been reported for the separation of 60 different metal complexes and ions, including [PtC1,]2- and [PtC16I2-, for which R , values are given with various eluents.82 A more sophisticated method of distinguishing between Pt" and Pt" species is uia photoelectron spectroscopy.301A study of a wide range of such complexes,including K,[PtX,] and &[PtX,] (X = C1, Br, CN or NO,), shows that the Pt 4f7,,binding energy shifts are larger for PtIVthan Pt" owing to the addition of extra ligands. Comparison with data for corresponding palladium complexes indicates that for the x-bonding CN- and NO; ligands there is more M L charge transfer with the smaller Pd. Halogenophosphine complexes. Halide-bridged species of the type [Pt,X,L,](BF4)2 (L = PPh,, PEt,, PMePh,, or p-CNC,H,Me, X = C1; L = CNMe, X = C1, Br,or Qhave been isolated from the novel reaction of trimethyloxonium fluoroborate on [PtX,L,] substrates :302 -+

2[PtX,L2] 296

297 298

299

300 301

302

+ 2(Me,0)BF4

4

[Pt,X,L,](BF,),

+ Me,O + 2MeCI

K. Thomas, J. T. Dumler, B. W. Renoe, C . J. Nyman, and D. M. Roundhill, Inorg. Chem., 1972, 11, 1795. M. Procop and J. Volter, Z . phys. Chem., 1972,250, 387. H. H. Patterson, J. J. Godfrey, and S. M. Khan, Inorg. Chem., 1972, 11, 2872. G. N. Papatheodorou and G. P. Smith, J . Inorg. Nuclear Chem., 1973,35, 799. D. S. Martin, R. M. Rush, R. F. Kroenig, and P. E. Fanwick, Inorg. Chem., 1973,12,301. W. E. Moddeman, J. R. Blackburn, G. Kumar, K. A. Morgan, R. G. Albridge. and M. M. Jones, lnorq. Chem., 1972, 11, 1715. P. M. Treichel, K. P. Wagner, and W. J. Knebel, l n o r g . Chim. Acta, 1972,6, 674.

410

Inorganic Chemistry of the Transition Elements

On the other hand, addition of mercury(I1) halides to the related species [PtX,L,] (X = C1, Br or I; L tertiary phosphines or arsines) has yielded adducts of the type [PtX,(AR,)2HgX,].236 From i.r. studies and X-ray data for [PtCl,(PMe,Ph)HgX,],237 the double halide-bridged structure (49; M = Pt) is indicated with square-planar Pt and tetrahedral mercury. A di-adduct, [PtCl2(PMe3),(HgCl2),], was also reported which was assigned structure (64) by analogy with the mono-adduct.

Other authors report the synthesis of [Pt{ Ph,PCH,C(CF3)=CHPPh2)X2] (X = C1 or SCN) via treatment of [PtX,]'with Ph2PC=CCF3.267 Particularly interesting is the unprecedented bond cleavage during attack on Pt, with the formation of a three-carbon chain from two acetylene groups. 1.r. data indicate S-bonding of the thiocyanate ligand. A range of acyl complexes of formula tran~-[PtCl(COR)(PPh,)~3have also been prepared by reaction of the appropriate acyl chloride with [Pt(PPh,)2(C2H,)].303 In contrast to previous suggestion^,^'^ a reassignment of the P t 4 1 bands shows that the acyl group has a strong trans effect. Since acyl groups are known305to be strongly electronwithdrawing by inductive mechanisms, the present conclusion provides strong additional evidence that the identity of the donor atom dominates the trans influence, the electronegativity of the ligand as a whole being of relatively small importance. Treatment of [PtCl,(PhCN),] with the bulky tertiary phosphines PBu\(oethylphenyl) and PBu',(o-isopropylphenyl) has been shown to yield the internally metallated complexes [Pt,Cl,(P-C),] [P-C = CH(Me)C,H,PBu', or C(Me)2C6H,PBu\].238 Also reported are the o-metallated triarylphosphite derivatives (50; M = P t ; R = H, C1 or Me; X = C1, Br or I), obtained by boiling [PtX,(P(OAr),),] in d e ~ a l i n . ~The tendency to undergo metallation increases in the order I < Br Cl. Synthesis of the [PtX,(P(OAr),},] starting materials was achieved via direct reaction of Na,[PtCl,] with the appropriate t r i a r y l p h ~ s p h i t e In . ~ ~addition, ~ i.r. and n.m.r. studies indicated that the complexes had cis-geometry. The dimeric complexes (65; L = PPr, or PBu,) are reported to undergo

-=

(65) 303

304 305

S. P. Dent, C. Eaborn, A. Pidcock, and B. Ratcliff, J . Organometallic Cham., 1972,46, C68. M. C. Baird and G.Wilkinson, J . Chem. SOC. (A), 1967,865. P. R. Wells. S . E. Ehrenson, and R. W. Taft, Progr. Phys. Org. Chem., 1968,6, 147.

The Noble Metals

41 1

H-D exchange in MeC0,D-D,O containing HClO, to yield products containing deuteriated phosphine l i g a n d ~In . ~contrast, ~~ no exchange occurs with similar non-bridged substrates or when L = PEt,. Electron binding energies have been measured for the C12p3,, level in a wide range of chloro-platinum(I1) compounds, including cis-[PtCl,(PPh,),], cis- and trans-[PtCl,(PBu~),], and trans-[PtHCIL,] (L = PPh, or PPhMe2).307A correlation was noted between these values and the associated 'CI n.q.r. frequencies. These observations were employed to discuss the structure and bonding in Zeise's salt and its analogues. Group VZ Donors. 0-Donor ligands. The hitherto unknown grey-black oxide Na,Pt02 has been prepared, and shown to be isotopic with Li,CuO, from X-ray powder data.,'* A theoretical study has attempted to rationalize the bonding in many transition-metal dioxygen adducts, including platinum species. Few complexes of platinum with the hard OH- ligand are known in view of HSAB considerations. However, stable complexes of the type [Pt,(OH),(PRJ4](BF4), (R = Et or Ph) have recently been isolated employing reaction (30).241Their i.r. spectra confirm the presence of co-ordinated OH groups

'

[PtCIJPRJ,]

+ 2AgBF4

moist

AgCl

+ [ P ~ z ( ~ H ) , ( P R , ) ~ ] ( B F ~ ) z(30)

[v(OH) = 3500 cm- '1, and suggest dimeric structures with double hydroxybridges. Interestingly, excess phosphines do not cleave these bridges, despite the ready cleavage of analogous chlorobridged species.242A cyclic voltammetric study of the o-quinone complex(45 ;M = Pt ;X,Y = vacant) has revealed reversible one-electron oxidation to give compounds thought to contain co-ordinated semiquinone radicals., The oxidation may also be accomplished with oxidants such as NiS4C4(CF3), or AgPF,. Thermogravimetric curves for solid K,[Pt(C,0J2],2H20 and other transition-metal oxalates indicate that the thermal stabilities of the anhydrous complexes decrease with increase in electron affinity of the central metal ion.' 5 8 AH values were obtained for both dehydration and decomposition. Subsequent studies showed carbon dioxide as the only gaseous product, the decomposition occurring uia electron transfer from a C202- ligand to the central platinum.159 Two related papers have reported conductivity309and redox, studies on single crystals of several partially oxidized platinum complexes, including Kl~,Pt(C20J,xH,0 and Mgo~,,Pt(C2O4),5.3H,0. The temperature dependence of the conductivity followed a log 001- (1/T)* relationship, consistent with a phonon-assisted hopping model recently proposed. Furthermore, the application of d.c. fields of greater than 200 V cm-' to K,~6,Pt(C2O&,XH20 has been shown3" to induce an oxidation-reduction reaction, yielding C. Masters, J.C.S. Chem. Comm. 1973, 191. D. T. Clark, D. Briggs, and D. B. Adams, J.C.S. Dalton, 1973, 169. 308 W. Urland and R. Hoppe, 2.anorg. Chem., 1972,392,23. 309 T. W. Thomas, C. H s y M. M. Labes, P. S. Gomm. A. E. Underhill, and D. M. Watkins, J.C.S. Dalton, 1972, 2050. 310 P.S. Gomm, A. E. Underhill, and D. M. Watkins, J.C.S. Dalton, 1972, 2309. 306

307

412

Inorganic Chemistry of the Transition Elements

Kl~,4H,~,,Pt(C204)2,nH,0. In contrast the analogous Mgo.,,Pt(C204),,-

5.3 H,O undergoes no such reaction even up to 3000 Vcm- '. Mixed 0-donor and N-donor Iigands. In a series of related papers Volshtein and co-workers3' 1--3 l4 have described the synthesis of a number of new complexes of the amino-acids proline and glycine. Treatment of K,[PtCl,] with excess I-proline (LH)led to the isolation of K[PtCl,L] (66), the first reported Pt complex of p r ~ l i n e . Here ~ ~ ' L is bidentate, co-ordinating i k z both the imino N and a deprotonated carboxy-group. Derivatives containing unidentate L and LH may be obtained from (66) employing Scheme 18. Other proline complexes

K

H,C-

I oc-

NH

c1 c1

reported include cis- and trans-isomers of the chelate species [PtL,], and the mixed [PtL(L€€)C1].3 Similarlythe salts trans- [PtX,( NH,CH,CO, ) (NH,)] (X = C1, Br,or I), containing a unidentate glycinate ligand (gl), have been prepared by neutralizing the protonated complexes trans-CPtX,(NH,)(glH)] in

Scheme 18

acetone.313In contrast, when neutralization is performed in water, closure of the glycine ring occurs leading to the chelate species [PtX(gl)(NH,)] (X = C1 or Br). A subsequent paper describes the synthesis of the new complexes (67) and derivatives via Scheme 19.314Interestingly, a comparison of the rates of ring311

'12 313 314

L. M. Volshtein and 0. P. Slyudkin, Russ. J . l n o r g . Chem., 1972, 17, 236. L. M. Volshtein and 0.P. Slyudkin, Russ. J . l n o r g . Chem., 1972, 17, 1168. L. M. Volshtein, L. F. Krylova, and I. G. Luk'yanova, Russ. J . lnorg. Chem., 1972,17, 563. L. M. Volshtein and L. F. Krylova. Russ. J . Inorg. Chem., 1972,17, 1648.

413

The Noble Metals

closure of glycine in the final anion cis-[Pt(NH,)(NH,C0,)C12]- and the analogous trans-isomer (above), shows a much faster rate for the trans species.

S-Donor Zigands. Cysteine complexes of formula [PtL,] have been prepared by treating K, [PtCl, J with excess cysteine hydrochloride.249 Their i.r. spectra confirm co-ordination via S and 0 sites, and suggest structure (68). Similarly 0

0

the P-keto-sulphoxide complex [PtL,] (L = PhCOCH,SOMe) has been shown to haqe structure,(54; M = Pt).zsOCompounds of the 3-substituted rhodanine RNCOCH,SCS (R = 3-alkyl) have also been reported, including [PtL,Cl,] ; 2 5 3 i.r. studies show this product to contain an unco-ordinated olefinic group and unidentate bonding ziia the thiocarbonyl S . The reaction of K,[PtCl,] with ligand ( 5 9 in aqueous ethanol has yielded the orange bis-complex [PtL, Interestingly, i.r. and 'H n.m.r. studies suggest SN-co-ordination, whereas SO-bonding occurs in the analogous palladium compound. Another paper reports the first systematic study of metal complex formation by the pyridine thiol ligands (69a -c), including the isolation of the square-planar [PtL,]C1,.3 l 5 This formulation is supported by conductivity and i.r. measurements, which also indicate co-ordination uia S in 315

B. P. Kennedy and A. B. P. Lever, Canad. 3. Chem., 1972,50,3488.

Inorganic Chemistry of the Transition Elements

414

SH

SH

SH

each case, rather than N. Yellow indole complexes of formula [Pt2L2X,] (X = C1 or Br) have also been synthesized :260

They are assumed to have dimeric halogen-bridged structures. More interesting is the isolation of the related benzothiazole compound [PtLiX,] [L' = (58)], for which X-ray spectra confirm unidentate bonding through the S atom. This result contradicts earlier opinion that S-heteroatoms are incapable of metal bonding. Six pairs of cis-trans isomeric complexes of the type [PtA(R,SO)Cl,] (A = a-, p-, or y-picoline; R,SO = DMSO or DESO) have been prepared : 3 1 6 K[PtACl,]

+ R,SO

K[Pt(R,SO)CI,]

-+ cis-[Pt

A(R,SO)Cl,]

+ C1-

+ A -+ trans-[Pt A(R,SO)Cl,] + C1-

(31) (32)

All of the trans-isomers isomerize to the cis-form when heated in the solid state. Also reported are the compounds cis- and trans-[PtA(DMSO)Cl,] (A = NH,OH, acetaldoxime, or acetoxime), which are the first known complexes where A is not NH,, H,O, or an anion.317 In a related study, new complexes of tetramethylenesulphoxide have been described including K[Pt(TMSO)CI,], and cis- and trans-[Pt(TMSO)ACI,] (A = py, piperidine, Et,NH, EtNH,, or NH,).3'8 Like DMSO and DESO, a strong trans-influence is ascribed to TMSO, which is further shown from i.r. to be S-bonded to Pt. A further similarity is the ready isomerization of the trans-[Pt(TMSO)ACl,] species on dry heating. An interesting attempt has been made to prepare hightemperature superconductors by reacting cyanine dye bases (L) with equimolar amounts of K[PtC13(DMS0)].202 However, the product trans-[PtCl,(DMSO)L] showed no evidence for intermetallic interactions, having conductivities in the range of organic insulators. New complexes of the methylene-bridged dithiols Ph,P(S)CH,P(S)Ph, and Ph,P(S)CH,P(S)Me, have been synthesized : 2 5 6 Ptci, 316 317

318

+ (L-L) EQL

~P~(L-L)CI,I

Yu. N. Kukushkin and E. D. Ageeva, Russ. J. Inorg. Chem., 1972,17, 767. Yu. N. Kukushkin, A. I. Stetsenko, S. G. Strelin, and V. G. Duibanova, Russ. J . Inorg. Chem., 1972, 17, 561. Yu. N . Kukushkin and T. Naidenova-Todorova, Russ. J . Inorg. Chem., 1972,17, 559.

The Noble Metals

415

Their i.r. spectra indicate the presence of six-membered ring chelates. However, the corresponding S-bridged ligands R,P(S)SP(S)R, undergo cleavage during complex formation to yield phosphorodithioate compounds with stable fourmembered rings. Also described are dithiophosphinate complexes of the type (57; M = Pt, R = F, Me, Et, or OEt), together with the dimer [Pt2S,P,(CF3),] of proposed structure (70). isolated from refluxing mixtures of PtCl, and HS2P(CF3),.258 A correlation was observed between the Pt -S stretching frequencies and the first electronic transition, while the substituents fell in the spectrochemical order OEt F > Me Et.

-

-

Two complementary papers report the isolation and separation of a range of dithio- and perthio-aryl complexes using K,[PtCI,] as starting material.259,3 1 9 The perthioaryl (carboxylic) acid complexes may alternatively be obtained ilia the oxidative addition (33). This process is readily reversed,

abstraction of S with triphenylphosphine being rationalized in terms of Scheme 16 (M = Pt). A single crystal X-ray analysis of the p-dithiocumate complex shows it to be the dimer [Pt,(p-dtc),], with two bridging and two terminal dithiolate ligands (Table 8).31 Examination of v(CS) stretching bands indicates that the analogous dithiobenzoate and dithiotoluate complexes have similar dimeric structures. In a related study, a reinvestigation of the reported3,* reaction between [M(S-S),] [M = Pd or Pt"; S-S = S,CNR, (R = Me or Et), S,COR (R = Et or PhCH,), SP(OEt),, and S,PR, (R = Me, Et, or Ph)] and tertiary phosphines has indicated stepwise cleavage of the M-S bonds to generate four-co-ordinate complexes of formula (71) and (72).321All the ionic complexes (72) revert back to (71) in non-polar solvents via nucleophilic attack by (S-S)- on M. In addition, when (S-S) = S,COR or S,P(OEt),, nucleophilic attack can also occur on a co-ordinated alkoxy-group, yielding the novel compounds (73) and (74), respectively. 319

320 321

J. M. Burke and J. P. Fackler, Inorg. Chem., 1972,11, 3000. J. P. Fackler and W. C. Seidel, Inorg. Chem., 1969,8, 1631. J. M. C. Alison and T. A. Stephenson,J.C.S. D a l t o ~ 1973. . 254.

Inorganic Chemistry of the Transition Elements

416

The facile hydrolysis of methylisothiourea, MeSC(NH,)=NH, by K,[PtCl,] to yield complex (75) provides another example of enhanced electrophilicity of a ligand via metal ~o-ordination.~~’ Scheme 20 was suggested for the reaction. Subsequently a second product (76) was isolated, which from analysis and i.r.

(75)

(76)

data was believed to be the first reported complex containing cyanamide (HN=C=NH) as a ligand.323Co-ordination via N was indicated.

[Pt2(SMe)C1,]’--

[PtCI,IZ

[C13Pt(SMe)12-

Scheme 20

Related compounds of the type [Pt(SMe)(NH,)Cl], can be similarly synthesized by treatment of methylisothiourea with cis-[Pt(NH,),Cl,], or directly via reaction between methanethiol and K[Pt(NH),CI,]. The C12p3,, binding energies of cis- and trans-[Pt(SEt,),Cl,] have been measured as part of an extensive study of chloro-platinum(r1)complexes.307 322

”’

Yu. N. Kukushkin. V. V. Sibirskaya, S. D. Banzargashieva, and V. N. Shvedova, Russ. J. Inorg. Chem., 1972,17,298. Yu. N. Kukushkin, V. V. Sibirskaya, S. D. Banzargashieva, and 0. I. Arkhangel‘skaya, Russ. J. Inorg. Chem., 1972,17. 1972

The Noble Metals

417

Following g preliminary account,261a full description has appeared of the use of the dithio-complexes Cp,Nb(SR), (R = Me or Ph) as ligands, giving with [PtCl,(PhCN),] the red-purple derivatives [Pt(Cp,Nb(SR),},]BF,.262 By analogy with the corresponding Ni cation for which an X-ray analysis has been performed, the structure (59; M = Pt) is suggested with tetrahedral co-ordination about the Pt. The preparation of [Pt(SC&1,)2] has also been reported :264 K,[PtCl,]

+ SC6C1,H

Hzo- [Pt(SC,Cl,),]

Full details have now been given27' for the synthesis of the sulphur dioxide derivatives [Pt(SO,)(PPh,),], following a brief c o m m u n i ~ a t i o n Anaerobic .~~~ addition of SO, to benzene solutions of [Pt(PPh,);] was employed, the dark-purple product being air-sensitive and readily oxidized to the sulphatospecies [Pt(SO,)(PPh,),],H,O. Se-Donor ligands. In the course of an investigation of the complexing behaviour of the ligand (PhO),P(S)Se-, the yellow [PtL,] has been isolated from hot ethanolic mixtures of L and K2[PtC1,].165 U.v.-visible spectral studies indicate that the ligand generally forms a chelate structure (35) with four-membered rings, and that the crystal field of Se is weaker than S. However, nephelauxetic parameters suggest that replacement of S by Se leads to a slight increase in the covalent character of the M-chalcogen bond. Another interesting paper describes the synthesis of the first selenocarbamato-complexes : 2 7 2 [PtCl,(PPh,),]

+ [Bul;NH,] [OSeCNBuZ]

[Pt(PPh,),(OSeCNBul;)]

Molecular weight and i.r. measurements indicate that the selenocarbamate ligand is unidentate in the solid state, but that in solution partial dissociation of PPh, occurs, causing the ligand to become bidentate as in (59; M = Pt). Group V Donors. N-donor ligands. The new cationic species [Pt(NH,),L](NOJ, (L = DMSO or C2H4) have been prepared.324Since these complexes undergo only very slow aquation, it has been possible to measure the acidity (KJ of the ammonia ligands trans to the L group. Instability constants for the removal of one co-ordinated ammonia by water were also reported. Unusually stable five-co-ordinate complexes of formula [PtX(PPh,O)(PPh,OH)(phen)] and [PtX(PR,),(phen)]BF, (X = C1 or Br; R = Et or Ph) have been isolated from the facile reaction of 1,lO-phenanthroline with acetone solutions of [Pt ,X,(PPh O)(PPh,OH),] and [Pt ,X2(PR ,),I, respectively. Decomposition of [PtX(PR,),(phen)]BF, in hot methanol or CH,Cl, leads to the squareplanar complexes [PtX(PR,)(phen)]BF,. A u.v.-visible spectroscopic study of a range of related Pd" and Pt" bipyridine complexes, including [PtX,(bipy)] (X = C1, Br, or I) and [Pt(py),(bipy)], has shown large shifts with change in solvent, which may be correlated with the ET parameters of the solvents.279

,

324

M. I. Gel'fman, N. M. Karpinskaya and V. V. Razumovskii, Russ. J . Znorg. Chem., 1972, 17, 1021.

418

Inorganic Chemistry of the Transition Elements

Other authors have measured C12p3,, binding energies for the [PtCl,(bipy)] case, as part of an extensive investigation of chloro-platinum complexes.307 A correlation was established between the C1 binding energies and the associated 35C1n.q.r. frequencies. Bu'

H,",

H Bu'

c1I

H C=N-Pt-N=C

/

H

I

c1

/ Bu'

N:N\

OH-+ air

'NNH, H

/N>C' I: Pt :I C<.N/ \N$'N / H H

Ac

AC

,Scheme 21

Treatment of trans-[PtCl,(Bu'CN),] with hydrazine hydrate in ethanol has This led to the new white complex [P~C~,{HN=C(BU~)NHNH,),].~~~ compound undergoes the reactions shown in Scheme 21, producing chelated triazabutadiene compounds. X-Ray (Table 8) and ESCA data indicate extensive delocalization of electron density within the chelate rings, suggesting a similarity to dithiolen complexes, which is confirmed by their reversible one-electron reductions to parama netic s ecies. Complexes of the ligand thiazolidine-2thione (L = S=CNHCH,CH, ) have also been prepared, of general formula PtL,X, (n = 2,3, or 4; X = C1, Br, or I):,*'

*

K,[PtCl,]

+ nL + excess HX

PtL,X,

I.r., l H n.m.r., and u.v.-visible spectral data confirm that the ligand is N-bonded in these compounds, while conductivity measurements show that they are 1 :2 electrolytes in dilute aqueous solution. Other new complexesdescribed are the propanol oxime(LH = EtCH=NOH) derivatives cis- and trans-[Pt(LH),Cl,], [Pt(LH),L], and [Pt(LH),]2+.326 325 326

R. Mason, K. M. Thomas, A. R. Galbraith, and B. L. Shaw, J.C.S. Chem. Comm., 1973, 297. A. I. Stetsenko, S. G. Strelin, and B. S. Lipner, Russ. J . Inorg. Chern.. 1972, 17, 1428.

419

The Noble Metals

The last-mentioned cation behaves as a tetrabasic acid, whose four K , values were reported. Complexes of the biologically important purine bases adenosine and tetra-acetyl-adenosine have been synthesized :327 K,[PtX,]

+ HX + L

H O

[PtL,X,],3H20 (X = C1 or Br)

Structure (77) is suggested from i.r. and 'H n.m.r. data.

OH

OH

Another study of possible biochemical interest described the preparation of the activated amino-acid ester complexes trans-[PtX,(NH2CH,CO2R),1 (X = C1 or Br; R = numerous aryl substituents) via treatment of trans[PtX,(NH,CH,CO,H),] with substituted The Pt" functions as a N-terminal protecting group in these compounds, permitting reaction with a wide variety of nucleophiles on the N-co-ordinated esters (Scheme 22). Further 0

G1yY \

Gly-Gly-OEt

[PtX2(Gly-Gly-OEt),]

(X = Br)

[Pt X 2(Gly- GIy-Gly -0 Et)2 1 (X = Br) (R2 = H or NH,; R 3 = H or Et) Scheme 22

327 328

N. Hadjiliadis, P. Kourounakis, and T. Theophanides, lnorg. Chim. Acta, 1973,7, 226. W. Beck. B. Purucker, andE. Strissel, Chem. Ber., 1973,106,1781.

420

Inorganic Chemistry of the Transition Elements

examples of reaction on co-ordinated ligands include the protonation of the isocyanato-complex [Pt(PPh,),(NCO),] to yield [Pt(PPh,),(NHCO,Et),Pt(PPh,),](BF,),, and attack of methoxide ion on the carbonyl group in [Pt(PPh,),(CO)( CO,Me)]BF, giving the ester trans-[Pt(PPh,),(C0,Me)2].143 A re-investigation of the behaviour of solutions of trans-[PtC12(C0)(4-NCpy)] in MeCN has shown that the changes in the i.r. spectrum, previously attributed329to the formation of acetonitrile complexes, arise instead from reaction with halide ions (X = C1 or Br) dissolved from the i.r. cell to give tr~ns-[PtCl,(CO)X].~~~ This illuminating observation may assist other researchers confronted with puzzling ix. spectra. The new binary dinitrogen species PtN, has been identified from i.r. measurements of low-temperature matrices formed by the co-condensation of Pt and pure N,.331Observation of only the mono(dinitrogen) complex suggests that, unlike CO, dinitrogen prefers low co-ordination numbers in its binary compounds with metals. The magnetic c.d. spectrum of [Pt(NH3),I2' has been measured in both 3 2 Comparison with previous electronic transition water and a~etonitrile.~ assignments supports the belief that Pt" has an empty 6 p , orbital of low energy, which is probably important in SN2transition states for substitution reactions. The enthalpy of dissolution of [Pt(NH,),]X, (X = Br or I) has also been measured in water and aqueous ammonia.333In addition, a value of - 158.2 kcal mol-l was calculated for the standard enthalpy of formation of the bromide salt. Other physical studies include the two-electron polarographic reduction of [Pt(NH,),Cl]NO, and [Pt(NH,),(py)Cl]NO, in 0.5MNaC104r334and a polarized single-crystal spectral investigation of the yellow Cossa's salt K[Pt(NH,)C1,],H,0.335 A similar study of the red Cossa's salt suggests the presence of small amounts of octahedral [PtXV(NH3)Cl 5] - ions, giving rise to a mixed-valence electron transition at 23 800 cm- '. In support of this conclusion, the new compound K2[Pt(NH,)C1,][Pt(NH,)Cl5],2H20, containing alternately stacked planar Pt" and octahedral PtIVanions, has been prepared by mixing 1 :1molar amounts of K[Pt(NH,)Cl,] and K[Pt(NH,)Cl,]. Two related papers have reported conductivity309 and redox310 studies on single crystals of several partially oxidized platinum complexes, including K,Pt(CN),C1,,,,2.6H2O and K, ,,,Pt(CN),,1.8H20. The temperature dependence of the conductivity followed a log occ - (1/T)* relationship, consistent with a phonon-assisted hopping model. Furthermore, the application of d.c. fields of greater than 200 V cm-l to Kl.6,Pt(CN),,1.8H,0 has been shown310 to induce an oxidation-reduction reaction, yielding K, .74Ho~,6Pt(CN)4,xH,0. P-Donor and As-donor ligands. The co-ordinating ability of the ligand ( 3 9 has been investigated with a wide range of metals, resulting in the isolation of the 329

330 331 332 J33

334 335

T. Weil, P. Schmidt, M. Rycheck. and M. Orchin, Inorg. Chem., 1972,8, 1002. L. Spaulding, B. A. Reinhardt, and M. Orchin, Inorg. Chem.. 1972,11, 2092. J. K. Burdett, M. A. Graham, and J. J. Turner, J.C.S. Dalton, 1972, 1620. H. Isci and W. R. Mason, Inorg. Nuclear Chem. Letters, 1972,8, 885. T. A. Kuzina, V. A. Palkin, and N. N. Kuz'mina, Russ. J . Inorg. Chem., 1972, 17, 1739. V. M. Kiseleva, M. I. Gel'fman, and V. V. Razumovskii, Russ. J . Inorg. Chem., 1972, 17, 1171. P. E. Fanwick and D. S . Martin, Inorg. Chem., 1973,12,24.

The Noble Metals

42 1

complex [PtL,Cl,] via direct reaction between L and ethanolic [PtC1,]2-.175 1.r. data indicate Pt-P bonding, and together with solid reflectance spectra support trans square-planar geometry. Similar extensive studies with the mixed phosphine-diarsine ligand (23) have yielded pale yellow [PtLCl].' O 5 However, in contrast to the corresponding tritertiary phosphine (Ph,PC,H,),PPh, it was not possible to prepare bimetallic or trimetallic derivatives with the mixed ligand, owing to the lower donor ability of arsenic compared with phosphorus. Group IF/ Donors. C-Donor ligands. The cationic isocyanide complex [Pt(CNMe),](PF,), has been obtained via direct reaction between aqueous K,[PtCl,] and excess MeNC.286This complex reacts with MeNH, to yield the white air-stable species [Pt(C(MeNH)2)4]2+,which is the first example of a transition metal co-ordinated solely by ligands of the resonance-stabilized carbene type (63). 'H N.m.r. and i.r. data support structure (63; M = Pt) with the ligands in the amphi configuration, while the invariance of the 'H n.m.r. between -50 and -90°C indicates appreciable multiple bonding in the s~~~ N - C - N grouping. A related study by Bonati and c o - ~ o r k e r produced similar products of formula cis-[PtC12(R' NC) (C(R'NH) (R2NH))] from the attack of primary aromatic amines (R2NH&on cis-[PtCl,(R'NC),] (R' = p tolyl or cyclohexyl). They also described attack on these substrates by alcohols (R20H>to yield analogous carbenes of the type cis-[PtCl,(R'NC) (C(RINH)(OR')]]. Other authors2*' suggest that when the substrate has R = pN02C6H,, a bis-carbene complex cis-[PtC1,(C(p-N0,C6H4NH)(OEt))21 is formed. Also reported is nucleophilic attack by ethanol on the isocyanides (R' = Ph, p-MeOC6H,, or p-N02C6H4; cis-[PtCl,(R'NC)(PR~)] PR: = PPh,, PEtPh,, PEt,Ph, or PEt,) to give cis-[PtCl,(C(R'NH)(OEt))(PR31. Carboxamido-complexes of the type [PtC1L2(CONR1R2)] (L = phosphine, arsine; R' = H or alkyl) have been synthesized :288 [PtCl,L,]

+ CO + R'R'NH

+

[PtClL2(CONR1R2)]

Their 'H n.m.r. spectra indicate trans geometry with a high barrier to rotation about the C-N bond. Analogous thiocarboxamido-compounds [PtC1L2(CSNMe,)] were obtained by oxidative addition of ClC(S)NMe, to [PtL,]. Both series of complexes are air-stable solids which are stable in water, in contrast to similar alkoxycarbonyl derivatives. Si-Donor, Sn-donor, and Pb-donor ligands. Treatment of the Pt * complex [Pt(PPh,),(C,H,)] with excess organosilicon hydride HSiY [ Y, = Ph,, Ph,Me, Ph,H, Et,, (EtO),, etc.] in the absence of solvent has provided a new and convenient route to a wide range of hydrido-organosilyl derivatives of the type [PtH(SiY,)(PPh,)2].337 Pt-H bands are observed at 2080-2105 cmand 'H n.m.r. spectra suggest cis-geometries.The complexes decompose slowly

,

',

336

33'

F. Bonati, G. Minghetti. and E. Maionica, Gazzetta, 1972, 102,731. C. Eaborn, A. Pidcock, and B. Ratcliff, J . Organometallic Chem., 1972,43, C5.

Inorganic Chemistry of the Transition Elements

422

in benzene, which probably explains the failure of previous attempts338 to isolate a range of such complexes using a solvent. Also described are the bis-silyl (Y3= C1, or C1,Me). '19Sn Mossbauer spectra species [Pt(SiY,),(PPh,Me),] have been recorded for a wide variety of trichlorostannyl metal complexes, including cis- and trans-[Pt(PPh,),X(SnClJ] (X = H or Cl).'l In addition, the to contain tr~ns-[PtCl,(SnC1,),]~- and red complexes previously [Pt(SnC1,),I3- anions have been shown to have identical Mossbauer and i.r. parameters, suggesting the latter formulation for both. Following the recent preparation290 of [M(PEt,),(PbPh,),] (M = Pd or Pt), the analogous triphenylphosphine complexes have now been synthesized by the oxidative addition of hexaphenyldilead to [M(PPh3)4].291 The Pt complex decomposes slowly in dichloromethane to give cis-[Pt(PPh,),(PbPh,)Ph]. On the other hand the corresponding [Pt(PPh,),(PbMe,)Me] may be obtained directly via treatment of [Pt(PPh,),] with Me,Pb,. Group ZZZ Donors. B-donor ligands. In an extension of recent on Pt 7c-borallyl complexes, a unique series of complexes of the 7c-B3H$- ligand have been prepared with Ni, Pd, and Pt":341 cis-[PtCl,(PR,),]

+ CsB,H, + Et,N

--+

[Pt(PR3),(B3H,)]

+ CsCl + Et,NHCl

'H N.m.r. studies show the 7c-borallyl species to be more stereochemically rigid than the o-B3H, metalloboranes, while an X-ray structure for [Pt(PMe,Ph),(B,H,)] (Table 8) reveals general features similar to known 7c-ally1 complexes. The reactivity of the compounds towards oxygen, water, and heat decreases down the series Ni > Pd >'Pt. A grey product, tentatively assigned the structure (78), has been isolated from the reaction of BF,,Et20 on ~is-[Pt(py),(NOz),].~~~ The BF, molecules are rapidly replaced in solution.

Platinum(w).-Group VII Donors. Paper chromatographic methods have been reported for the separation of 60 different metal complexes and ions, including [PtCl,], - and [PtCI,]' - for which R , values with various eluents were given.82 A more sophisticated method of distinguishing between Pt" and PtIVspecies is via photoelectron spectroscopy.301A study of a wide range 338

339 340

341

342

Y. 'Yamamoto, T. Hayashi, and M. Kumada, J . Organometailic Chem., 1971.28. C37. J. E. Young, R. D. Gillard, and G. Wilkinson, J . Chem. SOC., 1964, 5176. A. R. Kane and E. L. Muetterties, J . Amer. Chem. SOC.,1971,93, 1041. L. J. Guggenheim, A. R. Kane, and E. L. Mueterties, J . Amer. Chem. Soc., 1972,94,5665. D. Humphreys and P. J. Staples, J.C.S. Dalton, 1973, 897.

The Noble Metals

423

of such complexes, including K,[PtX,], K,[Pt&] (X = C1, Br, CN, or NO&, and'K,[Pt(CN),XY] (XY = Cl,, C1, Br, or Br,), shows that the Pt4f712 binding energy shifts are larger for PtrVthan Pt" owing to the extra ligands. In addition, measurement of C12p binding energies reveals higher values for bridging than for terminal chloride ligands. New hydridocarbonyl complexes of the type [Pt(H),(CO)X,] and Et,N[Pt(H),(CO)X,] (X = C1, Br, I, or CNS) have been prepared, and their i.r. and u.v.-visible spectra recorded.,,, Group VZ Donors. The hitherto unknown red P-Na,PtO, has been prepared, and shown from single-crystal X-ray data (Table 8) to be an orthorhombic variant of the Li,SnO, type.308Also reported for the first time is the lithium salt of [Pt(OH),I2- :344

The presence of the co-ordinated hydroxy-groups was confirmed from i.r. and thermogravimetric data. Oxidative addition of iodine to [Pt(acac),], either in the solid state or in carbon tetrachloride solution, has yielded the black complex [Pt(acac),I, U.v.-visible and mass spectral measurements show the reaction to be reversible in solution or in the gas phase, and a singlecrystal X-ray analysis (Table 8) indicates trans octahedral geometry for the product. Heating metallic Pt with excess BrS0,F for 3 weeks at 95°C produces the dark-brown fluorosulphate complex [Pt(S0,F),].346 This reaction is somewhat surprising in view of the reported347 inertness of Pt in boiling fluorosulphuric acid. The first sulphoxide complexes of PtIV have been prepared, via reaction (34) (L = DMSO or DES0).348 Co-ordination through S is indicated from i.r. data. However, the R,SO ligands are less strongly held to PtIVthan Pt", being readily replaced by chloride ions.

Group V Donors. Following a recent report3,' that K,[Pt(NO,),] is obtained as the initial product from the attack of HNO, on K,[Pt(NO&,], a study of the subsequent reaction of the former with warm HNO, has produced a cherry-red compound formulated as K3Pt2(No2)6(No3),.350 Since only half the complex was converted into [PtI6I2- with KI, the presence of both Pt" and Pt" oxidation 343

344

345 346 341 348 349

350

L. N. Rachkovskaya, N. K. Eremenko, and K. I. Matveev, Russ. J. lnorg. Chem., 1972,17, 1173. N. U. Venskovskii, L. D. Borzova, B. N. Ivanov-Emin, B. E. Zaitsev, and A. I. Ezhov, Russ. J . lnorg. Chem., 1972,17, 1738. P. M. Cook, L. F. Dahl, D. Hopgood, and R. A. Jenkins, J.C.S. Dalton, 1973, 294. W. M. Johnson, R. Dev, and G. H. Cady, Inorg. Chem., 1972,11,2260. A. A. Woolf and J. N. Brazier, J . Chem. SOC.,1967,99. Yu. N. Kukushkin and V. N. Spevak, Russ. J . lnorg. Chem., 1972,17, 872. L. K. Shubochkin, E. F. Shubochkina. M. A. Golubnichaya, and L. D. Sorokina, Russ. J. Inorg. Chem., 1971,16,877. L. K. Shubochkin, E. F. Shubochkina, M. A. Golubnichaya, and L. D. Sorokina, Russ. J. Inorg. Chem., 1972,17, 394.

424

Inorganic Chemistry of the Transition Elements

states was indicated. A dimeric structure with bridging nitrato- and nitrogroups was therefore proposed and supported by i.r. evidence. A related investigation of the aquation of K,[Pt(NO,),] showed it to be accompanied by a redox process, as in Scheme 23.," The cherry-coloured (79) was a dimeric structure with bridging nitrato groups, on the basis of i.r. and thermogravimetric measurements. K,[Pt(NOJ,]

+ 2H2O

[Pt(NO,),(H,O),] 2N02

+ H20

Kz[Pt(NO3,]

80°C

+ 2KNO2

+

[Pt(NOJ4(H,O)2] 2KNO2 K,[Pt(N02)4] +2H,O+ 2NOz

+

H N 0 3 + HNO, *2HNO, + 2HN03 3% K2(N0,),Pt(N03),Pt(ONO),

+

Scheme 23

(79)

Platinum(I1) diamines such as cis-[Pt(MeNH,),Cl,] have been shown to be oxidized by atmospheric oxygen in HClO, solution to give PtIVcon pound^.^^^ This result is not surprising in view of the redox potentials of 0.6-4.7 V measured for the [Pt(NH,R),C1,]/[Pt(NH,R)2C12] couples (R = H or Me), Another paper reports the electrochemical interconversion of a number of Pt" and PtIVcomplexes containing unsaturated ligands such as CN-, SCN-, and ~ y r i d i n e53. ~Acceleration by bridging halides was observed and comparison with unsaturated complexes made. The overall results were explained in terms of a molecular orbital model. Group IV Donors. Ii9Sn Mossbauer spectra have been recorded for a wide variety of trichlorostannyl metal complexes, including [Pt(PPh,),Cl,(SnC1,),].Si A correlation was observed between the isomer shifts of all the compounds and the Sn 4 1 stretching frequencies. Platinum(V) -The oxide KPtO,, presumably containing formal oxidation state PtV,has been r e p ~ r t e d . ~ "

Table 8 X-Ray data for platinum compounds Compound [FePtz(CO), P(OPh3)3)3 1

R 0.062

Comments Triangular metal cluster in which co-ordination about Fe and Pt is octahedral and square planar, respectively.The short Pt -Pt

Ref. a

co

351

L. K. Shubochkin, E. F. Shubochkina, M. A. Golubnichaya, and L. D. Sorokina, Russ. J . Inorg.

352

Chem., 1972,17, 1210. Yu. N. Kukushkin, E. F. Strizhev, B. A. Kiasnov, and A. V. Gordievskii, Russ. J . Inorg. Chem., 1972,17, 1499.

The Noble Metals

425

Table &continued Comments Rej. indicates some multiple bond character Filled P-tungsten-type structure h with 'filling' oxygen atoms in square plane about Pt. Chains of Pt atoms run parallel to all 3 cubic axes Orthorhombic variant of Li,SnO, c type

R

Compound

Ni,. 2 s P t 3 0 4

0.056

P-Na,PtO,

0.081

Na,PtO, a-Na,PtO, trans-[Pt(acac),I,]

Powder patterns only

-

Each Pt" is octahedrally bonded d by two 0's in acac and by two 1's in trans configuration. Weak intermolecular bonds between iodides (3.559A) e Square plane about Pt, with trans phosphines. The S is weakly bonded to I (I-S = 3.391 A). Dimer has Pt -Pt = 2.870 A in f a distorted square antiprism of S atoms. Two bridging and two terminal dithiolate ligands.

0.040

0.027

0.099

cis-[PtBr,(NH

,),I

Powder patterns of yellow and red forms. Suggests different colours are due to different Pt -Pt distances between the planar molecules Square plane about Pt with extensive delocalization in chelate ring

-

0.042

[Pt { HNC(Bu')N,Ac) ,]

Ac

I

H

N-N,

I (.

C=-N/ Bu * ' H

C

/N-%C

Pt -" + .

I Ac

/ But

::I

g

h

426

Inorganic Chemistry of the Transition Elements

Table %-continued Compound Pt4(MeC0,),(N0),,2MeC0,H

R 0.066

[PtCI,(PPhMe,),HgC1,]

0.057

[Pt(PPh,),(PbPh,)Ph]

0.070

[Pt(PPhMe,),(B,H,)]

0.054

0.0426

Comments Rej. Tetranuclear complex containing both NO and acetate bridges. Square plane of 3 0 ' s and one N about each Pt. Pt atoms form rectangle. L P ~ N O= 120" indicating NOSquare plane about Pt and tetrahedron around Hg. Complex contains two bridging C1 atoms between Pt and Hg cis-square-planar configuration. Pt-Pb = 2.698A Square plane of two P's and one x-borallyl group about Pt. Similar structure to isoelectronic C,H, (n-allyl) complex Diffraction data at - 170 "C. trans-Square planar complex with Pt bridge-bonded to the unique (4,5-position) basal B atoms in each B,H,, ligand. The bridged B-B bond is nearly perpendicular to the Cl--Pt -€I axis

((I) Ref. 293. ( b ) D. Cohen, J. A. Ibers, and R. D. Shannon, Znorg. Chem., 1972, 11, 2311. (c) Ref. 308. (4 Ref. 345. ( e ) M. R. Snow and J. A. Ibers, Znorg. Chem., 1973, 12, 224. v) Ref. 319. (9) V. A. Palkin, N. N. Kuz'mina, V. E. Gorbunov. and 0.N. Evstafeva, Russ. J. Znorg. Chem., 1972, 17, 290. (h) Ref. 325. (i) P. De Meester and A. C. Skapski, J.C.S. Chem. Comm., 1972, 1039.0 P. De Meester and A. C. Skapski, J.C.S. Dalton, 1973, 1194. ( k ) Ref. 237. (0 ref. 291. ( m ) Ref. 341. (n)J. P. Brennen, R. Schaeffer, A. Davison, and S. S. Wreford, J.C.S. Chem. Comm., 1973, 354.

7 Silver Silver(I).-Group VII Donors. Formation of adducts of the type AgX,MX (X = C1 or Br ; M = Et,N, Bu,N, Ph,H,N, Li, etc.) has been observed :354 AgX

+ MX K1AgX,MX

Equilibrium constants I(, were obtained from measurements of the Ag activity of the mixtures, and revealed greatest stability for the bromocompounds. The electronic absorption spectra of the silver halides (X = Cl, Br, or I> have been recorded in passing from the solid to the molten state.35s Both the observed energy jumps at the melting points, and the bathochromic shift with temperature increase were accounted for in terms of the same structural modification. Other workers have reported the activities of AgCl in +

353 354

3s5

C . Lai and A. T. Hubbard, Inorg. Chem., 1972,11,2081. L. M. Mukherjee, J. D. Czaban, R. S. Schultz. R. W. Atwell, and R. J. Krohn, J . Inorg. Nuclear Chem., 1972,34, 3944. I. G . Murgulescu, E. Popa, and E. Ivana, Rev. Roumaine Chim., 1973, 18, 189.

H20-acetone

NH3

=

H2O

H2O

mns-[Pt(en)CI(NO)L] ci~-rPt(en)CI,L]~ [pt(en),LI3 [Pt(en)L,I2 IP~L,I

potentiometric titration

u.v.-visible spectra

Showed that Pt" complexes with the bidentate L( = H,NC2H4-N-NO) are weaker acids than corresponding ethylenediamine complexes

g

Comments .Rej. Measured instability constants for a removal of NH2R by solvent. The presence of hydride decreases strength of trans-Pt NH,R bond Measured acid dissociation constants h removal of first Br ligand by water b Measured acid disociation constants aquo-complexes Instability constants for removal c of first C1 by water found to be independent of nature of L Measured acid dissociation C constants, and compared. with DMSO-aquo-complexes Investigated formation of new d species Protonated and non-protonated e complexes formed depending on pH f Determined composition of complexes only

( a ) I. V. Gavrilova, M. 1. Gel'fman, and V. V. Rezumovskii, Russ.J . Znorg. Chem., 1972, 17, 727. (b)Yu. N. Kukushkin and K. M. Trusova, ibid., p. 233. ( c ) Yu.N. Kukushkin, K. M. Trusova, and T. Todorova-Naidenova, ibid., p. 1352; DESO = diethylsulphoxide, TMSO = tetramethylenesulphoxide.(d) H. Stiinzi and G . Anderegg, Acta Chem. Scand., 1973,56, 1698. ( e ) V. M. Ivanov, A. I. Busev, and V. N. Figurovskaya, Russ. J . Znorg. Chem., 1972,17, 566. v) G. D. Ginzburg, A. D. Troitskaya, and V. V. Sentemov, ibid., p. 1019. (9) 0.N . Adrianov and N. S. Gladkaya, ibid., p. 301.

Et, Pr, Pri, Bu, Bui, or Bus) Nitrosimidoethylamine

(R

PR3

CN', NH, 4-(2-Pyridylazo)resorcinol

'-

c1

H-, OH-, Cl; Br','SCN-,

H2O

H2O

H2O

[PtBr,(H,O)(DMSO)] [PtBr(H,O),(DMSO)] potentiometric [PtCl,L] (L = DMSO, DESO or TMSO) potentiometric [PtC12(H20)L] [PtCI(H,O),L] (L = DESO or TMSO) pH and u.v.-visible [Pt( edta)] data u.v.-visible spectra

potentiometric titration potentiometric

Zlc,thod of Study potentiometr ic titration with acid

H20

+

+

+

[PtBr3(DMSO)] -

+

H2O

Complex trans-[PtH(NH,R)(PPh3),It (R = H or Me)

+

+-

Br

(3Ck70)

SolI?ccnt

Ligand

Table 9 Stability constant data for platinum compounds

+

2

p

$

i$

2

3*

2

Inorganic Chemistry of the Transition Elements

428'

Table 10 1.r. structural studies of platinum complexes Complex [PtX(SMe,) ,]BF, cis-[PtCl,(SMe,),] truns-[PtX,(SMe,),](X C1, Br, or I) PrN[PtX,(SMe,)] M~P~(cs,),I [Pt(CS JPMePh,),] [Pt(CS,O)(PMePh,),l [P~(cs,o)(PP~~),~

Other studies Results and conclusions H n.m.r. Assignments proposed. The ciscomplex found in two forms with very different i.r. spectra

'

=

rpt(en)x,i (X = C1, Br, or I) [Pt(en),]Cl,,H,O trans-[Pt(NH ,),LX]Y (X = C1 or Br; Y = ClO,, BPh,, or N, , L = neutral molecules) p t x L ,I (L = PPh,. AsPh,, SbPh,, py, pic, NH,, or bipy; X = NCO or CI)

r

Raman

Far i.r. Crystal data Raman Far i.r. -

__

4

R eJ: U

Found that v(CS) and v(PtS) b varied in the series Pt(CS,)i -. Pt(CS,), Pt(CS,O). Also showed the complex previously reportedc as Pt(CS,)(NH,),,H,O is better formulated as [PtW H [Pt(CS,),],2 H, 0 Group vibrations assigned using d C-deuteriated ethylenediamine, and various Z. M -M interactions between cation and anion do not affect i.r. spectra Group vibrations assigned using C-deuteriated compounds. Assigned all bands and compared with [Pt(NH,)J4+ Showed that v(PtC1) depends on o-donor power of L, and also on nature of Z Assigned most bands. Pt--NCO frequencies compared with corresponding C=N frequencies, to estimate importance of back- bonding

h

(a) P. L. Goggin, R. J. Goodfellow, S. R. Haddock, F. J. S. Reed, J. G. Smith, and K. M. Thomas, J.C.S. Dalton, 1972, 1904. ( 6 ) J. M. Burke and J. P. Fackler, Inorg. Chem., 1972, 11, 2744. (c) K. A. Kofmann, Z . anorg. Chem., 1897, 14, 263. (4 R. W. Berg and K. Rasmussen, Spectrorhim. Arta, 1973, 29A, 37. ( e ) R. W. Berg and K. Rasmussen. ibid., 319. cf)D. W. James and M. J. Nolan, Znorg. Nuclear Chem. Letters, 1973,9, 319. (g) N. V. Ivannikova, N. I. Gel'fman, and V. V. Razumuvskii, Russ. J . Inorg. Chem., 1972, 17, 879. (h) A. H. Norbury and A. I. P. Sinha, J . Inorg. Nuclear Chem., 1973, 35, 1211.

Table 11 N.m.r. studies of platinum complexes Complex cis-, tr~ns-[PtX,L,] (X = Cl or Br, L = n-dodecylamine) cis-[P t X,L,], [PtBrL,]Br, [PtL,]Br,

Probe 5N

Re$ Results and conclusions a Found J(PtH) values for cis-[PtX,L,] complexes were larger than for trans-isomers, as previously observed for phosphine complexes

[P~LC~,] -, [PtUNHJ,] (L = chelated, and Nco-ordinated glycine)

'H

Also studied N - and C-methyl glycine-complexes. Showed that both 3-bond 3J(PtH) and 4-bond ,J(PtH) spin coupling constants

+

b

The Noble Metals

429

Table 11-continued Complex

Probe

Results and conclusions

R q.

maximize when Pt and H (or Me) are trans. and are much smaller when gauche trans-[PtH(NCS)L,] 31P, (L = AsEt, or phosphines) variable temperature

Confirm that broadening of highfield hydride bands is due to interaction between hydride protons and quadrupolar 14N nucleus as previously suggestedd

c

[PtCl(acac)(2-chloromethylpyridine)]

A locked structure is present at low temperatures in which methylene protons occupy two non-equivalent positions. Averaging of proton sites occurs at high temperatures via rotation about Pt -N axis

e

Variabletemperature

H cis-[~t~2~,-j 'H [X = C1 or I ; L = PMe,Ph P(O-MeC6H4)Me,] [P~X,L~LZ-J, [P~X,L;I [L = PMe,Ph, PBu,, P(MeC6H4)3]

trans-[PtX,(PBu,),], [PtX(PEt,),]ClO,, cis-[PtX,(PBu,)J, (X = O N 0 2 , N3, NCO, NCS, NO,, CN, C1, Br, or I)

31P

Investigated tertiary phosphine f catalysis of phosphine ligand exchange, and cis- trans isomerization. Results confirm consecutive displacement mechanism for isomerization via an ionic intermediate [PtXL,] T X Observed effects of anionic ligands on 'J(PtP) coupling constants

9

( a ) P. S. Pregosin, H. Omura and L. M. Venanzi, J Amer. Chem. Soc., 1973, 95, 2047. (b) L. E. Erickson, M. D. Erickson, and B. L. Smith, Znorg. Chem., 1973,12,412. (c) A. Pidcock, J.C.S. Chem. Comm., 1973, 249. ( d )J. Powell and B. L. Shaw, J . Chem. Soc., 1965, 3879. ( e ) F. Coletta, R. Ettorre, and A. Gambaro, J.C.S. Dalton, 1973,684. v) D. G. Cooper and J . Powell, J . Amer. Chem. Soc., 1973, 95, 1102. ( 9 ) G. G . Mather, G . J. N. Rapsey, and A. Pidcock. Inorg. Nuclear Chem. Letters, 1973, 9, 567.

Inorganic Chemistry of the Transition Elements

430

molten MgC1,-KCl and molten MgC1,-NaCl-KCl solvents at 475 OC, employing an e.m.f. method. 5 6 Mass spectral measurements have provided the equilibrium pressures of AgI, Ag313,I, and I, above solid AgI at 750 K.357 Group VZ Donors. O-Donor ligands. Heterosiloxanes containing the hitherto unknown Ag--C--Si linkage have been prepared by treating [AgCl(PMe,),] ( n = 1-3) with an equimolar amount of sodium trimethylsilanolate : 3 5 8

SiMe,

I

PMe, SiMeJ

I

Me3P Si Me, (80)

Molecular weight. mass spectral, 'H n.m.r. and i.r. spectral data indicate structures (80)- (82) for the products. On the other hand, an attempt to prepare Ag' complexes with the potentially terdentate ligand trithiodiacetylacetone, led instead to the stable adduct AgN03,L.359Its i.r. and u.v.-visible spectra indicated unco-ordinated L, suggesting only very weak bonds between Ag and the central ligand S atom. Both 1 :1 and 1 :2 complexes of the novel tetra-azahexaoxa-macrotricyclic ligand (83) have been observed in CDCl, solution, and the L,2AgNO, species

356

35' 358 jS9

H. L. Jindal, Austral. J . Chem., 1973, 26, 57. M. Binnewies and H. Schafer, Z. anorg. Chem., 1972,395,63. H. Schmidbaur, J. Adlkofer, and A. Shiotani, Chem. Ber., 1972,105, 3389. A. Furuhashi, M. Kawano, N. Tashiro, and A. Ouchi, J . Inorg. Nuclear Chem., 1972,34,2960.

The Noble Metals

431

was isolated.360They showed similar 'H and I3C n.m.r. spectra, indicating the same symmetry for the Ag' cations in each compound. The much greater (x lo6) stability of the 1 :2 complex suggests that the Ag+ ions are inside the ligand in both cases, being co-ordinated to the two N and two 0 atoms of one of the twelve-membered rings, with both cations sharing the 0 sites in the' bridges. Another paper reports the synthesis of a Ag' complex of 8-hydroxy7-nitroso-quinoline-5-sulphonic acid :3 61 4AgN0,

+ 2Na,L

boil

Ag[(AgL),Ag]

+ 4NaN0,

The shift to higher frequencies of the v(N0) band supports chelation ilia the 2-nitroso-l-naphthol site. Co-ordination of the second L to Ag results in the formation of the anionic complex, probably of tetrahedral geometry. The polarographic behaviour of AgClO, has been investigated in anhydrous DMSO, DMF, MeCN, PhCN, PhNO,, and other solvents.362The half-wave potential was observed to be related to the donicity of the solvents, unless specific cation-solvent interactions occur. A re-investigation of the thermal decomposition of the dioxan complex AgC104,3Lhas enabled the construction of an enthalpy cycle in which dioxan complexes are favoured only if the lattice energy of the complex exceeds that of the parent AgX salt plus the heat of vaporization of dioxan.36 S-donor ligands. Reaction of the 2-mercaptopyrimidines (84; R = H, Bus, Bz, Ph, p-tolyl, o-MeOC,H4, or m-N02C6H4) with AgNO, in ammoniacal aqueous ethanol has yielded the pale yellow precipitates (85).364This behaviour

contrasts with reaction with related 2-mercaptopyrimidines (R = Me, Et, Bun, Bui, or allyl), which gives only black Ag,S. An i.r. investigation of Ag2S0, has shown it to have structure (86),containing both Ag-0 and Ag-S bonds (strong i.r. bands both above and below 950 cm-').365 360 361 362

364

365

J. Cheney, J. M. Lehn, J. P. Sauvage, and M. E. Stubbs, J.C.S. Chem. Comm., 1972, 1100. M. M. Aly, I. M. Issa, M. G. Allam, and M. T. El-Haty, J. Inorg. Nuclear Chem., 1973, 35, 2080. 0. Duschek and V. Gutman, Z. anorg. Chem., 1972,394,243. J. C. Barnes and C. S. Duncan, J.C.S. Dalton, 1972, 1732. A. M. Bhatti and N. K. Ralhan, J. Indian Chem. Soc., 1973,50, 145. B. Nyberg and R. Larsson, Acta Chem. Scand., 1973,27,63.

432

Inorganic Chemistry of the Transition Elements

Two related papers report the isolation of and stability constant for the formation of the supercomplex Ag[Ni(RS),],' (R = NH,C,H,S-) :366, 3 6 7 Ag'

+ [Ni(RS),], + Ag[Ni(RS),]:

The ligand [Ni(RS),] employs S donor atoms in forming the supercomplex with Ag', the latter species being detected by solubility, chromatographic, and spectrophotometric methods. Group V Donors. N-donor ligands. In a continuing investigation of the coordination behaviour of the ketoxime HL (87), the white complex [Ag(HL),]NO3 has been isolated from the direct reaction between HL and AgNO, in

Ph

4

NOH

refluxing aqueous ethanol.,"' This diamagnetic species is a 1 : 1 electrolyte in water, and i.r. measurements indicate unidentate co-ordination of HL tia the pyridine N atom. A series of red amine complexes of the type [AgX,] [Cr(NCS),(PhNH,),] (X = NH,, MeNH,, or EtNH,) has also been reported,,"' and their i.r. spectra confirm N-thiocyanate bonding. The equilibrium constant for the formation of Ag2+ and Ag from Ag' in water is extremely low (1 x lop2?. However, an example of ligand-induced disproportionation of Ag' has now been reported in aqueous methanol, using 1,4,8,11 -tetra-azacycl~tetradecane.~~~ the ligand 5,5,7,12,12,14-hexamethylFree metal and the Ag'I-L complex are formed rapidly. In contrast, when dry acetonitrile is employed as solvent no disproportionation occurs, and the 366

367

368 369

370

S. A. Grachev, L. I. Shchelkunova, and Yu. A. Makashev, Russ. J . Inorg. Chem., 1972, 17, 706 S. A. Grachev, L. I. Shchelkunova, Yu. A. Makashev, and T. S. Burzina, Russ. J . Znorg. Chem., 1972,17, 1010. D. B.,V. M. Malone and B. Sen, J . Inorg. Nuclear Chem., 1973,35,2114. P. K. Mathur and L. N. Srivastava, J . Inorg. Nuclear Chem., 1973.35. 2112. M. 0.Kestner and A. L. Allred, J. Amer. Chem. Sor , 1972,94, 7189.

433

The Noble Metals

white [AgLIClO, is formed. This latter species disproportionates in water or methanol : 2[AgL]+

-+

[AgL]'+

+ L + Ago

(35)

A comparative study has appeared of the X-ray photoelectron spectra of a range of Ag' and Ag" N-donor complexes.371The Ag3d3/, and 3d,/, binding energies show little dependence on the formal oxidation state, but peak widths are usually considerably broader (-0.8 eV) for the paramagnetic Ag" species. In the course of these studies the new compound [Ag2(dipic)],H,0 (dipic = pyridine 2,6-dicarboxylato) was isolated. Also reported is a comprehensive i.r. and Raman spectral investigation of the series of complex silver anions C[AgX,](C = Me,N or Ph,As; X = CN or NCO), Me,N[Ag(SCN),], and Me,N[Ag(SeCN),].372 The spectra were interpreted in terms of linear Dooh or bent C2,rstructures, and the fundamental frequencies of the anions were tentatively assigned. P-Donor, As-donor, and Sb-donor ligands. Treatment of AgCl with trimethylphosphine has produced the new complexes [Ag(PMe,)Cl),, [Ag(PMe,),Cl],, [Ag(PMe,),Cl], and the unstable ionic [Ag(PMe3)4]C1.373The structures (88) PMe,

and (89) were assigned to the tetra- and di-meric species on the basis of spectral data. Related monomeric complexes of the type [AgL,]X (L = AsPh,; X = NO3, ClO,, or BrO,) and [AgL,X] (L = PPh, or AsPh, ; X = SCN or NCO) have been independently prepared : 3 7 4

The thiocyanato-complex is S-bonded (i.r.) as expected for a '6' class compound. Similarly, the observed v(C0) (1305 and 1310 cm-') indicate that the CNOligand is N-bonded, in keeping with the greater affinity of Ag for N than for 0. 371

372 373 374

P

D. P. Murtha and R. A. Watlon, Inorg. Chem., 1973,12, 368. 0.H. Ellestad, P. Klaeboe, E. E. Tucker, and J. Songstad, Acta Chem. Scund., 1972,26, 3579. H. Schmidbaur, J. Adlkofer, and K. Schwirten, Chem. Ber., 1972,105,3382. R. N. Dash and D. V. Ramana Rao, 2. anorg. Chem., 1972,393, 309.

Inorganic Chemistry of the Transition Elements

434

A similar study describes the synthesis of an even wider range of thiocyanatocomplexes of formula [Ag(CNS)L] (L = PMe,, PBu", or PPhEt,), [Ag(CNS)(PPh,Et)], and [Ag(CNS)(APh,),] (A = P, As, or Sb).375Molecular weight measurements on the [Ag(CNS)(PBu:)] and [Ag(CNS)(PPh,),] species in acetone and chloroform, respectively, showed both to be monomers. In addition, i.r. data revealed bridge bonding of the thiocyanate ligand in all the 1:1 and 1 :2 complexes. By analogy with the X-ray structure of [Ag(CNS)(PPr",],376 all the 1 :1complexes were assumed to have double chain structures with --Ag-SCN-Ag-SCNchains cross-linked in pairs by Ag-S bonds. On the other hand, the 1 :2 species probably have dimeric structures involving a central planar (AgSCN), ring, in view of X-ray studies on [Ag(SCN)(PPh,),]., The heat of reaction (36) (hfacac = hexafluoroacetylacetonate) has been [Ag(hfacac)(PPh,)] + PPh,

-+

[Ag(hfacac)(PPh,),]

(36)

measured in dichloromethane, and the Ag-PPh, dissociation energy estimated to be 18.4 kcal mol-' (ignoring solvation effects).378 Group ZV Donors. "'Sn Mossbauer spectra have been recorded for a wide range of transition-metal trichlorostannyl complexes, including [Ag(PPh,),(SnCl,)].S1 The isomer shifts of the compounds were correlated with the S n 4 1 stretching frequencies. Silver-Metal BDnded Compounds. Stable salts of formula Me,N[Ag(M(CO),Cp),] (M = Mo or W) have been isolated from aqueous diglyme solutions of Na[M(CO),Cp] and AgN03.379Since their i.r. spectra are similar to those of the known Hg[M(CO),Cp], the complex anions are believed to be non-centrosymmetric, with the first reported cases of linear M-Ag-M bonding. Silver(n).-New fluorides of this unusual silver oxidation state have been described, including M'AgM"'F, (MI = K, Rb, or Cs; M"' = T1, In, Ga, Al, Sc, Fe, or C O ) , , ~ and ~ Ag[MF,] (M = Rh, Pd, or Pt).382 Some of these complexes show remarkable colours and complicated magnetic behaviour. Mixed-ligand complexes of Ag" have been prepared for the first time by displacing neutral terdentate dipicH, ( = pyridine 2,6-dicarboxylic acid) from [Ag(dipic)(dipicH2)],4H 0 :

,

[Ag(dipic)(dipicH,)],4H20 375 376

377 378 319

380

3a2 383

+L

Hzo

[Ag(dipic)L],xH,O

J. L. Cox and J. Howatson, Inorg. Chem., 1973, 12, 1205. C. Panattoni and E. Frasson, Acta Cryst., 1963,16, 1258. J. Howatson and B. Morosin, Cryst. Struct. Comm., 1973,2, 51. W. Paitenheimer and E. H. Johnson, Inorg. Chem., 1973, 12, 1274. P. Hackett and A. R. Manning,J.C.S. Chem. Comm., 1973,71. R. D. Fischer and K. Noack, J Organometallic Chem., 1969.16, 125. B. Miiller and R. Hoppe, 2. anorg. Chem., 1972,395,239. B. Miiller and R. Hoppe, Z . anorg. Chem., 1972,392, 37. D. P. Murtha and R. A. Walton, Inorg. Chem., 1973,12, 1278.

The NobIe Metals

435

(L = 2,2',2"-terpyridyl, 2,2'-bipyridyl, or l,l0-phenanthroline). Ionic derivatives of general formula [Ag(pyridine carboxylate)(terpy)](S,O,)+,xH,O have also been reported. The remarkable stability of these complexes towards water reduction was ascribed to their unusually high co-ordination number (for AgU), and the strong stabilizing influence of 2,2',2"-terpyridyl. Addition of AgX (X = C10, or NO,) to an aqueous suspension of the ligand 5,5,7,12,12,14hexamethyl-1,4,8,1l-tetra-azacyclotetradecane leads to disproportionation according to the stoicheiometry :370

The yellow [AgLIX, showed a magnetic moment (peff = 2.14BM) and an e.s.r. spectrum characteristic of a Ag" d9 species. A comparative study has appeared of the X-ray photoelectron spectra of a range of Ag' and Ag" N-donor c ~ m p l e x e s . ~The ~ ' Ag3d3,, and 3d,,, binding energies show little dependence on the formal oxidation state, but peak widths are usually considerably broader (ca. 0.8 eV) for the paramagnetic Ag" species. This increased width may be caused partly by the presence of 'multiplet splittings.. In the course of these studies the new orange-brown isoquinoline-lcarboxylato-complex [AgL,] was also isolated :

SilverQII).-To date the only reported Ag"' complexes are guanidine derivatives.384 However, oxidation of the known Ag" octaethylporphinatospecieswith Fe(ClO,J, in CHC1,-MeOH solution has yielded the corresponding Ag"' metalloporphyrin. 38 The crystalline product is diamagnetic, as expected for a d8 compound. In both this complex and previous guanidine species the extraordinary stabilization of the central d8 ion arises from the square-planar co-ordination to four N atoms.

Table 12 X-Ray data for silver compounds R 0.1

Ag,NO

11

Fe(acac),,AgClO,

384

385

0.042

0.13

Comments Orthorhombic. SrZ is octahedral. Most of the Ag+ is surrounded by weakly angled dumbells of oxygen. Also some metallic regions First good quality X-ray measurements. Now locate NO, in a more reasonable position. Contains Ag', Ag", and Ag"' Ag is bonded to one acac 0,one C10, oxygen, and to central C of other acac ring. Therefore exhibits trigonalpyramidal co-ordination as in other AgClO, aromatic adducts +

S. Sailendra and N. G. Podder, J. Indian Chem. SOC., 1970,47, 39; and references therein. K. Kadish, D. G. Davis, and J. H. Fuhrhop, Angew. Chem Internat. Edn., 1972,11, 1014.

Re! a

b

c

436

Inorganic Chemistry of the Transition Elements

Ag is nearly linearly co-ordinated by S atom and one of sulphite O's, resulting in chain-like structure

0.067

AgNaS0,,2H20

/Ag-o,

-0,

o"0

S

/At?\

0

0

Ionic structure contains dinuclear complexes Ag2(tu)g with C, symmetry. Distorted tetrahedron of S atoms about each Ag. Two of the 6 S atoms of dimer are bridging ligands in four-membered Ag-S-Ag--S ring Erbium atoms at centre of octahedra. Ag atoms at centre of flattened tetrahedra disposed in two parallel lines. First crystal structure of a Ag"' complex. Square plane of N atoms about Ag. The fairly uniform multiple bonding in the C-N bonds indicates that the highly charged Ag3 is accommodated by extensive delocalization over the whole biguanide structure

0.048

+

AgErSe,

0.077

[Ag(C6N1OH 16)i(ci0&

0.08 1

+

( a ) H. L. Keller and H. Miiller-Buschbaun, Z . anorg. Chem., 1972, 393. 266. ( b ) C. H. Wong, T. H. Lu, C . N. Chen, and T. J. Lee, J . Znorg. Nuclear Chem., 1972,34,3253.( c ) L. R. Nassimbeni and M. M. Thackeray, Znorg. Nuclear Chem. Letters, 1973, 9, 539. (d) L. Nunisto and L. 0. Larsson, Acta Cryst., 1973, B29,623. (e) M. R. Udupa and B. Krebs, Inorg. Chim. Acta, 1973, 7 , 271. fl M. Julien-Pouzol and M. Guittard, Ann. Chim., 1973, 8, 139. ( 9 ) M. L. Simms, J. L. Atwood, and D. A. Zatko, J.C.S. Chem. Comm., 1973. 46.

8 Gold Co-ordination studies of this metal have increased significantly over the past two years. Cluster Compounds.-Details have appeared for the preparation of salts of octakis(triaryl phosphine) enneagold trications (Scheme 24). Their con-

+

AuNO~L

[Au,L, JX,

X

=

PF,,BF4,C10,. or picrate ;

L

=

PPh, or P(p-MeC,H,),

Scheme 24

ductivity, and i.r. and 31Pn.m.r. spectra are consistent with the ionic formulation, while preliminary X-ray data (Table 14) confirm the presence of the 38h

F. Cariati and L. Naldini, J.C.S. Dalton, 1972, 2286.

H,O

0.1MNaCIO, in 95 7; EtOH

Pyridine

13 Alkyl pyridines

AgL, are highest complexes found. except for L = 3,5-dimethyl-l-phenyl pyrazole, when [AgLJClO, was isolated

potentiometric

f 9

h

K , / K, high. No relationship between acidity constants of ligands and stability of complexes K:, > K 3 > K1 for each ligand. No correlation between K , of ligands and stability of complexes Composition curves indicate a 1 :1 complex. Determined KStab

potentiometric

potentiometric and conductimetric

pH and pAg measurements

e

H,O, H,O-EtOH

2-Dimethylaminoethanethiol hydrochloride AgL

dioxan-H,O AgL; (n = 1-3)

Monoethanolamine, Diethylanolamine, Triethylanolamine

d

C

b

a

Re$

Stability constants determined for last three ligands only. Co-ordination behaviour of (A) explained in terms of relative stability of aliphatic and aromatic nitrile complexes with Ag' .

Amino-alcohols

NC 1.r.

AgL, (n = 1 or 2)

AgL; (n = 1 or 2)

2.15

Log K1= 2.01, log K z

potentiometric. Also solubulity method =

Found linear relationship between log Ksrab.and 1/D, in accordance with Born theory

Comments Found linear correlation between stability of complexes and ( a log K,, + P 1% KOJ-

potentiometric

Method of study potentiometric

CH,CN (A) propylene carbonate or MeNO, Ph CH,CN, PhCN, p-NO,C,H,CH,CN

0

EtOH-HZO AgL;

Pyridine

AgLL (n = 1 or 2)

H,O

Complex

Solvent

Oxine 5-Acetyloxine 5-Nitro-oxine

Table 13 Stability constant data for silver compounds

Ligand

4

W P

H,O

Ni(NH,C,H,S),

Ag[Ni(RS),]

AgL

Complex

2' spectroscopic, and solubility methods

+

Measured stability constant for formation of the Ag' supercomplex : Ag+ 2Ni(RS), + Ag[Ni(RS),];

Estimated stability of AgL

solvent extraction

-.

2

3

00

rn

5

?! i!

3

$. z.

2

2

%

5 G

1 n5

All complexes have K > 4, with S ligands k forming more stable complexes than 0-donors. Conclude Ag bonds at heteroatom

'H n.m.r.

Also measured calorimetrically the AH and j AS changes accompanying complex fortfiation. In addition, measured X, of ligand

potentiometric

+

Comments Rej. i L,Ag+ cation prevails for all salts (L,AgX) except X = CN, I-, Br-, Cl-, provided L:Ag 3 4. For X = C1 and Br, the equilibrium L,Ag+X- + L,AgX X, was detected. When L :Ag = 3, L,Ag+X- predominates for X = PF,, BF,, ClO,, and tetrahedral L,AgX for X = C1, Br, I, CN, NCO, S,PF,

Method of study n.m.r.

(a) H. F. Steger and A. Corsini, J . Inorg. Nuclear Chem., 1973, 35, 1621. (b) M. Molina, M. Angst, E. K. Garcia, and C. V. Melios, ibid., 1972, 34, 3215. (c) J. Bjerrum, Acta Chem. Scand., 1972,26,2734. (4 M. Molina and S. Tabak, J . Inorg. Nuclear Chem., 1972,34,2985. (e) W. C. Boring and R. T. Iwamoto, Znorg Chim. Acta, 1973,7,264. (t) L. V. Van Poucke and Z. Eeckhaut, Bull. SOC.chim. belges.. 1972,81,363. (8) P. K. Migal and K. 1. Ploae, Russ. J. Inorg. Chem., 1972,17,1375. (h) M. L. Mittal and A. V. Pandey, J. Inorg. Nuclear Chem., 1972, 34, 2962. (i) E. L. Muetterties and C. W. Alegranti, J . Amer. Chem. SOC.,1972, 94, 6386. (j)L. C . Van Paucke, G. F. Thiers, and Z. Eeckhaut, Bull. SOC. chim. belges., 1972,81,357. ( k ) K. K. Deb, J. E. Bloor, and T. C. Cole, Znorg. Chem., 1972,11,2428. ( l ) T . Sekine and Y. Takahashi, Bull. Chem. SOC.Jupin, 1973,46, 1183 . (m)Ref. 366.

H,O

MeCN

H, :

2-Thenoyltrifluoroacetone

(X = 0 or S)

NH,(CH,),SO, ( n = 2. 3. 4, 5)

uz]

Solvent

w P

The Noble Metals

439

AugL, cage. A related synthetic route yielded yellow crystals of [Au(P(ptolyl),)],(BPh&,, which was shown from X-ray studies (Table 14) to contain a distorted Au, octahedron.387 In common with several other Group IB complexes, this novel cluster does not obey the effective atomic number rule. An electronic interpretation is advanced for the bonding in such clusters. Gold(I).-Group VII Donors. The Raman spectrum has been recorded for Au1,which is known to have a chain structure.388 Three chain vibrations were observed and assigned. Complexes of the types [AuLX] (L = phosphine or phosphite; X = C1, Br, or I) and [AuLX,] have been prepared, and their far-i.r. spectra recorded. 89 Comparison of trans A u - C l stretching frequencies suggests that the relative trans-labilizing influence of neutral ligands is very similar in Au', Au"', and Pt" compounds. Other new halogenophosphine species reported include [Au(PCy,)X] H[AuCl,]

+ PCyF

[Au(PCy,)Cl]

[Au(PCy3)X]

(X = Br, I, acac, C02C,F,)

The nature of their Au-X far4.r. bands indicates monomeric structures, while other i.r. evidence suggests that the acetylacetone ligand is C-bonded to gold. Group VI Donors. Heterosiloxanes of formula [APh,-Au-OSiMe,] (A = P or As) have been described, containing the hitherto unknown A u - O - S i linkage., 58 Their synthesis involved reaction between equimolar amounts of NaOSiMe, and [Au(PPh,)Cl). Treatment of AuCl with thio-ethers has produced the series of complexes [AuLCl] [L = Me,S, Et,S, (Me,C)S, Me,Se].391 On the other hand, the dithio-ethers RS(CH,),SR (R = Me or Et; n = 2 or 3) reduce H[AuC1,],3H20 to give the dimers (90). The proposed stiuctures were

I

R

I

R

supported by 'H n.m.r. data, which also revealed rapid exchange of co-ordinated thio-ethers with excess ligand in solution. Other authors have also measured 'H n.m.r. and i.r. spectra of the [Au(Me,S)X] (X = C1 or Br) species.392The results indicate that SMe, has a much lower trans-influence than PMe,. 387

388 389

390 391

392

P. L. Bellon, M.Manassero, L. Naldini, and M. Sansoni, J.C.S. Chem. Comm.. 1972, 1035. D. Breitinger and K. Kohler, Inorg. Nuclear Chem. Letters, 1972,8,957. D. R. Williamson and M. C. Baird, J . Inorg. Nuclear Chem., 1972,34, 3393. J. Bailey, J . Inorg. Nuclear Chem., 1973,35, 1921. K. C.Dash and H. Schmidbaur, Chem. Ber., 1973,106,1221. P. L. Goggin, R. J. Goodfellow, S. R. Haddock, F. J. S. Reed, J. G. Smith, and K. M. Thomas, J.C.S. Dalton, 1972, 1904.

Inorganic Chemistry of the Transition Elements

440

The NN-diethylselenocarbamate complex [Au(Et,dsc)] can be prepared oia the sequence [AuBr,]-

+ Zn(Et,dsc), +,[Au(Et,dsc)]

provided that the product is rapidly extracted and purified.,', The Au' compound disproportionates rapidly in solution. Group I VDonors. A new improved route has been found to isocyanide complexes of the type [Au(RNC)Cl], via reaction of RCN with the corresponding dimethylsulphidc compound :394 [Au(Me,S)CI]

C1 + RNC CH [Au(RNC)CI] fast

The synthesis of novel bis(isocyanide) species [Au(RNC),]+ has also been described. Some of these complexes react with alcohols to yield carbene products : [Au(R'NC)Cl]

+ R20H

--t

[Au((R1NH)(R20)C}CI]

'l'Sn Mossbauer spectra have been recorded for a wide range of transitionmetal trichlorostannyl complexes, including [ A U ( P P ~ , ) , ( S ~ C ~ , The ) ] . ~isomer ~ shifts of all the compounds were correlated with the S n 4 1 stretching frequencies. Guld(I1[).-Group VIIDonors. Complexes ofthe type [AuLX,] ( L = phosphine or phosphite; X = C1, Br or I) have been prepared, and their far4.r. spectra recorded.389Comparison of trans A u - C l stretching frequencies with those of related compounds suggests that the trans-labilizing influence of neutral ligands is very similar in Au', Au"', and Pt" species. Group V I Donors. During an attempt to measure the mass spectrum of BrSO,F, reaction with Au metal was noted, leading to the chemistry shown in Scheme 25.346The yellow-orange [Au(SO,F),] melts at 94°C. Its Raman spectrum confirms the presence of co-ordinated SO,F-, and suggests a polymeric structure in keeping with other fluorosulphates in which the SO,F- group acts as a bridge. 9 5 Oxidative addition of chloride to the dithio-ether complex (90) has yielded ionic Au'" species, for which 'H n.m.r. data suggest the structure (91; X = Cl, Br or I; Y = AuCl,, Br or I).391 Au

+ excess BrS0,F

-

Br,

+ Au(SO3F),,2BrSO3F I vac. 155 O C

[Au(SO,F),]

Au(SO,F),,BrSO,F Scheme 25

3y3 3y' 3y5

J. G. M. Van der Linden and W. P. M. Nijssen. 2. anorg. Chiwi.. 1977. 392, 93. F. Bonati and G. Minghetti, Gazzetta, 1973,103, 373. H. A. Carter, S. P. L. Jones, and F. Aubke, lnorg. Chem.. 1970,9, 2485.

The Noble Metals 441 An interesting paper has reported the absorption of heavy metal salts such as H[AuCl,] by cotton fabrics containing polyethylene (and polypropylene) sulphide functional Such fabrics may have practical application as filters for the removal of heavy metals from aqueous solution.

-

I

x

Bis-(NN-dialkyldiselenocarbamate) complexes of formula [Au(R,dsc),]Z (R = Et or Bu; Z = Br or AuCl,) have been prepared via prolonged treatment of [AuBr,]- with [ Z n ( R , d ~ c ) , ] . ~Their ~ ~ v(CN) stretching frequencies are about 10 cm- lower than for the corresponding S analogues. [Au(Et,dsc),]Br reacts with bromine to give the mono-species [AuBr,(Et,dsc)]. Other authors have reported alternative routes to the related dihalogeno-(NN-dialkylthioselenocarbamate) compounds [AuX,(R,CNSSe)] (X = C1, Br or I; R = Me or Et) :396 N~[AuX,],~H,O

+ Me,CISn(R,CNSSe)

[AuX,(R,CNSSe)]

1.r. and 'H n.m.r. measurements indicate square-planar co-ordination about Au"' in all cases, with planar tbioselenocarbamate skeletons. In addition, little difference was suggested between the ionic character of A u 4 and Au-Se bonds. Group V Donors. In a continuing investigation of the co-ordination behaviour of the ketoxime (87), the new orange complex [AuLCI,] has been isolated : 3 6 8 AuCI,

+ HL

[AuLCl,]

Bidentate co-ordination of L via the pyridine and oxime N atoms was indicated from i.r. data. On the other hand, reaction of AuCl, with equimolar amounts of isonicotinic acid esters has been shown to give yellow adducts of general formula AuCl3,4RO2CC,H,N (R = Et, Bun, pentyl', heptyl", or o ~ t y l " ) . ~ ~ ~ From cryoscopic molecular weight measurements all were shown to be monomeric in benzene at high dilution, but polymerization increases with increased concentrations. 1.r. spectral studies established co-ordination of isonicotinic esters via the pyridine N, as in structure (92). 3y6

3y7

N. Sonoda and T. Tanaka, J . Inorg. Nuclear Chem., 1973,35,1145. V. I. Zelenov, E. V. Yavorskaya, and N. D. Klyueva, Russ. J . Inorg. Chem., 1972,17, 83.

442

Inorganic Chemistry of the Transition Elements

c1 c1 R02C

c1

\ / \ /

-Au /

c1

AU-

\ I\ Cl

c1

(92)

Gold(V)--Salts of [AUF,] - containing the novel AuV oxidation state, have been isolated via Scheme 26.398Alternatively,the caesium salt can be obtained by direct oxidation of Cs[AuF,] with fluorine. Raman spectra were recorded, and X-ray powder patterns showed the salts to be isomorphous with related [MF,]- (M = Ru, Ir or Pt) salts.

2XeF,

+ Cs[AuF,]

Scheme 26

Table 14 X-Ray data for gold compounds Compound R Comments 0.052 Anion essentially octahedral, in keeping [Xe2F1 11~AUF61 with t& configuration of Au”. Cation approximates two XeF: ions linked by a F ion 0.055

Au is linearly co-ordinated. Phenyl and pentafluorophenyl rings are planar

b

0.053

Dication contains distorted Au6 octahedron. Distortion corresponds to squeezing of octahedron along a C, axis

C

P

I

I

P 398

Re t a

K. Leary and N. Bartlett, J.C.S. Chem. Comm., 1972,903.

443

The Noble Metals Table l d c o n t i n u e d R

Compound

rA ~ ~ L ~ I ( P F 6)

[Au,Cl,(PhSC,H,PhS)]

.-

Comments RCj. Preliminary. Confirms presence of AugL, d cage

0.062

Each dimer contains one Au-Au bond bridged through S by two bidentate S,P(OC,H,), ligands. Dimers linked through Au atoms (staggered) to form linear chains of weak Au-Au bonds. Each Au surrounded by distorted square plane of two S atoms and two Au atoms

0.074

Dimers contain planar S--C--(-S linkages. Each Au is bonded to a S and C1 atom with C1-Au-S almost linear (177.8') Ph

I

/

e

f

c1

AU

0

\

S

/

I

Ph Dimeric. Each Au is linearly linked to two S atoms in two different dipropyldithiocarbamate ligands. Molecules form linear Au chains with alternating distances 2.76 and 3.40 A

g

( a ) K. Leary, A. Zalkin, and N. Bartlett, J.C.S. Chem. Comm., 1973, 131. (b) R. W. Baker and P. J. Pauling, J.C.S. Dalton, 1972, 2264. (c) Ref. 387. (d)Ref. 386. (e) S. L. Lawton, W. J. Rohrbaugh, and G. T. Kobotailo, Znorg. Chem., 1972,11, 2227. (f) M. G. B. Drew and M. J. Riedl, J.C.S. Dalton, 1973, 52. (9)R. Hesse and P. Jennische, Acta Chem. Scand., 1972, 26, 3855.

9 Reviews The following relevant reviews appeared between June 1972 and June 1973 : 'Some Aspects of Catalytic Synthesis in Rhodium Chemistry'. R. D. Gillard and B. T. Heaton, Coord. Chem. Rev., 1972,8, 149. 'Transition-metal Nitrido-complexes'. W. P. Grifith, Coord. Chem. Reo., 1972, 8, 369. 'Chelating Dioxygen Compounds of the Platinum Metals'. V. J. Choy and C. J. O'Connor, Coord. Chem. Reo., 1972,9, 145. 'Pt"-catalysed Substitutions of PtIVComplexes'. W . R. Mason, Coord. Chem., Reo., 1972, 7, 241. 'Kinetics of Ni, Pd, and Pt Complexes'. A. Peloso, Coord. Chem. Rev., 1973,10, 123. 'Pd"-catalysed Exchange and Isomerization Reactions'. P. M. Henry, Accounts Chem. Res., 1973, 6, 16. 'Addition Reactions of Butadiene Catalysed by Pd Complexes'. J. Tsuji, Accounts Chem. Res., 1973,6, 8.

( a ) V. I . Belevantsev, G. R. Kolonin, and S. K. Ryakhovskaya, Russ. J . Znorg. Chem., 1972, 17, 1303. (b) M. H . Ford-Smith, J . J. Habeeb, and J. H. Rawsthorne, J.C.S. Dalton, 1972, 21 16. (c) M. R. Caira, G. V. Fazakerley, P. W. Linder, and L. R. Nassimbeni, Znorg. Nuclear Chcm. Letters, 1973,9, 25. (d)H. Schmidbaur and R. Franke, Chem. Ber., 1972, 105, 2985.

d e Showed formation of 1 :2 and 1 :4complexes with AuX(X = N O , BF,, or halide). Former assigned linear ionic structure, while latter thought to contain tetrahedral Au-P, cations.

1.r. and 'Hn.m.r,

AuL, (n = 1, 2, or 4)

PMe, and P(OMe),

G

3

8

ib"

L?

r;

2

*'

5

%

2

h*

-9

Q

c

Job's continuous variations study of reaction of L, HC1 with Na[AuCI,], 2H,O indicates formation of a 1 :2 (L :Au) complex. Probably co-ordinated tiiu 0 sites

u.v.-visible spectra

AuL,

2 0 4 n s.

Tetracycline

Ref a

b

u.v.-visible spectra

Comments Hydrolysis constant determined for equilibrium [AuCl,]- + H 2 0 + [AuCI,OH]- + H + + C1Measured equilibrium constants for the oxidative addition reactions. [Au(CN),l-+ X2 + trans-[Au(CN),X,]K decreases in series C1 > Br > I

H2O

C1, Br, and I

AuCI,

Method of study

partition technique, or potentiometric

H,O

c1

Complex

Au(CN)~X,

Solvent

Ligand

Table 15 Stability constant for gold compounds

The Noble Metals

445

To, Rh, Ir. Annual Survey Covering Year 1971’, M. Green and T. A. Kuc, J. Organometallic Chem., 1973, 53, 285. ‘Ni, Pd, Pt. Annual Survey Covering Year 1971‘. T. R. Jack and J. Powell, J . Organometallic Chem., 1973,53, 215.

4 Scandium, Yttrium, the Lanthanides, and the Actinides BY J. A. McCLEVERTY

1 Scandium and Yttrium

Structural Studies.-In [Sc(acac),], which has an only slightly distorted octahedral structure,' the apparent radius of the Sc"' ion is 0.68A and the intrachelate and interchelate 0-0 separations are 2.72 and 2.94-3.09 A, respectively (bond lengths, co-ordination numbers, and other structural comments are given in Table 1).The disilylamides, M(N(SiMe,),},, M = Sc or Eu, have an unusual pyramidal structure' in the solid state, but dipole moments in solution indicated a planar arrangement of the amide ligands. The bonding is regarded as predominantly ionic and this is consistent with bond length data; these are similar to those found in K[N(SiMe3),],2dioxan. The M-N-M bond angles are 115.5" (Sc) and 116.6" (Eu). Chemical Studies.-Mixed ligand complexes of scandium have been obtained3 containing edta and either Tiron, sodium 2,3-dihydroxynaphthalene-6sulphonate, or pyrocatechol. These mixed complexes are generally more stable than their yttrium analogues, but are more susceptible to hydrolysis. The stability of tartrate complexes has also been inve~tigated.~ Reaction of sodium with yttrium in liquid ammonia in the molar ratios 3: 1 and 1:1 under pressure and at moderate temperatures gave' Na,[Y(NH,)J and Na[Y(NH,),]. Y(NH,), was obtained from Na[Y(NH,),] and NH41, or from YI, and KNH, in liquid ammonia. Reaction of Y metal with ammonia under conditions different to those above gave YN. By heating [Sc(en),X,] (X = C1 or Br) in vacuo, cis-[Sc(en),X,]X was formed,6 but treatment of [Sc(en),Br,] with NH,X in vacuo gave [Sc(en),X,]. The enthalpy and entropy of vaporization of ScF, fell7 in the range 88.5088.57 ( f2.50) kcal mol- and 48.05-48.06 cal gm mol- at 298.25 K. Studies of the phase diagrams of ScX,-Sc (X = C1 or Br) revealed' the existence of Sc,X,, and Sc,Cl, could also be prepared by the reaction of Sc vapour with

'

'

T. J. Anderson, M. A. Neuman, and G. A. Melson, Inorg. Chern., 1973,12,927. J. S . Ghotra, M. B. Hursthouse, and A. J. Welch, J.C.S. Chem. Cornrn., 1973, 669. Z . Soylemez and U. Y. Ozer, J . Inorg. Nuclear Chem., 1973,35,545. K. K . Tripathy and R. K. Patnaik, J . Inorg. Nuclear Chem., 1973,35, 1050. A. Stuhr, H. Jacobs, and R. Juza, 2.anorg. Chem., 1973,395,291. M. R. Wagner and G. A. Melson, J . Inorg. Nuclear Chem., 1973,35,869. T. Petzel, Z . anorg. Chern., 1973,395, 1. B. C. McCollum, M. J. Camp, and J. D. Corbett, Inorg. Chem., 1973,12,778.

446

447

Scandium, Yttrium, the Lanthanides, and the Actinides

a 2 tJ

g

c

."!

Ld

a z

8

&

I

ea

.C(

c . '

a

a

%

B &8

. n

2

2

5 w

.d

8Y

8Y

Eil

.C(

w

4

t

nn

' "0

8x"

P4 m

ON

0

3

Y

c3

Y

v1

M

n

n m

Om

z"

v

h

a h

e .C(

(d

U

d

U

lnorganic Chemistry of the Transition Elements

448

ScC1,; Sc,X, is isomorphous with Gd,Cl,. The heats of formation of YOCl and TbOCl were found' to be - 238.6 and - 234.0 kcal mol- (at 298 K). Reaction of MC1, or MCl,,nTHF (M = Sc or Y) with the appropriate lithium reagent gave1*M(CH2QMe,),,2THF(Q = Cor Si),andSc(CH,SiMe,(o-MeOC,H,)},. The unexpectedly low co-ordination numbers were attributed to the bulk of the ligands. 2 The Lanthanides The metallic radii and electronic configuration of the 5f and 6d metals have been correlated," and are summarized in Tables 2 and 3. The set of radii Table 2 Metallic radii of lanthanide and actinide metals, and their electronic coujigurat ions No. of' f electrons 0 0 0

Metal

Na"

Nme

cs

1 2 3 3

1 2 3 3.1-3.8 3.8

2 2 2 2 2 3 2 2 2 2 2 3 3

3 3 3 2 3 3 3 3 3 3 2 3

0.2(3.8) 0.9( 3.1) 0.9(3.1) 2(3) 3 4 5 7 7 8 9 10 11 12 14 14

Ra

2

2

0

AC

3

3

0

4

4 4 5 4 6 6 6 7 7 7

0 0 0 1 0 0 0 0

Ba La Ce ci

P Y Pr Nd

Pm Sm ELI Gd Tb DY Ho Er Tm Yb Lu

Th u

P

Pa ci

P

uu

3

3

P Y NP

3

P Y

lo

3, 4, 5, 6, 7

0 0

F. Weigel and V. Wishnevsky, Chem. Ber., 1973,106, 1976. M.F.Lappert and R. Pearce, J.C.S. Chem. Comm., 1973,126. W.H.Zachariasen, .IInorg. . Nuciear Chem., 1973,35,3487.

Metallic radius (A, for 12 co-ord.) 2.719 2.236 1.877 1.707 1.827 1.824 1.828 1.821 1.811 1.804 2.041 1.802 1.781 1.773 1.765 1.756 1.747 1.940 1.735 2.293 1.977 1.798 ca. 1.80 1.642 1.775 1.542 1.548 1.548 1.503 1.511 ca. 1.53

449

Scandium, Yttrium, the Lanthanides, and the Actinides

Table %continued Metal

N,"

N,b

Pu c1

2

3, 4, 5, 6, 7

Nm'

P Y

Am u

P

Cm u

P

Bk u Cf Es

2 3 2

P 2 2

6.2 5.4 5.2 4.7 4.7 5.1 3.9 3.9 3.8 3.5 4.0 3.5

Metallic radius ( A ,for 12 co-ord.) 1.523 1.571 1.588 1.640 1.640 1.592 1.730 1.730 1.743 1.782 1.704 1.767

N o . of f electrons 1.8 2.6 2.8 3.3 3.3 2.9 5.1 5.1 6.2 6.5 7.0 7.5

(21, 3, (4) (2),3(4)

a No. of nonlf-electrons i n outer shell in gaseous atoms. No. of non-f-electrons in outer shell in solution or saturated solids.c No. of non-f-electrons in the metal.

Table 3 Predicted metallic radii for the elements Ra to Es, for diflerent numbers of non-f-electrons in outer shelf of metallic elements ( N , ; see 'Table 2) N m

2

3

4

1.977 1.798 1.767 1.90 1.88 1.87 1.86 1.86 1.84 1.83 1.81

1.642 1.748 1.734 1.723 1.715 1.709 1.704 1.689 1.679

5

6

7

1.622 1.610 1.601 1.594

1.542 1.532 1.530 1.526

1.503 1.499

Element

Ra Ac Th Pa U

2.293

NP Pu Am

2.10

Cm Bk Cf Es

2.03 2.01

refers to 12-co-ordination and is based on the observed atomic volumes of the metals. The empirical correlation between metallic radius, the number of bonding electrons, and number off electrons was used to deduce the metallic valence of these metals. The conclusions presented earlier' were generally confirmed for the elements Th -+ Np and deductions as to the metallic valence of the elements Fe 4 Es presented. Structural Studies.-The compound N a H 0 ( G e 0 ~ ) ~ 0 ~ was 0 H prepared13 l2

l3

W. H. Zachariasen, Acta Cryst., 1952, 5, 19, 660, 664; Norweg. Acad. Sci, (Oslo), Law of Mass Action Centenary Volume, 1964, 185. A. N. Christensen, Acta Chem. Scand., 1972, 26, 1955.

450

Inorganic Chemistry of the Transition Elements

hydrothermally from Ho(OH), and NaOH in a vessel previously used to make germanates. In the crystal there were two independent Ho atoms, each of which is seven-co-ordinate (0 atoms). The polyhedra are of the same type found in monoclinic HoO(OH),'~and one metal atom has six 0 atoms in a trigonal prismatic arrangement, the seventh being normal to a prism face. The other Ho atom has essentially the same geometry, but the seventh 0 atom is displaced so that the polyhedron could be described as a distorted cube, with one corner missing. The metal atom in [La(DMSO),(NO,),] is ten-co-ordinate,' having idealized D,, symmetry, being dodecahedral; the structure is similar to that in lanthanum carbonate octahydrate.16 In [Yb(DMSO),(NO,),], the metal atom is nine-co-ordinate," the co-ordination polyhedron being a slightly distorted face-centred trigonal prism (the NO, groups are bidentate). The Nd atom in Nd2(S0,),,8H,0 is eight-co-ordinate,18 four of the 0 donor atoms being contributed by two uni- and one bi-dentate SO, groups; the sulphato-groups bridge the Nd atoms. [Yb,(C,04),(H,0),],2H2019is isotypic with S C , ( C , O ~ ) , , ~ H , O , and ~~ the eight-co-ordinate Yb atom exists within a distorted dodecahedral polyhedron. The oxalato ligands are bridging. The structure of the nicotinic acid complex [Ho(C,H~NCO~H),(H,O)~][C~(NCS),],~H~O is that of a polymer made up of eight-co-ordinate Ho atoms2' (three acido ligands and two water molecules) linked by the carboxylato-groups. The acido ligands appear to be zwitterionic, with the proton attached to the N atom. The structure of [La(C H,NCO,H),( H o),]is broadly similar. is nine-coThe Pr atom in polymeric [Pr(N(CH,C0,),)(H,0)2],H20 ordinate, the co-ordination polyhedron being described either as a distorted, tricapped trigonal prism or as a distorted capped square antiprism.22 Each nitriloacetate ligand is septadentate with one carboxylato 0 atom co-ordinated to two adjacent Pr atoms, and two carboxylato 0 atoms co-ordinated to Pr atoms in adjacent molecules. In the related complex [Dy(N(CH,CO,),)(H20),],2H,0, the metal atom is eight-~o-ordinate,~~ with five carboxylato 0 atoms, two water molecules, and one N atom in the co-ordination sphere. Each nitrilotriacetate ligand is sexidentate but one carboxylato 0 atom is not co-ordinated to any metal; two carboxylato 0 atoms are co-ordinated to metal atoms in adjacent molecules. The co-ordination polyhedron is a distorted dodecahedron with triangular faces. l4

l6 l7 l8

l9 2o 21 22

23

A. N. Christensen, Acta Chem. Scand., 1965, 19, 1391. K. K. Bhandary and H. Manohar, Acta Cryst., 1973,29B, 1093. D. B. Shin and H. A. Eick, Inorg. Chem., 1968,7, 1340. K. K. Bhandary, H. Manphar, and K. Venkatesan, Cryst. Structure Comm., 1973,2, 79. L. A, Aslanov, V. B. Rybakov, B. M. Ionov, M. A. Porai-Koshits, and V. 1. Ivanov, Doklady Akad. Nauk S.S.S.R., 1972, 204, 508. E. Hansson, Acta Chem. Scand., 1973,27,827. E. Hansson, Acta Chem. Scand., 1972,26, 1337. J. Kay, J. W. Moore and M. D. Glick, Inorg. Chern., 1972,11,2818. L. L. Martin and R. A. Jacobson, Inorg. Chem., 1972,11,2785. L. L. Martin and R. A. Jacobson, Inorg. Chem., 1972,11,2789.

Scandium, Yttrium, the Lanthanides, and the Actinides

451 The 1:1 adduct formed between [Eu(dpm),] and 3,3-dimethylthietane 1-oxide has a wedged octahedron structure,', with the sulphoxide 0 atom occupying one of four positions in the octahedral plane. It was observed that the structure must raise questions as to the usual assumptions of axial symmetry for shift reagent complexes in solution (see below). The N atom in [Lu(dpm),(py)] occupiesz5 a vertex of the capped trigonal prism formed by the 0 , N donor atom set. The structure of [E~(dpm),(py),],~~ which is comparable to that of Ho(dprn),(4-pi~),,~~ is best described as a square antiprism containing a near two-fold axis. The Eu atom lies 0 . 3 4 . 4 A out of the molecular planes of four of the five ligands, and because of the low symmetry, t w o geometric factors are necessary to account for the observed 'H n.m.r. spectral shifts. The metal atom in [La(bipy),(NO,),] is ten-co-ordinate,28 since the nitrate groups are bidentate; the co-ordination polyhedron is best described as a bicapped dodecahedron. In LaFe(CN),,5H20 the cyanide groups bridge2' the six-co-ordinate Fe atom and the nine-co-ordinate La atom (surrounded by six N atoms and three HzO groups). The metal atom in the hexamethylphosphoramide complex, Pr(HMPA),Cl,, is octahedrally ~o-ordinated~', the amide being bonded uia one 0 atom. Reaction of LuC1, in THF with l-lithio-2,6-dimethylbenzene(Ar) gave3' [Li(THF),][LuAr,]. The crystal structure determination established the metal co-ordination geometry as tetrahedral. The structure of [K((MeOCHZCHz),O}][Ce(C8H8),] consists32of discrete [Ce(n-C,H,),]- ions in a contact ion-pair arrangement with the K+-diglyme cation; the rings are planar. Chemical Studies.-Reaction of Yb with sodium in liquid ammonia at 150 "C at 200 atm. gave3, Na,[Yb(NH,),], and single crystals could be obtained at 180 "C and 6000 atm. The species Na[Yb(NH,),] was obtained3, at 190 "C and 5000 atm. Hydrazine hydrate reacted35 with lanthanide(II1)ions in weakly acidic solution giving [La(NzH,)3X3],nHz0 (X = C1, n = 2; X = Br, n = 3), [ H4)6] 2 [ O4] 3,3H 2 O, [La(NzH4)3(OAc)3],4Hz0, and [ H4)(j (Cz0,),],5H20. Succindihydrazide (L) complexes36,MLzX3,nH20(M = La, Nd, Sm, Eu, Gd, Yb, and Y, n = 2, X = NO, or C10,; n = 3, X = Cl), in which the secondary amide N atoms were bonded to the metal, and tetra24

25 26 27

2a

29

30 31

32 33 34

35 36

J. J. Uebel and R. M. Wing, J . Amer. Chem. Soc., 1972,94, 8910. S. J. S. Wasson, D. E. Sands, and W. F. Wagner, Znorg. Chem., 1973,12,187. R. E. Cramer and K. Seff, Acta Cryst., 1972, B28, 3281. W. de W. Horrocks, J. P. Sipe, and J. R. Luber, J . Amer. Chem. SOC.,1971,93,5256. A. R. Al-Karaghouli and J. S.. Wood, Znorg. Chem., 1972,11,2293. W. E. Bailey, R. J. Williams. and W. 0.Milliyan. Acto C r v ~ t .1973. . B29. 1365. L. J. Padonovich and M. D. Glick, J . Inorg. Nuclear Chem., 1973,35,2745. S . A. Cotton, F. A. Hart, M. B. Hursthouse, and A. J. Welch, J.C.S. Chem. Comm., 1972, 1225. K. 0.Hodgson and K. N. Raymond, Znorg. Chem., 1972,11,3030. C . Hadenfeldt and H. Jacobs, 2. anorg. Chem., 1972,393, 11 1. A. Stuhr, H. Jacobs, and R. Juza, Z. anorg. Chem., 1973,398, 1. R. Ya. Aliev, M. N. Guseinov, A. D. Kuliev, and D. B. Musaev, Russ.J . Inorg. Chem., 1973,18, 199. N. K. Dutt and A. S. Gupta, Indian J . Chem., 1973,11, 180.

452

Inorganic Chemistry of the Transition Elements methyleneurea (tmu) [M(tmu),(NCS),] (M = La + Nd), [M(tmu),(NCS),] (M = Sm -+ Er, Y) and [M(tmu),(NCS),] (M = Tm ---* Lu) have been described. The shifts of the ethylenediamine proton resonances in [M(en)4]3+ (M = Ce + Ho) were i n t e r ~ r e t e din , ~terms of a contact mechanism, and calculations of geometric factors in terms of dodecahedra1 and square antiprismatic co-ordination geometry indicated that either model could be used to explain the spectral data. Ten-co-ordinate [M(napy),][ClO,], (M = Nd -+Eu) and 12-co-ordinate [M(napy),][ClO,], (M = La -+ Pr) have been obtained,' with 1,8-naphthyridine. A series of related nitrates. [M(napy),(NO,),] (tenco-ordinate, M = Sm + Yb, Y) and [M(napy),(NO,),] (12 co-ordinate, M = La --+ Nd) has also been r e p ~ r t e d . ~ ' Reaction of La, Laz03, and carbon under C O gave41 LaO,C, which, on hydrolysis, afforded mainly acetylene (the enthalpy of formation of the oxycarbide was - 320 f 2 kcal g atom- '). Neodymium(II1) oxide catalysed4, the conversion of para- and ortho-hydrogen in extrinsic magnetic fields. Treatment of NdCl, with NaOH in dry methanol afforded4, Na[Nd(OH),]. The hydroxychlorides M(OH),Cl (M = Eu, Tb, Dy, Ho, or Er) are isostruct ~ r a having 1 ~ ~ the monoclinic (all)and orthorhombic (Dy, Ho, and Er) modifications of Yb(OH),Cl. Hydrothermal treatment of the appropriate carbonates gave45 M,0,(C03) (M = Dy, Ho, Er, or Y ; p = 9.3, 10.7, 8.5, and 4.3 BM, respectively). By using Na,CO,, NaHCO,, trichloroacetic acid, and urea as precipitants in aqueous solution, the species M2(CO3),,8H20 (M = La or Ce; lanthanite type), M,(CO,),,nH,O (n = 2 or 3, M = Nd, Sm, Gd, Dy, Ho, Er, or Y ; tengerite type) and M,O(CO,),,nH,O (M = La, Ce, Nd, and Sm, n = 1 or 2; mono-oxocarbonate type) have been prepared;46 hydrated double carbonates (M = La, Ce, Nd, Sm, Gd, Dy, or Y) were also identified. Carbonates of the tengerite type, M,(CO,),,nH,O (M = Y, Er, Ho, or Gd) were obtained47 from MCl, and NH4(0,CCC13}. Cerium(1v)phosphate sulphates have been reduced48 to their Ce"' counterparts. CeH2P,0,,1.33H,0 was synthesized4' in the reaction of CeIV ions with H,P04, and has been used as an alkali-metal ion exchanger. Fusion of 37

38 39 40

'l 42

43

44

45 46

47 48

49

M. Perrier and G. Vicentini, J . Inorg. Nuclear Chem., 1973,35, 555. E. R. Birnbaum and S. Stratton, Inorg. Chem., 1973,12, 379. R. J. Foster, R. L. Bodner, and D. G. Hendricker, J . Inorg. Nuclear Chem., 1972,34, 3795. R. J. Foster and D. G. Hendricker, Inorg. Chim. Acta, 1972,6,371. A. D. Butherus and H. A. Eick, J . Inorg. Nuclear Chem., 1973,35, 1925. D. D. Eley, H.Forrest, D. R. Pearce, and R. Rudham, J.C.S. Chem. Comm., 1972, 1176. S. G. Malyugina, L. D. Borzova, B. N. Ivanov-Emin, B. E. Zaitsev, and A. I. Ezhov, Russ. J . Inorg. Chem., 1972,17, 1692. P. V. Klevtsov, L. Yu. Kharchenko, T. G. Lysenina, and K. A. Grankina, Russ. J . Inorg. Chem., 1972,17, 1512. A. N. Christensen, Acta Chem. Scand., 1973, 27, 1835. K. Nagashima, H. Wakita and A. Mochizuki, Bull. Chem. SOC.Japan, 1973,46, 152. H. Wakita and K. Nagashima, Bull. Chem. SOC.Japan, 1972,45,2476. K.-H. Konig and G. Eckstein, J . Inorg. Nuclear Chem., 1973,35, 1359. G. Alberti, U. Constantino, and L. Zsinka, J . Inorg. Nuclear Chem., 1972,34,3549.

Scandium, Yttrium, the Lanthanides, and the Actinides

453

rare earth sulphides with P,S,, at 700 "C gave5' the orthothiophosphates, MPS, (M = La -+ Sm). Treatment of Ce"' or Ce" ions with Na,H,IO, gave5' first CeH10,,3H20 which decomposed on heating into Ce,I,O, and Ce,I,O,. Reaction of M,O, with SO, gave5, M202(S04)(M = La -+ Sm); CeO, did not react in this way. The selenites M,(Se0,),,3H20 (M = La, Ce, Pr, Nd, Eu, or Gd) contained5, uni- and bi-dentate selenite groups. Lanthanum vanadate, LaVO,, is dimorphic, its crystalline form depending on the mode of pre~ipitation;~, from solution a hexagonal form isomorphous with other lanthanide vanadates could be obtained, and on heating the precipitates obtained from solution, a monoclinic modification could be prepared. Comparison of the dimorphic forms of a series of lanthanide chromates, arsenates, phosphates, and vanadates, MXO,, led to a correlation between the radius of M3+ and that of Xv, and it was predicted that PmAsO, would exhibit dimorphism. Reaction of Eu,O, or EuO with VO, gave55 Eu,VO, which decomposed on heating in oacuo into Eu,V,O, and EuO, and then EuVO,; in oxygen, Eu,VO, decomposed giving EuVO, and Eu,O,. Reaction of EuO with V 2 0 3 afforded E u , V O ~ . The ~ . Raman spectra of CsLa(CrO,), and CsM(CrO,),,H,O (M = Pr -+ Gd) indicated56 that the chromate ion was bonded covalently to the lanthanide atom. From the system M(NO,),,KOH, and K,MoO, in water, the basic molybdates M(OH)(MoO,),nH,O (n = 1, M = Gd -+ Lu; n = 2, M = Sm, Eu, or Tm) were obtained,57 and a similar yttrium monohydrate was also isolated. Reaction of M,O, with MOO, afforded5*M,O,(MOO,)~ ( n = 1,2,3, or 4) depending on reaction temperature (M = La -+ Lu). The pertechnates, M(TcO,),,nH,O (M = Pr, n = 3 or 4; M = Nd, n = 4) have been prepared5' and may be progressively dehydrated to M(TcO,), on heating. The electron transfer spectra of M4+, obtained by dissolving lanthanide (Tb or Pr) oxides (less than 1 mole%) in ZrO,, have been measured;60 the substantial difference between these spectra and those obtained in T h o , was related to differences in the ionic radii of Zr4+ and Th4+. Using 'H n.m.r. spectral studies at low temperature, the hydration number of

V. V. Yampol'Skaya and V. V. Serebrennikov, Russ. J. Inorg. Chem., 1972,17, 1771. A. H. Lokio, Actn Chem. Scnnd., 1973,27, 146. s 2 A. A. Grizik, N. G. Abdullina, and N. M. Garifdzhanova, Russ. J. Inorg. Chem., 1973,18, 313. s3 K. I. Petrov, Yu. M. Golovin, M. B. Varfolomeev, and E. M. Remennik, Russ. J. Inorg. Chem., 1973, 18, 201. " R. C. Ropp and B. Carroll, J. Inorg. Nuclear Chem., 1973,35, 1153. 5 s T. Shin-Ike, G. Adachi, and J. Shiokawa, Bull. Chem. SOC.Jnpnn, 1973,46, 1878. 5 6 Yu. M. Golovin, V. V. Kravchenko, K. I. Petrov, and T. I. Kuzina, Russ. J . Inorg. Chem., 1972, 17, 1693. A. P. Perepelitsa and V. N. Solomakha, Russ. J . Inorg. Chem., 1973, 18, 14. M. V. Mokhosoev, E. I. Get'man, F. P. Alekseev, and S. N. Loboda, Russ. J. Inorg. Chem., 1973, 18, 312. 5 9 L. L. Zaitseva, A. V. Velichko, P. N. Petrov, and N. T. Chebotarev, Russ. J. Inorg. Chem., 1972,17, 1379; L. L. Zaitseva, A. V. Velichko, and N. T. Chebotarev, ibid., p. 1382. 6 o N. van Vugt, T. Wigmans, and G. Blasse, J. Inorg. Nuclear Chem., 1973,35,2601. 50

51

''

454

Inorganic Chemistry of the Transition Elements

lanthanide cations, and their complexes formed with anions, were studied6' in water-acetone mixtures. The minimum hydration number for the ClO, salts of Lu, Er, Yb, Pr, Nd, and Ho was 6 , 6 or 7,6 or 7 , 6 , 6 , and 3, respectively, and for the NO, salts of Tb, Dy, and Tm, 2, 3, and 2, respectively. There was considerable evidence for ClO, and NO, co-ordination. Using ultrasonic relaxation techniques, differences of solvation of Er(NO,), and ErC1, in water and methanol have been established.6 Thermodynamic parameters for the formation of MIO;' (M = lanthanide ion) in aqueous solution were consistent63 with inner sphere co-ordination. The relative tendencies of outer versus inner sphere co-ordination were found to be a function of the basicity of the ligand. Thus ligands whose acids had pKa values less than 1 (ClO,, C1-, NO,, or SCN-) mainly formed outer sphere complexes whereas those whose acids had pK, values greater than 1 (IO;, F-) formed mainly inner sphere complexes. The aluminium isopropoxide complexes M[Al(OPr'),], (M = La-Lu, Y, and Sc, not Pr) were obtained64hy the following reactions: MC1,,3PriOH with KAl(OPr'), in propan-2-01, M(OPr'), with Al(OPr'), in the same solvent, and MC1, with AlC1, and potassium in Pr'OH. The proposed structure of the

1 -Al-OPr'

.

I

-Al

I isopropoxide complexes is shown in (1); attempts to isolate Ce(OPr'), were unsuccessful. Mixed ligand complexes containing 2,3-dihydroxynaphthalene and edta have been obtained6' with La, Ce, Pr, Nd, Sm, Eu, and Gd. The nitrates K3M(N0J9 (M = Pr, Nd, Sm, or Er) have been prepared,66 and the Pr complex is 12-co-ordinate (six NO, groups bidentate) with a distorted icosahedral geometry. Spectral studies e ~ t a b l i s h e d that ~ ~ in M(NO,),,nH,O (M = Tb, Dy, Ho, Er, Tm, or Yb; n = 4 or 6) both the NO, and H,O groups

61

62

63 64 65

66 67

A. Fratiello, V. Kubu, and G. A. Vidulich, Inorg. Chem., 1973, 12,2066. J. Reidler and H. B. Silber, J.C.S. Chem. Comm., 1973, 354. G. R. Choppin and S. L. Bertha, J . Inorg. Nuclear Chem., 1973,35, 1309. R. C. Mehrotra, M. M. Agrawal, and A. Mehrotra, Synth. Inorg. Metal Org. Chem., 1973,3, 181. N. S. Poluektov, L. A. Alakaeva, and M. A. Tishchenko, Russ. J. Inorg. Chem., 1973,18,40. W. T. Carnall, S. Siegel, J. R. Ferraro, B. Tani, and E. Gebert, Inorg. Chem., 1973,12, 560. B. N. Ivanov-Emin, Z. K. Odinets, B. E. Zaitsev, A. I. Ezhov, and K. Del'pino, Russ. J. Inorg. Chem., 1972,17, 1517.

Scandium, Yttrium, the Lanthanides, and the Actinides

455

were co-ordinated. The heats of formation of M:M~(N0,),,,24H20 (M' = Mg, Zn, Cu, or Co; M2 = La or Ce) have been measured.68 Complexes of ethoxypyridino-2-phosphonates(2) were obtained69 by treating the diethoxyphosphonates with MCl, (M = Ce + Yb).

Dimethylformamide adducts of the perrhenates, La(DMF),(ReO,), and M(DMF),(ReO,), (M = Ce + Lu or Y), have been de~cribed.~'In N N dimethylacetamide, La"', Pr"', and Nd"' underwent polarographically an irreversible three-electron r e d ~ c t i o n , ~whereas the tervalent ions of Gd to L y except for Sm, E y and Yb, gave rise to an irreversible threeelectron reduction with a pre-wave. SmIII, Ed1', and Yb"' were reduced in two steps, the first being a reversible one-electron process and the second irreversible formation of Mo. The urea in the complexes [M(CO(NH2)2)3(0Ac),],1.5H,0 (M = La -+Sm) is O - b ~ n d e d . ~Diacetamide , (da)', and di-n-butyramide (db)74 complexes, [M(da)4(C104)3] (M = La, Nd, Gd, Ho, or Yb) and [M(db),(ClO,),] (M = La -+ Lu, or Y) have been reported, and the antipyrine [(3) ap] complexes, [M(ap),][BPh,], (M = La, Pr, Nd, Sm, Gd, Dy, Er, or Yb) are apparently six-co-ordinate.7 5 In the insoluble 2,5-piperazinedione(L) Me

68

69 70

71 72

l3

74 75

E. I. Guzhavina, K. Ya. Mishin, V. K. Filippov, and M. A. Yakimov, Russ. J . Inorg. Chem., 1973, 18, 189. N. N. Speza, N. M. Karayannis, and L. L. Pytlewski, Inorg. Chim. Acta, 1972,6,639. M. B. Varfolomeev, V. V. Kravchenko, A. L. Mayants, V. E. Plyuschev, and K. I. Petrov, Russ. J. Inorg. Chem., 1973,18,349. M. Aihara and S. Misumi, Bull. Chem. SOC.Japan, 1973,46, 175. Yu. G. Sakharova, L. F. Firsova, I. Ya. Evtushenko, and N. N. Sakharova, Russ. J . Inorg. Chem., 1973, 18, 343. C. Airoldi and Y. Gushikem, J . Znorg. Nuclear Chem., 1972,34,3921. Y. Gushikem, C. Airoldi, and 0. L. Alves, J . Inorg. Nuclear Chem., 1973,35, 1159. R. W. Bashioum, R. L. Dieck, and T. Moeller, Inorg. Nuclear Chem. Letters, 1973,9,773.

456

Inorganic Chemistry of the Transition Elements

complexes ML,(C104), (M = La .-+ Er, or Y) the ClO, groups were apparently co-ordinated.76From thermodynamic data, it was apparent that the 1 .1 and 1 :2 lanthanide(rI1) (La, Pr, Sm, Gd, Ho, or Er) o-(2-thiazolylazo)cresol complexes were of the inner sphere type.’ A series of double sulphates C S ~ ( S O ~ ) , M ~ ( S O ~ )has ~ , ~been H,O described7g and a comparative study made of some lanthanide andactinide sulphates ;79 the majority of the lanthanide sulphate complexes were of the outer sphere type. Sulphoxide complexes containing trans-1,4-dithiane 1,4-dioxide (tdtd)gO and tetramethylenesulphoxide (TMSO),gl La(tdtd),(C10,),,5H20,M(tdtd),(C10,),,3H20(M = Nd, Tb, Er, Lu,or Y),M(TMSO),(N03)3 (M = La or Ce), M(TMSO),.,(NO,), (M = Pr, Nd, Sm, or Eu), and M(TMSO),(NO,), (M = Gd -,Lu, or Y)have been prepared. A series of carboxylates, M(O,CR), (R = alkyl, phenyl, CH,CI, CHCl,, or CC1,) has been synthesized” and shown to decompose thermally into M,O,(CO,) and M 2 0 3 (M = Pr, Nd, or Sm). 1.r. spectral studies of lanthanide (Pr -+Lu, except Eu, Gd, Sm, and Tb) propionates indicatedg3 that the M-0 bonds were only slightly covalent. By controlling experimental conditions, the formation constants of Dy(OAc), + and Dy(0Ac); were obtained,g4 and that for the latter was greater than that for the former; it was not known whether the acetate was uni- or bi-dentate. A series of o-sulphobenzoates M,(C,H,O,S),,nH,O (n = 11-16, M = La + Sm) has been described.” Fumarate complexes of the lanthanides are more stable than their maleate counterparts.g6 Thermodynamic parameters have been obtainedg7 from stability constant studies of malonate and hydrogen molanate complexes. At pH values less than 1.6, citric acid (citHj) forms the neodymium complex, Nd(citH,)’+, but at pH values above 1.6, Nd(cit) was precipitated.gg This redissolved at pH 6.6 giving a hydroxocitrato-complex, but, at high citric acid concentrations, [Nd(cit),] - was formed. Lanthanide oxalatochlorides, M(02C,0,)C1,3H,0 (M = Pr, Nd, or Sm), were dehydratedg9 giving MOCl, but the Eu complex gave Eu(C,O,) and then Eu,(C,O,),O, whereas Ce(C,O,)Cl afforded Ce(C,O,)O and then CeO,. Stability constants have been obtained for HoIn and Yb” ethylenediamine

76

” 78

79 ‘O

” 83 84

85

86

87 89

J. C. Prado and G. Vicentini, Inorg. Nuclear Chem. Letters, 1973,9,693. F. Kai, Y. Sadakane, H. Yokio, and H. Aburada, J . Inorg. Nuclear Chem., 1973,35,2128. L. D. Iskhaklva, V. E. Plyushchev, and N. B. Berlin, Rum. J . Inorg. Chem., 1973, 18, 363. A. V. Stepanov, Russ. J . Inorg. Chem., 1973,18, 194. R. Najjar and G. Vicentini, Inorg. Nuclear Chem. Letters, 1973,9, 577. G. Vicentini and L. B. Zinner, J . Inorg. Nuclear Chem., 1973,35, 215. ’ R. C. Paul, G. Singh, and J. S. Ghotra, Indian J . Chem., 1973, 11, 294. K. I. Petrov, M. G. Zaitsev, and V. E. Plyushchev, Russ. J . Inorg. Chem., 1973,18,356. M. Doyle and H. B. Silber, J.C.S. Chem. Comm., 1972, 1062. S. B. Pirkes, R. T. Buchkova, E. A. Didenko, and M. T. Shestakova, Russ. J . Inorg. Chem., 1972, 17, 1535. G. R. Choppin, A. Dadgar, and R. Stampfli, J . Inorg. Nuclear Chem., 1973,35,875. I. Dellien, Acta Chem. Scnnd., 1973,27, 733. L. G. Tebelev, V. M. Levedev, and V. M. Mikolaev, Russ. J . Inorg. Chem., 1973, 18, 35. A. M. Mulokozi and F. Weigel, J . Inorg. Nuclear Chem., 1973,35, 1487.

Scandium, Yttrium, the Lanthanides, and the Actinides

457

disuccinates and as par ate^,^' and for lanthanide ethylenediamine NN’diglutarates.” Stability constants and appropriate thermodynamic functions were also obtained9, for Pr, Eu, Ho, and Lu iminodiacetates (AH,), e.g. M(A),3- 2 n (n = 1 + 3). Protonated methyliminodiacetates (MeAH,),’, e.g. M(HMeA),(NO,) (M = La -+ Sm) and monoethylenediamine diacetatesg4 (H,E), e.g. M(E)Cl,nH,O (M = La -+ Yb, except Eu) have been isolated; in the latter the M-O bond is essentially ionic whereas the M-N bond is partly covalent. Unit cell dimensions have been reported9’ for M(A)C1,3H20 (M = Pr -+ Lu). No appreciable polymerization occurredg6in concentrated aqueous solutions of La or Nd hydroxonitrilotriacetates but, with the heavier lanthanides, dimerization, uia hydroxo bridges, occurred in dilute solution. A series of mixed ligand chelate complexes was obtainedg7with Ho and Er and 5-sulphosalicylate (ssa) and edta, N-hydroxyethylethylenediamine-triaceticacid, 1,2diaminocyclohexanediamine-tetra-acetic acid (Y), i.e. [M(Y)(ssa)], and iminodiacetic acetate, hydroxyethyliminodiacetic acid and nitrilotriacetic acid, [M(Y)(ssa),] ;with higher carboxylates, no mixed chelate complexes were produced. In the presence of an excess of hydroxyethylethylenediamine triacetic acid (H,A), [Eu(A)(HA)I2- was formed.98 Lanthanum(n1) formed” 1 :1 complexes with nitrilotriacetic acid and 8-hydroxyquinoline, or 2-picolinic acid and 8-hydroxyquinoline-5-sulphonicacid. Reaction of MCl, (M = Eu or Er) with Na,edta or of M,O, with H4edta gives‘” NaEM(edta)- and HEM(edta), respectively. The structures of the two forms of [Eu(edta)]- in solution correspond to those of the crystalline forms isolated. Thus they differ in the number of ligand donor atoms coordinated (five or six) and number of molecules of water of hydration (three and two or one). In [Er(edta)]-, the ligand i s six-co-ordinate, and one form contained no water whereas the other is a monohydrate. The labilities of the metal-donor atom bonds in La and Lu edta complexes have been studied”’ by ‘23 n.m.r. spectroscopy. The M-0 and La-N bonds were labile, whereas the Lu-N bond had a long lifetime. The exchange of ligands in the La edta complex was catalysed by OH-. With cyclohexanediaminetetracetic acid, Eum formed102 1: 1, polymeric, 1 :2, and hydroxo-complexes. 0. P. Sunar, S. Tak, and C. P. Trivedi, J . Znorg. Nuclear Chem., 1973,35,314. I. P. Gorelov and V. A. Babich, Russ. J. Inorg. Chem., 1973, 18,440. 92 I. Grenthe and G. Gardhammer, Acta Chem. Scand., 1972,27,3207. 9 3 V. P. Khramov, G. A. Aliev, and L. V. Dvornikova, Russ. J . Inorg. Chem., 1973,18, 340. 94 N. I. Sevost’yandva,L. I. Martynenko, and V. I. Spitsyn, Russ. J . Inorg. Chem., 1972, 17, 1689. 9 5 A. Oskarsson, Acta Chem. Scand., 1972,26, 2126. 96 N. I. Snezho, L. V. Anan’eva, N. I. Pechurova, L. I. Martynenko, and V. I. Spitsyn, Russ. J. Znorg. Chem., 1972,17, 1539. 97 T. Taketatsu and S. Yoshida, J. Inorg. Nuclear Chem., 1973,35, 881. 98 N. N. Tananaev, E. Bryukher, and N. A. Kostromina, Rum. J . Znorg. Chem., 1972,17, 1683. 9 9 R. C. Sharma and J. P. Tandon, Indian J . Chem., 1973,11, 374. l o o T. V. Ternovaya and N. A. Kostromina, Russ. J . Inorg. Chem., 1973,18, 190. T. Ryhl, Acta Chem. Scand., 1972,26,4001. N. N. Tananaeva and N. A. Kostromina, Russ. J . Znorg. Chem., 1973,18,352. 90

91

Inorganic Chemistry of the Transition Elements

458

Fresh evidence has been presentedlo3 to show that the primary N atom in protonated lanthanide histidinates is the one carrying the extra proton. Stability constant data have been obtained for lanthanide (La, Ce, Pr, Nd, or Y) I-asparginates and l-glutaminates;lo4for a series of some di- and tri-peptide complexes103 (Nd, Eu, Gd, Ho, and Yb), and for 7-bromo-S-hydroxy-5quinolinesulphonates (La -+ Lu, Y).' O6 Lanthanide(II1) acetates reacted' O7 with pyridine-2,6-dicarboxylic acid (dpcH,) giving two series of complex: M(dpc)(dpcH),6H20(M = La -,Sm, Gd, or Tb) and [M(dpcH),],H,O (M = Sm, Gd -+ Ho, or Yb). Within each series the complexes are apparently isostructural (X-ray powder data). X-Ray photoelectron spectral studies of [M(dpc)(dpcH)],6H2O (M = Ce or Pr) and [Dy(dpcH),] indicated that there was no ligand decarboxylation, all N atoms were co-ordinated, no distinction could be made between the different 0 atoms, and no significant differences could be detected between the Ce and Pr complexes on one hand and the Dy species on the other (attempts to determine the 4s bonding energies in the Ce, Pr, and Dy complexes were unsuccessful). However, on the basis of the recent structural determination1 O 8 of Na, [Yb(dpc),],H,O, it was proposed that the P-form of [Sm(dpc)(dpcH)],6 H 2 0 and [M(dpc)(dpcH)] (M = Ce, Pr, or Gd; obtained by dehydration of the hexahydrates) contain the structural unit shown in (4). Thus, these complexes are polymeric by virtue of the bonding of three carboxylato 0 atoms to each metal centre. The environment at the metal atom comprises two N atoms, three carboxylate 0 atoms from dpc and dpcH, one additional carboxylate 0 atom from dpcH, and a further three carboxylate 0 atoms from adjacent molecules. For the a-form of the Sm complex, and for the remaining [M(dpc)(dpcH)],6H,O, a broadly similar structure can be proposed, but containing a modified unit as shown in (5). The species [Dy(dpcH),] is nine-co-ordinate, containing three fully co-ordinated dpcH - ions. The failure of the anhydrous compounds to react with pyridine indicated that they were co-ordinatively saturated.

(4)

lo3

Io4 lo5 lo7

(5)

A. D. Jones and D. R. Williams, Inorg. Nuclear Chem. Letters, 1972,8, 1009. R. C. Tewari and M. N. Srivastava, J. Inorg. Nuclear Chem., 1973,35, 3044. P. Feige, D. Mocker, R. Dreyer and R. Munze, J . Inorg. Nuckar Chem., 1973,35, 3269. G. S. Manku, Bull. Chem. SOC.Japan, 1973,46,1704. D. L. Hoof, D. G. Tisley, and R. A. Walton, J.C.S. Dalton, 1973,200. .I.Albertsson, Acta Chem. Scand., 1970,24, 1213.

Scandium, Yttrium, the Lanthanides, and the Actinides

459

The magnetic properties of [Pr,(thd),] (p = 3.36 BM) have b e e n m e a s ~ r e d ' ~ ~ over a temperature range. Nd"' and La"' acetylacetonates formed'" 1 :1 adducts with bidentate bases, viz. 2,T- and 4,4'-bipyridyl, o-phenanthroline, ethylenediamine, propylenediamine, and 1-amino-2-hydroxypropane.The salts [CsM(hfa),] (M = Eu and La) have been prepared"' from [M(hfa),] and [Cs(hfa)] using cation exchange techniques. The fluorescence spectra of [C5H1,NH,] [M(ArCOCHCOR),] [M = La, Pr, Nd, or Eu; Ar = (1-FC6H4, 4-F-(2,3, or 5)-MeC6H,, or 2- or 3-ClC&,; R = Me, Et, or Ph], have been examined1l2 in the solid state at 77 K. Correlations were drawn between these spectra and possible site symmetries in the Eu3+ complex (all species are eight-co-ordinate). Stepwise equilibrium constants and derived thermodynamic parameters for the reaction of [M(ttfa),] with 2,2'-bipyridyl showed"3 that up to two molecules of base could be added. The stepwise heats and entropies of addition depended on the ionic radius of MI*' (La, Nd, Gd, or Lu), and the adducts were stabilized by large exothermic enthalpy changes. One and two molecules of tributylphosphate could be added to [Eu(ttfa),].' l4 Reduction of the appropriate trifluorides, sesquisulphideq and Eu,03 with gaseous lanthanide metals afforded' l 5 highly pure SmF,, EuF,, YbF,, SmS, YbS, and EuO. 1.r. spectral studies have been made'I6 of fluoro- and fluorochloro-carbons adsorbed on ErCl, and ErF, ; bonding was presumed to occur between the F-atoms and the metal. Reaction of Ce'" carbonate with peroxydisulphuryl difluoride gave'I7 CeO(SO,F),, and with CeF,, CeF,(SO,F) was formed. Treatment of La,O, with KBF, in molten KCl afforded"* KLaF,. The compound previously known as GdCll.5, * o.06 has been identified'" as Gd,Cl,, in which [Gd:' (C1-),Jn units are thought to be present. The compound contains infinite chains of Gd atoms which are octahedrally co-ordinated by the C1 ions, each octahedron sharing opposite edges with neighbours thereby forming elongated chains (shortest Gd-Gd distance is 3.35A). Heats of vaporization of NdC1, and GdCl, have been obtained120 from mass spectral studies, and enthalpy changes in the dissocation of anhydrous YCl,, TbCl,, and ErCl, determinedI2' over the range 0-100 "C. The electronic absorption spectra of [EuCl6J3- and Eu(HA) (HA = di-2-ethylhexylphosphoric acid) have been obtained12' in ethanolic HCl and in the log 'lo

li2

115

11*

li9 120 122

B. Kanellakopulos and C. Aderhold, Inorg. Nuclear Chem. Letters, 1973,9, 121. I. Yoshida, H. Kobayashi, and K. Ueno, Bull. Chem. SOC.Japan. 1973.46. 2140 C. E. Higgins, J . Inorg. Nuclear Chem., 1973,35, 1941. K. C. Joshi and V. N. Pathak, J . Inorg. Nuclear Chem., 1973,35,3161. A. S. Kertes and E. F. Kassierer, Inorg. Chem., 1973,11,2108. K. Akiba, J . Inorg. Nuclear Chem., 1973,35,2525. T. Petzel and 0.Greis, Z . anorg. Chern., 1973,396,95. M. D. Taylor and T.-T. Cheung, J . Inorg. Nuclear Chem., 1973,35,3499. R. Dev, W. M. Johnson, and G . H. Cady, Inorg. Chem., 1972,11,2259. V.K. Pyrina and M. E. Prostakov, Russ. J . Inorg. Chem., 1973,18, 348. D. A. Lokken and J. D. Corbett, Inorg. Chern., 1973,12,556. S. Clach, A. J. C. Nicholson, D. L. Swingler, and R. J. Thistlethwaite, Inorg. Chem., 1972,12,2072. G. A. Krestov, V. A. Kobenin, and S. V. Semenovskii, Russ. J . Inorg. Chem., 1973,18, 1. Yu. A. Barbanel' and N. K. Mikhailova, Russ. J . Inorg. Chem., 1973,18,365.

460

1norganic Chemistry of the Transition Elements

phosphoric acid diluted with decane. A series of phenylhydrazine (L) complexes ML,Cl,,H,O(M = Eu -+ Lu) has been prepared',, and complements a similar series describedlz4 for the earlier lanthanides (La + Sm, Y); these compounds are best formulated as [ML2(H2O)C1I2+.A series of benzidine (L') complexes'25 ML' C1,,2THF (M = Eu + Lu), which contained sixco-ordinated M, and o-tolidine (L2, 4,4'-diamin0-3,3'-dirnethyldiphenyl),l~~ [ML2(H20),C1]C1 (M = La -+ Lu, Y) has also been described. In [M(bipy),(N0,),],2H20 (bipy = 4,4'-bipyridyl; M = La, Nd, Sm, Tb, or Er) the metal atom is probably ten-co-ordinate, with bidentate nitrate groups and water bonded to the whereas [M(bipy)Cl,] (M = Nd, Sm, or La) and [Er(bipy)C1,],4H20 are probably polymeric. Treatment of lanthanide bromides with o-phenanthroline in mole ratio 1 :3.5 afforded12' [M(phen),Br,],x H 2 0 (M = La -+ Lu, Y; x varying from 5 to 10, predominantly 9); with an excess of phen, [M(phen),Br3],9H,O (M = Nd or Sm) was obtained whereas, with a deficiency of phen, [M(phen),Br,],xH,O (M = Pr, x = 12; Sm, x = 9 ; Dy, x = 2, Er, x = 4)was formed. Reaction of NH,CN with liquid ammonia solutions of Ce, Pr, Sm, Ho, Eu, or Yb afforded129crystalline M(CN), (all) and M(CN)2 (M = Sm, Eu, or Yb), although these could alternatively be prepared from Hg(CN), and the metal in uacuo. EuCN has been observed13' at high temperatures in a mass spectrometer. Reaction of [Ce(n-C,H,),Cl] and [Ce(n-C,H,),Cl,] with NaBH, in respectively; THF afforded' 3 1 [Ce(n-C,H,),BH,] and [Ce(n-C,H,),(BH,),], these borohydridec contain Ce-H-B bridges. Lanthanide Shift Reagents.-The use of lanthanide shift reagents in 'H n.m.r. spectroscopy has been reviewed.',, It has been suggested133 that the simultaneous use of a shift reagent with a relaxation reagent might overcome resolution and interpretation problems. Thus [Gd(fod),] has a long electron spin relaxation time and a highly isotropic magnetic moment but causes only broadening of n.m.r. signals without alteration of chemical shifts, whereas [Eu(fod),] effectively functions as the shift reagent. The susceptibility of [Eu(dpm),] in solution was lower than that in the solid state, and decreased',, with increasing co-ordination ability of the solvent or added substrate. The magnetic properties of the complex in solution were also dependent on the presence or absence of dimers and the co-ordination number and geometry of

lZ4 lZ5

lZ6 12'

13' 13'

133 134

S. M. F. Rahman, J. Ahmad, and M. M. Haq, J . Inorg. Nuclear Chem., 1973,35, 1011. S. M. F. Rahman, J. Ahmad, and M. M. Haq, J . lnorg. Nuclear Chem., 1971,33,4351. S. M. F. Rahman, J. Ahmad, and M. M. Haq, J . lnorg. Nuclear Chem., 1972,35, 1707; ibid., 1972, 34, 1460. S. M. F. Rahman, J. Ahmad, and M. M. Haq, J. Inorg. Nuclear Chem., 1973,35,3349. A. Anagnostopoulos, J. lnorg. Nuclear Chem., 1973,35, 361 1. N. I. Lobanov, Russ. J. Inorg. Chem., 1972, 17, 1491. I. J. McColm and S . Thompson, J. lnorg. Nuclear Chem., 1972,34, 3801. D. L. Cocke, K. A. Gingerich, and J. Kordis, J.C.S. Chem. Comm., 1973, 561. S. Kapur, B. L. Kalsotra, R. K. Multani, and B. D. Jain, J . Inorg. Nuclear Chem. 1973,35, 1689. R. van Ammon and R. D. Fischer, Angew. Chem. lnternat Edn., 1972,11,657. G. N. La Mar and J. W. Faller, J . Amer. Chem. Soc., 1973,95, 3817. D. Schwendiman and J. I. Zink, lnorg. Chem., 1972,95,3051.

Scandium, Yttrium, the Lanthanides, and the Actinides

46 1

the substrate. 1-Adamantane was used as a substrate molecule to show that the dipolar shift mechanism was dominant, but that a substantial scalar mechanism may contribute to the shift of protons close to the source of unpaired spin density. S t ~ d i e s ' ~of ' complexes formed between [Eu(dpm),] or [Eu(fod),] and diacetoneglucose, aniline, and compound (6) have revealed that, whereas the

c1

Cl

v

c&:

c1

H

ligand in the first was rigid at the point of attachment to Eu, the other two were not. Thus shift ratios for the aniline complex could not be accounted for by any rigid model for the complex. It was that for magnetically anisotropic lanthanide complexes, the pseudo-contact contributions to the induced shift may, under certain particular conditions, be described by the usual mathematical expressions (see ref. 150) even when the susceptibility is not axially symmetric. It was found,137however, by using [Pr(fod),] or [Eu(fod),] with borneol and isoborneol, that there was an orientational effect on the shift ratios, since the metal ligand axis was not collinear with the magnetic axis. A study of [Eu(dpm),(3-pic),] showed13' clearly that the n.m.r. data could not be interpreted in that system on the assumption that the magnetic and Eu-N axes coincided. Chemically induced dynamic polarization has been observed13' in the presence of [Eu(fod),] and [Pr(fod),]. Gas chromatographic studies of ethers, ketones, alcohols, esters, olefins, and alkanes, using columns with liquid phases containing P-diketonate complexes in squalane, revealed14' that the more nucleophilic organic substrates reacted more strongly with the P-diketonates than the less basic ones. Er"' complexes of fluorinated P-diketones (especially 3-trifluoroacetyl-d-camphorate, facam) reacted more strongly with these nucleophiles than did similar non-fluorinated Er'" complexes. The retention time of THF increased exponentially with the inverse of metal ionic radius in the facam chelates of a variety 135 13' 13' 13* 139

I. M. Armitage, L. D. Hall, A. G. Marshall, and L. G. Werbelow, J. Amer. Chem. SOC., 1973,95, 1437. J. M. Briggs, G. P. Moss, E. W. Randall, and K. D. Sales, J.C.S. Chem. Comm., 1972, 1180. G. E. Hawkes, D. Leibfritz, D. W. Roberts, and J. D. Roberts, J. Amer. Chem. Soc., 1973,95, 1659. R. E. Cramer and R. Dubois, J. Amer. Chem. SOC.,1973,95,3801. . J. Bargon, J. Amer. Chem. SOC., 1973,95,941. B. Feibush, M. F. Richardson, R. E. Severs, and C. S. Springer, jun., J. Amer. Chem. SOC., 1972, 94, 6717.

462

lnorganic Chemistry of the Transition Elements

of lanthanides. In squalane, [Tb(facam),] appeared to be dimeric, whereas [Er(dpm),] was monomeric and had a trigonal prismatic structure. To explain the experimental results, a reaction scheme was proposed involving the dissociation of a fused monocapped trigonal prismatic dimer in solution to give a trigonal prismatic monomer which then co-ordinated the substrate, thereby forming a monocapped trigonal prismatic 1 : 1 adduct. With [Eu(dpm),], 3,3-dimethylthietane 1 -oxide and DMSO gave 1 : 1 adducts, which had near perfect wedged octahedral structures, the Lewis bases occupying one of four equivalent positions of lowest ~ y m m e t r y . The ' ~ ~ species [M(dpm),] (M = La, Pr, Eu, Er, Ho, or Lu) were monomeric in dry CCl, and 1 :1 adducts were formedf4' with pyridine, borneol, and neopentanol. However, lanthanide shift reagents (L) could react with substrates (S) by a two-step mechanism, viz.

L

+ S + LS, and LS + S + LS,

and this has been confirmedl4, by a detailed study of the shifts of 3-(p-chlorophenyl)-3,5,5-trimethylcyclohexanone caused by [Eu(fod),]. Evidence for 1 : 1 and 1:2 adducts in solution was obtained from the systems [Eu(fod),]n ~ r c a m p h o r , [' Pr(fod),]-borneol,' ~~ 45 [Eu(fod),]-optically active alcohols,l 46 [M(fod),] (M = Pr, Nd, Tb, Er, or Yb) or [M(dpm),] (M = Pr or Eu), [M(fod),] (M = Pr or Eu), [Pr(tta),]- or [Eu(hfac),]-HMPA-DMSO, or -Et3N,147and [Eu(fod),]-acetone, DMSO, propan-2-01, or P-pic01ine.l~~ The pseudo-contact shifts recordedf4' for the 1 : 1 adduct of [M(dpm),] (M = Eu, Pr, or Yb) with o-phenanthroline or 2,2'-bipyridyl were not in accord with the Robertson-McConnell expression,' which assumed axial symmetry about the metal Lewis-base bond. The spectra of the phen complexes were relatively insensitive to variations in temperature, whereas the temperature variations of the spectrum of [M(dpm),(bipy)] could be explained by biphenyltype rotational isomerism of unidentate bipy. Further co-ordination by substrates added to [M(dpm),(phen)] and its bipy analogues was not observed. In addition to 1 : 1 and 1:2 adducts, the system [M(fod),]-(7c-C5H5)Fe(CO),CN] (M = Pr, Eu, Ho, or Yb) also contained15' 1:3 adducts. However, the relative successive formation constants for the 1 :2 adducts decreased in the order Pr > Eu > Ho > Yb, indicating greater steric crowding with the heavier metal complexes. Induced shifts in organic cations such as cyanine dyes and quinolinium and 14' 142 143 144 145

14' 14' 149 150

151

R. M. Wing, J. J. Uebel, and K. K. Andersen, J. Amer. Chem. SOC., 1973,95, 6046. J. S. Ghotra, F. A. Hart, G. P. Moss, and M. L. Staniforth, J.C.S. Chem. Comm., 1973, 113. B. L. Shapiro and M. D. Johnston, jun.,J . Amer. Chem. SOC.,1972,94,8185. V. G. Gibb, I. M. Armitage, L. D. Hall, and A. G. Marshall, J . Amer. Chem. SOC., 1972,94,8919. J. W. ApSimon, H. Beierbeck, and A. Fruchier, J. Amer. Chem. SOC.,1973,95,939. N. H. Andersen, B. J. Buttino, and S. E. Smith, J.C.S. Chem. Comm., 1972, 1193. D. F. Evans and M. Wyatt, J.C.S. Chem. Comm., 1973,339. J. Reuben, J . Amer. Chem. SOC., 1973,95, 3534. N. S. Bhacca, J. Selbin, and J. D. Wander, J. Am&. Chem. SOC.,1972,94, 8719. H. M. McConnell and R. E. Robertson, J . Chem. Phys., 1958,29, 1361. R.Porter, T. J. Marks, and D. F. Shriver, J . Amer. Chem. SOC., 1973,95, 3548.

Scandium, Yttrium, the Lanthanides, and the Actinides

463

quaternary ammonium salts have been effected"' by [Eu(fod),] ; shifts were also observedis3 in the proton resonances of the cations in [R,N)[M(NO,),] and [R,N],[M(NO,),] (M = La + Lu; R = Pr" or Bun). In the first case, the reagents apparently formed contact ion pairs, and in the second, the shifts were ascribed to a dipolar mechanism, and the cation-anion distance was calculated to be 6-7 A. A study has been madeis4 of butanol and a-methylbenzylamine adducts of the chiral shift reagents derived from Eu, Gd, Tb, Er, Ho, or Tm and 3-tbutylhydroxymethylene-( +)-camphorate. In the absence of added substrates, the shift reagents were dimeric in CCl,. A large contact term contribution to the induced shifts was observed'55 in the 13Cn.m.r. spectra of pyridine and y-picoline in the presence of [Eu(dpm),], [Pr(dpm),], and [Eu(fod),]. Both Fermi contact and pseudo-contact shifts have been inducedl 5 6 in pyridine, 3,5-lutidine, and isoquinoline by [Eu(dpm),]. An evaluation of the effect of [M(dpm),] (M = Eu, Er, Ho, Dy, Nd, Tb, Pr, and Yb) on the 13C n.m.r. spectrum of isoquinoline establishedis7 that [Eu(dpm),] and its Nd analogue had the greatest influence, the Dy, Ho, and Tb complexes were intermediate, and the Er and Yb complexes had least effect.

(7) X

=

C1,OMe, or OPh

The equilibrium between two chair forms of (7) was determined158 using [Eu(fod),]; this caused a large variation of 3J(HP) attributed to an increase in the concentration of the axial phosphoryl conformer. 3 The Actinides This section deals with the structure and chemistry of actinide compounds and complexes, excluding derivatives of uranyl and related systems. Structural Studies.-A review of the loose connection between the electronic behaviour and structure, and chemistry, of the transuranic elements has appeared.' 5 9 In Am2(S0,),,2H,O, each Am atom is eight-co-ordinate,'60 152 153 154 155 156

157

158 159 160

R.E. Graves and P. I. Rose, J.C.S. Chem. Cornm., 1973, 630. I. M. Walker and D. H. Weeden, Inorg. Chem., 1973,12,772. R. E. Denning, F. J. C. Rossotti, and P. J. Sellars, J.C.S. Chem. Comm., 1973, 381. M. Hirayama, E. Edagawa, and Y. Hanyu, J.C.S. Chem. Comm., 1972, 1343. 0. A. Gansow, P. A. LoeMer, R. E. Davis, M. R. Willcott, tert., and R. E. Lenkinski, J. Amer. Chem. Soc., 1973,95,3390. 0. A. Gansow, P. A. Loemer, R E Davis, M. R. Willcott, tert., and R. E. Lenkinski, J. Amer. Chem. SOC.,1973,95, 3389. T. Sat0 and K. Goto, J.C.S. Chem. Comm., 1973,494. C . K. Jorgensen, Angew. Chem. Internat. Edn., 1973,12, 12. J. H. Burns and R. D. Baybarz, Inorg. Chem., 1972,11,2233.

Inorganic Chemistry of the Transition Elements

464

Table 4 Structural data obtained from actinide complexes Ref. 160

Bond lengths/A 2.38-2.5 1(SO,) 2.4 1-2.55( H ,O)

161 162

2.39(0) 2.31(0)

166

3.96(Th-Th)

167

2.28-2.42(F)

UC1,

168

CfCI,

171

2.87(Cl) 2.64(C1) 2.82(6C1) 2.92(3C1) 2.69(2C1) 2.81 (4C1) 2.94(2C1)

Complex Am2(S04)3.8H20

172 173 174

3.28-3.40(1) 3.26-3.39(1) 2.38(U-H)

175

2.73(U-C) 2.63(U-Cl) 2.68(U-~C) 2.33(U-C) 2.81(U-C) 2.66(U-C) 1.41(C-C)

176 177 178

Co-ord. no. and structure Eight-co-ord.; intermediate between antiprism and dodecahedron Antiprismatic Slightly distorted square antiprismatic Ten-co-ord. with respect to Th Eight-co-ord. ; tricapped trigonal prism Hexagonal UC1, modified to nine-co-ordination Orthorhombic modification eight-co-ord. Seven-co-or dinat e Seven-co-ordinate 14-co-ord.; capped hexagonal antiprism Distorted tetrahedral

Distorted tetrahedral; u-c-c, 175" Pseudo-tetrahedral Sandwich

the co-ordination polyhedron being intermediate between a square antiprism and a dodecahedron (structural parameters, Table 4). Each metal atom is coordinated by four 0 atoms belonging to SO, groups, and four water molecules, crosslinking between the Am atoms occurring via sharing of sulphate ions, and there is extensive hydrogen bonding involving the water molecules. The 0 atoms in [Hf(tfa),] are in an antiprismatic arrangement,I6' the chelate rings being approximately planar; [Np(acac),] is slightly distorted'62 from the square antiprismatic arrangement. Crystal structure parameters have been obtained'63 for MC1, (M = Th, Pa, U, or Np) and MBr, (M = Th or Pa) by a comparison of quantitative X-ray powder data with single crystal Bond lengths for the halides were calculated, and the covalent radii of the MIv ions estimated at 1.71 (Th), 1.64 (Pa), and 1.61 A (U and Np), respectively. CfF3 exhibited'65 a high-temperature 16'

163 164 165

G. F. S. Wessels, J. G. Leipoldt, and L. D. C. Bok, Z . anorg. Chem., 1972, 393, 284. B. Allard, Acta Chem. Scand., 1972,26,3492. D. Brown, T. L. Hall, and P. T. Moseley, J.C.S. Dalton, 1973, 686. R. L. Hoard and J. V. Silverton, Znorg. Chem., 1963,2, 235. J. N. Stevenson and J. R. Peterson, J . Znorg. Nuclear Chem., 1973,35, 3481.

Scandium, Yttrium, the Lanthanides, and the Actinides

465

LaF,-type trigonal structure as well as the known YF,-orthorhombic modification. The Th atoms in [NH,],[Th,F,,],H,O are bridged'66 by three F atoms in a triangular plane, there being six terminal F atoms in an essentially equatorial plane, perpendicular to the three-fold axis defined by ThF,Th. The axial sites, coincident with the three-fold axis, are 'occupied' by one H,O and one NH: group, respectively. In CsU,F,, each U atom is eight-~o-ordinate'~~ with respect to F in polyhedra which share edges forming U,F,, sheets. The co-ordination polyhedra approximate to tricapped trigonal prisms, tlie ninth corners of these polyhedra being a half-filled eight-fold set of F atoms so that the U co-ordination number is effectively 8;. A neutron diffraction study of anhydrous UC1, has confirmed' 6 8 earlier 'X-ray crystallographic work;' 6 9 the two sets of U-Cl bond lengths in the co-ordination dodecahedron were closer than the previous report had indicated. Single crystal and powder diffraction studies of CmC1, e ~ t a b l i s h e d that ' ~ ~ the chloride has a UC1,-type hexagonal cell; the melting point was 695 & 10". CfC1, has two crystalline modifications :I one of hexagonal UC1,-type containing nine-co-ordinate Cf, and one of orthorhombic type containing eight-co-ordinate Cf. The ionic radius of six-co-ordinate Cf3 was calculated to be 0.93 A. AmI,, prepared by treating Am metal with HgI, at low pressure and 30O0C, is monoclinic,172 and the metal atom is seven-co-ordinate with respect to iodine. The radius of Am" was calculated to be 1.22 A, 0.01 8, greater than that of EuI,.17, The magnetic moment of AmI, was 6.7 + 0.7 BM. A neutron diffraction study of U(BH,), e ~ t a b l i s h e d 'that ~ ~ the U atom is 14-co-ordinate with respect to hydrogen. Four of the six BH, groups surrounding the metal atom are bonded to it via two H atoms, using their remaining atoms to bridge neighbouring U atoms in a helical polymeric structure. The two other BH, groups, in a cis-configuration, we bonded to the uranium via three H atoms. The overall co-ordination polyhedron was described as a capped hexagonal antiprism. The co-ordination geometry of [U(n-C,H,CH,Ph),Cl], obtained by reaction of UC1, with TlC,H,CH,Ph, can be describedi7' as a distorted tetrahedron; the U atom lies 0.43 A above a plane defined by the centres of the three n-bonded cyclopentadienyl rings (a displacement of 0.82 8, was actually expected). In the quasi-tetrahedral [ U ( ~ C - C ~ H , ) ~ C ' ~76Pthe ~ ] , U-C(acety1ide) ~ bond

'

+

166 167

171

174

17'

R. A. Penneman and R. R. Ryan, J.C.S. Chem. Comm., 1973,69. A. Rosenzweig, R. R. Ryan, and D. T. Cromer, Acta Cryst., 1973, B29,460. J. C. Taylor and P. W. Wilson, Acta Cryst., 1973;B29, 1942. R. C. L. Mooney, Acta Cryst., 1949,2, 189. J . R . Peterson and J. R . Burns, J . Znorg. Nuclear Chem., 1973,35, 1525. J. H. Burns, J. R. Peterson, and R. D. Baybarz, J . Inorg. Nuclear Chem., 1973,35, 1171. R. D. Baybarz, L. B. Asprey, C. E. Strouse, and E. Fukushima, J . Inorg. Nuclear Chem., 1972, 34, 3427. E. K. Hulef R. W. Lougheed, J. D. Brady, R. E. Stone, and M. S. Coop$ Science, 1968, 158,486. E. R. Bernstein, W. C. Hamilton, T. A. Keiderling, S. J. LaPlaca, S. J. Lippard, and J. J. Mayerle, Inorg. Chem., 1972,11,3009. J. Leong, K. 0. Hodgson, and K. N. Raymond, Inorg. Chem., 1973,12,1329. J. L. Atwood, C. F. Hains, M. Tsutsai, and A. E. Gebala, J.C.S. Chem. Comm., 1973,452.

466

lnorganic Chemistry of the Transition Elements

is significantly shorter than the U-C(C, H5) bonds. All four cyclopentadienyl rings in U(C5H5), are n-bonded,'" the molecule having a pseudotetrahedral structure. The two planar cyclo-octatetraenyl rings in U(1,3,5,7-C,H4Me4), are rotated178from the eclipsed conformation by 14" and the methyl groups are tilted from the ring plane by ca. 4.1"towards the metal. Chemical Studies.-Uranium hydride reacts with nitrogen, or U metal with NH,, giving'79 UN and U,N,. Treatment of ThC1, and UC1, with LiNEt, affordslgOthe volatile Th(NEt,),, and the previously described U(NEt,),.'81 Extraction of HC1 solutions containing Th" and NCS- ion, using tricaprylmethylammonium salts, affords' 8 2 [Th(NCS),]' -. The metal phosphine oxide complexes [M(R,PO),(NCS),] (M = Th, U, Np, or Pu; R = Me, Ph, or NMe,) are probably eight-co-ordinate,' 8 3 as may be the octamethylphosphoramide (OMPA) species, [M(OMPA),(NCS),]. It seems likely that the metal atoms in [M(OMPA),.,Cl,] are seven-co-ordinate. Reaction of arsenic with neptunium hydride affords' 84 NpAs,, which may be isostructural with UAs, and so belong to the same space group as ThAs,. The diarsenide is stable in vacua up to 600 "C but decomposes at higher temperatures to NpAs. Reaction of plutonium184 and a m e r i ~ i u m ' ~hydrides with arsenic gave PuAs and AmAs. From the U0,-H,O system, U0,,2H20, U0,,0.8H20, a-, p-, and yUO,(OH), and U,O,(OH), were iso1ated;ls6 all could be dehydrated to U,O,. Methods of obtaining high equilibrium concentrations of unsequestered Puv, especially as P u O i , have been suggested.' 87 Electrochemical reduction of [Pu0,l3- gave188PuO;+ in a one-electron step and then, after addition of a further two electrons, PuO,. The existence of N p 0 3 + in Cs,NpOCI, has been proposed.lg9 However, studies of this compound in HCl have establi~hed"~ the presence of equimolar amounts of Np" and Npv', and that the oxychloride is, in fact, a 1: 1 mixture of Cs,NpCl, and Cs,NpO,Cl,. From aqueous solutions of Npv"' containing LiOH and [Co(NH,),]Cl,, Li[Co(NH,),]Np,0g(OH),,2H~0 has been isolated.'" Each N p atom is apparently octahedral, each octahedron being linked in chains by sharing two 0 atoms at opposite corners. In solution, this complex afforded the [NpO,(OH),I3 J. H. Burns, J . Amer. Chem. SOC.,1973,95, 3815. K. 0.Hodgson and K. N. Raymond, Inorg. Chem., 1973,12,458. 179 H. Tagawa, Bull. Chem. SOC.Japan, 1973,46,1158. I a o G. W. Watt and K. F. Gadd, Inorg. Nuclear Chem. Letters, 1973,9, 203. 1 8 1 R, G. Jones, G. Karmag, G. A. Martin, and H. Gilman, J . Amer. Chem. SOC.,1956,78,4285. 18' T. Sat0 and S. Kotani, J . Inorg. Nuclear Chem., 1973,35,2547. i 8 3 Z . M. S. Al-Kazzar, K. W. Bagnall, and D. Brown, J . Inorg. Nuclear Chem., 1973,35, 1501. I a 4 J. P. Charvillat and D. Damien, Inorg. Nuclear Chem. Letters, 1973,9, 337. J. P. Charvillat and D. Damien, Inorg. Nuclear Chem. Letters, 1973,9, 559. l a 6 H. R. Hoekstra and S. Siegel, J . Inorg. Nuclear Chem., 1973,35, 761. G . L. Silver, J . Inorg. Nuclear Chem., 1973,35, 1369. L. Martinot and G. Duyckaerts, Inorg. Nuclear Chem. Letters, 1972,8, 861. 189 K. W. Bagnall and J. B. Laidler, J . Chem. SOC.(A), 1966, 516. 190 V. 1. Blokhin, V. P. Shilov, N. N. Krot, and A. D. German, Russ. J . Inorg. Chem., 1972,17, 1438. J. H Burns, W. H. Baldwin, and J. R. Stokely, Inorg. Chem., 1973,12,466. 178

Scandium, Yttrium, the Lanthanides, and the Actinides

467

ion. The thermal expansion coefficient of 248Cm0, has been measured.'92 Calcination of Cm3+ from Dowex 5OW-XS resin in air of 0, gavelg3Cm,O,SO, at 900 "C and Cm,O, at 1175 "C; stable Cm,(SO,), was believed to exist between 700 and 870 "C. The ionic radius of Cm3+ in Cm,O,SO, was calculated to be 0.98 A. The ionic radius of Es3+ in Es,O, was estimatedIg4to be 0.93 A, approximately midway between those of Gd3+ and Tb3+in their oxides M2°3'

By heating ThCl, in a sealed Pyrex tube at 180 "C, ThSiO, was formed.Ig5 From e.s.r. spectral studies of Uv doped into LiNbO,, LiTaO,, or BiNbO, (g ca. 0.7),an octahedral co-ordination of the uranium ion was estab1i~hed.l~~ In Na,UF8, however, the g-factor (1.2) was consistent with eight-fold cubic co-ordination. Attempts have been made to interpretlg7the electronic spectra of Pu3+,Am4+, Cm4+, Bk2+9,+ and Es4+, and to predict those of Cm2+, Cf4+,and Es3+ in aqueous solutions. The rate of reduction of BkIVin H,SO, solution was inversely proportional to acidity,Ig8 and closely paralleled the efficiency of production of H,O, in H,SO,. The stability of BkIVin HC10, and aqueous NaH,P,07 was also investigated. The extent of polymerization of Pu" was dependent'" on the acidity of the solution, and the kinetics of rate of polymerization have been evaluated. Nitrates, especially those of Li', A13+, and Na', aged precipitated Pu" polymers up to certain concentrations of NO,. Treatment of the complex [U(HMPA),Cl,] with AgClO, in acetone containing HMPA gave2" [U(HMPA)S(CIO,),]. In solution this probably existed in the equilibrium [U(HMPA),(OC103)]3+ + 3C10,

+ HMPA + [U(HMPA)5]4+ + 4C10,

The structure of Th(02)(S0,),3H,0 contains bridging peroxy-groups and bidentate SO, (8). Thermal decomposition gave [Th(O,SO,)(p-O)], and finally The stability constants of Th4+ with malonic (1:2 complexes), succinic (1 : l), phthalic (1 :2), maleic (1:2), and glutaric (non-chelating)acids have been 19* 193 194

lg5

19* 19'

2oo 201

M. Noe and J. R. Peterson, Inorg. Nuclear Chem. Letters, 1972,8, 897. W. H. Hale, jun., and W. C. Mosley, J . Inorg. Nuclear Chem., 1973,35, 165. R. G . Haire and R. D. Baybarz, J . Inorg. Nuclear Chem., 1973,35,489. D. P. Sinha and R. Praxad, J . Znorg. Nuclear Chem., 1973,35,2612. W. B. Lewis, H. G. Hecht, and M. P. Eastman, Znorg. Chem., 1973,12, 1634. L. P. Varga, R. D. Baybarz, M. J. Reisfeld, and L. B. Asprey, J . Znorg. Nuclear Chem., 1973,35, 2775; L. P. Varga, R. D. Baybarz, M. J. Reisfeld, and W. B. Volz, ibid.,p. 2787; L.P. Varga, R. D. Baybarz, M. J. Reisfeld, and J. B. Mann, ibid., p. 2303. R. G. Gutmacher, D. D. Bode, R. W. Lougheed, and E. K. Hulet, J . Znorg. Nuclear Chem., 1973, 35, 979. D. A. Constanzo, R. E. Biggers, and J. T. Bell, J . Inorg. Nuclear Chem., 1973,35, 609; J. T. Bell, D. A. Constanzo, and R. E. Biggers, ibid., 623; J. T. Bell, C. F. Coleman, D. A. Constanzo, and K.E. Biggers, ibid.,p. 629. J. G. H. du Preez and H. E. Rohwer, Inorg. Nuclear Chem. Letters, 1972,8,921. V. Raman and G. V. Jere, Indian J . Chem., 1973,11,31.

Inorganic Chemistry of the Transition Elements

468

measured.202 The free energies, enthalpies, and entropies of formation of monoglycollato complexes of Eu3+, Am3+, Cm3+, and Bk3+ have been determined (Table 5).203 The formation constant of Am"', Cm"', PmI'I, EU"', and Lu"' lactic acid complexes have also been measured2', by electrophoretic QH2

Table 5 Free energy, enthalpy, and entropy changes for the formation of actinide 111 and europium

Eu Am Cm

Bk

-AG /kcal mol3.44 f 0.02 3.51 f 0.02 3.51 3.61

k 0.02 k 0.01

-AH /kcal mol-I 0.53 f 0.35 1.33 k 0.44 0.93 & 0.37 1.21 k 0.241

AS /cal deg-' mol-

'

+ +

9.7 1.2 7.3 f 1.5 1.3 8.6 8.1 0.8

*

methods. The methods described were especially useful in the determination of complex formation constants of transuranic elements in tracer amounts. A series of P-diketonate (dik ; acac, tfa, hfa, benzoylacetone, dibenzoylmethane, ttfa, benzoyltrifluoracetone) complexes, [M(dik),] (M = Th, U, or Ce) have been prepared205and studied by i.r. spectroscopy. Reaction of potassium pyrazolide and its 3-methyl analogue with Th, U, Np, and Pu halides in the presence of (CF,),CO afforded206the tetrakis-substituted complexes (9).

(9) R = I3 or Me

Reaction of ThC1, or UCI, with di-isobutoxyphosphate (dibp) gave207 [Th(dibp),Cl] (diamagnetic) and [U(dibp),Cl] (p = 2.7 BM). Treatment of neptunium hydrides with selenium gave2'* NpSe, (isostruc'02

203 '04 '05

'06 '07

208

G. Tomat, L. Magon, R. Portanova, and A. Cassol, Z . anorg. Chem., 1972,393, 184. G. R. Choppin and G. Degischer, J. Znorg. Nuclear Chem., 1972,34, 3473. M. Sakanoue and M. Nakatani, Bull. Chem. Soc. Japan, 1972,453429. T. Yoshimura, C. Miyake, and S. Imotu, Bull. Chem. SOC.Japan, 1973,46,2096. W. Andruchow and D. G. Karraker, Znorg. Chem., 1973,12,2194. C. M. Mikulski, L. L. Pytlewski, and N. M. Karayannis, J. Znorg. Nuclear Chem., 1973,35,2102. D. Damien, N. Damien, J. Jove, and J. P. Charvillat, Znorg. Nuclear Chem. Letters, 1973,9, 649.

Scandium, Yttrium, the Lanthanides, and the Actinides

469

tural with US,, Use,, and NpS,) which progressively decomposed with increasing temperature to give Np,Se, (similar to Np,S,, U3S5, and U,Se,), and finally to y-Np,Se, (cubic). There was no evidence for NpSe,, in contrast to PuSe, and Use,. Similar treatment of plutonium hydride with Te vapour afforded,'' PuTe, (similar to AmTe,) which decomposed thermally according to the scheme PuTe,

PuTe2-x

q-Pu,Te,

- y-Pu,Te, 900 "C

ThF, reacted,'' with N,H,F and anhydrous hydrazine giving [N2H5],[ThF,], ThF,(N2H,), and (ThF,),(N,H,), ; the first decomposed thermally into [N2Hs] [ThF,], N,H,F,, aQd hydrazine. The far-i.r. spectra of a series of rubidium uranium complex fluorides, RbF,nUF4 (n = 1, 3, or 6), nRbF,UF, (n = 2 or 3), 2RbF,3UF4, and 7RbF,UF, have been measured the F-U-F bending, R b F lattice, and U-F stretching vibrations weFe identified. UF, reacted with alkali-metal fluorides in C6F12 giving,', Na,UF, which decomposed thermally giving first Na3UF9 and then NaF and UF6. Fluorination of CfCl,, CfF,, or Cf203 under mild pressure gave213green CfF,, which is isostructural with UF,. The heats of solution of the halides MX, (M = Th, U, or Np; X = C1, Br, or I) have been measured214 in HC1 solution (Table 6), and from these the Table 6 Heats andfree energies of formation of actinide tetrahalides (solids) MX4 ThCl, ThBr, ThI, UBr, UI4 NpBr4

Heats of'soln./kJ mol- ' 1 M-HCl 6M-HCl -241.8 & 0.7 - 188.2 & 0.4 -233.9 & 0.8 -283.5 f 1.3 -322.0 f 0.6 -276.0 & 1.2 -264.6 0.5 -205.7 & 0.9 - 289.9 + 1.3 -240.2 & 1.3 -258.8 k 0.5 - 199.2 k 0.4

Heat ofjormationl

kJ mol- ' -118.4 -963.4 -633.0 -802.5 -511.5 -773.2

11.0 & 1.4 f 1.8 + 3.4 & 4.0 _+ 1.7

standard entropies of formation derived. Treatment of U,(SO,),,SH,O with HC1 and NH,F afforded," UF,H,O, whereas reaction of UH, with HCl, HBr, and Me1 at ca. 300 "C afforded UCl,, UBr,, and UI,, respectively; with HCl, traces of UC1, were identified. Uranium(n1)has extreme reactivity towards most anions and organic solvents and consequently its chemistry is limited ; attempts to repeat the preparation of UCI,(MeCN) from the trichloride and acetonitrile216 were unsuccessful. Two series of U"' chloro-complexes have '09 'lo

'11 212

'13

'I4 '15 '16

D. Damien, Inorg. Nuclear Chem. Letters, 1973, 9, 453. P. Glavic, J. Slivnik, and A. Bole, J . Inorg. Nuclear Chem., 1973,35, 427. T. Soga, K. Ohwada, and M. Iwasaki, J . Inorg. Nuclear Chem., 1973,35,2069. V. Rak and P. Horacek, Coll. Czech. Chem. Comm., 1973,38,42. R. G. Haire and L. B. Asprey, Inorg. Nuclear Chem. Letters, 1973,9, 869. J. Fuger and D. Brown, J.C.S. Dalton, 1973,428. R. Barnard, J. I. Bullock, B. J. Gellatly, and L. F. Larkworth, J.C.S. Dalton, 1973,604. J. MacCordick and C. Brun, Compt rend., 1970,270, C , 620.

470

1norganic Chemistry of the Transition Elements

been isolated:217red MUC1,,5H2O (M = K, Rb, or NH,) and green MUCl,, xH,O (M = Rb or NH,). The electronic and i.r. spectra of the red species were consistent with the co-ordination of C1-, whereas those of the green complexes were similar to those of U"' sulphate complexes and the hydrated U"' ion. With 1-phenyl-2,3-dimethyl-5-pyrazolone(phaz) and 4-dimethylaminophenazine (dmaz), the complexes [U(phaz),]Cl, and [U(dmaz),][BPh,] were obtained, using the red chloride in ethanol. Polarographic and coulometric reduction in DMSO of MCl, (M = Th, Pa, U, or Np) has been investigated (Table 7).218 Both the uranium and neptunium compounds were reduced to MI" and then Mo,but PaC1, was reduced directly to Pao and thorium to Th" and then Tho.

Table 7 Polagraphic data obtained from actiniddl V ) tetrachlorides in DMSO MCl4 UCl, NPCl4 PaCl, ThCl, a

E,IV"

Couple

- 1.22

UIV

-2.16 - 0.47 -2.19 - 1.49 - 1.64 - 2.31

+

u"'

U"' + u*

Np'" + Np"' Np"' -+ Npo PaIV3 Pao ThiV+ Th" Th" -+ Tho

In DMSO us. S.C.E. at room temperature (no. of electrons involved established by coulometry).

The enthalpies of solution of anhydrous UCl, in HMPA, DMSO, dimethylacetamide, and DMF have been determined.219Complexes were formed of the type UCl,,nL, where L = solvent molecule and n = 2 (HMPA, DMF), 2.5 (DMA),or 3 (DMSO). These compositions were compared with the stoicheiometries of the isolated complexes, and it yas suggested that donor atom strength and the size and structure of the solvent molecules were necessarily important in determining the stoicheiometries of the UC1,-solvent adducts. Phosphine oxide adducts, [MCl,(Me,PO),] (M = Th, Pa, or U, n = 6 ; M = U, n = 3; EUl = U or Np, n = 2) and [MCl,(OMPA),.,] (M = Np or Pu) have been prepared;220 PuCl,L, (L = Ph,PO or HMPA) was also described. Thermolysis of UCl,(Me,PO), in vacuo gave P-UCl,(Me,PO),, and it was suggested, on the basis of i.r. spectral studies, that the hexakisphosphite had an ionic structure [UCl,(Me,P0),](4 - x)+ [UC1, - ,(Me, PO), -y](4-x1-. [U(acac),Cl,] is apparently co-ordinatively unsaturated2, and with L (THF or Ph3PO)or L-L(dimethoxyethane, bipy, or phen) afforded the eight-co-ordinate [U(acac),Cl,L,] and [U(acac),Cl,(L-L)]. Addition to UC1, in dimethoxyethane of bipy or phen (L-L) afforded,,, [UCl,(L-L), 3.

,

217

'I8 219

z20 221 222

R. Barnard, J. I. Bullock, B. J. Gellatly, and L. F. Larkworth, J.C.S. Dalton, 1972, 1932. L. Astheimer and K. Schwochan, J . Inorg. Nuclear Chem., 1973,35,223. J. G. H. du Preez and J. Koorts, Inorg. Nuclear Chem. Letters, 1973,9,99. Z . M. S. Al-Kazzar, K. W. Bagnall. and D. Brown, J . Inorg. Nuclear Chem.. 1973.35. 1493. L. Doretti, P. Zanella, S. Faieschini, and G. Faraglia, J . Znorg. Nuclear Chem., 1973,354 31 71. L. Doretti, S. Sitran, P. Zanella, and G. Faraglia, Znorg. Nuclear Chem. Letters, 1973,9, 7.

Scandium, Yttrium, the Lanthanides, and the Actinides

471

The preparations of AmCl, and AmBr, from the metal and Hg" halides, have been described;,,, the former is orthorhombic whereas the latter is tetragonal. From electronic spectral observations,224 the existence of [AmC1,I3- in ethanolic solutions of AmIn containing HC1 has been confirmed. Magnesium reduction of and Fm11'226 chlorides, in the presence of SmC1, in aqueous ethanol, afforded the CP', Es2+, and Fm2+ ions, which were cocrystallized as chlorides with SmCl,.

Reaction of [U0C1,I2- in nitromethane with phenazine (10) (L) afforded the stable free-radical chloride salt, [LH;'] [Cl-1. The mechanismz2' apparently involved bonding L and H,O to the U 0 3 + group, followed by transfer of both water protons to the phenazine, and reduction of U 0 3 + ,giving [LH,] [UO,Cl,]. With [UOBr,]'-, [LH;'] [Br-] was formed, and similar cation radicals were produced with benzo[a]phenazine, dibenzo[ac]phenazine, 2,3-bis-(2-pyridy1)quinoxaline and acridine. Oxidation of phenot hiazine, 1,3-dimethylalloxazine,and 3,1O-dimethylisoalloxazine to the corresponding cation free radicals without protonation was achieved using [UCl,]-, and these were isolated as [UCl6l2- salts. Thus, Uv serves as either a one-electron reducing agent in the form of [UOC15]2- in the presence of H,O (proton and 0 source), when [U0,C14]2- is formed, or as a one-electron oxidizing agent in the form of [UCl,]-, when [UC1,I2- is formed. It was observed that phenazine reacted with [UCl,] - giving [UCl,(L)]. Vibrational spectral analysis of [M(~C-C~H~)~(BH,)] (M = Th or U) established228 that the BH, group is terdentate. A series of alkyl and aryl comple~es,~,'[U(n-C,H,),R] (R = Me, CH-LH,, Pr', Bun, But, cis- and transbut-2-enyl, allyl, neopentyl, C d p h , CH,Ph, Ph, p-MeC&, and C6F5)have been prepared from [U(7c-C5H5),C1] with LiR or MgRBr. These complexes are paramagnetic Lp = 2.72 (Ph), 2.88 (CECPh)], having a 5f' configuration. 223 224 225

226

z2'

228 229

R. D. Baybarz, J . Inorg. Nuclear Chem., 1973,35,483. Yu. A. Barbanel', V. P. Kotlin, and A. G. Gorskii, Doklady Akad. Nauk S.S.S.R.,1972,202, 98. N . B. Mikheev, V. I. Spitsyn, A. N. Kamenskaya, N. A. Rozenkevitch, I. A. Rumer, and L. N. Auerman, Inorg. Nuclear Chem. Letters, 1972,8, 869. N. B. Mikheev, V. I. Spitsyn, A. N. Kamenskaya, B. A. Gvozdev, V. A. Druin, I. A. Rumer, T. S. Dyachkova, N. A. Rozenkevitch, and L. N . Auerman, Inorg. Nuclear Chem. Letters, 1972,8,929. J . Selbin, D. G. Durrett, H. J. Sherrill, G. R. Newkome, and M. Collins, J . Inorg. Nuclear Chem., 1973,35, 3467. T. J. Marks, W. J. Kennelly, J. R. Kolb, and L. A. Shimp, Inorg. Chem., 1972,11,2540. T . J. Marks, A. M. Seyam, and J. R. Kolb, J . Amer. Chem. SOC.,1973, 95, 5529; G. Brandi, M. Brunelli, G. Lugli, and A. Mazzei, Inorg. Chim. Acta, 1973, 7 , 319; A. E. Gebala and M. Tsutsui, J . Amer. Chem. SOC.,1973,95, 91.

472

Inorganic Chemistry of the Transition Elements

In ‘H n.m.r. spectral studies restricted rotation, occasioned by steric crowding, was observed about the U-CHMe, bond, and analysis of the isotropic ‘H n.m.r. shifts indicated large contact shift contributions. The mechanism of spin distribution involved negative spin density on the a-GI atom in the alkyl or aryl group. While the complexes were remarkably thermally stable, the U-C cr-bond was susceptible to protolysis, indicating that it is somewhat ionic. Hydrolysis of [U(n-C,H,),Ph] afforded benzene. Reaction of Rh, U, or Pu metal with C8H, in uucuo in the presence of Hg as catalyst afforded”’” [M(n-C,H,),] (M = Rh, U, or Pu). A series of ring-substituted 7c-cyclooctatetraenyl uranium complexes has been 2 3 2 using the appropriate cyclic tetraene. Hydrogenation of [U(n-C,H,(CH=CH,),} ,] afforded [U(n-C,H,Et,),]. The complexes [M(n-C,H,R),] (M = U, Np, or Pu, R = Et or Bun) are isomorphous for a given substituent, but not for a given metal with different substituents. 4 Uranyl and Related Compounds

Structural Studies.-In y-UO,(OH),, the U atom has a distorted octahedral structure233 consisting of the two uranyl 0 atoms and four secondary OH groups (Table 8). Each OH group is shared between two octahedra so that a puckered layer arrangement is formed, and while each uranyl 0 atom is associated with only one metal atom within each layer, it is hydrogen bonded to a hydroxy-group in an adjacent layer. The structure is broadly similar to that of P-UO,(OH),. The structure of U02S04,3.5H,0, a metastable product of the U0,-SO,H,O system,234consists235 of infinite chains of sulphate tetrahedra linked to uranyl pentagonal bipyramids. The UO, group is co-ordinated by three HzO molecules and by two 0 atoms contributed by unidentate SO4 groups. These sulphate ions are, however, terdentate with respect to three U 0 2 groups. The remaining water is surplus (0.5) and may be replaced by other hydrogenbonding groups. Treatment of uranyl nitrate with ethylcarbamate afforded2,, UO,(O= C(NH,)(OEt)),(NO,),, in which the linear UO, group is perpendicular to an equatorial plane defined by two bidentate NO, groups and the two amidic 0 atoms at the corners of an irregular hexagon. In [NH4],[U0,(C03)3], the U atom is eight-~o-ordinated,~~~ again within a distorted hexagonal arrangement, in which the carbonato-groups are bidentate. The NHf ions fill holes within the crystal lattice and are linked via hydrogen bonds to the anions. z30 231

’”

233 z34

235

236 237

D. F. Starks and A. Streitweiser, J . Amer. Chem. SOC.,1973,95, 3423. A. Streitweiser and C. A. Harmon, Inorg. Chem., 1973,12, 1102. D. G. Karraker, Inorg. Chem., 1973,12, 1105. S. Siegel, H. R. Hoekstra, and E. Gebert, Acta Cryst., 1972, BZS, 3469. E. H. 0.Cordfunke, J . Inorg. Nuclear Chem., 1972,34, 1551. N. ,P. Brandenburg and B. 0. Loopstra, Cryst. Structure Comm., 1973,2,243. R. Graziani, G. Bombieri, E. Forsellini, S. Degetto, and G. Marangoni, J.C.S. Dalton, 1973,451. R. Graziani, G. Bombieri, and E. Forsellini, J.C.S. Dalton, 1972,2059.

(TH = protonated thiamine)

[UO,(salen)MeOH]

CUO,(C,H,O,),(PY)I

Complex

246

243

242

242

240

239

Ref. 238

Bond lengths/A 2.47(neighb. CO; 0) 2.41(0, CO,) 2.66(0xy0) all +0.03 2.63-65(oxy 0) 2.43-46(CO; 0) 1.74(U=O) 2.49(C,04, H,O) 1.63(U=O) 2.43(C204,five-membered chelate ring) 2.57(C204, four-membered chelate ring) 1.69(U=O) 2.37iu-oj 1.77(U=O) 2.37-39( 0) 2.63(U-N) 1.79(U=O) 2.25(0, salen) 2.33(0, salen) 2.45(U- 0,MeOH) 2.54-57( N) 1.76-77( U=O) 2.66-69(Cl) 1.78(U=O)

Table 8 Structural data obtained from uranyl complexes

Octahedral (D4J

Seven-co-ord.; slightly distorted pentagonal bip yramid

Seven-co-ord.

Seven-co-ord.

Eight-co-ord. ; hexagonal bipyramid, see formula (12)

Seven-co-ord.

w

4 P

2

z

3

b

2 -.

z

Q

*2

c

3

5 3

b

I-

cb s

Eight-co-ord. ;irregular hexagonal bipyramid

;

23.

Co-ord. no. and structure Seven-co-ord.; irregular pentagonal bipyramid ; see formula (11)

474

Inorganic Chemistry of the Transition Elements

The oxydiacetate complex [U02{0(CH2C02)2)]nis polymeric, as indi~ a t e in d (1 ~ l),~ and ~ the metal has an irregular pentagonal bipyramidal structure. In Na2[U02{O(CH2C02)2}],2H20, however, the U atom is eightco-ordinate, the oxydiacetate ligands being terdentate affording239an irregular

H2

H 2

(1I ) (UO, axis perpendicular to page)

hexagonal arrangement. In the pyridine N-oxide species, U 0 2 {O(CH2CO,),)(C,H,NO),, however, the co-ordination polyhedron is like that in (1 l), the bidentate diacetate being replaced by the N-oxide (0-bonded). The oxalate complex U02(C20,),3H,0 contains2,’ seven-co-ordinate uranium(vI), by virtue of binding of two oxalato-groups, one ‘belonging’ to a neighbouring metal atom, and one H 2 0 molecule. Thus each oxalate is quadridentate with respect to two U atoms. In attempts to repeat the preparations of ammonium uranyl oxalato-complexes,241the species [NH4],[UO2(C2O4),], The [NH4]2,[U02(C20,),], and [NH4]2n[U02(C204)2]nwere structure of the first is shown in (12). The planes defined by the two C O , groups in the unique oxalate ring are inclined to each other at an angle of 37”. The formation of such a species is surprising, in view of the considerable steric strain in the system. In [NH,]2n[U02(C204)3],,,a polymeric species is formed

(12) (UO, axis perpendicular to page) 238 239 240

241 242

G. Bombieri, E. Forsellini, R. Graziani, G. Tomat, and L. Magon, Inorg. Nuclear Chem. Letters, 1972,8, 1003. G. Bor, L. Magon, L. Maresca, and G. Natile, J.C.S. Dalton, 1973, 1308; G . Bombieri, R. Graziani, and E. Forsellini, Inorg. Nuclear Chem. Letters, 1973, 9, 551. N. C. Jaydevan and D. M. Chackraburtty, Acta Cryst., 1972, B28,3178. M. G. Wyruboff, Bull. SOC.France, Minerol., 1909,32, 340. N. W. Alcnck. J.C.S. Dalton, 1973, 1610, 161, 1614.

Scandium, Yttrium, the Lanthanides, and the Actinides

475

in which one oxalato-group is ter- and one quadri-dentate (13), thereby forming a double chain structure. In [NH,],,[U0,(C,04),]n, one oxalate is bidentate with respect to the UO, group, whereas the other is bidentate to the same uranyl ion and unidentate to another, once again forming a chain (single) structure. In both of the polymeric species, the metal atom is seven-co-ordinate.

/ ‘ 0

(1 3) (UO, axis perpendicular to page)

In the tropolonato-species U0,(C,H50,),(C,H,N), the metal atom is se~en-co-ordinate,~~~ the pyridine molecule readily undergoing exchange reactions with other Lewis bases. The Schiff base complex [U02(salen)(MeOH)] has a slightly irregular pentagonal bipyramidal structure244 in which the short intermolecular distance between an 0 atom of the NN’-bis(salicy1idene)-1,Zdiaminoethane and that of the methanol group in an adjacent molecule suggests hydrogen bonding. The Schiff base ligand is essentially planar. In the NN’-bis(salicy1idene)-1,5-diamino-3-azapentanecomplex, [UO,(saldien)], the U atom is also s e ~ e n - c o - o r d i n a t e the , ~ ~U=O ~ bond’ lengths being unequal, differing by 20 from the mean distance of 1.68 8. The symmetry of [U02C14]2-, as its protonated thiamine salt, is essentially D4h,as expected.246 General Chemistry.-It seems likely, from X-ray powder diffraction dats?,that the species n M 0 , 2 U 0 3 ( 4 - 2n)H,O (M = Ca, Sr, Pb, or Ba; 0 dn < 2) has a structure consisting247of hexagonal layers of (UO,)(O,OH), (n d 2) similar to those in Ca(UO,)O, and U308,the layers being connected by H 3 0 + and M 2 + . Vibrational spectroscopic studies indicated248 that in these mixed 243

244

243

246

247 248

G. Bombieri, S. Degetto, G. Marangoni, R. Graziani, and E. Forsellini, Inorg. Nuclear Chem. Letters, 1973,9, 233. G. Bandoli, D. A. Clemente, U. Croatto, M. Vidali, and P. A. Vigato, Inorg. Nuclear Chem. Letters, 1972,8, 961. M. N. Akhtar and A. J. Smith, Acta Cryst., 1973, B29,275. A. Marzotto, G. Bandoli, D. A. Clemente, F. Benetollo, and L. Galzigna, J . Inorg. Nuclear Chem., 1973.35.2769. R. Sobry, J . Inorg. Nuclear Chem., 1973,35, 1515. R. Sobry, J . Inorg. Nuclear Chem., 1973,35,2753.

476

Inorganic Chemistry of the Transition Elements

oxides, the U-0 distances are in the range 1.70-1.78A. Dehydration ap(n # 0). The vibrational spectrum of parently gave M,[(UO,)O,(OH),-,], U0,,2H20 indicated that there are two different uranyl sites and that, on partial dehydration, UO, (0.7-O.8H2O) was formed, which was probably best formulated as (UO,)(O)(OH),. Subsequent dehydration of this afforded ' chains. a species in which the UO:' group was replaced by U-0-U-0 Spectral studies have established249that when UO:' ions in sulphate solutions are adsorbed in cation and anion exchange columns, the species present in aqueous and non-aqueous phases are [U02(HS04)]+, [U02(S04),]*-, and [UO,(SO,),]"-. Adducts containing two molecules of Lewis base are obtained when uranyl sulphate is treated2" with C,H,NO and its methyl (2,3,4), 4-cyano, and 2,6-dimethyl analogues; [UO,(C,H,NO),(SO,)] was believed to be six-co-ordinate with bidentate sulphate. Similar nitrate and thiocyanate complexes, viz. U0,(C,H,NO),(N03)2 [ n = 2 (eight-co-ord) or 31 and UO,(C,H,NO),(SCN),, are known.25' 1.r. spectral studies of Th" and UO;' nitrates in diphenyl and dibenzyl sulphoxides indicated,', the formation of 1:4 and 1 :3 complexes with respect to the metal. In the pH range 4.0-6.0, furfuryl thiol formed2531: 1 and 2: 1 complexes with uranyl ion, and their stability has been determined. With thiamine (T) chloride and nitrate, uranyl chloride and nitrate formed2', the species [TI [UO,(H,O),Cl,],H,O and [U02(TN03)(N03)2],H20;in the latter the thiamine was present as the unprotonated mononitrate. Uranyl complexes of m-mercaptoacetamidophenol have been r e p ~ r t e d , ~ "and the stability constants of uranyl-2-dimethylaminoethanethiolhydrochloride complexes determined.256 The Group VA oxide adducts [UO,(QCNEt,),L] (L = Me,NO, Q = S or Se: L = Ph,PO or Ph,AsO, Q = Se) have been reported,257and [U02(OAc)2(Me,NO)(H,0)], have been isolated. Reaction of uranyl nitrate with Me,NO afforded the eight-co-ordinate [UO,(Me,NO),(NO,),] (NO, bidentate) and the salt [UO,(Me,NO),] [NO,],. A uranyl acid (H,L), Na, [UO,complex of 7-nitroso-8-hydroxyquinoline-5-sulphonic L2]2H,O, has been prepared,258 and ThL2,4H20 has been described as eight-co-ordinate (both complexes are deprotonated at the sulphonate group). When UO,(OH),(O,CH) is shaken with hot water, UO,(OH)(O,CH),H,O is formed.259The basic formate can also be obtained from the dihydroxide using T102CH,and its thermal decomposition gives UO, or a-U,O,, depending on the temperature. Reaction of UO,(C,O,) with Tl,C204 in water *

249 250

252

253 254 255

25h 257

259

C. Heitner-Wirguin and M. Gantz, J . Inorg. Nuclear Chem., 1973,35, 3341. I. S. Ahuja and R. Singh, Inorg. Nuclear Chem. Letters, 1973,9, 545. 1. S. Ahuja and R. Singh, J . Inorg. Nuclear Chem., 1973,35, 561, M. K. Gadia and R. S. Rai, Indian J . Chem., 1973,11, 392. R. S. Saxena and S. S. Sheelwant, J . Inorg. Nuclear Chem., 1973,35,941. A. Marzotto, J . Inorg. Nuclear Chem., 1973,35,3403. S . N. Kakkar, N. S. Poona, and P. V. Khadikar, J . Inorg. Nuclear Chem., 1973,353021. M. S. Shahid, H. G . Heal, and H. Garcia-Fernandez, J . Inorg. Nuclear Chem., 1973,35, 1691. B. Zarli, L. Volponi, L. Sindellari, and G. G. de Raoli, J . Inorg. Nuclear Chem., 1973, 35, 231. M. M. Aly, M. Makhyou, and S. El-Ezaby, J . Inorg. Nuclear Chem., 1973,35,2727. S. Sampath and G. Aravamudan, J . Inorg. Nuclear Chem., 1973,35, 1377.

Scandium, Yttrium, the Lanthanides, and the Actinides

477

affords260 T1,[U0,(C,04)2],2H,0 which decomposes thermally to give Tl,UO,, which is isostructural with its Cs and Rb analogues, and then U,O,. The stability constants of a series of 1: 1: 1 complexes of UO;' with bidentate carboxylic acids and phenolic acids have been measured.261 These acids included phthalic, succinic, adipic, and 3,5-dinitro- and 5-sulphosalicylic acids. Formation constants for mixed metal complexes of In"' and UO;' with malic, citric, and tartaric acids have also been reported.262 For the first two acids, the equilibrium UO;'

+ In3+ + 2H3L + [UO,InL,]- + 6H'

can be written and, for tartaric acid, UO;'

+ In3+ + 2H4L + [UO2InL2J3- + 8H+

With mordant black dyes (viz. eriochrome Black T, solochrome Black 6BN, and calmagite) uranyl nitrate forms2631 :2 complexes. The stability constants of uranyl amino- and mercapto-acid complexes have been determined.264Among the acids investigated were cysteine, methionine, p-alanine, anthranilic acid, serine, threonine, and N-ac-'ylglycine. Stability constants of a series of chloro-, bromo-, iodo-, and nitro-substituted salicylic and of o-pyrocatechinic, y-resorcylic, and gentisic acids266complexes of UO;' have been measured; 1: 1 and 1:2 species were identified. It was observed that there was a distinct dependence of stability constant on the charge of the central metal atom in UO$+, NpO;, and Pu3+ tropolonato Uranyl complexes of 2,4-acetoacetoxylidide (14) have been described,268 and two series of ferrocenyl-P-diketonate compounds, (15) and (16), have been

(14) R'

260

261 262

263 264 265

266

"' 26a

=

Me: R2

=

Me,C,H,

N. C. Jayadevan, R. M. A. Dias, and D. M. Chackraburtty, J . Inorg. Nuclear Chem., 1973, 35, 1037. V. D. Khanolkar, D. V. Jahagirdar, and D. D. Khanolkar, J . Inorg. Nuclear Chem., 1973,35,931. G. Markovits, P. Klotz, and L. Newman, Inorg. Chem., 1972, 11,2405. S. P. Mushran, 0. Prakash, and R. Murti, J . Inorg. Nuclear Chem., 1973,35,2119. A. Raghavan and M. Santappa, J . Inorg. Nuclear Chem., 1973,35,3363. D. V. Jahagirdar and D. D. Khanolkar, J . Inorg. Nuclear Chem., 1973,35,921. A. N. Pant, R. N. Soni, and S . L. Gupta, J . Inorg. Nuclear Chem., 1973,35. 1390. L. Magon, A. Bismondo, G . Bandoli, and R. Portanova, J . Inorg. Nuclear Chem.. 1973.35, 1995. A. D. Taneja and K. P. Srivastava, J . Inorg. Nuclear Chem., 1973,35, 1397.

inorganic Chemistry of the Transition Elements

478

discussed.269Complex (15) is monomeric and L = H,O, Bu”,O, C,H,N, or DMSO, whereas complex (16) is polymeric, with L = H,O or Bul;PO. Treatment of UO2C1,,3H,O with the T1’ salt of (17) in ethanol afforded270[U02-

(15) L = H,O, Bu,PO, C,H,N, or DMSO (UO, axis perpendicular to page)

Fe

(16) (UO, axis perpendicular to page)

269

U. Casellato, M. Vidali, P. A. Vigato, G. Bandoli, and D. A. Clemente, Inorg. Nuclear Chem. Letters, 1973,9, 299. M. Vidaii, P. A. Vigato, G. Bandoli, D. A. Clemente, and U. Casellato, Inorg. Chim. Acta, 1972, 1972,6, 67 1.

*’’

Scandium, Yttrium, the Lanthanides, and the Actinides

479

(salenNR'R2),] in which the Schiff base was terdentate. When treated with Pd(PhCN),CI, in aqueous ethanol, [U0,(H,0),(sa1enNR1R2),]PdC1, was formed. Although in the solid state both co-ordinated bases were terdentate, there was evidence that in benzene or chloroform solution one base was bidentate (NR1R2not bonded) and that there was site exchange between bonded and non-bonded NR1R2 groups. When [U0,(salenNR'R2),] (R' = H, R2 = Ph) was dissolved in acetone a pink solution was formed, which gradually became red because of the formation of [UO,(~alenNR'R~)~(acetone)~] (neither NRIR1 group bonded). After some time a yellow solid, [UO,(salenNR'R2),(acetone)] precipitated, in which only one of the NR1R2 groups was bonded to the uranyl group, the other being displaced by acetone. From uranyl nitrate and (17), [UO,(HsalenNHR),(NO,),] (R = Et or Ph) was formed; the Schiff base was bidentate, the NHR groups being unco-ordinated and NO, being bonded. A series of sevenco-ordinate complexes, [UO,(saldiamine)(EtOH)] has been obtained271 by reaction of UOf' in ethanol with Schiff bases obtained by reaction of salicylaldehyde with optically active diamines [e.g. (+)- and meso-butanediamine and cyclohexanediamine and (-)- and meso-stilbenediamine]. When no ethanol was incorporated in the complexes, they were probably polymeric. Reaction of UO,SO, and ThCl, with phenylhydrazine (L1) and benzidine (L2)affords272[U02L1]S04 and [U0,L2(THF)]S04,[ThL:]C14, and [ThL;C12]C12. The first two were described as 1 : 1, the third and fourth as 1 :4and 1:2 electrolytes in DMSO, respectively, and it was suggested that the coordination numbers were six, six, eight, and four, respectively, the hydrazine, for example, being bonded through the NH, and the NHPh group! Complexes of 4,4'-bipyridyl (bipy), e.g. [U02(bipy)X2], (X = C1 or +SO,), and [UO,(bipy), ,s(N03)2]nhave been reported;273these appear to contain bridging bipyridyl and bidentate SO, or NO, groups, thereby giving polymeric structures. In [UO,(bipy)X,] (bipy = 2,2'-bipyridyl; X = C1 or OAc) and [UO,(bipy)SO,], the organoheterocyclic is bidentate and the metal atom is six~o-ordinated.,~ In~ [UO,(bipy),(NO,),], however, the nitrate groups are bidentate and the metal atom is formally ten-co-ordinate. Similar o-phenanthroline complexes were obtained27s when X = C1 or SO, but, in [UO,(phen)(NO,),], the metal is only eight-co-ordinate. Treatment of UF, with water and H F gave276UOF,, but there was no evidence for U,O,F, or U,O,F,. This compound is very hygroscopic, dissolving in water to give UOi+ ions. Thermolysis above 150 "C gave UF, and UO,F,. From the system U0,-HF-H,O the basic fluorides U02(0H),F, -,,nH,O

271

272 213

214

276

A. Pasini, M. Gullotti, and E. Cesarotti, J. Inorg. Nuclear Chem., 1972,34, 3821. S. M. F. Rahman, J. Ahmad, and M. M. Haq, Z . anorg. Chem., 1972,392, 316. I. S. Ahuja and R. Singh, Austral. J . Chem., 1973,26, 1871. I. S. Ahuja and R. Singh, Inorg. Nuclear Chem. Letters, 1973,9,283. I. S . Ahuja and R. Singh, J. Inorg. Nuclear Chem., 1973,352075. P. W. Wilson, J.C.S. Chem. Comm., 1972,1241.

480

Inorganic Chemistry of the Transition Elements

(x = 0.3 + 1.2; n = 1 or 2) have been ~ b t a i n e d , , ' ~ >and , ~ ~the species MU0,F,,4H20 (M = Ni, Zn, or Mn) have been described279as isostructural. The i.r. spectra of U02F2,nH,0 (n = 1-4), U02(0H)F,nH20 (n = 1 or 2), UO,F,,nHF,mH,O (n = 2, 1, or 0.5; m = 4,2 or 1.5) have been measured.280 Reaction of UO,(OAc), with [NH,OH]HF, in aqueous H F gave281 [NH,OH],[UO,F,], which decomposed thermally to UF,. By varying the reaction stoichiometries, [NH,OH] [UO,F,] was obtained; this decomposed to UF, and UO,F,. Reaction of UO,X, (X = C1, Br, or I) with the potentially chelating phosphine or arsine oxides (CH2PPh,0), or (CH,Ph2As0), (L-L) afforded2*, U02X, (L-L). When X = Cl or Br, the compounds were nonelectrolytesand probably polymeric, whereas the iodide was slightly conducting in nitrobenzene. Reaction of [Et,N],[UO,Br,] with liquid ammonia gave283[UO,(NH,),NH,] [NH,Br],, the ammonium bromide being detected by X-ray powder diffraction. The species UO,(NH,),NH, is presumably polymeric containing bridging amido groups. Deammoniation afforded UO,NH(NH,Br), which apparently may not have contained discrete linear UO, groups. Dissolution of UO,NH(NH,Br), in NH, at - 78 "C afforded UO2NH,2NH,, but reaction of [UO,(NH,),] [NH,Br], with methanol or with benzoic acid afforded UO,(OMe),,MeOH and [NH,] [UO,(O,CPh),], respectively. The neptunyl complexes, NpO2,I0,,2H,O, NpO2,IO,,O.5KI0,,2H,0, Np02(103)2,2H20, [Co(NH,)6i[(Np0,),(10,),i,4H,0 and [Co(NH3)6][(Np0,),(10,),],7H20 have been prepared.284 From i.r. spectral studies it appeared that Np0,,I03,2H,0 contained the Np'

o\

'0'

1-0

group whereas

/ I \ 0-Np. some of the others may contain bridging iodates, e.g.Np-0 Plutonyl nitrate, when treated285with COZ- at pH 4-7, gave PuO,CO,, which is isostructural with UO2CO,.

27'

V. P. Seleznev. A. A. Tsvetkov, B. N. Sudarikov, B. V. Gromov, and Yu. M. Khozhainov, Russ. J . lnorg. Chem., 1972, 17, 1644. A. A. Tsvetkov, V. P. Seleznev, B. N. Sudarikov, and B. V. Gromov, Russ. J . Znorg. Chem., 1973, 18, 5. A. A. Udovenko, Yu. N. Mikhailov, R. L. Davidovich, and V. G . Kuznetsov, Russ. J . Inorg., Chem., 1972,17, 1439. A. A. Tsvetkov, V. P. Seleznev, B. N. Sudarikov, and B. V. Gromov, Russ. J. Inorg. Chern., 1973, 18, 41 1. B. Sahoo and K. C . Satpathy, J . Inorg. Nuclear Chem., 1973,35,2136. S . S. Sandhu and S . S . Sandhu, Indian J . Chem., 1973,11,369. G. W. Watt and K. F. Gadd, Inorg. Chem., 1972,11, 3135. B. I. Blokhin, T. N. Bukhtiyarova, N. N. Krot, and A. D. German, Russ. J . Inorg. Chem., 1972, 17, 1742; A. Yu. Tsivadze, B. I. Muchnik, and N. N. Krot, ibid., p. 1746. J. N. Navratil and H. L. Bramlet, J . Inorg. Nuclear Chem., 1973,35, 157.

'" 279

280 28' 282 283 284

285

Author Index Aalbers, D. L., 255 Abalyaeva, V. V., 8, 13 Abdrakhmanov, R. S., 349 Abdullina, N. G., 453 Abduragimova, R. A., 64 Abe, M., 143, 145 Abel, E. W., 186, 189 Ablov, A. V., 227, 250, 261, 289, 323, 401 Abrahams, S. C., 173 Abramova, E. A., 78 Abramowitz, S., 174 Aburada, H., 456 Abu Salah, 0. M., 298 Abzhieva, E. M., 160 Ackerman, J., 117 Ackermann, R. J., 27 Adachi, G., 453 Adam, L., 293 Adams, D. B., 411 Adams, D. M., 92, 118 Adams, R. D., 272 Adamson, A. W., 100, 111, 236, 347, 377 Addison, A. W., 371 Addison, C. C., 224 Aderhold, C., 459 Adler, B., 29 Adlkofer, J. 430,433 Adrianov, 0. N., 427 Aganiyazov, K., 160 Agar, N. K., 245 Agarwal, N. K., 105, 226, 313 Agarwala, U., 113, 227, 341 Ageev, M. N., 71 Ageeva, E. D., 414 Aggarwal, R. C., 22, 56 Agrawal, M. M., 454 Agrawal, Y. K., 37 Ahlborn, E., 61, 117 Ahluwalia, S. C., 23 Ahmad, J., 460, 479 Ahmad, N., 8,394 Ahtee, M., 78 Ahuja, I. S., 476, 479 Aihara, M., 455 Ainscough, E. W., 394 Airoldi, C., 455

Aitken, G. B., 245 Akabori, K., 214 Akbar-Ali, M., 196 Akhtar, M., 207,475 Akiba,, K., 459 Akimov, V. K., 177 Akita, T., 228 Akiyama, T., 104 Alakaeva, L. A., 454 Albano, V. G., 200,301, 362 406 Alberti, G., 33, 452 Albertsson, J., 458 Albrecht, R., 197 Albridge, R.G., 409 Alcock, N. W., 260,291,474 Aleeva, G. P., 161 Alegranti, C. W., 438 Aleksandrov, G. G., 314 Alekseev, F. P., 453 Aleskovskii, V. B., 119 Alexander, M. D., 255, 257 Alexandrov, G. G., 48 Alferov, V. A., 108 Alich, A., 123, 201 Aliev, G. A., 457 Aliev, R. Ya., 100, 191, 331, 451 Alison, J. M. C., 415 Aliwi, S. M., 332 Al-Jarah, R. H., 114 Al-Karaghouli, A. R., 332, 45 1 Al-Kazzar, Z. M. S., 466,470 Al-Khafagi, F., 3 Allais, G., 71, 82 Allam, M. G., 431 Allan, M., 304 Allard, B., 464 Allcock, H. R., 122 Alleaume, M., 96 Allen, A. D., 357, 359 Allen, G. C., 7,96 Allin, B. J., 46 Allison, D. A., 207 Allison, G. B., 146 Allman, R., 43, 163 Allpress, J. G., 83

481 R

Allred, A. L., 432 Allulli, S., 33 Al-Niaimi, N. S., 332 Alper, H., 203, 206 Alt, F., 164 Alt, H., 95 Altukhova, 0. A., 161 Alves, 0. L., 455 Aly, M. M., 193, 222, 225, 431,476 Alyamovskaya, K. V., 32 Alyea, E. C., 8,21,22,223 Alymov, I. M., 27 Amaudrut, J., 13, 18 Ambe, F., 193 Ambe, S., 193 Amelinckx, S.,72 Amestoy, P., 82 Ametani, K., 108 Aminov, T. G., 51 Amit, M., 191 Amma, E. L., 285, 300 Amos, L. W., 67 Amosov, V. M., 161, 163 Anagnostopoulos, A., 460 Anand, S.K., 167 Anan’eva, L.V.,457 Anashkina, A. A., 331 Anderegg, G., 427 Andersen, K. K., 462 Anderson, N. H., 462 Anderson, J. S., 4, 71 Anderson, K. D., 40 Anderson, 0.P., 185,305 Anderson, T. J., 446 Ando, T., 332 Andrae, K., 26 Andreeva, M. I., 82 Andrelezyk, B.,242 Andresse, A. F., 44 Andretti, G. D., 318 Andrew, J. E., 311 Andrews, M., 131 Andrianov, V. G., 200 Andronov, E. A,, 408 Andruchow, W., jun., 144,468 Ang, H. G., 376

482 Angelici, R.J., 190, 332, 404 Angell, C. L., 140 Angelov, B., 297 Angenault, J., 64 Angoletta, M., 388 Angst, M., 438 Anisimov, K. N., 41 Annabi, F., 103 Ansell, G. B., 406 Anson, F. C., 109, 352 Anstis, G. R.,83 Antolini, L., 258, 313 Antonescu, L., 149, 163 Antonova, S. S., 160, 161 Antsyshkina, A. S., 379 Antti, B. M., 311 Anugul, S., 13 Aoki, T., 255 Aoyama, M., 136 Apers, D. J., 117 Apraksin, I. A., 33 Apsimon, J. W., 462 Araneo, A., 387,390 Aravamudan, G., 250, 396, 416 Arbin, C. G., 82 Archer, R.D., 144 Archer, L. J., 135 Aresta, M., 123, 129, 210 Arkhangel’skaya, 0. I., 416 Arkhipova, N. V.,333 Armit, P. W., 351 Armitage, I. M., 461,462 Armor, J. N., 95, 344, 345, 352 Armstrong, D. R.,2 Armstrong, R. L., 177 Arnold, G. P.,97 Artemenko, M. V., 305,306 Arzatullova, R. M., 19 Asher, L. E., 108 Ashley-Smith, J., 388 Ashworth, T., I89 Aslanov, L. A., 450 Asmus, E., 56 Asprey, L. B., 152, 174, 465, 467,469 Astakhov, A. I., 18,56 Astheimer, L., 177, 470 Astrov, D. N., 7 Atherton, N. M., 57 Atovmyan, L. O., 162, 163 Attali, S.,231 Attridge, C. J., 38 Atwell, R.W., 426 Atwood, J. L., 436,465 Aubke, F., 440 Audette, R.J., 227 Audibert, M., 119, 156 Auerman, L. N., 471 Auk, J. L., 331

Author Index Aurivillius, K., 118 Autti, C. J., 238 Avdagic, M., 114 Avdeef, A., 297 Averill, B. A., 36, 220 Aver’yanova, L. N., 15, 33, 83 Avilov, V. A., 44 Avinens, C., 119, 156 Avny, Y., 393 Avrill, D. F., 250 Axtell, D. D., 300 Aymonino, P. J., 32, 42, 64 Azzaro, M., 20

Babenko, N. L., 52 Babich, V. A., 457 Babievskaya, I. Z., 35 Bacci, M., 237, 243 Backes, J., 218 Baddley, W. H., 389 Baenziger, N. C., 404 Batzel, V., 232 Baffier, N., 103 Bagdasarov, Kh. S., 64, 143 Bagger, S., 264, 269 Bagnall, K. W., 466, 470 Bai, K. S., 273 Bailey, J., 301, 439 Bailey, N. A., 305 Bailey, R.A., 191, 371 Bailey, W. E., 451 Baillie, T. J., 231 Baird, M. C., 285, 374, 410 439 Bak, R.,49 Bakakin, V. V., 158 Baker, L. C. W., 165 Baker, R.W., 394,443 Baker, V. S., 165 Balashov, D. V., 15, 33, 83 Balashov, V. A,, 156, 160 Balch, A. L., 296, 343, 356, 403 Baldwin, W. H., 466 Balestrieri, F., 105 Balko, E. N., 371 Ball, A. W. L., 9 Ball, D. E., 95 Ball, R. D., 229, 356 Ballhausen, C. J., 180 Baluka, M., 177 Balundgi, R. H., 281,288, 317 Balzani, V., 110, 114 Bamford, C. H., 168, 187 Bancroft, G. M., 344 Bando, Y., 42 Bandoli, A., 269

Bandoli, G., 404, 475, 477 478 Banerjee, A. K., 147 Banerji, S. K., 333 Banks, C. V., 280 Banks, E., 102 Banninger, R.,260 Banzargashieva, S. D., 416 Baran, E. J., 32, 64 Baranovskii, I. B., 374, 376, 379, 384, 390 Baranowski, B., 98 Barbanel, Yu. A., 459,471 Barber, M., 64,89 Barberon, M., 97 Barbier, J. P., 195 Barbucci, R.,304, 332 Barclay, D. J., 352 Barefield, E. K., 259, 276 Bargon, J., 461 Barinskii, R. L., 74 Barker, M. G., 16,45, 64 Barkhanova, N. N., 331 Barlex, D. M., 364 Barnard, R., 469, 470 Barnes, J. C., 431 Barnett, B. L., 281 Barnett, K. W., 93 Barnhardt, D., 318 Barr, M. L., 332 Barraclough, C. G., 131 Barral, R.,145 Barrett, A., 165 Barrick, J. C., 170 Bars, O., 138 Barskaya, I. B., 35 Barsukova, M. L., 15 Bartecki, A., 51 Barth, P.,218 Bartlett, B. L., 119 Bartlett, N., 442, 443 Barton, J., 309 Bartram, S., 28 Basargin, N. N., 38 Bashioum, E. W., 455 Basitova, S.M., 178 Basolo, F., 345,317, 389 Bassi, G., 309 Basso-Bert, M., 20 Basson, S. S., 134 Basu, P. K., 252 Bates, J. B., 118 Battaglia, L. P., 406 Battistuzzi, R.,242, 281, 399 Batyr, D. G., 224,261 Bau, R.,122, 131,200 Bauchet, M., 50 Baucom, E. I., 296 Bauer, R.A., 307 Baumgartner, E.,332 Baxendale, J. H., 262, 347

483

Author Index Baybarz, R. D., 463,467, 465,471 Bayer, E., 4,41 Bayer, G., 15 Bazhin, N. M., 83 Bazuev, G. V., 7 Beale, J. P., 31 Bear, C. A., 189 Beattie, J. K., 119 Beauchamp, A. L., 306 Beaumont, P. M. H., 365 Beaver, J. A., 150 Beck, W., 142, 187, 279, 367, 368,419 Beck, W., 187,367, 368,419 Becker, C. A. L., 235 Becker, F., 67 Beckham, T. M., 260,261 Bedford, R., 302 Beg, M. A., 134 Behrens, H., 209,232 Beierbeck, H., 462 Bekebrede, W. R., 33,82 Bekkerman, L. I., 17 Belan, L. I., 146 Belcher, R., 64,396 Belevantsev, V., 244,444 Belford, R. C. E., 31 1 Belford, R. L., 50, 301, 310 Belichuck, N. I., 250,289 Bell, A. P., 25,40 Bell, B., 129, 358, 359 Bell, C. F., 192 Bell,J. D., 266 Bell, J. R., 309 Bell, J. T., 447 Bellerby, J., 209 Bellon, P. L., 301, 362, 439 Belluco, U., 364 Belousov, E. A., 332 Belov, N. V., 15, 32 Belucco, u., 404 Belyaev, I. N., 30, 33, 83, 146 Belyaev, R. A., 64,83 Belyaeva, V. K., 147 Ben-Bassat, A. H. I., 401 Bencze, L., 132 Bender, J., 50 Benemann, J. R., 128 BeneS, P., 158 Benetollo, F., 475 Benetti, G., 285 Benfield, F. W. S., 135 Bennett, J. P., 254 Bennett, L. E., 254 Bennett, M. J., 201, 356 Bensoam, J., 152 Beran, G., 399 Berch, M. L., 124 Berdinkov, V.M.,83

Bereman, R. D., 28, 75, 313 Beresneva, T. I., 77 Beresten, N. E., 158 Berezin, B. Ya., 68 Berg, R. W., 406,408,428 Berger, A., 315 Bergland, D., 270 Bergman, A. G., 156 Berjoan, R., 103 Berkooz, O., 102 Berkovskii, B. P., 147 Berlin, N. B., 456 Bernal, I., 26, 131, 145, 220, 356 Bernard, J., 103, 157 Bernard, M. A., 263 Bernheim, R. A., 352 Bernier, J. C., 41, 45, 158 Bernstein, E. R., 465 Bernstein, P. K., 263 Bertacco, A., 244 Bertaut, E. F., 160 Bertha, S. L., 454 Bertbold, H. J., 21 1 Bertrand, J. A., 242 Besrest, F., 96 Besse, J. P., 101 Bessonov, A. F., 15, 82 Beuter, A., 152 Bexman, S. A., 298 Beyer, L., 253 Bezman, S. A., 298 Bezrukov, I. Ya., 64,65 Bezukladnikov, A. B., 13 Bhacca, N. S., 462 Bhandary, K. K., 450 Bhat, A. N., 21 Bhat, G. A., 332 Bhatnagar, I. K., 63, 163 Bhatt, K., 37 Bhattacharya, P. K., 51, 280, 332 Bhattacharyya, A., 250 Bhatti, A. M., 431 Bhaumik, B. B., 61 Bhavsar, G. P., 222 Bhayat, I. I., 376 Bianchi Orlandini, A., 241, 251,294 Bianchi, A., 251 Bianco, V. D., 210 Biagini-Cingi, M., 314 Bichon, J., 4 Biedermann, H. G., 213,218 Bielanski, A., 43 Bierstedt, P. E., 161 Bifano, C., 102 Biggers, R. E., 467 Bigoli, F., 195 Bigotto, A., 247 Bigorgne, M., 27

Bijkerk, L., 376 Billings, G. K., 120 Binder, H., 94 Binnewies, M., 430 Biradar, N. S., 22, 58,253 Birch, C. G., 239 Birchall, T., 203, 337 Bird, P. H., 20 Birkelund, F., 191 Birkenberg, R., 49 Birker, P. J. M. W. L., 262 Birnbaum, E. R., 389,452 Birner, P., 305 Biryukov, A. A., 353 Bismondo, A., 477 Bissell, E. C., 122 Biswas, A. B., 63, 163 Bizri, 0. F., 43 Bjerrum, J., 331,438 Blackburn, J. R., 409 Blackmer, G. L., 266 Blackmore, T., 193 Blackwell, L. J., 224 Blagrove, R. J., 268, 308 Blaizer, M. M., 235 Blake, A. B., 311 Blake, D. M., 406 Blasse, G., 79, 154, 157, 228, 453 Bless, P. W., 49 Blessel, K., 396 Blight, D. G., 326 Blinn, E. L., 57, 226, 279 Blinov, V. A., 15 Blokhin, V. I., 466, 480 Blokhina, G. E., 146, 152 Bloor, J. E., 438 Bluestein, A., 308 Blum, H., 219 Blumenthal, W. B., 30 Bobbitt, J. L., 235 Bobkova, M. V., 161 Bocard, C., 145 Bocharov, V.V.,332 Bochkareva, V.A., 152, 153 Bock, C. R., 347 Bode, D. D., 467 Boden, G., 180 Bodner, R. L., 192,298,452 Bodyn, V. G., 222,227,261, 323 Bohland, H., 58 Boelhouver, C., 137 Boschen, I., 163 Bose, D., 162 Bose, R., 127 Bogdanov, A. P., 227 Bogdanov, G. A., 161 Bohres, E. W., 172 Boian, P., 165 Bojarski, K., 98

Author Index

484 Bok, L. D. C., 134, 464 Bokii, N. G., 39, 146 Bole, A., 469 Bolgar, T. S., 374, 375 Boller, H., 29, 44 Bol‘shakov, A. M., 177 Bol’shakov, K. A., 353 Bombieri, G., 472,474,475 Bonamico, M., 245,250,273 Bondarev, V. A., 138 Bonati, F., 421, 440 Bond, A. M., 48 Bondar, I. A,, 82 Bondarenko, V. V., 64, 83 Bonfoey, D. B., 289 Bonnett, J. J., 356 Bonnett, R., 58 Bonniol, A., 112 Booth, B. L., 187, 231, 381 Bor, G., 168,474 Borden, R.S . , 20 Boring, W. C., 438 Borisov, A. K., 15, 83 Borisov, V. V., 353 Borisova, L. V., 175 Bornand, J. D., 98, 138 Borodina, N. P., 29 Borodko, Yu. G., 2, 11, 24 Borzova, L. D., 423,452 Boschmann, E., 396 Bose, K. S.,293, 396 Bose, N., 275 Both, E., 45 Bottari, E., 332 Bottei, R.S., 20 Bottomley, F., 345, 356, 358 Bouaziz, R.,16, 158 Boucher, C., 16 Boucher, L. J., 197, 198,262 Boudreaux, E. A,, 6 Boulle, A., 104 Bouloux, J.-C., 49, 64 Bounsall, E. J., 364 Bow, J. J., 262 Bourgeois, L., 158 Bowden, J. A., 90, 131 Bower, B. K., 116 Bower, W. S., 156 Bowers, R. H., 280 Bowmaker, G. A., 298 Bowman, A. L., 97 Bowman, J. T., 260 Boyd, G. E., 118 Boyd, P. D. W., 9 Boyer, P., 36 Boylan, M. J., 209 Bozhelvol’nov, E. A., 110 Bradford, C. W., 354 Bradley, D. C., 8, 223, 236 Bradley, W. L., 138 Brady, J. D., 465

Braganza, D. A., 33 Braibanti, A., 287 Brainina, E. M., 36 Brainina, 2.M., 39 Braithwaite, M. J., 246, 394 Braitsch, D. M., 69 Bramekamp, K. J., 19 Bramlet, H. L., 480 Brandi, G., 471 Brandenburg, N. P., 472 Brand, A., 88 Brandt, A. O., 104 Bratishko, V. D., 76 Brattas, L., 4 Brauer, D. J., 28 Braiir, G., 43, 73 Bravard, D. C., 145 Brazier, J. N., 423 Breckenridge, J., 273 Bredesen, D., 168 Breeze, P. A., 89 Bregeault, J.-M., 309 Breitinger, D., 12, 439 Bremner, P. R., 5 Brennan, J. B., 426 Brennan, T. F., 131 Bresier, L. S., 2 Bressan, M., 246 Breusov, 0. N., 71 Brewer, P., 58 Briabanti, A., 195 Brice, M. D., 91 Bricker, C., 118 Bridges, D. L., 225 Briggs, D., 41 1 Briggs, J. M., 461 Bright, D., 302 Brink, R. W., 190 Briscoe, G. B., 213 Brisdon, B. J., 243 Brisse, F., 82, 99 Britnell, D., 154 Brixner, L. H., 160, 161 Brnicevic, N., 84 Brobyshev, V. N., 71 Brock, C. P., 233, 392 Brockliss, L. D., 298 Broda, H., 73 Brodersen, K., 254 Bronzan, P., 33 Brookes, P. R., 394 Brookes, R. W., 305 Brooks, J. J., 251, 397 Broomhead, J. A., 346 Brough, B. J., 200 Browall, K. W., 406 Brower, W. S., 31 Brown, A. G., 177 Brown, C. K., 365 Brown, D., 464,466,469,470 Brown, D. A., 142

Brown, D. H., 101, 102, 150, 161 Brown, G. F., 145 Brown, G. H., 105 Brown, I. D., 12, 15, 118, 178 Brown, J. J., jun., 63 Brown: J. N., 241 Brown, M. E., 63,241 Brown, M. L., 207 Brown, S. D., 119 Brown, T. M., 37,75 Browning, I. G., 265 Browning, J., 271 Brownstein, S., 77 Brubaker, G. R.,258 Bruce, D. M., 169 Bruce, M. I., 200,201, 298, 337, 338,406 Briiser, W., 68 Bruice, T. C., 257 Brun, C., 469 Brunelli, M., 471 Brunner, H., 191,209 Brunton, G., 30, 118, 144 Brush, J. R.,315 Brushmiller, J. G., 255, 263 Brusset, H., 64, 82 Bryukher, E., 457 Bryukhova, E. V., 27 Buchbinder, M., 95 Buchkova, R.T., 456 Buchler, J. W., 86 Buckingham, A. D., 339 Buckingham, D. A., 258,264 Bucksch, R., 177 Budiu, T., 16 Budo-Zahonyi, E., 332 Biinzli, J. C., 84, 85 Burger, H., 21, 25 Buisson, D. H., 312 Bukanova, A. E., 379 Buketov, E. A,, 59 Bukhalova, G. A., 156 Bukhtiyarova, T. N., 480 Bulgak, I. I., 224 Bullock, J. I., 78, 469, 470 Bulycheva, T. V., 373 Bunel, S.,293 Burclova, J., 158 Burkhardt, T. J., 126 Burdett, J. K., 270, 420 Burg, A. B., 233 Burger, K., 219 Burgess, J., 174, 331 Burke, J. M., 284, 408, 415, 428 Burley, J. W., 187 Burlitch, J. M., 123, 124, 185, 193 Burmeister, J. L., 27 Burnham, R. A., 186

48 5

Author Index Burns, J. H., 463,465,466 Bums, R. C., 128 Burriel-Marti, F., 34 Bursh, T., 406 Bursill, L. A., 137 Buryak, N. I., 280 Burzina, T. S., 432 Busch, D. H., 214,215,255, 258,259,277,292,296, 332 Buser, H. J., 21 1 Busetto, C., 248 Busetto, L., 364 Busev, A. I., 52, 177, 427 Bushnell, G. W., 61, 395 Buslaev, Yu. A., 77, 133, 152 153, 177 Buss, B., 122, 163 Butenkova, T. V., 344,352 Butherus, A. D., 452 Butler, I. S., 41, 90, 188 Butler, K. D., 344 Butler, W. M., 210 Buttino, B. J., 462 Butukhanov, V. L., 119, 157 Buxton, G. V., 5 Buzina, N. A., 365 Byers, W., 195, 266, 284, 398 Cadiot, M., 66 Cady, G. H., 66,423,459 Caglio, G., 388 Cahen, D., 298 Caira, M. R., 53,444 Calabrese, A., 64 Calderazzo, F., 1,40, 169, 221,225,247 Calderon, J. L., 124 Calhoun, H. P., 126 Calligaris, M., 248, 268 Calves, J. Y., 152 Calvo, C., 63, 64,65, 178, 244,325 Cameron, A. F., 237 Camp, M. J., 28,446 Campbell, J. A., 20 Campbell, M. J. M., 238 Camus, A., 383 Candela, G. A., 165 Cannas, M., 303 Cannell, L. G., 24 Cannillo, E., 16 Canty, A. J., 339 Capestan, M., 101 Card, D. W., 238 Cardwell, T., 396 Carey, E. F., 55 Cariati, F., 193, 248,436 Carlisle, G. O., 54, 55, 250, 316 Carlson, T. A., 96

Carnall, W. T.,454 Carpy, A., 61, 82 Carr, B., 302 Carr, S. G., 9 Carroll, B., 64,453 Carroll, W. E., 203 Carta, G., 303 Carter, H. A., 440 Carter, R. L., 118 Carturan, G., 404 Carty, A. J., 203,232, 337, 369, 399 Carunchia, V.,269 Carver, J. C., 96 Casalot, A., 42, 61 Casellato, U., 478 Casey, A. T., 48, 56 Casey, C. P., 126 Cassol, A., 468 Cassoux, P., 271 Castro, C. E., 217 Cattalini, L., 397 Caughlan, C. N., 20 Cauletti, C., 109, 226, 400 Caulton, K. G., 21 1 Causse, I., 24 Cavell, R. G., 21, 109, 195 284,398 Cecconi, F., 272 Celap, M. B., 264 Cenini, S., 363 Cervone, E., 109,226,400 Cesarotti, E., 479 Cetina, R., 332 Cetinkaya, B., 91 Chaban, N . F., 175 Chackraburtty, D. M., 474, 477 Chaikovskii, S. P., 50 Chaisson, D. A., 346 Chakrabarty, D. K., 63, 163, 178 Chakravorti, M. C., 173, 177, 179 Chakravorty, A,, 218,243, 281, 288, 317 Chamberland, B. L., 12, 60 116 Chaminade, J. P.,76,77,82 Chan, F. L., 32,82 Chan, L., 95 Chan, L. Y. Y., 189 Chan, S. C., 255 Chan, S. F., 255 Chan, T. D., 140 Chandra, S., 220, 348 Chandra, S. V., 280 Chandrasekharen, M., 396 Chang, J. R., 191 Chang, S. C., 332 Chmg, S. W.-Y. N., 124

Chang, Y. A., 97 Chapman, K., 226 Charreton, B., 165 Charvillat, J. P., 466, 468 Chase, L. L., 96 Chasteen, N. D., 41 Chatt, J., 120, 129, 130, 136 167, 171, 233, 357, 358, 359,361,403 Chaudhry, S. C., 241 Chaudhuri, M.K., 173, 179 Chawla, K. L., ‘68 Cheam, V., 333 Chebotarev, N. T.,177, 180, 453 Chebotin, V. N., 30 Chechegoeva, E. V., 133 Cheetham, N., 43 Chekhovskoi, V. Ya., 68 Chen, C. N., 436 Chen, H.Y., 72 Chen, S., 253 Cheney, G. E., 332 Cheney, J., 431 Cheney, R., 279 Chepiga, M. V., 97 Cheredruchenko, I. F., 15 Cheremisina, I. M., 153, 398 Cherepanova, E. A., 6 Cherkasova, T.G., 365 Chernaya, N. V., 52 Chernikov, S. S., 400 Chernov, R. V., 12, 17 Chernukha, T. S., 37 Chernyak, A. S., 77 Cherwinski, W. I., 296, 394, 403 Cheung, T.-T., 459 Chevrel, R., 138 Chia, L. S., 207 Chiacchierini, E., 105 Chieh, P.C., 399,406 Chien, J. C. W., 116 Chiesi-Villa, A., 314 Chikanova, M. K., 13 Chincholkar, V. S., 64, 82, 83, 157 Chini, P., 362 Chirina, N. A., 28 Chistola, V. D., 38 Chistyachenko, I. N., 52 Chistyakov, S. I., 3 Chiswell, B., 196, 214, 252 Chivers, T., 11 Choplin, A., 242,332 Choppin, G. R., 454,456, 468

Chopra, S. L., 225 Chow, K. K.,287, 399 Chow, S. T., 314 Choy, V. J., 381

Author Index

486 Christensen, A. N., 449, 450, 452 Christiansen, V. H., 27 Christophliemk, P., 236 Chudaeva, G. V.,238 Chuklantsev, V. G., 32, 82 Chumakov, V. G., 404 Chung, H. N. P., 106 Chung, J., 113 Churchill, M. R.,124, 209, 213,275,298 Churikova, I. M., 332 Chuvaev, V. F., 31, 34, 65 Ciani, G., 301,406 Clach, S., 459 Clack, D. W., 192 Clapp, C. H., 299, 397 Clardy, J., 207 Clark, D. T., 41 1 Clark, D. W., 118 Clark, G. R., 294, 306 Clark, H. C., 296, 394,403 Clark, R.,201 Clark, R. J. H., 13, 61 Clary, J. C., 254 Clay, R.M., 301 Clearfield, A., 31, 356 Clegg, W., 185 Clemens, J., 349 Clement, D. A., 365 Clemente, D. A., 404,475, 478 Clerbols, L., 158 Cloyd, J. C., 246 Cocke, D. L.,5,460 Codding, P. W., 69 Coe, J. S.,397 Cohen, D., 426 Cohn, K., 246 Coldbeck, M., 187 Cole, T. C., 438 Cole-Hamilton, D. J., 351 Coleman, C. F., 467 Coleman, W. M., 250 Coles, M. A., 13 Coletta, F., 429 Colin, G., 8 Colleman, J. P., 269 Collier, M. R., 25 Collin, G., 97 Collins, M., 471 Collins, R.K., 9 Collins, R.L., 223 Collman, J. P., 206, 233, 339, 362 Colovos, G., 145 Colsmann, G., 60 Colton, R.,90, 131, 169 Colville, N. J., 188 Commons, C. J., 90,131 Conder, H. L., 228

Condren, S. M.,46 Connolly, N. G., 95 Connor, J. A., 64,89,90 Conroy, L. E., 4 Constant, G., 218 Constantino, U., 33,452 Constanzo, D. A., 467 Conway, D. C., 171 Cook, D. F.,274,278 Cook, P. M., 423 Cookson, P. G., 280 Cooper, D. G., 394,429’ Coops, M.S., 465 Coope, V. W., 253 Copeland, V. C., 305 Coppens, P., 93 Copperthwaite, R. G., 8, 223 Copsey, D. N., 391 Corain, B., 375 Corbett, J. D., 30,446,459 Cord, P. P., 119 Cordfunke, E. H.P., 244,472 Corefield, P. R.,246 Corfield, P. W.,299 Corradi, A. B.,406 Comu, R.J. P., 201 Corsmit, A. F., 154,331,438 Cosgfove, J. G., 223 Cossee, P., 2 Costa, G., 241, 260 Cot, L.,119, 156 Cotton, F. A., 41,91, 124, 139,140, 141, 174,207, 272,281, 339,362 Cotton, S. A., 223,451 Couchot, P., 17, 46 Coucouvanu, D.,12,404 Couldwell, M. C., 114 Courtine, P., 119 Coutinho, C. B., 138 Coutts, R. S. P., 7, 10, 27 Coutures, J., 83 Couturier, Y., 332 Cova, G., 172 Coville, N. J., 90 Cowley, A. H., 208 Cox, J. L., 434 Cox, L. E., 142 Crabtree, R. H., 130, 357 Cradock, S., 171, 186 Craig, D. C., 31 Cramer, J. L., 207 Cramer, R.E., 289,451,461 Cras, J. A., 297, 313 Crawford, J. R., 345 Crawford, T. H., 249, 251, 397 Crawford, V. H., 308 Crease, A. C., 95 Cresp, T. M., 19 Creutz, C., 348

Crews, E. W., 304 Crichton, O., 191,270, 358 Cristini, A,, 303 Croatto, U., 475 Crociani, B., 87,404 Cromer, D. T., 406,465 Cronin, J. T., 195 Crosby, G. A., 389 Crow, J. P., 189 Crozat, M. M., 356 Crumbliss, A. L.. 260 Crutchfield, D. A,, 55 Cuche, C., 63 Cullen, D., 171, 356 Cullen, W. L., 189 Cullen, W. R., 189, 206, 207, 208,232 Cummins, D., 265 Cummings, S. C., 221, 241, 397 Cunningham, A. J., 213 Curtis, M. T., 96 Curtis, N. F., 259, 273, 274, 278,304,332 Czaban, J. D., 426 Dabrowiak, J. C., 214, 215, 259 Dadgar, A., 456 Dammgen, U., 21 Dahl, L. F., 185, 186, 230, 231,236,423 Dallavalle, F., 287 Dalton, J., 246 Daly, J. J., 115 Damaskina, 0. N., 261 D’Amow, H., 163 Damien, D., 466,468,469 Damien, N., 468 Dammann, C. B., 379 Daran, J.-C., 218 Dang, T. P., 365 Danil’tsev, B. I., 15, 32 Danilczuk, E., 253 Danilina, L. I,, 367 Danot, M., 4 Danzer, H., 187 Danzer, W., 142 Dapporto, P., 251, 272 Darensbourg, D. J., 87, 124, 172 Darling, J. H., 393 Darlington, C. N. W., 78 Darriet, B., 82, 157 Darriet, J., 49 Dartiguenave, M., 285 Dartiguenave, Y., 285 Das, A. K., 197 Das, P. N. M., 35 Dash, K. C., 439

487

Author Index Dash, R. N., 433 Dau, E., 191 Dauerman, L., 16 Davankov, V. A., 314 David, P. G., 222, 225 Davidovich, R. L., 480 Davidson, D. E., 137 Davidson, P. J., 24,91 Davies, M. B., 104 Davies, N., 39 Davis, B. R., 145, 220 Davis, D. G., 100, 148, 435 Davis, P. H., 301 Davis, R. E., 463 Davis, S.R., 106 Davison, A., 124,426 Day, E. D., 195,284, 398 Day, J. P., 90 Day, K., 112 Day, P., 357 Dayal, R. R., 82 De, R. L., 112 Deacon, G. B., 280 Dean, W. K., 186, 190, 205 Deane, M., 132 Dearman, H. H., 48, 102 Deb, K. K., 438 Debaerde Maeker, T., 406 De Beer, J. A., 205 De Boer, B. G., 174,209 De Boer, J. J., 302 De Boer, J. L., 1 De Bolster, M. W. G., 104, 105,194 De Brabander, H. F., 332 De Broin, C. E., 223 Debuyst, R.,117 Decinti, A., 293 Decker, N., 263 Deckers, J. J., 264 Deeming, A. J., 356 De Filippo, D., 402 Deganello, G., 364,404 Degetto, S., 397,472,475 Degischer, G., 468 Degueldre, L., 158 Dehand, J., 200 Deheyes, L. J., 255 De Jong, B. H. W. S., 156 De Jong, J. A. M., 365 Dekanenko, V. M., 71 Dekhanov, N. M., 5 De Koch, R. J., 41 Delamerre, C., 32 Delavignette, P., 71 Delbaere, L. T. J., 146, 206 Delia, T. J., 195, 194 De Liefde Meijer, H. J., 10 De Lima, C. G., 219 Dellien, I., 456 Delphin, W. H., 144

Del’pino, K., 454 De Luca, J. P., 97, 102 De Meester, P., 238, 306,426 Demenev, A. V., 156 Den Heijer, J., 194 De Montauzon, D., 228 Denisov, N. T., 13 Denisova, T. B., 36 Denne, W. A., 151 Denning, R. E., 463 Dent, S. P., 410 Deodata de Azevedo, M., 162 Deppisch, B., 64 De Raoli, G. G., 476 Dereigne, A., 350 Dernier, P. D., 4 De Rumi, V. B., 104,332 De Ryke, R., 289 Deschanvres, A., 71, 83, 151 Desgardin, G., 83, 151 Despotovic, Z., 84 Dessy, G., 245,250, 273 Deutch, J. M., 39 Deutsch, E., 108 Dev, R., 66,423,459 Devale, S., 58 Devillanova, F., 402 Devin, C., 13 Dewan, J. C., 162 De Wit, D., 168 Dhindsa, K. S., 23 Dias, R. M. A., 477 Dickens, P. G., 60,151 Didenko, E. A,, 456 Diderberg, O., 301 Dieck, R. L., 455 Dieckmann, U., 145 Diedershagen, H. L., 94 Diemann, E., 42, 61, 117, 166 Dierdorf, D. S., 217 Dietz, K. P., 305 Dietzer, F., 332 Dietzsch, W., 57 Dikareva, L. M., 374, 379 Dillon, K. B., 310 Dilworth, J. R., 171, 358, 361 Dimbylow, C. S., 151 Dinein, J. S., 253 Dines, M. B., 299 Diogenov, G. G., 119 Dion, C., 59 Dirreen, G. E., 189 Distefano, G., 202 Di Vaira, M., 251,294 Dixneuf, P., 91 Dixon, E. E., 308 Dixon, K. R., 395,401 Djordjevid, C., 66, 75, 85 Doadrio, A., 67 Dobbie, R. C., 126 Dobbs, B., 38

Dobson, G. R., 91, 125 Dodd, D., 260 Doedens, R. J., 310,406 Doemeny, P. A., 130 Dolcetti, G., 172, 233, 362 Dollimore, L. S., 264, 373 Dolphin, D. H., 239 Domingos, A. J. P., 356 Dondoni, A., 397 Donohue, P. C., 97 Doretti, L., 470 Dorfman, A. E., 148 Dorfman, Ya. A., 44 Dori, Z., 150, 304 Dorman, W. C., 138 Dormond, A., 2,26 Dorner, H., 270 Dorokhova, E. N., 164 Doronzo, S., 210 Dorrian, J. F., 16 Dosser, R. J., 167 Dotson, R. L., 196 Douek, J. A., 21 Douglas, B. E., 262, 264, 266 Douglas, W. E., 201, 327, 399 Douglas, W. M., 190, 205 Dove, M. F. A., 117 Doyle, M., 456 Drago, R. S., 296 Drakesmith, A. J., 379 Dremin, A. N., 71 Dreos, R., 247 Drew, J., 241, 275 Drew, M. G. B., 9, 86,144, 150,154,299,443 Drew, R. E., 66 Dreyer, R., 458 Driessen, W. L., 193 Driessen-Fleur, A. H. M., 195 Drobot, D. V., 173 Drobotenko, V. V., 60 Dropesky, B. J., 27 Druin, V. A., 471 Dubina, N. N., 148 Dubler, E., 325 Dubois, R., 461 Dubois, T. D.,295 Dubovitskii, V. A., 27 Dubrov, Yu. N., 143, 147 Duclos, J. M., 331 Duff, E. J., 239 Duff, J. M., 372 Duffy, D. J., 227,263, 351 Dufresna, A., 219 Duggen, D. M., 274 Duibanova, V. G., 414 Dukes, G. R., 315 Dukhanin, V. S., 228 Dulova, V. I., 332

Author Index

488 Dumler, J. T., 409 Dumora, D., 98, 102 Dunaevskaya, N. A., 65 Duncan, C. S., 431 Duncan, J. L., 245 Dunell, B. A., 254 Dunks, G. B., 127 Dunski, N., 249 Dunster, M. O., 186 Dupont, L., 301 Du Preez, J. G. H., 467,470 Duran, J. A., 332 Durif, A., 17, 32 Durney, M. T., 123 Durrett, D. G., 148, 471 Duschek, O., 431 Dustin, D. F., 127 Dustov, U., 19 Dutt, N. K., 451 Dutta, R. L., 55 Dutta-Ahmed, A., 6 Duyckaerts, G., 466 Dvornikova, L. V., 457 Dwivedi, C. D., 333 Dwivedi, J. S., 113, 227 Dwyer, F. P., 359 Dwyer, M., 258 Dyachkova, T. S., 471 Dyakov, V. A., 82 Dyatkina, M. E., 57 Dyatlova, N. M., 331 Dyer, D. S., 20 Dyke, J. M., 7 Dyrek, K., 43, 59 Dyrkacz, G., 116 Dyrssen, D., 332 Dyunov, P. V., 82 D’Yvoire, F., 103 Dzhiyanbaeva, R. Kh., 19 Dziembaj, L., 158 Dzierzgowski, S., 5 Eaborn, C., 410,421 Eachus, R. S., 340 Earley, J. E., 349 Easteal, A. J., 15, 16 Eastman, M. P., 467 Eaton, G. R., 47, 198, 351, 356 Eaton, S. S., 47, 198, 262, 351, 356 Ebel, H., 64 Ebina, F., 265 Ebinger, H. S., 190 Ebsworth, E. A. V., 171, 186, 381 Eckberg, R. P., 106 Eckstein, G., 452 Edagawa, E., 463 Edgar, B. L., 227

Edmundson, S. R.,250 Edshammar, L. E., 392 Edwards, A. J., 77, 252 Edwards, D. A., 153, 176, 299 Edwards, P. A., 69 Eeckhaut, Z., 332,438 Efimov, A. I., 44 Efimov, 0. N., 8,44 Efimushkina, L. I., 30 Efraty, A., 91 Efremov, V. A., 156, 158 Eholie, R. E., 96 Ehrenson, S. E., 410 Eichhorn, G. L., 328 Eick, H. A., 450,452 Einstein, F. W. B., 66, 189, 198,208,232, 388, 392 Einstein, J. R., 279 Eisenberg, R., 204, 338, 356 Ekberg, J. O., 27 Ekstrom, T., 15, 60, 79, 137, 151 El-Aggan, A. M., 143 El-Azmerlli, M. A., 143 Elbinger, G., 211 Elding, L. I., 407 Elegant, L., 20 Eley, D. D., 452 El-Ezaby, S., 476 El-Ezaky, S., 222 El-Haty, M. T., 431 Elias, H., 3 Eliseev, S. S., 143, 144, 146, 156 Elix, J. A., 19 Eller, P. G., 286, 295, 402 Ellermann, J., 209, 232 Ellestad, 0. H., 433 Ellis, J. D., 5 Ellis, P. D., 207 El-Sayed, L., 291 Elschenbroich, Ch., 94 El-Shamy, H. K., 150 Elson, C. M., 233 Elson, R. E., 244 El-Tonkhy, A., 291 Emad, A., 298, 305 Emel’yanov, V. S., 44 Emel’yanova, I. A,, 177 Emerson, K., 298, 305 Emori, S., 314 Emoto, K., 150 Endell, R., 88 Endicott, J. F., 258, 260, 266, 346, 378 Enemark, J. H., 210 Engelhardt, L. M.,241, 308 Engelmann, A., 94 Epstein, E. F., 26, 356 Epstein, P., 331

Ercoli, R., 41 Eremenko, N. K., 423 Eremenko, V. N., 97 Eremin, M. V., 107 Eremin, Yu. G., 148 Erickson, L. E., 429 Erikson, M. D., 429 Ermakov, A. N., 49,147 Ermakova, M. P., 71 Ernst, R. D., 122 Eroshok, B. G., 267 Ershova, M. M., 133 Ershova, Z. H., 28 Eshchenko, L. S., 224 Espenson, J. H., 115 Estienne, J., 121, 241 Ettorre, R.,429 Euier, R. A., 258 Evans, D. F., 462 Evans, G. O., 189,190 Evans, H. J., 130 Evans, H. T., jun., 165 Evans, I. P., 343 Evans, S., 116 Eventova, I. I., 49 Everett, G. W., jun., 47, 350 Evstaf eva, 0. N., 426 Evtushenko, I. Ya., 455 Ezerskaya, N. A,, 389 Ezhkova, Z. I., 50 Ezhov, A. I., 156, 308, 423, 452,454 Ezhov, V. K., 78 Ezhov, V. M., 15, 33, 83 Ezhov, Yu. S., 158 Fabretti, A. C., 397 Fabrizzi, L., 304, 332 Fachinetti, G., 6, 221 Fackler, J. P., 284, 297, 311, 398,408,415,428 Fadeeva, N. V., 7 Faggiani, R., 64 Falconer, W. E., 42 Faleschini, S., 470 Falk, K. E., 332 Fal’kengof, A. T., 139 Fallani, G., 251, 272 Faller, J. W., 460 Fantucci, P., 390 Fanwick, P. E., 409,420 Faraglia, G., 470 Faraone, F., 380 Farber, M., 49, 158 Fares, V., 245, 250, 273 Farina, R. D., 58 Farmer, J. B., 313 Farmery, K., 258, 259 Farnham, P. H., 233 Farrington, D. J., 217

Author Index Faucherre, J., 333 Favero, G., 370, 375 Fawcett, J. P.,168 Fay, R. C., 21, 53 Fayolle, J. P., 83 Fazakerley, G. V., 444 Fealey, T., 349 Featherstone, J. L., 57 Fedorov, A. A., 162 Fedorov, L. A., 39 Fedorov, V. E., 137, 153 Fedoroyako, L. I., 34 Fee, W. W., 292 Feibush, B., 461 Feige, P.,458 Feitnecht, W., 107 Feldberg, S., 407 Felix, N. S., 59, 63 Felps, S., 119 Feltham, R. D., 343 Fenske, R. F., 189 Fenster, A. E., 41 Fenton, D. E., 302, 311 Ferguson, J., 107,207 Ferguson, J. E., 361 Fergusson, J. E., 178,213, 356,361,406 Fernando, Q., 299 Fernando, W. S., 92 Fernandopulle, M. E., 213 Ferner, R., 27 Ferraro, J., 285 Ferraro, J. R., 454 Ferraudi, G., 378 Feschotte, P., 98 Fetchin, J. A., 284, 398 Field, J. S., 392 Figgis, B. N., 4, 8, 47, 109, 198 Figlarz, M., 137 Figurovskaya, V. N., 427 Filatenko, L. A., 156 Filipovic, I., 332 Filippov, A. A., 404 Filippov, V. K., 455 Firsova, L. F., 455 Fischer, E. O., 88, 92, 127, 203 Fischer, J., 30 Fischer, K., 100, 115 Fischer, R. D., 151, 160, 161,434,460 Fischer, R. G., 297 Fish, R. H., 316 Fisher, D. R., 202 Fiti, M., 262, 347 Fitzgerald, R. J., 381, 382 Fitzsimmons, B. W., 221 Flack, H. D., 392 Flahaut, J., 8, 96,97 Fleckenstein, J., 30

489 Fleischauer, P.D., 100 Fleischer, E. B., 325 Fleischer, M., 98 Fletcher, S. R., 122 Flint, C. D., 110, 114 Florke, 0.W., 15 Flood, T. C., 137 Floriani, C., 6, 221, 225, 247 Flowers, J. M., 48 Flynn, C. M., jun., 50 Fochi, G., 6 Forster, M., 245 Foffani, A., 202 Folkers, J. B., 98 Folkesson, B., 57, 171, 344, 357, 383 Fomicheva, K. K., 161 Ford, G. J., 331 Ford, P. C., 346, 347 Forder, R. A., 2, 121 Ford-Smith, M. H., 444 Form, G. E., 51 Forrest, H., 452 Forsellini, E., 472,474,475 Forster, D., 364 Foster, R. J., 192,452 Foster, S. I., 119 Fotiev, A. A., 59, 64, 157 Fouassier, C., 156 Foust, A. S., 88 Foust, R. D., 347 Fowles, G. W. A., 74, 86, 154 Fox, J. P.,260 Frais, P.W., 167, 178 Francis, B. R., 135 Franco, J. I., 361 Frank, S. N., 109 Franke, R., 444 Fransson, G., 305 Franzen, H. F., 72, 156 Fraser, A. R., 20 Fraser, C. J. W., 174 Frasson, E.,434 Fratiello, A., 34, 454 Frazer, F. H., 331 Frazer, M. J., 226 Frazier, R. H., jun., 130 Frech, G., 226 Frederick, C. G., 108 Fredette, M. C., 170 Frenz, B. A., 41, 139, 140, 141 Fresco, J. M., 288 Freundlich, W., 161 Frey, M., 82 Frey, W. A., 117 Fridman, A. Y., 331 Fridman, S. L., 30 Friedberg, F., 252 Friedman, R. M., 30 Fries, D. C., 284, 398

Frisch, P. D., 230 Fritchie, C. J., 324 Fritz, H. P., 265 Fruchart, E., 97 Fruchart, R., 97 Fruchier, A., 462 Frunze, M. F., 37 Frye, H., 190 Fuchs, J., 163 Fuss, H., 64 Fuger, J., 469 Fuhrhop, J. H., 100,148,435 Fujieda, S., 151 Fujii, Y., 263, 265, 247 Fujinaga, T., 150 Fujito, J., 256 Fukui, K., 34 Fukushima, E., 152,465 Fukuyo, M., 222 Fukuzumi, K., 136 Fumita, Y., 50 Funke, A., 21 1 Furuhashi, A., 235, 300,430 Furukawa, Y., 265 Fusi, A., 248 Fusu, I. L., 261 Gaboriaud, F., 224 Gadd, K. F., 466,480 Gadia, M. K., 476 Gaegar, F. M., 376 Gaffield, W., 316 Gafney, H. D., 347 Gagliardi, E., 222 Gaidaenko, N. V., 143, 144, 146, 156 Gaisinskaya, 0. M., 136 Gal, A. W., 313 Galbraith, A. R., 418 Galdysz, J. A., 210 Gale, R., 391 Galizziolo, D., 193 Galliart, A., 37 Galsbsl, F., 376 Galy, J., 15, 32, 49, 59, 61, 64,79, 82, 157, 158 Galzigma, L., 475 Gambaro, A., 429 Gambino, S., 41 Gamsjaeger, H., 107 Gandolfi, M. T., 110 Ganelin, V. L., 128 Ganescu, I., 261 Ganguli, K. K., 316 Gans, P., 88, 331 Gansow, 0. A., 463 Gantsev, A. G., 254 Gantz, M.,476 Gaponenko, V. A., 107 Garaj, J., 310 Garbuz, V. V., 17 3

Author Index

490 Garces-Muiioz, J. M., 33 Garcia, E. K., 438 Garcia-Fernandez, H., 476 Card, G. L., 119 Gardhammer, G., 457 Gargano, M., 211 Garifdzhanova, N. M., 453 Garifyanov, N. S., 95, 349 Garkushenko, T. L., 161 Gamer, C. D., 117 Garner, C. S., 110 Garnett, J. L., 70 Garnovskii, A. D., 22,251 Garrard, J. E., 169 Garrov, P. E., 297 Gash, A. G., 300 Gatehouse, B. M., 79 Gatilov, Yu. V., 83, 146 Gatteschi, D., 272, 295 Gatti, G., 24 Gaughan, A. P., 338 Gaultier, M., 119 Gaus, P. L., 260 Gavrilova, I. V., 427 Gaylor, J. R., 349 Gazo, J., 303, 310 Gebala, A. E., 325, 465, 471 Gebert, E., 454,472 Geiger, W . E., 272 Geils, R.,43 Gel’fman, M. I., 417,420, 427,428 Gellatly, B.,469, 470 Gellings, P. J., 15 Gel’man, A. D., 466,480 Genchel, V. G., 19 Gene, R. J., 315 Geoffroy, G., 251,397 George, R. D., 359 George, T. A., 129, 135, 387 Georgiou, D., 365 Gerard, J., 36 Gerasenkova, A. N., 327 Gerbelev, N. V., 222, 227, 261,294, 323 Gergely, A., 332 Gerloch, M., 8 German, A. M., 84 Gertner, M. D., 95 Gervais, D., 20 Get’man, E. I., 119, 156, 157, 160,453 Geurts, P. J. M., 300 Gheorgiu, C., 163 Ghilardi, C. A., 247, 251 Ghotra, J. S., 446,456,462 Ghosh, N. N., 250 Ghosh, S. N., 192 Giannoccaro, P., 211 Giannotti, C,, 127 Gianoglio, C., 64

Gibalo, 1. M., 85, 86 Gibb, T. C., 354 Gibb, V. G., 462 Gibbs, G. V., 96 Gibson, J. F., 8,223 Gibson, K., 264,269 Gicquel, C., 16, 158 Gidney, P.M., 374,402 Giesder, U., 10 Giezydski, R., 5 Gill, D. F., 340, 394 Gill, J. B., 244 Gillard, R. D., 51, 255, 264, 265, 371, 373, 374, 375, 403,422 Gillespie, R. J., 77, 212 Gillman, H. D., 244 Gilman, H., 466 Gilroy, M., 254 Gilson, T. R., 43 Gindin, L. M., 161 Gingerich, K. A., 5, 460 Ginsberg, A. P., 171,173 Ginsburg, G. D., 286,407, 427 Giordano, P., 91, 362 Giovanoli, R., 107 Girgis, A. Y ., 265 Girgis, N. N., 59,63 Girling, R. L., 285 Gironx, E. L., 324 Giusto, D., 172, 173 Gizhinskii, A. R., 160 Gladden, J. K., 235 Gladkaya, N. S.,427 Gladysz, J. A., 120 Glass, W. K., 142 Glavic, P., 469 Glazer, A. M., 78 Glazkov, Yu. V., 372 Gleitzer, C., 156 Glemser, O., 122, 163 Glick, M. D., 110, 243, 450,451 Gliezes, A., 28 Glinkina, M. I., 175 Glinskaya, L. A., 161 Glivicky, A., 25 Glockling, F., 186, 272 Gloeikles, D., 156 Glowiak, T., 179 Glukhov, I. A., 143, 144, 146 Glushkova, M. A., 133, 177 Gluzman, E. M., 19 Go, S., 5 Gobillon; Y., 158 Goddard, J. B., 65 Godfrey, J. J., 409 Godina, N. A., 82 Godun, I. V., 6 Goedkin, V. L., 191,215, 216,275

Goepplinger, W. F., 7 Goggin, P. L., 408,428, 439 Goh, L.-Y., 253 Goh, S. H., 253 Goldberg, D. E., 332 Goldberg, I. B., 7 Golding, B. T., 260 Golding, R. M., 227, 263 Gol’dshtein, L. M., 15 Goldstein, M., 238 Golebiewski, A., 134 Goloshchapov, M.V., 193 Golosnitskaya, V. A., 38 Golovin, Yu. M., 119, 453 Golub, A. M., 37, 82, 160 Golubnichaya, M. A., 375, 423,424 Gomes-Costa, R., 162 Gomez-Lara, J., 332 Gomm, P. S., 411 Gonas, A. M., 65 Gonzalez, S. G., 113 Gonzalez-Quintana, J. A., 104,332 Good, M. L., 45, 177,220, 348 Goodell, D. C., 244 Gooden, C. E., 156,161 Goodfellow, R. J., 408, 428, 439 Goodgame, D. M. L., 220, 238 Goodman, P., 151 Goossens, J. W. M., 397 Goodwin, H. A., 222 Goodyear, J., 191 Gopal, R., 63, 65 Gorbunov, V. E., 426 Gordeev, 1. V., 108 Gordievskii, A. V., 424 Gore, E., 146, 259,296 Gorelov, 1. P., 332,457 Gorichev, I. G., 228 Gorochov, O., 97 Goroshchenko, Ya. G., 17 Gorskii, A. G., 471 Goryachev, Yu.M., 108 Gossink, R. G., 158 Gosteva, G. P., 77 Goto, K., 463 Gottlieb, I. M., 64 Gould, E. S., 53 Gouterman, M., 239 Gouzerh, P., 113 Govil, P. K., 333 Grachev, S. A., 332,432 Graddon, D. P., 281 Graham, M. A,, 270,420 Graham, W. A. G., 88,172, 201 Gramlich, V., 64

49 1

Author Index Grandjean, D., 138,203 Grankina, K. A., 452 Grannec, J., 82 Gravereau, P., 224 Graves, R. E.,463 Gray, H. B., 125, 133, 195, 262,263,304 Gray, L. W., 348 Graybeal, J. D., 300 Graziani, R.,472,474,475 Greatrex, R., 205,354 Green, C. R., 404 Green, D. W., 69,70 Green, J. C., 116 Green, M., 2, 5 , 132,241, 308, 349,388 Green, M. L. H., 69, 120, 121, 127, 129, 135, 142, 327, 399 Greene, D. L., 240 Greenough, P., 110,114 Greenwood, N. N., 354 Gregson, A. K., 52 Greiner, J. D., 174 Greis, O., 459 Grekov, S. D., 66 Grenthe, I., 457 Grey, I. E., 15, 103 Grieb, M. W., 269 Griesser, R., 332, 333 Griffith, W. P., 351, 354 Griffiths, E. H., 300 Griffiths, R., 44 Grigor’eva, L. P., 36 Grim, S. O., 90,271 Grishina, 0. N., 95 Grizik, A. A., 453 Groenbaek,-Hazell, R., 109 Groeneveld, W. L., 192, 193, 194, 195 Groenveld. W. L., 104, 105 Gromov, B. V., 76,480 Gromozova, I. K., 166 Groult, D., 156, 158 Gruhn, R., 72,76 Gruen, D. M., 69,70 Gruen, L. C., 268,308 Gruywagen, J. J., 161 Grzeskowiak, R., 238 Guainazzi, M., 41 Guamaschelli, C., 333 Guastalla, G., 104 Guastini, C., 314 Giidel, H. U., 107, 114, 191 Guen, L., 96 Guenot, J., 137 Guerchais, J. E.,51, 146, 158,220,238 Guest, A., 180 Guggenberger, L. J., 2,

90, 135,239, 356 Guggenheim, L. J., 422 Guglielmetti, R., 238 Guillermet, J., 119 Guillevic, J., 138 Guisto, D., 190 Guitel, J. C., 17, 309 Guittard, M., 97,436 Gulko, A., 407 Gullotti, M., 248, 479 Gundobin, V. N., 83 Gupta, A. S., 451 Gupta, S., 218 Gupta, S. K., 146 Gupta, S. L., 162, 331, 477 Gurevich, L. M., 13 Gurevich, M. Z., 193 Gurevich, P. A., 95, 245 Gurtler, O., 305 Gurumurthy, C. V., 194 Gur’yanova, E. N., 21 Guseinov, M. N., 451 Gusev, A. I., 48, 70 Gushikem, Y., 455 Gustafson, C. R., 532 Gutmacher, R. G., 467 Gutman, V., 431 Guzhavina, E. I., 455 Gvozdev, B. A., 471 Gwost, D., 21 1

Habashi, F., 299 Habboush, D. A., 200 Habeeb, J. J., 444 Hacker, M. J., 364 Hackett, P., 124, 327,434 Haddock, S. R., 408,428, 439 Hadek, V., 138 Hadenfeldt, C., 451 Hadjiliadis, N., 419 Hagenmuller, P., 61, 76, 82, 98,157 Hagihara, N., 235 Hahn, H., 44, 314 Haight, G. P., jun., 119, 134 Haigh, I., 42, 174 Haigh, J. M., 53 Haines, L. I. B., 226 Haines, L. M., 383 Haines, R. A., 255, 304 Haines, R. J., 136, 200, 205 Hains, C. F., 465 Haire, R. G., 467 Hakoila, E. J., 332 Halbert, E. J., 213 Halder, M. C., 146 Hale, W. H., jun., 467 Halfpenny, M. T., 287 Halko, D. J., 58

*

Hall, A. J. T., 232 Hall, D., 229, 260 Hall, J. R., 191 Hall, L. D., 461,462 Hall, S. R., 228 Hall, T. L., 464 Hallock, S. A., 185 Hamaguchi, T., 136 Hamer, A. D., 247,366, 370 Hamilton, D. S., 389 Hamilton, G. J., 314 Hamilton, W. C., 465 Hammond, G. S., 125,265 Handlovic, M., 278 Hanii, F., 278 Hanke, K., 325 Hanna, M. W., 41 Hansen, J. E., 27 Hansen, J. F., 27 Hanslik, J., 236 Hansson, E.,450 Hanuza, J., 177 Hanyu, Y., 463 Haq, M. M., 460,479 Haque, S. M. E.,88 Hara, T., 239 Harari, D., 103, 158 Harbourne, D. A., 207 Harcourt, R. D., 366 Hardcastle, K. I., 207 Hardt, H. D., 98 Hardy, A., 224 Hardy, R. W. F., 128 Hargis, L. G., 99, 111 Hargreave, M. M., 119 Harjulin, C., 309 Harland, P. W., 136 Harlow, R. L., 281 Harmon, C. A., 472 Haroske, C., 139 Harries, H. J., 331 Harrington, P. C., 257 Harris, C. M., 213, 227 Harris, D. H., 69 Harris, R. O., 354 Harris, T. V., 20 Harrison, B., 224, 391 Harrison, W., 235, 310 Harrod, J. F., 302 Hart, F. A,, 451,462 Hartl, H., 163 Hartung, H., 10 Hartwell, G. E., 297 Haser, R., 223 Hashimoto, Y., 3 Hassanein, M., 325 Haszeldine, R. N., 381 Hata, T., 331 Hatami, H., 151 Hatfield, W. E.,48, 102, 106, 305, 308, 323

492 Hatterer, A., 156 Hattori, C., 257 Hauck, J., 177 Haupt, H. J., 185, 187 Hawke, D. J., 395 Hawkes, G. E., 461 Hawthorne, M. F., 127, 380 Hay, R. W., 278 Hayashi, T., 422 Hayes, R. G., 64 Hayes, S. E., 124, 185 Haymore, B. L., 382 Hazell, R. G., 294 Heal, H. G., 476 Healy, P. C., 139, 198, 263, 309 Heath, G. A., 108, 120, 167 Heaton, B. T., 374, 375,402 Heber, R., 58 Hecht, H. G., 467 Hedwig, G. R., 193, 308, 332 Heim, J. M., 328 Heitner-Wirguin, C., 476 Held, R., 305 Helle, J. N., 302 Heller, W., 5 Helling, J. F., 6 Hellmuth, C. F., 288 Hemmerich, P., 196 Hemmes, P., 158 Hempel, J. C., 48, 102, 106 Hendricker, D. G., 192, 298, 452 Hendrickson, D. N., 274 Hendriksma, R. R.,176 Heng, K. B., 281 Henkin, R. I., 324 Henrici-Olive, G., 58, 98, 269 Henry, R. P., 49, 56, 67 Henzi, R., 225 Henzler, T. E., 30 Herberhold, M., 87, 93, 95 Herceg, M., 318 Hercules, D. M., 142 Herde, J. L., 386 Hermann, H., 89 Hem, D. H., 7 Herpin, P., 99 Herring, F. G., 313, 340 Herrington, D. R.,262 Herskovitz, T., 220 Hertel, H., 245 Herve, A., 88 Herve, G., 163,164 Herzog, S., 179 Hesse, R., 443 Hessett, B., 3 Hester, R. E., 94 Hewaidy, I. F., 59, 63 Hewat, A. W., 82 Hewat, E. A., 83

Author Index Hewitt, B. J., 23 Heyman, L. E.,279 Heyn, B., 139 'Hidai, H., 270 Hidai, M., 18, 393 Hidaka, J., 100, 101, 264, 265 Higgins, C. E., 459 Higginson, W. C. E., 331 High Tower, T. C., 242 Higson, B. M., 265 Hikita, T., 18 Hill, K. E., 208 Hill, M. N. S., 288 Hill, N. J., 116 Hill, W. E., 246 Hillier, I. H., 64, 89 Hillman, M., 26 Hinckley, C. C., 10 Hintze, R. E., 346 Hipp, C. J., 277 Hirabayashi, M., 42 Hiraga, K., 42 Hirayama, M., 463 Hirotsu, K., 222 Hjerten, I., 309 Ho, T.-L., 8 Hoard, R. L., 464 Hobson, A. D., 268 Hoch, M. O., 35 Hodge, A., 57 Hodgson, D. J., 106, 305, 379 Hodgson, K. O., 451,465,466 Hodouin, D., 72 Hoefdraad, H. E., 154 Hofer, R., 187 Hohn, B., 245 Hoekstra, H. R., 466,472 Hoel, E. L., 380 Hoffman, H., 51 Hoffmann, J. J., 190 Hoffman, M. Z., 111,253 Hoffmann, N. N., 233 Hoffman, N. W., 362 Hogarth, J. W., 359 Holah, D. G., 192, 367 Holland, R. J., 261 Holland, W. J., 36 Holliday, A. K., 23 Holloway, C. E.,84 Holloway, J. H., 169 Holm, R. H., 47, 198, 220, 262, 318, 326, 350, 351, 356 Holste, G., 138 Holt, S. L., 87, 117 Homeier, E. H., 35 Homma, M., 263 Hoof, D. L., 199,370,247,458 Hooper, A. J., 45, 64, 96 Hooper, N. E., 167 Hoppe, R., 12, 15, 102, 116, 197,268, 297,411,434

Hopgood, D., 423 Horacek, P., 469 Horiuchi, H., 42 Horn, V.,260 Homer, S.M., 323 Horowitz, A., 191 Horrocks, W. de W., 451 Horsley, S. E., 33 Horyn, R., 73 Hoskins, B. F., 234, 249, 324 Hota, N. K., 232, 354 Hou, F. L., 189 Houlihan, J. F., 4 House, D. A., 101,114 Howard Lock, H. E., 167, 180 Howard, J., 201, 338 Howatson, J., 434 Howe, R.F., 137 Hoyer, E., 57, 58 Hrung, C. P., 171 Hsieh, A. T. T., 205, 285, 347 Hsin, S., 8 Hsu, C., 411 Huang, D. T., 50 Huang, T., 8 Hubbard, A. T., 426 Huber, F., 187 Huber, H., 270, 393 Huber, M., 103 Huber, P. R., 332, 333 Hudman, C. E., 25 Huffman, H. L., 52 Hugel, R., 195, 245, 332 Huggins, R. A., 151 Hughes, A. N., 367 Hughes, M. C., 99 Hughes, M. N., 239,247 Hughes, R. E., 123 Hughes, W. B., 132 Hui, B. C., 367 Hulet, E. K., 465, 467 Hulett, L. G., 351 Hull, J. R., 93 Hulliger, F., 73 Hulmes, R., 212 Hummelink-Peters, B. G. M. C., 313 Humphreys, D., 422 Hunt, G. W., 300 Hunter, P. W. W., 275, 302 Hunter, R. G., 395 Hursthouse, M. B., 223, 236, 241,275,446,451 Hussen, E., 78 Hutchinson, B., 9 Hutchinson, J. R., 262 Hutchinson, M. H., 331 Huttner, G., 88,90 Hyde, B. G., 4, 174 Hyde, C. L., 124

493

Author Index Ibarra, C., 293 Ibers, J. A., 124, 126,220,226, 233, 268, 298, 356, 364, 382, 389, 392,426 Ibraeva, T. D., 18 Ibrahim, E. D., 11 Ichikawa, M., 131 Idogaki, T., 107 fgnat’eva, E. K., 18 Iida, Y., 396 Iijima, K., 113, 153 Iijima, S.,71 Ikeda, S., 5, 31, 153 Ikramov, Kh. U., 136, 145, 147,254 Il’chenko, L. I., 36 Win, E. G., 77 Il’ina, E. S., 238 Il’ina, L. A., 373 Il’yasov, A. V., 117, 147 Il’yasov, E. A., 79 Il’yukevich, L. A., 372 Ilyukhin, V. V., 15, 32 Imai, K., 317 Imotu, S., 468 Inazu, T., 321 Indubala, S., 106 Ing, S. D., 300 Ingle, W. M., 229 Ingraham, L. L., 260 Ingri, N., 305, 311 Inomata, T., 396 Inoue, H., 253, 390 Interrante, L. V., 406 Iordanov, N., 177 Ionov, B. M., 450 Irving, H. M. N. H., 114 Irving, R.J., 282 Isakova, R. N., 156 Isci, H., 420 Ishida, K., 15 Ishimori, T., 348 Ishiyama, T., 346 Iskander, M. F., 150,291 Iskhaklva, L. D., 456 Ismailzade, I. G., 79 Isobe, K., 193, 281 Issa, I. M., 431 Issleib, K., 10 Isupova, E. N., 82 Ito, T., 228, 256 Ivana, E., 426 Ivannikova, N. V., 428 Ivanov, B. N., 156 Ivanov, E. V., 227 Ivanov, V. I., 450 Ivanov, V. M., 427 Ivanova, E. K., 332 Ivanova, I. F., 147 Ivanova, I. M., 161

Ivanov-Emin, B. N., 119, 308, 423,452,454 Ivanovskii, I. E., 28 Ivarsson, G., 305 Iverson, A. A., 3 Ivleva, I. N., 2, 11 Iwamoto, R. T., 239,438 Iwamoto, T., 271 Iwasaki, H., 83 Iwasaki, M., 469 Iwashita, T., 107 Iwata, M., 253 Iyenger, R. R., 293 Jablonski, C. R.,93 Jabs, W., 179 Jackels, S. C., 217, 259 Jackson, S. E., 116 Jacobs, H., 446,451 Jacobsohn, K., 162 Jacobson, R. A., 253,280,304, 450 Jacobson, S. E., 190,399 Jacot-Guillarmod, A., 24 Jahagirdar, D. V., 477 Jahny, J., 56 Jahr, D., 243 Jain, B. D., 460 Jain, J. P., 134 Jain, P. C., 166 Jain, S. C., 21 James, B. D., 39 James, B. R.,268, 368 James, D. W., 376,428 James, T. A., 394 Jameson, R.F., 332 Jamieson, P. B., 173 Jansen, M., 268 Jansen-Ligthelm, C. D., 192 Janson, T. R.,198 Jaulmes, S., 96 Jawad, H., 97 Jayadevan, N. C., 474,477 Jeannin, Y., 28, 218 Jeffery, E. A., 130, 357 Jeffery, J. W., 244 Jeffrey, K. R., 177 Jeffreys, J. A. D., 150 Jeitschko, W., 73,97, 156, 158, 160 Jejurkar, c. R.,280 Jellinek, F., 43, 72, 332 Jenkins, R. A., 423 Jennische, P., 443 Jensen, A., 27 Jensen, F. R., 261 Jensen, K. A., 327 Jensen, S. J., 191 Jere, G. V., 467 Jeremic, M., 124 Jesson, J. P., 135, 212, 213, 239, 342, 370

Jessop, K. J., 227 Jeter, D. Y., 106, 305 Jewess, M., 60 Jewsbury, R. A,, 369 Jezowska-Trzebiatowska, B., 42, 149, 177,179,210 Jindal, H. L., 430 Job, R., 257 Joba, S., 273 Joesten, M. D., 312 Johnson, A,, 350 Johnson, B. F. G., 339,356 Johnson, D. K., 313 Johnson, D. P., 75 Johnson, D. R.,264 Johnson, D. W., 198 Johnson, E. H., 434 Johnson, G. G., jun., 32, 82, 161 Johnson, J. E., 304 Johnson, K. E., 280 Johnson, M. R.,260 Johnson, N. P., 179 Johnson, S. M., 404 Johnson, V., 73 Johnson, W. M., 423,459 Johnston, M. D., jun., 462 Johnston, J. R.,36 Jokisalo, L., 304 Jones, A. D., 458 Jones, D. H., 224 Jones, E. M., 90 Jones, G. R., 42 Jones, J. G., 217 Jones, M. M., 409 Jones, R. G., 466 Jones, R.D. G., 208,232 Jones, S. P. L., 440 Jongejan, A., 82 Jordan, B., 63, 381 Jordan, W. T., 266 Jorgensen, Ch. K., 166,463 Joshi, K. C., 105, 332,459 Jove, J., 468 Jozefowiz, E., 195 Julien-Pouzol, M., 436 Jurnak, F. A., 110 Juza, R., 446,451 Kaas, K., 262 Kabesova, M., 303 Kabiruddin, S. K., 16, 134 Kablitz, H. J., 27 Kachapina, L. M., 2, 11 Kaczmarek, M., 332 Kadomstseva, V. M., 353 Kadish, K., 100, 148,435 Kagan, H. B., 365 Kageyama, H., 271 Kagramanyan, Z. G., 4

Author lndex

494 Kahn, A. H., 165 Kahn, O., 41 Kai, F., 456 Kaizaki, S., 100, 101 Kaizu, Y., 239 Kakkar, S. N., 54,476 Kalechits, 1. V., 133 Kalinen, A. I., 82 Kalinichenko, A. A., 34 Kalinichenko, A. M., 17, 34, 160 Kalinichenko, I. I., 310 Kalinichenko, N. N., 49 Kalinina, S. S., 34, 35 Kalinnikov, V.T., 48, 51 Kallel, A., 64 Kallweit, R., 27 Kal’naya, G. I., 305,306 Kalsotra, B. L., 68, 167,460 Kalva, K. L., 209 Kamamura, K., 163 Kamata, K., 147 Kamberi, B., 264 Kamenar, B., 162 Kamenev, V. F., 86 Kamenskaya, A. N., 471 Kampe, D. J., 71 Kanazawa, S., 263 Kandasamy, D., 195 Kane, A. R., 422 Kanellakopulos, B., 459 Kane-Maguire, L. A. P., 101, 254,258, 345, 353 Kapila, V. P., 17 Kapoor, P. N., 69,176,188, 360,406 Kapur, S., 68, 167, 460 Kapur, V. K., 9 Karadakov, B. P., 18 Karagiannidis, P., 141 Karal’nik, S. M., 306 Karayannis, N. M., 8, 9, 105, 111, 194, 195, 219, 314, 455,468 Karczynski, F., 294, 332 Karlova, E. V., 45 Karlsson, R., 241 Karlysheva, K. F., 27 Karmag, G., 466 Karpeiskaya, E. I., 267, 408 Karpenko, T. F., 161 Karpinskaya, N, M., 417 Karpov, V. N., 156 Karpova, 0. I., 56 Karraker, D. G., 468, 472 Karunaratne, S., 288 Kasimov, G. G., 75 Kasper, J. S., 406 Kaspi, P., 354 Kassierer, E. F., 459 Kas’yanenko, A. I., 56

Kaszirer, F., 401 Katcher, M. L., 185 Kato, M., 317 Katz, J. J., 198 Katz, L., 79 Kawachi, M., 143 Kawase, A., 222 Kawaguchi, S., 193, 281 Kawai, T., 332 Kawakulo, S., 136 Kawano, M., 300,430 Kawasaki, K., 263 Kawashima, M., 150 Kay, A,, 150 Kay, J., 110, 450 Kazanskii, L. P., 165 Kebir, A., 117 Kedzia, B. B., 42 Keiderling, T. A., 465 Keii, T., 5 Keilig, W., 211 Keler, E. K., 82 Keller, H. L., 436 Kelly, D. A., 177 Kelly, J. N., 89 Kemmitt, R. D., 364 Kemmler-Stack, S., 30 Kenisaran, M. M., 68 Kennedy, B. P.,245,413 Kennedy, D. J., 191 Kennelly, W. J., 12, 471 Kepert, D. L., 139, 162, 326 Keppie, S. A., 69 Kerby, R. C., 43, 60, 64 Kereichuk, A. S., 332 Kergoat, R., 51, 146, 152, 158 Kerridge, D. H., 200 Kertes, A. S., 459 Kessler, H., 156 Kestigian, M., 33, 82 Kestner, M. O., 432 Ketov, A. N., 77 Ketteringham, A. P., 139, 370 Kettle, S. F. A., 88 Khachaturov, A. S., 2 Khadikar, P. V., 54, 476 Khamar, M. M., 44 Khan, M. M., 22, 245, 300, 331,351 Khan, R. A., 134 Khan, S. M., 409 Khanolkar, D. D., 477 Khanolkar, V. D., 477 Kharchenko, L. Yu., 161,452 Khariton, K. S., 401 Kharitonov, Yu. Ya., 152,374 Kharitonova, G. S., 35 Khar’kova, A. M., 97 Kharlamova, E. N., 21 Khedder, N., 238 Khidekel, M. L., 8, 13, 133

Khodoshova, T. S., 152 Khokhlova, L. I., 20 Khotsyanova, T. L., 26 Khozhainov, Yu. M., 480 Khramov, V. P., 457 Khvatinskaya, D. Ya., 73 Khvostova, I. B., 13 Kida, S., 267, 289, 319 Kidd, R. G., 3, 78 Kiefer, G. W., 130 Kiener, V., 203 Kiesel, R. F., 47,49 Kihlborg, L., 158 Kiilholma, P., 332 Kilyakova, G. A., 24 Kilcrease, H.G., 255 Kim, B. K., 162 Kincaid, J., 224 King, E. F., 45 King, E. L., 105 King, J. A., 240 King, R. B., 69, 91, 95, 126, 176, 188,235, 360,406 King, R. M., 47, 350 Kingston, J. V., 369 Kinnaird, J. K., 269 Kintopf, S., 27 Kiparisov, S. S., 64, 83 Kiraby, R., 332 Kirchner, R. M., 126.318,364 Kirilova, N. I., 48, 70 Kirk, A. D., 100 Kirmse, R., 57, 58 Kirtley, S. W., 131, 168 Kir’yanov, K. V., 84 Kisch, H., 130 Kisel, N. G., 15, 156 Kiseleva, V. M., 420 Kiskis, R. C., 261 Kislyakov, 1. P., 156 Kiss, B. A., 163 Kisternmacher, T. J., 98 Kita, J., 34 Kiyama, M., 228 Kjekshus, A., 4,29,44, 352 Klabunde, U., 74,90 Klaeboe, P., 433 Klaue, W., 221 Klassen, D., 102 Kleinert, P., 21 1 Klemick, F., 6 Klemm, W., 49 Kleppa, 0. J., 103 Kleshchev, G. V.,15 Kleshnina, S. I., 211 Klevtsov, P. V., 15, 33, 156, 157, 160, 161, 452 Klevtsova, R. F., 156, 158, 160,161 Kleykamp, H., 361, 391

495

Author Index Klimak, Z. A., 138 Klimenko, E. P., 61 Klimova, N. M., 133 Klinga, M., 304,309 Klingen, W., 44, 314 Klinehamer, J. W., 197 Klonis, H. B., 105 Klokhryakov, K. A., 373 Klopova, Zh. G., 85 Klotz, P. L., 407, 477 Klotzbiicher, W. E., 270 Kluess, C., 25 Klyuchnikov, N. G., 191, 228 Klyuchnikov, V. M., 33 Klyuchnikova, E. F., 142 Klyuev, L. I., 136 Klyueva, N. D., 441 Knebel, W. J., 409 Kneifel, H., 41 Kno, K.-W., 256 Knoll, L., 212 Knop, O., 79,82 Knoth, W. H., 346, 354 Knox, S. A. R., 359 Knudsen, J., 219 Knyazeva, E. N., 18, 19 Kobayashi, H., 55, 239, 242, 243, 256, 267, 282, 311, 319, 395,459 Kobb, J. R., 12 Kobelt, R., 212 Kobenin, V. A., 459 Kobilov, N. K., 178 Kobotailo, G. T., 443 Kobycheva, T. A., 82 Kochetkova, A. P., 373 Kochurovskaya, G. G., 19 Koda, Y., 346 Kodama, M., 247 Kodorntseva, A. V., 38 Kohler, E., 29 Kohler, F. H., 270 Kohler, K., 12 Konig, E., 9, 214, 222 Koerner von Gustorf, E., 89 Kofmann, K. A., 428 Kohler, K., 439 Kohout, J., 303 Koine, N., 264 Koizumi, S., 396 KojiC-ProdiC, B., 83 Kojima, H., 235 Kojima, M., 255 Kojima, Y., 264 Kojiman, T., 166 Kokal, A. V., 306 Kokanov, S. A., 33 Kokot, E., 225, 314 Kokot,I. F., 119,156,157,160 Kokunov, Yu. V., 152, 153 ’ Kokura, M., 270,393

Kolaiik, Z., 162 Kolb, J. R., 471 Kolbin, N. I., 174 Kolich, C. H., 10 Kolobova, N. E., 41 Kolodny, R. A., 247 Kolodyazhnyi, Yu. V., 22 Kolomina, L. N., 322 Kolonin, G. R., 444 Kolpikova, E. F., 148 Kolsbova, N. E., 48 Kolta, G. A., 59, 63 Kol’tsov, S. I., 119 Kolychev, V. B., 331 Komarov, N. V.,21 Komarov, V. E., 29 Komatsu, S., 235 Komissarova, L. N., 31, 34, 35 Komiya, S., 342 Komoto, R. G., 206 Konarev, M. I., 177 Kondilenko, I. I., 1.54 Kondrat’eva, 0. I., 95 Konev, V. A., 104 Konig, K.-H., 452 Konkin, V. D., 36 Konno, M., 256 Konovalov, L. V., 408 Konunova, Ts. B., 37 Konysheva, L. I., 50 Konyukhora, N. E., 310 Koon, S. S., 269 Koorts, J., 470 Kopanev, V. D., 77 Kopchikhin, D. S., 76 Kopwillen, A., 166 Korber, P., 325 Kordis, J., 460 Korenev, Yu. M., 28 Korfmacher, W., 70 Kornilov, 1. I., 71 Kornilova, V. I., 85 Korobova, I. A., 65 Koroleva, L. N., 82 Korol’kov, D. V., 139 Kororezov, A. Z., 152 Korosteleva, A. I., 400 Korotchenko, N. A., 161 Korotkevich, I. B., 156 Korovin, S. S.,33 Korshunov, B. G., 78 Kortram, I. E., 194 Korverranta, J., 303 Kosinova, N. M., 31 Kostel, P. J., 128 Kostiner, E., 49, 193 Kostromiila, N. A., 457 Kotani, S., 466 Kotel’nikova, A. S., 178 Kotera, Y., 156

Kotlyar, A. G., 30 Kotlyar, E. E., 138 Kotlin, V. P., 471 Kotorlenko, L. A., 161 Kourounakis, P., 419 Kovba, L. M., 161 Kovgan, L. N., 63 Kovzun, I. G., 12 Kow, W. E., 376 Koyama, K., 3 Koyama, M., 150 Kozeeva, L. P., 160, 161 Kozhevnikov, P. B., 177 Kozhina, 1. I., 44, 142 Kozhukharov, V. S., 64 Kozlov, V. V., 163 Kozlowska-Rog, A., 43 Koz’min, N. A., 175 Koz’min, P. A., 175, 177, 178 Kozyrkin, B. I., 84 Krasil’shchikov, B. R., 147 Krasnov, B. A., 424 Krasnyanskaya, N. A., 49, 67 Krasochka, 0. N., 163 Krasser, W., 172 Krausse, J., 115, 116 Krauzol’dt, N. P., 163 Kravchenko, V. V., 83, 119, 453,455 Kravtsova, E. A., 398 Krebs, B., 163,436 Kreidler, E. R.,156 Kreis, G., 88 Kreissel, F. R.,88, 92, 127 Kreiter, C. G., 88,92, 127 Krestov, G. A., 459 Kretovich, V. L., 128 Krieger, J. K., 39 Krieger, R., 100 Krigbaum, W. R., 262 Krishnamachari, N., 244 Krishnamacharyulu, J., 34 Krishnamoorthy, C. R., 331 Krishnamurthy, M., 245 Krishnan, G., 250 Kristanova, L., 224 Kristoff, J. S., 232 Krivobok, V. I., 156 Krivutskii, V. P., 97 Kriza, A., 22 Kroenig, R. F., 409 Krohberger, H., 209,232 Krohn, R. J., 426 Krokhina, N. F., 251 Kroneck, P., 149 Krot, N. N., 466,480 Kruck, Th., 94, 212, 234 Kruczynski, L., 41, 206, 362 Kruegger, C., 28 Kruger, C., 281 Kruger, G., 187

Author Index

496 Kruse, W., 116 Krylov, A. A., 177 Krylov, E. I., 15, 75, 82, 83, 236 Krylova, L. F., 412 Krylov, V. S., 64 Kryukova, N. A., 7 Kubas, G. T., 220 Kubiak, R., 73 Kubilus, V., 117 Kubu, V., 454 Kuchen, W., 245 Kiindig, E. P., 270 Kukushkin, Y. N., 267, 367, 373, 384, 408, 414, 416, 423, 424,427 Kuliev, A. A., 4 Kuliev, A. D., 191, 331, 451 Kulikova, I. M., 74 Kulikova, T. M., 38 Kulishov, V. I., 39 Kulkarni, A. D., 97 Kulkami, V. M., 22, 58 Kumada, M., 422 Kumar, G., 409 Kumar, R., 104 Kumok, V. N., 120 Kunaszewska, M., 195, 331 Kunau, I. P., 234 Kuncheva, D. St., 18 Kundig, E. P., 393 Kunnin, B. T., 309 Kupcik, V., 325 Kupryszewski, G., 332 Kurahashi, M., 222 Kurbanov, K. H. M., 156 Kurganov, A. A., 314 Kurimoto, R. K., 110 Kuroda, K., 266 Kuroya, H., 254,406 Kuroya, M., 255 Kurzelna-Cedzynska, K., 331 Kushakbaev, A., 136 Kustin, K., 143, 162, 332 Kustov, Yu. A., 158 Kuszaj, J., 243 Kutal, C., 111, 377 Kutoglu, A., 26, 43, 406 Kuyper, J., 366 Kuzina, A. F., 175, 177 Kuzina, T. A., 420 Kuzina, T. I., 119, 453 Kuz’ma, Yu. B., 98, 138, 175 Kuz’ma, Yu. V., 97 Kuz’mina, N. N., 420,426 Kuznetsov, E. V., 18 Kuznetsov, S. I., 26 Kuznetsov, V. A., 15 Kuznetsov, V. G., 175, 178, 480 Kuznetsov, V. I., 119

Kuznetsov, V. Ya., 82 Kuznetsova, L. I., 22, 251 Kvashenko, A. P., 82 Kvashina, E. F., 2 Kvichko, L. A., 36 Kwak, Y., 113 Kwan, T., 50 Kwiatkowski, E., 332 Kyger, L., 241 Kyuno, E., 254, 273 Labbe, Ph., 82 Labes, M. M., 105, 194, 219, 411 Labrouc, D., 231 Lacey, M. J., 52, 292 Ladriere, I., 117 Lahuerta, P., 24 Lai, C., 426 Laidler, J. B., 466 Laing, K. R., 346 Laing, M., 187, 189 Laitinen, H. A., 119 Lalor, F. J., 132, 203 LaMar, G. N., 99,326,460 La Monica, G., 363 Lamotte-Brasseur, J., 301 Land, J. E., 76 Landa, B., 77 Landis, A. L., 31 Lane, B. C., 389 Lane, L. W., 321 Lane, R. H., 254 Langer, D., 312 Langer, M., 191 Langfelderova, H., 310 Langford, C. H., 101,254 Langhout, J. P. M., 397 Laplaca, S. J., 465 La Place, G., 43, 46, 64 Lappert, M. F., 24, 25, 69, 91,

448 Lapporte, S. J., 339 Lapsina, A., 66 Larcielle, P., 97 Larin, G. M., 48, 57 Larionov, S. V., 373 Larking, I., 163 Larkworthy, L. F., 44,98, 221,169,470 Larsen, E. M., 35, 326 Larson, A. C., 406 Larson, K. W., 255 Larsson, L. O., 224, 436 Larsson, R., 57, 332, 431 Lascelles, K., 96 Lassau, C., 140 Lati, J., 296 Latyaeva, V. N., 24,27, 29, 59, 60 Latysh, G. N., 77

Lau, C. F., 20 Laude, J. P., 64 Lauer, L., 285 Lauher, J. W., 233 Laugt, M., 309 Laurent, B. J. P., 20 Lauterwein, J., 196 Lavaud, D., 64 Lawless, K. R., 71 Lawton, S. L., 443 Leary, K., 442, 443 Lebedeva, L. I., 166 Lebedeva, N. E., 193 Leblanc, J. C., 2, 26 Le Blanc-Soreau, A., 4 Le Borgne, G., 203,280 Lee, G. R., 148 Lee, K. M., 94 Lee, K. S., 224 Lee, K. W., 196,252 Lee, T. J., 436 Le Flem, G., 117 Legasov, V. A., 12,61, 152 Leggett, J. D., 379 Legg, J. I., 250, 265 Legzdins, P., 95, 338 Lehmkuhl, H., 27 Lehn, J. M., 431 Leibfritz, D., 461 Leigh, G. J., 129, 136, 167, 171.233. 358. 359 Leipoldt, J. G., 134, 464 Leitch, D. M., 381 Leitnaker, J. M., 97 Leitsin, V. A., 66 LeMay, H. E., 255 Le Moigne, F., 2, 26 Lenhert, P. G., 312 Lenkinski, R. E., 463 Lenzi, M., 152 Leonard, A. J., 96 Leong, J., 465 Leonidov, V. Ya., 136 Leonov, D., 393 Leonova, I. I., 74, 77 Leonyuk, N. I., 156 Le Parmentier, L., 83 Lepeshkov, 1. N., 119 Lepingle, V., 117 Leporti, E., 287 Leroy, J. M., 59 Lester, J. E., 233 Leung, L. M., 406 Levason, W., 197 Levedev, V. M., 456 Levenson, R. A., 48 Lever, A. B. P., 198, 217, 245, 413 Levin, F. Ya., 71 Levin, W., 174 Levison, J. J., 366, 400

Author Index Levitzki, A., 315 Lewis, D. F., 133 Lewis, D. L., 305 Lewis, H. C., jun., 167 Lewis, J., 356 Lewis, W. B., 467 Leyrie, M., 164 Lhoste, J. M., 196 Li, N. C., 309, 332 98, 191 Li, T.-I., Libbey, E. T., 344 Libit, L., 269 Libowski, T., 27 Licis, M. S., 158, 160, 161 Liebertz, J., 82 Liegeois, C., 16 Liegeois-Duyckaerts, M., 154 Lieto, L. R., 119 Likachina, V. V., 56 Lim, H. S., 352 Limar, T. F., 15 Liminga, R., 83 Lin, C. Y., 267 Lin, G. H. Y., 379 Lin, H. W., 382 Lin, T. S., 237 Linck, R. G., 102 Lindoy, L. F., 277 Linder, E., 312, 373 Linder, P. W., 444 Lindner, E., 9, 190 Lindgren, O., 278 Lindquist, O., 325 Lineva, A. N., 59, 60 Lingafelter, E. C., 318 Linke, S., 257 Lins, R. W., 173 Lintvedt, R. L., 242, 243 Lindner, E., 194 Lipatova, N. P., 74 Lipner, B. S., 418 Lippard, S. J., 12, 121, 133, 465 Lis, T., 179 Lishko, T. P., 37 Lisitsyana, E. S., 308 Little, M. A., 105, 194 Little, R. G., 406 Litvinchuk, V. M., 134 Liu, C., 35 Liu, S. T., 162, 332 Livingstone, E., 196 Livov, N. P., 128 Llinas, M., 225 Lloyd, D. J., 79 Lloyd, J. C., 286 Lo, G. Y. S., 147 Lobachev, A. N., 15 Lobanov, F. I., 85,86 Lobanov, N. I., 460 Lobas, L. M., 30

497 Loboda, S. N., 453 Lobov, B. I., 110 Lock, C. J. L., 167, 170, 178, 180 Lockhart, J. C., 288 Loeffler, P. A., 20,463 Lofgren, P., 118 Lohn, J., 194 Logai, S. E., 174 Logan, N., 224, 391 Lohmiiller, G., 64 Loiseleur, H., 287, 314 Lokio, A. H., 453 Lokken, D. A., 459 Lokshin, B. V., 41 Long, G. J., 225 Long, M. A., 70 Longo, V., 33 Loopstra, B. O., 472 Lorenz, H., 88 Lorenz, I. P., 194, 312, 373 Lorenzo, F., 67 Lorthioir, G., 97 Losman, D., 308 Lougheed, R. W., 465,467 Love, J. L., 178, 356, 361 Lovecchio, F. V., 215 Lovold, K., 160 Lownds, C. M., 200 Lethbridge, J. W., 104, 114 Lu, T. H., 436 Luber, J. R., 451 Lucas, C. R., 2,69,284, 399 Luchinskii, G. P., 1, 3 Luchkina, S. A., 95 Lucid, M. L., 53 Ludi, A,, 191, 211 Lugli, G., 471 Lugovi, S. V., 164 Lukashenko, E. E., 404 Lukashenko, G. M., 97 Lukaszewicz, K., 73 Lukehart, C. M., 281 Luk'yanova, I. G., 412 Lundberg, B. K. S., 238, 305, 311 Lundberg, M., 82, 157 Lundgren, G., 310 Lundstrom, T., 97 Lunenok-Burmakina, V. A., 161 Lupenko, E. K., 44 Lutsyk, V. I., 156, 160 L'vova, F. P., 21 Lynch, D. F., 83 Lynden-Bell, R. M., 144 Lyness, W., 158 Lynton, H., 241,275 Lyons, J. R., 255,265 Lysenina, T. G., 452 Lysenko, Yu. A., 20, 34

Lyubchenko, Yu. A., 134 Lyzhina, L. D., 119 Ma, J. K. H., 332 Maas, E. T., jun., 69 Macaskova, L., 303 Macarovici, C. G., 15, 18 McAuliffe, C. A., 197, 231, 246, 286, 287, 294, 314, 399 McBride, D. W., 206 McBryde, W. A. E., 333 McCaffery, A. J., 391 McCarley, R. E., 69, 144 McCarthy, G. J., 151, 156, 160, 161 McCauley, J. W., 96 McCleverty, J. A., 132 Mac-Coll, C. R. P., 245, 253 McColm, I. J., 460 McCollum, B. C., 446 McConnell, H. M., 462 MacCordick, J., 469 McCormick, B. J., 57 McCormick, D. B., 305, 333 McCowan, J. D.$4, 25 MacDiarmid, A. G., 207, 229 Macdonald, C. G., 52,292 McDonald, D. P., 346 MacDonald, D. J., 5 McDonald, H. O., 46 McDonald, J. M., 389 McDonald, J. W., 145 McDowell, R. S., 174 Macero, D. J., 331 McEwen, G. K., 90 McFadyen, W. D., 290 McFarland, J. J., 395 McFarlane, F. E., 7 McFarlane, W., 126 McGarvey, B. R., 117 McGinnety, J. A., 301 McGlinchey, M. J., 93 McGlynn, S. P., 119 McGregor, A., 272 McGregor, K. T., 308 Machavariani, Z. N., 156 McKenna, C. E., 128 McKenzie, E. D., 265, 305 MacKenzie, R. E., 121 McKnight, G. F., 134 McKnight, M. D., 55 McLaughlin, J. R., 271 McPhail, A. T., 260, 286 McPherson, G. L., 98, 191 McQuillan, G. P., 245 McWhan, D. B., 4 McWhinnie, W. R., 213, 376 Madar, R., 97 Madden, D. P., 203, 337, 369 Maddock, S. J., 38 Madeja, K., 214

Author Index

498 Maden, S. K., 256 Maftakhov, A. G., 332 Magarill, S. A., 158 Magee, R. J., 315,386 Magnell, K. R.,332 Magnuson, R. H., 357 Magon, L., 468,474,477 Magri, A. L., 105 Mague, J. T., 340, 362 Marhnale, V. B., 22 Mahe, R., 64,82 Maher, J. P., 369 Mahmoud, F.T., 369 Mahmoudi, S., 174 Mahmud, M. U., 168 Maier, A. A,, 156, 160 Maionica, E., 421 Maisel, G., 87 Maisseu, A., 71 Majumder, M. N., 120 Makarov, V. A., 7, 59 Makarov, Yu. V., 41 Makarova, L. G., 127 Makashev, Y. A., 332,432 Makherjee, R.N., 284 Makhyoun, M., 222,476 Makitie, O., 34 Mako, F., 34 Makovsky, J., 191 Makridin, V. P.,3 Maksakova, R. V., 82 Maksin, V. I., 160 Maksudov, N. Kh., 19 Makurin, Yu. N., 75 Malaviya, J., 310 Malek, A., 288 Malevich, A. A., 65 Malhotra, K. C., 17, 241 Malik, A. U., 245, 300 Malik, W. U., 107, 134 Malin, J. M., 211, 332 Mal’kova, G. Ya., 27 Malone, D., 192,401 Malone, D. B. V. M., 432 Maltese, M., 109 Mal’tsev, V. T., 156 Malygin, A. A., 119 Malyshev, V. P., 59 Malyugina, S. G., 452 Mambetov, U. A., 19 Mamedova, Y. G., 322 Man, A., 261 Manapov, R. A., 21 1 Manassero, M., 439 Mande, C., 177 Manfrin, M. F., 110 Mangia, A., 199, 306 Mani, F., 237, 243, 251 Manku, G. S., 458 Mann, B. E., 340,394 Mann, J. B., 467

Manning, A. R., 124, 209, 327,434 Manning, P. G., 331, 332, 333 Manohar, H., 450 ManojloviC-Muir, Lj., 144 Manok, F., 294 Manolescu, D., 64 Manoli, J. M., 350 Manolov, K., 297, 332 Manoussakis, G. E., 21 Manzer, L. E., 296, 394,403 Maouche, Y., 99 Marangoni, G., 472, 475 March, F. C., 406 Marchenko, V. N., 20 Marcotrigiano, G., 242. 281, 399 Marcu, G., 16 Marei, S. A., 16 Marek, G. S., 28 Maresca, L., 474 Marezio, M., 4 Margerum, D. W., 307, 31 5 Margulis, T. N., 118 Marinov, M. R., 64 Marinin, A. S., 12, 61, 152 Markovits, G., 477 Mark, W., 31 Marks, T. J., 12,202,462, 47 1 Marnesca, L., 168 Marongiu, G., 303 Marov, I. N., 49, 143, 147 Marseglia, E. A., 12 Marsh, R.,263 Marshall, A. G., 461,462 Marshall, K. L., 191 Martell, A. E., 273 Martin, D. S., 254, 409, 420 Martin, G. A., 466 Martin, J. M., 284 Martin, L. L., 450 Martin, R.L., 7, 10, 27, 108, 305 Martinengo, S., 362 Martino, G., 140 Martinot, L., 466 Martirosyan, V. O., 143 Marty, L., 137 Martynenko, B. V., 193 Martynenko, L. I., 457 Marucco, J. F., 71 Marumo, F., 256 Marvich, R. H., 12, 237 Marzilli, L. G., 264 Marzotto, A., 475,476 Masaguer, J., 84 Masaki, M., 34 Maselko, J., 51 Mashihara, M., 332 Maslowsh, J., 331

Mason, R., 200, 327, 340, 361,384,418 Mason, S. F., 237, 376 Mason, W. R., 420 Masse, R., 15, 17, 32, 103 Massucci, M. A., 33 Masters, A. F., 108 Masters, C., 411 Mastropaolo, D., 91 Masuda, I., 218, 287 Mather, G. G., 144,429 Mather, R., 117 Mathew, M., 294, 399 Mathey, F., 152 Mathur, H. B,,332 Mathur, P. K., 432 Mathur, P. V., 110 Matienzo, L. J., 271 Matlin, S. A., 161 Matsudo, T., 264 Matsuda, Y., 113 Matsumoto, K., 254, 255,

406 Matsumoto, O., 15 Matsuo, H., 214 Matsuoka, N., 264 Matsuzaki, R., 136 Mattausch, H. J., 117 Mattes, R., 61, 118 Matthews, A. P., 110 Matthews, R. W., 3, 247, 370 Matts, T. C., 104 Mat’tsev, V. T., 156 Matveev, K. I., 423 Matveevicheva, V. A., 50 Matyash, I. V., 34 Matyashov, V. G., 52 Mayants, A. L., 455 Mayer, C., 383 Mayer, M., 16, 158 Mayer, T., 6 Mayerle, J. J., 465 Maylor, R., 244 Mays, M. J., 301 Mazhara, A. P., 153 Mazo, G. Y., 376 Mazurenko, A. G., 305 Mazza, M. C., 406 Mazzei, A,, 471 Mazzi, U., 246 Mazzocchia, C., 120 Meads, R. E., 79 Meakin, P., 135, 212, 213, 239,342,370 Mealli, C., 272 Medvedev, V. A., 136 Medvedeva, A. V., 39 Medzhidov, A. A., 322

Author Index Meek, D. W., 245, 246, 270, 286, 295, 299, 364, 399, 402,403 Meek, V. I., 399,403 Megaw, H. D., 78 Mehler, K., 27 Mehrotra, A., 454 Mehrotra, R. C., 19, 35,454 Meider-Gorican, J., 33 Meijer, H. J., 10 Meilman, M. L., 143 Meineke, E. W., 88 Mekhtiev, Z. G., 374, 379 Mel’chakavo, N. V., 49, 67 Melios, C. V., 438 Melmed, K. M., 12 Melnik, M., 303 Mel’nik, Ya. I., 95, 148 Mel’nikov, 0. K., 15 Melson, G. A., 289, 446 Memering, M. N., 125 Meneces, N., 245 Menge, R., 166 Merback, A., 84, 85 Mercer, E. E., 348, 381 Meredith, W. N. E., 89 Merijanian, A., 6 Merkulov, A. A., 83 Merle, A., 285 Merrell, P. H., 22, 214 Mertschenk, B., 42 Meschede, W., 118 Meshitsuka, S., 131 Mester, Z. C . , 139, 174 Mestroni, G., 383 Meullemeestre, J., 158 Meunier, G., 49 Meunier, R., 165 Meyer, E., 171, 356 Meyer, T. J., 207, 346 Meyerstein, D., 296 Michel, C., 156, 158 Michelson, K., 114 Michnik, M. A., 83 Micoud, M. H., 271 Middleton, R., 93, 191 Midollini, S., 237,272 Migal, P. K., 332,438 Mihichuk, L., 208 Mikhailov, S. V., 112 Mikhailov, Yu. N., 480 Mikhailova, L.G., 173 Mikhailova, N. K., 459 Mikhailova, S. V., 166 Mikhalevich, K. M., 134 Mikhalevich, K. N., 172 Mikheev, N. B., 471 Mikolaev, V. M., 456 Mikulski, C. M., 8, 105, 194, 195,219, 468 Milczarska, A., 332

499 Miller, D. A., 28 Miller, J. D., 376 Miller, J. S., 120, 210, 296, 356 Miller, P. T., 312 Miller, W. J., 96 Miller, W. V., 256 Milligan, W. O., 451 Mills, J. S.,403 Milner, J. O., 316 Milowski, K., 24 Milstein, J. B., 117 Minacheva, M. Kh., 36, 39 Miners, J. O., 320 Mines, T. E., 272 Minghetti, G., 421, 440 Mingos, D. M. P., 327, 345, 361 Mink, R., 9, 195 Mironov, V. E., 110, 331, 332 Mirrlees, M. S., 104 Mishin, K. Ya., 455 Miskin, B. K., 79 Miskowski, V., 262 Misoni, A., 271 Misra, G. N., 35 Missavage, R. J., 310 Misumi, S.,455 Misyoshi, T., 271 Mitchard, L. C., 142 Mitchell, P. C. H., 49, 56, 67, 130,150 Mitchell, P. D., 61 Mitchell, P. R., 255, 265 Mitchell, R. W., 338 Mitchener, J. P., 340 Mitra, G., 117 Mitra, R. P., 21 1 Mitra, S.,52 Mitsuya, M., 254 Mitsuya, Y.,15 Mittal, M. L., 333, 438 Mittal, S. P., 21 1 Mittelmeijer, M. C., 137 Mityureva, T. T., 15, 32 Miura, T., 101, 254, 376 Miyake, C., 468 Miyashita, A., 299 Mizin, V. G., 5 Mizukami, F., 256 Mocella, M. T., 36 Mochizuki, A., 452 Mocker, D., 458 Moddeman, W. E., 409 Modinas, A. G. J., 189 Mobius, R., 197 Moedritzer, K., 169 Moeller, C. W., 116 Moeller, T., 455 Moers, F.G., 365, 397 Moggi, L., 110

Mohai, B., 253 Mohajer, D., 239 Mohan, M. S., 331 Mohr-Rosenbaum, E., 73 Moise, C., 26 Mok, K. F., 376 Mok, K. S., 236 Mokhosoev, M. V., 59, 119, 156, 157,160,453 Mokhosoeva, I. V., 64 Mole, T., 70 Molina, C., 67 Molina, M., 438 Molin-Case, J., 216 Molnar, B., 219 Monaci, A., 296 Monfort, Y., 71 Montenero, A., 314 Montmory, M. C., 160 Moodie, A. F., 83 Mooney, A., 271 Mooney, R. C. L., 465 Moore, J. W., 110, 450 Moore, P., 104 Morar, G., 15, 18 Morassi, R., 251 Morazzoni, F., 193, 248 Morcom, R. E., 192 Moreira, J. E., 219 Moreland, J. A., 310 Morgan, K. A., 409 Mori, G., 287 Mori, M., 269 Moriarty, R. E., 122 Moriarty, R. M., 128 Morimoto, N., 42 Morita, H., 193 Moriwaki, T., 396 Morosin, B., 434 Morozov, A. I., 45,74,77 Morozov, I. S.,45 Morozova, I. D., 147 Morozova, M. P., 151 Morozova, S. V., 83 Morris, D. E., 364, 365 Morris, T. L., 247,403 Morrow, J. C., 379 Moseley, P. T., 68,464 Moskovits, M., 270,393 Mosley, W. C., 467 Moss, G. P., 461,462 Moss, K. C., 61 Mossop, W. J., 288 Motte, J. P., 156 Mounts, R. D., 299 Mouron, P., 31 Movius, W.G., 325 Mowat, G., 24 Mowat, W., 116 Much, H. J., 189

Author Index

500 Muchnik, B. I., 480 Miiller, A,, 42, 47, 61, 85, 117 153, 166, 174, 236 Miiller, B., 12, 434 Miiller, E., 115, 116 Miiller, F., 103 Miiller, J., 24, 42, 88, 270 Miiller, M. H., 40 Miiller-Buschbaum, H. K., 15,117,436 Muertterties, E. L., 21, 47, 135, 198, 212, 213, 234, 262, 342, 351,422,438 Muftakhov, A. G., 333 Muirhead, K. A. M., 120 Mukaida, M., 348 Mukaino, M., 321 Mukherjee, L. M., 426 Mukherjee, R. N., 109 Mukhin, V. G., 15 Mukhopadhyay, R. T., 120 Mulay, L. N., 4 Muljiani, Z., 239 Mulokozi, A. M., 456 Multani, R. K., 68, 167, 460 Mumme, W. G., 15,103 Munchenbach, B., 200 Munsey, W. R. C., 20 Munze, R., 458 Murakami, Y., 113 Murase, I., 249, 332 Murashko, N. I., 108 Murata, K., 31 Muratova, A. A., 18 Muresan, N., 36 Murgulescu, I. G., 426 Muriithi, N., 143 Murmann, R. K., 173 Murphy, C. N., 192 Murphy, D. P. H., 19 Murray, K. S., 47,48 Murray-Rust, J., 301 Murtha, D. P., 243,433, 434 Murthy, D. S., 223 Murti, R.,477 Musaev, D. B., 451 Musgrave, T. R., 237 Musher, J. I., 327 Mushran, S. P., 56,477 Muto, Y., 314, 317, 319 Myers, J., 217 Myers, J. F., 277 Nagai, Y., 365 Nagasawa, K., 42 Nagase, K., 46, 198, 372, 373 Nagashima, K., 452 Nagypal, I., 332 Naidenova-Todorova, T., 414

Naier, R. G., 35, 38 Najjar, R., 456 Vakahara, A., 294 Nakahara, M., 42,254 Nakai, K., 263 Nakamoto, K., 9, 166, 224, 285 Nakamura, A,, 135,366 Nakamura, T., 75, 147,244 Nakamura, Y., 193, 281 Nakao, Y., 294 Nakatani, M., 196,468 Nakayama, Y., 406 Nakhodnova, A. P., 63,64, 156 Nakon, R., 332 Naldini, L., 193, 436, 439 Nalewajski, R., 134 Nancollas, G. H., 332 Nandekar, A. K. N., 252 Napoletano, T., 387, 390 Napoli, A., 51, 331 Nappier, T. E., 364 Nardelli, M., 199, 266, 306, 314,406 Nardin, G., 248,268 Nardin, M., 97 Narula, S. P., 23 Narutis, V. P., 381 Nasakkala, M., 304 Nasanen, R., 304 Nascutiu, T., 354 Nassau, K., 156, 157, 161, 309 Nassimbeni, L. R., 53, 225, 436,444 Natarajan, P., 266, 346 Natile, G., 474 Natkaniec, L., 149 Naujock, D., 97 Navon, G., 352 Navratil, J. N., 480 Nazarchuk, T. N., 85 Nazarochkina, 0. A., 160 Neal, J. A., 295, 372 Nefedov, V. I., 35, 375, 384, 390 Negoiu, D., 22, 36 Neilands, J. B., 225 Neild, D. J., 60, 151 Nekhorosheva, N. I., 50 Nelson, J. H., 407 Nelson, N. J., 123, 201, 232 Nenakhova, K. V., 65 Nenova, P. P., 18 Neokladnova, L. N., 372 Nereson, N. G., 97 Nerubashchenko, V. V., 56 Nesmeyanov, A. N., 27, 127 Nesterenko, V. I., 79 Neuhaus, A., 73

Veuimin, A. D., 30 Neumann, F., 166, 185 Neuman, M. A., 446 Neuss, G. R. H., 381 Nevskaya, Yu. A., 18 Newkome, G. R., 471 Newman, A. R.,202 Newman, J., 209 Newman, L., 407,477 Newman, M. S., 332 Newman, P. W. G., 263,284 Newton, W. E., 145 Nezhel’skaya, L. A., 250 Nguyen, H. D., 97 Nguyen, H. Y., 139 Nguyen, M. H., 103,157 Nguyen, N. K., 142 Nguyen, Q. D., 78 Nicholls, D., 13 Nicholson, A. J. C., 459 Nicholson, B. K., 185 Nickolson, D. G., 352 Nicolini, M., 404 Nicpon, P. E., 399, 403 Nieh, M. T., 137 Nielson, D. O., 304 Nigam, H. L., 34, 166 Nihonyanagi, M., 365 Niizuma, S., 272 Nijssen, W. P. M., 440 Niketic, S., 255 Nikolaev, E. N., 180 Nikolaev, N. S., 136, 152 Nikolaev, R. K., 137 Nikonova, L. A., 44 Nimmo, K. M., 71 Nisel’son, L. A., 73 Nixon, J. F., 365 Noack, K., 434 Nobile, A. A., 371 Nockler, G. M., 225 Noe, M., 467 Noel, S . , 117 Norbund, C. A., 153 Nogina, 0. V., 27 Nolan, J. D., 196 Nolan, M. J., 376, 428 Nolander, B., 31, 82 Nomura, S., 143 Nomura, T,, 348 Nonaka, Y., 319 Nor, O., 114 Norbury, A. H., 408,428 Norbury, H., 400 Nordquest, K., 57 Norman, J. G., 339 Noro, K., 58 Noro, T., 58 Norrestam, R., 158 Norrin, R., 82 Norton, J. R., 172

501

Author Index Notte, C. R., 200 Novakov, T., 11 8 Novikov, G. I., 3, 153 Novikov, R. I., 28 Novikova, E. M., 160 Novin, R., 31 Novitskaya, G. N., 175, 177, 178 Novoselov, R. I., 244 Novoselova, A. V., 28 Novotny, M., 121, 133 Nowell, D. W., 33 Nowell, I. W., 91, 189, 228, 338 Nowlin, T., 246 Nunisto, L., 224,436 Nunn, E. K., 224 Nunziata, G., 332 Nuttall, R. H., 237, 271 Nyberg, B., 309,431 Nygren, M., 60, 79 Nyholm, R. S., 246, 354, 394 Nyman, C. J., 409 Oblova, A. A., 177 Obolonchik, V. A., 108 OBrien, H. A., 27 Obwander, J., 213 Ockers, S. T., 40 OConnor, C. J., 381 OConnor, J. E., 285 OConnor, M. J., 315 ODaly, C., 142 Oden, L. L., 138 Odent, G., 103 Odinets, Z. K., 454 Odom, J. D., 207 ODonnell, T. A., 125, 169 Odud, Z. Z., 164 Ogata, T., 272 Ogden, J. S., 393 Ogilvie, D. M. W., 104 Ogoshi, H., 224, 367 Ogura, T., 299 Ohkati, H., 332 Ohlsen, E. D., 143 Ohtaki, H., 302 Ohwada, K., 469 Ojima, I., 365 Oka, T., 108 Okamoto, K., 265 Okamoto, N., 172 Okamoto, S., 228, 229 Okano, I., 314 Okawa, H., 289, 319 OKeefe, M. A., 83, 174 Okudo, Y., 228 Okumoto, T., 264 Olazcuaga, R., 117 Oliver, F. D., 376 Olive, S., 58, 98, 269

Oldham, C., 139,370 Omura, H., 429 Omura, T., 196, 367 Ondrejovic, G., 303 Oniki, T., 267 Ono, A., 28 Ooi, S., 255,406 Ookawa, M., 5 Opalovskii, A. A., 137, 146, 152,153 Opendak, I. G., 180 Oppermann, H., 136 Orama, O., 304, 309 Orchin, M., 420 Orio, A. A., 246 Orlova, A. I., 36 Orrell, R. R., 32 Ortego, J. D., 287 Orth, C. J., 27 Orthanovic, M., 114 Osawa, A., 265 Osborn,J. A., 298 Osborne, C. V., 76 Oshima, E., 322 Osipov, 0. A., 22 Osipova, L. I., 70 Oskam, A., 366 Oskarsson, A., 457 Ostacoli, G., 332 Ostazewski, A. P. P., 298 Ostendorf, H. K., 9 Osterberg, R., 315, 322, 333 Ostfeld, D., 171 Oswald, H. R., 325 Otsuka, S., 135, 366 Ott, R., 44,314 Ouahes, R., 99 Ouchi, A., 196,235,300,430 Oughtred, R. E., 51 Ourusu, M., 97 Ovcharenko, A. G., 44 Ovcharova, G. P., 151 Ovchinnikov, I. V., 95 Ovchinnikov, K. V., 174 Ovchinnikova, N. A., 133 Owens, C., 9 Ozer, U. Y., 446 Ozerov, R. P., 7 Ozin, G. A., 270, 393

Pacer, R. A., 180 Paddock, N. L., 126, 235 Pages, M., 161 Pagliardini, A., 20 Paine, R.T., 179, 361 Pajunen, A., 303 Pak, T. A., 43 Palade, D. M., 238, 262

Palavit, G., 117 Palenik, G. J., 294, 369, 399 Paleos, C. M., 219 Palfalvy, M., 219 Pal'guev, S. F., 30 Palkin, V. A., 420, 426 Pallaci, G., 285 Palmer, G., 220 Palmer, K. J., 224 Palmieri, C. G., 406 Palozzotto, M. C., 227 Pan, K., 8 Panagiotopoulos, N. Ch., 118 Panattoni, C., 434 Panchal, B. R., 51, 332 Pande, C. S., 35 Pande, I. M., 244 Pandey, A. V., 333,438 Paneth, L. J., 391 Pannetier, G., 119, 309, 350 Pannu, B. S., 225 Panova, T. I., 82 Pansevich, V. V., 372 Pant, A. N., 162, 331,477 Paoletti, P., 304, 332 Papatheodorou, G. N., 191, 409 Papazian, H. A,, 32 Papin, G. G., 5 Paramonova, V. I., 331 Parant, C., 158 Parish, R. V., 133, 348 Park, I., 156 Park, I. H., 63 Parkash, A., 18 Parkash, R., 8 Parker, E. B., 379 Parker, H. S.,31, 156 Parker, W. G., 79 Parks, J. E., 326 Parmentier, M., 156 Parpiev, N. A., 12, 136, 145, 147 Parrett, F. W., 78 Parris, M., 255 Parry, E. P., 7 Parshall, G. W., 74 Partenheimer, W., 434 Parthe, E., 392 Partis, R. A., 206 Parygina, G. K., 398 Pasechnii, V. A., 154 Pasini, A., 248,479 Pasynkiewicz, S., 5 Pasynskii, A. A., 41,48 Patel, A. C., 251, 397 Patel, C. C., 219, 293, 396 Patel, H. A., 232, 399 Patel, K. C., 332 Patel, M. N., 332

Author Index

502 Patel, R. P., 331, 332 Patel, S. J., 110 Pathak, V. N., 105,459 Patmore, D. J., 206 Patnaik, R. K., 446 Patterson, G. S., 350 Patterson, H. H., 409 Paul, I., 88 Paul, 1. C., 301, 310 Paul, R. C., 8, 17,23,456 Pauling, P. J., 443 Pauson, P. L., 253 Pavlinova, A. V., 162 Pavlov, E. E., 71 Pavlov, N. N., 106 Pavlov, V. L., 34 Pavlova, M., 177 Pavlova, S. A., 156 Pavlova, Yu. N., 64 Pavlyachenko, M. M., 119 Pawson, D., 351, 354 Paxson, J. R., 91 Payne, D. H., 190 Payne, N. C., 257 Peach, M. E., 284, 300, 399 Peacock, R. D., 42, 174, 237 Pearce, D. R., 452 Pearce, R., 24, 25,448 Pears, P. G., 240 Pearson, R. G., 345, 353, 389 Peart, B. J., 376 Pehkovskii, V. V., 224,228 Pecht, I., 315 Pechurova, N. I., 68,457 Pedersen, E., 256 Pedersen, S. E., 228 Pederson, E., 101 Pedregosa, J. C., 32,64 Peet, W. G., 135 Pelizzi, C., 199, 306, 314 Pelizzi, G., 199, 306 Pelkonen, R., 34 Pell, S., 345 Pellacani, G. C., 242, 281, 285, 322, 397 Pelliccioni, M., 33 Pellinghelli, M. A., 195, 266 Pellizer, G., 260 Penavic, M., 162 Pencheva, T., 137 Pendbarkar, A. V., 177 Penel, C., 223 Penfold, B. R., 271 Peng, S.-M., 216 Penigault, E., 158 Penkova, V. G., 59 Penneman, R. A., 465 Percy, G. C., 299 Pereligina, M.S., 289 Perepelitsa, A. P., 160, 161, 453

Peresie, H. J., 352 Perez, G., 64, 158 Perez y Jonba, M., 83 Perkins, P. G., 2, 3, 161 Perrault, G., 16 Perret, R., 17, 46, 103 Perrier, M., 452 Perrin, A., 4 Perrin, C., 4 Perron, A., 82 Perry, D. L., 287 Pershin, S. V., 71 Perucaud, M. C., 99 Pervov, V. S., 136 Peshkova, V. M., 49,67 Pessa, M., 4 Pestunovich, V. A., 166 Petersen, F., 144 Petersen, J. D., 346 Peterson, E. J., 37 Peterson, J. R., 464,465, 467 Peterson, L. K., 239 Peterson, W. M., 381 Petillon, F., 220 Petitfaux, C., 332, 333 Petkova, D. Kh., 19 Petri, S., 332 Petrone, V., 105 Petrov, K. I., 34, 35, 83, 119, 453,455,456 Petrov, P. N., 453 Petrova, N. V., 19 Petrunin, V. F., 73 Petrusevich, I. V., 73 Petter, W., 211 Pettersson, L., 162 Pettit, Lm.,331 Petzel, T., 446, 459 Peyronel, G., 285, 313, 322, 397 Peytain, S., 119, 156 Pfluger, C. E., 281 Phatak, G. M., 113 Phillips, B., 137 Phillips, D. J., 196 Phillips, K. A., 125, 169 Phipps, D. A., 265 Pickerell, M. E., 196 Pickering, D. H., 322 Pidcock, A., 144, 410,421, 429 Pierce-Butler, M.,21 Pierpont, C. G., 388,356,406 Pierrot, M., 223 Pietropaolo, R., 380 Pignedoli, A., 285, 313, 322 Pignolet, L. H., 227, 263, 351 Pignolet, L. M., 285 Pilipenko, A. T., 56,68,84 Pinaev, G. F., 228 Pinart, J., 333

Pinnavaia, T. J., 36, 69 Piraino, P., 380 Pirkes, S. B., 456 Pisharody, K. R., 4 Pitsyuga, V. G., 119, 157 Pittel, B., 7 Pittman, C. U., 189 Pizzolato, P. J., 32 Pladziewicz, J. R., 346 Plastas, H. J., 90 Plautz, B., 74 Plautz, H., 74 Plekhov, V. P., 18 Plesknos, A. M., 52 Pletnev, A. I., 20 Plevey, R. G., 252 Ploae, K. I., 438 Plotkin, S. S.,83 Plovnick, R. H., 43 Plyushchev, V. E., 160, 161, 163,455,456 Poddar, R. K., 341 Podder, N. G., 435 Poddubnyi, 1. Ya., 2 Podergin, V.A., 138 Podmore, L. P., 7,45 Podolsky, G., 69 Podozerskaya, E. A., 82 Poe, A. J., 168, 364 Pogranichnaya, R. M., 56 Poh, B. L., 199 Pohl, V., 251 Poilblanc, R., 228, 231 Poix, P., 103, 158 Polaczek, A., 59 Polaczkowa, E., 59 Poland, J. S., 121 Poliakoff, M., 358 Polotebnova, N. A., 65 Polotnyuk, 0. Ya., 50 Poluektov, N. S., 454 Poluektova, E. N., 162 Polyachenok, L. D., 3 Polyachenok, 0.G., 3 Pomogailb, A. D., 19 Pontchow, C., 73 Ponticelli, G., 303 Poon, C. K., 236, 254 Poonia, N. S., 54,476 Popa, E., 426 Pope, M.T., 50, 65 Popitsch, A., 222 Popov, V. I., 64 Popov, Y.L., 262 Popova, Y., 332 Popp, R. C., 64 Porai-Koshits, M. A., 34, 152 379, 384,450 Portanova, R., 468,477

Author Index Porte, A. L., 60 Porter, R., 462 Portier, J., 82 Portnoi, K. I., 33 Poskozim, P. S., 253 Post, M. L., 282 Potapova, I. V., 34 Potenza, J., 91 Potter, D., 43 Pottkamp, F., 164 Potvin, C., 350 Pouchard, M., 61, 76, 77,82 Povey, D. C., 282 Powell, H. K. J., 114, 193,213 273, 308, 332 Powell, J., 394, 429 Power, L. F., 240 Pozdeev, A. A., 22 Prabhakaran, C. P., 219 Prabhananda, B. S., 57 Pradilla-Sorzano, J., 31 1 Prado, J. C., 456 Pravica, M., 396 Prakash, O., 56,477 Prasad, B., 56 Prasad, R. K., 58 Prasad, T., 22 Prasad, T. P., 166 Prasher, P., 68 Praxad, R., 467 Pregosin, P. S., 429 Prescott, A., 136 Preiss, H., 84 Preti, C., 402 Preti, G., 229 Preudhomme, J., 103 Prewitt, C. T., 239 Pribylov, K. P., 211 Prigent, J., 4 Prigs, B., 332 Prins, R., 118 Pritsker, B. S., 66 Procop, M., 409 Proffitt, R. T.,260 Proi'iilova, J., 158 Prokin, E. S., 28 Prokofeva, G. N., 46, 52 Prokofeva, I. V., 379 Prokudina, S. A., 119 Prostakov, M. E., 459 Protasova, V. I., 161 Prout, C. K., 146,162, 399 Prout, E. G., 200 Prout, K., 2, 121 Provotorov, M. V., 156,160 Prozorovskaya, Z. N., 31,34,

35 Prue, J. E., 49, 56, 67 Pryde, J. A., 44,73 Ptushkina, M. N., 166 Pu, L. s., 74

503 Pucascu, M., 165 Puddephat, R. J., 23 Pudovik, A. N., 18 Pujar, M. A., 253 Pulsford, J. D., 292 Puri, D. M., 18 Puri, J. K., 17 Purucker, B., 419 Pusa, P., 309 Puscasiu, M., 332 Puttov, A. I., 310 Puza, M., 106 Pyrina, V. K., 459 Pytlewski, L. L., 8, 9, 105, 111, 194, 195, 219, 314, 455,468

Quail, J. W., 227 Quagliano, J. V., 191, 275, 294 Quaglieri, P., 287 Quane, D., 119 Quarton, M., 64 Que, L., 263, 285, 351 Questlerova-Hvastijova, M., 303 Quinby, M. S., 343 Quist, A. S., 118 Qureshi, M., 16, 104

Rabeneck, H., 167 Rabinovich, I. B., 84 Rabinovitch, A. M., 29 Rachkovskaya, L. N., 423 Raddatz, A. E., 5 Radheshurar, P. V., 66 Radonovich, L. J., 451 Radoslovich, E. W., 303 Radul, K. K., 65 Raghavan, A., 477 Rahman, S. M. F., 460,479 Rai, A. K., 19, 35 Rai, R. S., 476 Raj, T., 8 Rajaram, J., 124 Raju, E. V., 332 Rak, V., 469 Rakhimov, K. R., 333 Rakhmatova, S. Y., 332 Rakitin, Yu. V., 57 Rakov, E. G., 76 Ralhan, N. K., 431 Ramamoorthy, S., 331, 332, 333 Raman, V., 467 Ramaswamy, B. S., 21 Ramaswamy, D., 106

Ramaswamy, K. K., 284,399 Rambidi, N. G., 158, 180 Ramey, K. C., 128 Ramondo, G., 64 Rancke-Madsen. R., 101 Randaccio, L., 247, 248, 268 Randall, E. W., 461 Ranney, J., 110 Rao, D. V. R., 197,433 Rao, K. R., 33 Rao, K. V. S., 180 Rao, P. R. M., 143 Raper, E. S.,51 Rapsey, G. J. N., 429 Rashid, M. S., 73 Rashkovitch, L. N., 82 Rasmussen, K., 406,408,428 Rasmussen, S. E., 241 Rasskazova, T. A., 152 Rastogi, D. K., 107 Rat, M., 82, 157 Ratcliff, B., 410,421 Rath, J., 254 Rathore, H. S., 104 Ratnasamy, P., 96 Rattray, A. D., 401 Rau, H., 24 Raubenheimer, H. G., 161 Rauh, E. G., 27 Raupach, M., 303 Rausch, M. D., 25 Raveau, B., 83,151, 156, 158 Ravez, J., 82, 98, 102 Rawsthorne, J. H., 444 Ray, K. C., 112 Raymond, K. N., 110,451, 465,466 Rayner-Canham, G. W., 198, 217 Raynor, J. B., 9 Razani, H., 349 Razavi, A,, 87 Razgon, E. S., 161 Razumov, A. I., 95,245 Razumovskii, V. V., 417, 420,427,428 Razuvaev, G. A., 24,27,29, 59, 60 Rea, J. R., 49, 193 Reader, J., 27 Reau, J. M., 117, 156 Rebhan, K. H., 243 Redfield, D. A., 407 Redwood, M. E., 186 Reed, C. A., 233,382 Reed, F. J. S., 408,428,439 Reed, J., 338 Reed, J. L., 377 Reed, J. W., 53

Author Index

504 Reedijk, J., 192 Rees, B., 93 Rees, C. W., 91 Rees, G. V., 399 Reheika, J. P., 4 Rehorek, D., 53, 305 Reichardt, W., 115 Reichert, B. E., 186 Reich-Rohrwig, P., 190, 209 Reidler, J., 454 Reiff, W. M., 211 Reimann, R. H., 187, 189 Reinhardt, C.A., 420 Reis, A. H., 213, 275 Reisfeld, M. J., 467 Reiter, L. G., 255 Rembaum, A., 138 Remeika, J. P., 4 Remennik, E. M., 453 Rempel, G. L., 338 Remy, P., 104 Renault, N., 103 Renoe, B. W., 409 Repelin, Y., 78 Rest, A. J., 191, 270, 339, 358 Rettig, S., 91, 199, 310 Reuben, J., 462 Reuter, B., 60 Reuther, H., 43 Revenko, M. D., 294,323 Reynaud, C., 31 Reynolds, W. L., 332 Reznik, B. E., 164 Reznik, E. M., 147 Ricard, L., 121, 141 Ricci, J. S., 356 Riccieri, P., 106, 110 Rice, D. A., 74, 86, 154 Richard, A., 113 Richards, R. L., 87, 120, 130, 299, 357,403 Richardson, F. S., 100,252 Richardson, M. F., 461 Richardson, R. T., 102 Richman, D. J., 238 Rieck, H., 297 Riedl, M. J., 443 Rieger, P. H., 65 Rieskamp, H., 61 Righini-Brand, A., 44 Rigo, P., 246, 370, 375 Riker, J. M., 402 Riker, M., 295 Riley, P.E., 252, 287 Rillema, D. P., 258 Rimbault, J., 245 Rimsky, A., 64 Ringel, C., 180 Rinke, K., 167 Ripan, R., 165

Risen, W. M., jun., 102 Rising, B. A., 288 Ritsma, J. H., 332 Ritter, G., 214, 222 Rius, G., 88 Rivest, R., 306 Rizvi, S . S. A., 8 Robbins, D. J., 69 Robbins, M., 108 Roberts, D. W., 461 Roberts, J. D., 461 Roberts, R. M. G., 186 Robertson, A., 171, 186 Robertson, G. B., 190 Robertson, R. E., 462 Robin, M. B.,357 Robinson, B. W., 284 Robinson, S. D., 342, 346, 366, 384, 394,400 Robinson, W. R., 228,229, 307 Robinson, W. T., 185,225, 269, 356, 361,406 Robson, R., 249,290 Rocchiccili-Deltcheff, C., 78 RoEek, J., 116 Roche, T. S . , 260 Rockenbauer, A., 332 Rockstroh, C., 124 Rodesiler, P. F., 223 Rodley, G. A., 263, 269 Rodriguez-Pofice, M., 34 Rogers, B. L., 41 Rogers, K. A,, 221 Rogers, M. T., 180 Rogozhin, S. V., 314 Rohbock, K., 86 Rohrbaugh, W. J., 443 Rohwer, E. F. C. H., 161 Rohwer, H. E., 467 Roitti, S., 33 Roletto, E., 332 Rolka, W., 26 Rollins, 0. W., 165 Romanovich, I. V., 158 Romers, C., 218 Ronis, M., 103 Roof, R. B., 406 Root, C. A., 288 Roper, W. R., 382 Ropp, R. C., 453 Ros, P., 2 Rose, J. C. W., 60 Rose, N. J., 217, 259, 277, 295, 372 Rose, P.I., 463 Roseman, P., 21 1 Rosenblum, C., 87 Rosenbuch, P., 205 Rosenkranz, A., 214 Rosenzweig, A., 465

Roshchupkina, 0. S., 24 Rossi, G., 16 Rossi, M., 211 Rossinskaja, E. R., 200 Rossman, G. R., 133 Rossotti, F. J. C., 310, 463 Roth, R. S., 31, 156 Roudant, M., 309 Roundhill, D. M., 409 Rouse, K. D., 82 Rouxel, J., 4 Rowbottom, J. F., 148 Rowbotham, P. J., 348 Rowe, Ch. R., 64 Rowe, M. D., 391 Roy, R. M., 244 Royer, A., 4 Royston, G. H. D., 403 Rozenkevitch, N. A., 471 Rozhdestvenskii, F. A., 7, 15, 82, 83 Rozhenko, S. P., 82 Rubin, B., 262 Rubin, E. M., 261 Rubinchik, Ya. S., 119 Rubinson, K. A., 220 Ruddick, J. D., 285, 338, 347 Rudenko, N. P., 35,38 Rudham, R., 452 Rudolf, M. F., 149 Rudzit, G. P., 95 Rudorff, W., 4, 30, 36 Ruff, J. K., 89 Ruiz-Ramirez, L., 341 Rumer, I. A., 471 Rundqvist, R., 97 Rundqvist, S., 73 Rush, R. M., 409 Rusholme, G. A., 207 Russell, B. A., 3 Russell, C. W. G., 48 Russell, D. R., 169,228 Russell, S . A., 130 Rutkovskii, Yu. I., 110, 331 Rutt, K. J., 239, 247 Ruvarac, A. Lj., 31 Ruzinsky, M., 331 Ryabchikov, I. V., 5 Ryabenko, D. N., 39 Ryabkova, T. P., 160 Ryabov, E. N., 6,142 Ryakhovskaya, S. K., 444 Ryan, A. A., 255 Ryan, R. R., 152, 197,465 Ryazantseva, 1. M., 17 Rybakov, V. B., 450 Rycheck, M.,420 Rycroft, D. S., 126 Ryhl, T., 457

Author Index Ryzhmanova, A. V., 245 Rza-Zade, P., 64 Sabbatini, N., 114 Sabherwal, I. H., 233 Sabri, M., 225 Saburi, M., 256,257,263 Sacco, A., 129, 211 Sacconi, L., 251, 272, 295 Sadakane, Y., 456 Sadavoy, L., 354 Sadikova, A. T., 152 Sadler, J. E., 1 Saegusa, T., 310 Saeki, M.,42 Saeki, Y., 70, 136 Safonov, V. V., 78 Sagara, F., 243, 311, 395 Sagi, S. R., 143 Saginashvili, R. M., 38 Saha, H. K., 146, 147 Sahoo, B., 480 Sailendra, S., 435 Saito, K., 256 Saito, Y., 9,253, 256 Saji, H., 64 Sajus, L., 145 Sakanoue, M., 468 Sakharova, N. N., 455 Sakharova, Yu. G., 455 Sakkab, N. Y., 381 Sakota, N., 264 Saksonov, Yu. G., 108 Sakurai, M., 247 Salamatin, B. A., 84 Sala-Pala, J., 51 Sales, K. D., 8, 223, 461 Salibekov, S. E., 33 Salienko, S. I., 11 Salje, E., 151 Sallach. R. A., 29 Sallomi, I. J., 252 Sal’mkova, L. N., 12OS Salser, G. E., 16 Samat, A., 238 Sammes, P. G., 161 Sampath, S., 476 Sams, J. R., 206 Samsonov, A. P., 332 Samsoneva, G. Ya., 156 Samuel, E., 25, 27 Samus, N. M., 261 260 Sanatappa, M., Sanchez-Batanero, P., 34 Sanders, J. R., 236, 341 Sanders, J. V., 83 Sandhu, R. S., 283 Sandhu, S. S., 283,480 Sandler, R. A., 6, 142 Sandrini, P., 363 Sands, D. E., 451

San Filippo, J., jun., 139 Sanger, A. R., 21, 109 Sanotus, A., 134 Sansoni, M., 362,439 Sansonov, A. P., 332 Sansregret, J. L., 389 Santappa, M., 477 Sanz, F., 115 Sanzgiri, J., 151, 160 Saran, M. S., 126, 235 Sarapu, A. C., 189 Sarchet, C., 314 Sargent, M. V., 19 Sargeson, A. M., 258,264 Sartori, G., 100 Sas, T. M., 193 Sasaki, M., 55, 319 Sasaki, Y., 163,271 Sastri, M.N., 164 Sata, T., 75 Sathianandan, K., 222 Satija, S. K., 87 Sato, F., 272, 284 Sato, M.,50, 272, 284 Sato, T., 244,463,466 Satpathy, K. C., 480 Sauerbrei, E. E., 64 Saunders, V. R., 64 Sauvage, J. P., 431 Saw, M., 59 Savariault, J. M.,271 Savchenko, E. P., 82 Savchenko, L. T., 17 Savenko, N. F., 34 Savel’eva, M.V., 161 Savic, J., 332 Savic, M.,332 Savino, P. C., 313 Savitskii, A. V., 66 Savitskii, E. M., 138 Savoshchenko, V. S., 82 Savos’kina, A. I., 15 Savrova, 0. D., 85 Sawada, K., 302 Sawai, T., 256 Sawodny, W., 152 Sawyer, D. T., 67 Saxena, R. S., 333,476 Saxena, U. B., 19, 35 Sbrignadello, G., 168 Scaramuzza, L., 245,250, 273 Scarle, R. D., 130 ScavniEar, S., 83 Sceney, C. G., 386 Schaap, H., 290 Schaap, W. B., 110 Schachtschneider, J. H., 2 Schafer, H., 74,96, 138, 167, 430 Schaeffer, M. A,, 136

Schaeffer, R., 426 Schaefer-King, M. A., 144 Schaffer, C. E., 327 Schartau, W., 15 Scheetz, B. E., 99 Scheidt, W. R., 67 Schelle, S., 90 Schenk, H. J., 177 Scherer, J. R., 316 Scheringer, C., 64 Schetty, G., 111 Scheunemann, K., 15 Schillaci, M. E., 27 Schiller, W., 163 Schilt, A. A., 110 Schindler, H. D., 26 Schlaepfer, C. W., 166 Schlein, W., 108 Schlientz, W. J., 89 Schmauss, G., 218 Schmid, G., 127,232,406 Schmidbaur, H., 430,433, 439,444 Schmidt, E., 209 Schmidt, G., 64 Schmidt, K. H., 166 Schmidt, P., 420 Schmidt, V., 36 Schmiedeknecht, K., 100, 115 Schmuckler, G., 407 Schmulback, C. D., 10 Schnaiderman, S. Ya., 18, 19 Schneggenburger, R. G., 20 Schneider, M. L., 90, 406 Schneider, P. W., 145 Schoeder, D. R., 253 Schollhorn, R., 4 Schonfield, B., 122 Schopper, H. C., 64 Schousboe-Jensen, H. V. F., 109,255 Schram, E. P., 6,13,49 Schrauzer, G. N., 130,260, 26 1 Schrieke, R. R., 186 Schriver, A., 332 Schroder, F. A., 137, 153 Schubert, W., 187 Schiier, H., 49 Schultz, A. J., 204, 338 Schultz, F. A., 149 Schultz, R. S., 426 Schulze, H., 153 Schumann, W., 68 Schun, R. A., 90 Schussler, D. P., 228, 229 Schwartz, J., 1 Schwarz, F. P., 239 Schwarz, W. H. E., 7 Schwarzenbach, D., 16, 211

Author Index

506 Schwarzenbach, G., 107 Schwarzhans, K. E., 218,243 Schwarzmann, E., 49 Schweitzer, G. K., 96 Schwendiman, D., 460 Schwing-Weill, M. J., 160 Schwirten, K., 433 Schwochau, K., 172, 177,470 Scollary, G. R., 369 Scott, K. L., 268 Scott, T. E., 73 Scozzofava, A., 243 Seabrook, C. J., 68 Seck, J. A., 260,261 Seddon, K. R., 13,132 Sedneva, R. M., 156 Sedor, F. A., 254 Seebach, G. L., 313 Seematter, D. J., 263 Seff, K. E., 252,287,451 Sefton, G. L., 225 Segal, J. A., 339 Seibold, C. D., 129 Seidel, W. C., 415 Seidl, V., 82 Seifer, G. B., 211 Seifert, H. J., 44, 144, 191 Sekine, T., 438 Sekizaki, M., 314 Selbin, J., 121,462,471 Seleznev, V. M., 480 Sellars, P.J., 463 Sellers, R. M., 5 Sellmann, D., 87, 88, 190 Sel'manshuk, N. N., 17 Selte, K., 44 Semerneva, G. A., 19 Semenov, E. V., 95, 148 Semenov, G. A., 180 Semenova, E. I., 349 Semenova, T. D., 156 Semenovskii, S. V., 459 Sen, B., 192, 196,401,432 Senegas, J., 158 Sengupta, A. K., 61 SenGupta, G. P., 55 Seno, T., 214 Senoff, C. V., 349,386 Sentemov, V. V., 286,407, 427 Serebrennikov, V. V., 453 Serebrennikova, T. E., 77 SBr6t de Roch, I., 145 Serezhkin, V. N., 161 Serebryakova, T. I., 138 Sergeev, N. S., 128 Sergeeva, A. M., 172 Sergent, M., 138 Sergienko, V. S., 152 Serov, G. V., 5 Seshaiah, U. V., 34

Sevost'yandva, N. I., 457 Seyam, A. M., 471 Shachilova, S. Ya., 66 Shafranskii, V. N., 261 Shah, J. R., 331 Shah, S. J., 57 Shahid, M. S., 476 Shakhno, I. V., 160, 161 Shakshooki, S. K., 16 Shankar, J., 113 Shanks, H. R., 151,156, 174 Shannon, J. S., 52,79, 292 Shannon, R. D., 63,64,65, 298, 325,426 Shapiro, B. L., 362, 462 Shaposhnikov, G. L., 128 Sharipov, D., 18 Sharma, B. C., 293, 396 Sharrna, B. K., 211 Sharma, G., 332 Sharma, K. M., 167 Sharma, R. C., 457 Sharov, V. A., 236 Sharp, D. W. A., 136 Sharples, K. B., 137 Sharrock, P., 99 Shaulov, Yu. K. H., 19 Shaver, A., 124 Shaw, B. L., 187, 340,372, 385,394,418,429 Shaw, G., 200,337,338,406 Shaw, H., 375 Shaw, V. H. L., 309 Shawl, E. T., 122 Shchegrov, L. N., 224 Shchelkunova, L. I., 332,432 Shchelolov, R. N., 83 Sheahan, R. M., 47 Shearer, H. M. M., 51,406 Sheelwant, S. S., 476 Sheftal, N. N., 156 Sheinkman, A. I., 15 Sheka, I. A., 15, 27, 32, 34 Shekhtman, V. Sh., 137 Sheline, R. K., 168, 185, 190 Shepherd, R. E., 332 Shergina, N. I., 66 Sheridan, P. S., 345 Sherrill, H. J., 471 Sherrill, J., 121 Sherrington, C.,331 Shestakova, M. T., 456 Shesterikov, M. N., 33 Shelton, R. A J., 96 Shevchenko, L. D., 136, 145, 147 Shevchenko, L. L., 68 ShibahaTa, T., 269 Shibanov, E. V., 32 Shibasaki, Y., 96 Shibata, M.,263,264

Siebert, G., 102 Shiever, J. W., 156, 157, 161, 309 Shigina, E. D., 164 Shilov, A. E., 2, 11, 13, 44 Shilov, V. P., 466 Shilova, A. K., 2, 11 Shimada, A., 222 Shimazu, M., 71 Shimizu, S., 228 Shimp, L. A,, 12,471 Shimura, Y., 100, 101,264, 265 Shin, D. B., 450 Shin, Y. A., 328 Shindler, Yu. M., 44 Shinik, G. N., 65 Shin-Ike, T., 453 Shinra, K., 218, 287 Shiokawa, J., 453 Shiotani, A., 430 Shirokov, N. I., 96 Shishkina, V. I., 38 Shishova, T. G., 162 Shitareva, G. G., 162 Shkodina, T. B., 236 Shkurman, E. P., 255 Shlenskaya, V. I., 353 Shlyakhter, E. Ya., 76 Shnaiderman, S. Ya., 46, 52, 61 Shodiev, F. Sh., 178 Shortland, A. J., 116, 122, 166 Showell, J. S., 165 Shriver, D. F., 123, 201, 232, 462 Shtokalo, M. I., 37 Shubina, L. V., 164 Shubochkin, L. K., 375, 389, 423,424 Shubochkina, E. F., 375,423, 424 Shukla, P. R., 310 Shul'man, V. M.,398 Shumyajskaya, N. G., 15,32 Shustorovich, E. M., 152, 153 Shute, R., 253 Shvedova, V. N., 416 Shveikin, G. P., 7 Shveima, J. S., 115 Sibert, J. W., 261 Sibirskaya, V. V., 416 Sidarous, S. F., 143 \ldorenko, I. A., 17 Sldorenko, Yu.A., 404 Sidorko, V. R., 97 Siebert, G., 116, 197 Siedcl, W., 100, 115 Siegcl, S., 454, 466, 472 Siegl. W. O., 206, 339

Author Index Siemens, R. E., 138 Siems, H., 194 Sievers, R. E., 105, 241, 461 Sievert, W., 85, 153 Siew, P.-Y., 241 Sigel, H., 260, 305, 312, 332, 333 Siiman, O., 195 Silber, H. B., 454, 456 Silver, G. L., 466 Silverthorn, W. E., 129, 142 Silverton, J. V., 464 Silvestri, G., 41 Simandi, L. I., 332 Sime, R. J., 173 Simic, M., 111 Simm, G. L., 186 Simm, G. R., 48 Simms, M. J., 154 Simms, M. L., 436 Simms, P. G., 133 Simon, G. L., 185, 230, 231, 236 Simpson, G. D., 54 Simpson, J., 185 Simpson, R. T., 399 Simpson, S. R., 93, 191 Sindellari, L., 476 Singh, B. P., 134, 251 Singh, G. P.,280, 456 Singh, K. K., 58 Singh, M.K., 332 Singh, P. P., 244, 305, 379 Singh, R., 251,476, 479 Singh, S. P., 56 Singleton, E., 187, 189, 383 Sinha, A. I. P., 408, 428 Sinha, D. P., 467 Sinibaldi, M., 16 Sinitsina, I. V., 110 Sinitsyn, N. M., 353 Sinn, E.,213,263, 316, 320 Sipe, J. P.,451 Sirina, T. P., 66 Siroky, O., 107 Sitran, S., 470 Sizova, R. G., 32 Sjoberg, B., 315, 322 Skapski, A. C., 122,238,306, 426 Skarstad, P. M., 123 Skell, P. S., 93 Skelton, B. W., 304, 306 Skokan, A., 73 Skolozdra, 0. E., 172 Skopenko, V.V., 37 Slade, P.G., 303 Slegina, V. I., 70 Sleight, A. W., 64, 108, 154, 156, 158, 160, 161 Slinkard, W. E.,245, 402

507 Slisskaya, M. P., 160 Slivko, T. A., 163 Slivnik, J., 469 Slobodcbikov, A. M., 119 Slobodin, B. V., 59 Slobodyanyuk, A. A., 15,82 Slocum, D. W., 93 Slyudkin, 0. P., 412 Slyusarenko, K. F., 305 Smallwood, R. J., 236 Smeggil, J. G., 28 Smirnov, M. V., 29 Smirnov, V. M., 119 Smironov, V. P.,7 Smith, A. A., 255 Smith, A. E., 286 Smith, A. J., 475 Smith, A. W., 221 Smith, B. E., 39 Smith, B. L., 429 Smith, D. L., 250 Smith, D. P., 50, 65 Smith, D. W., 48 Smith, F. E., 222 Smith, F. T., 295 Smith, G. D., 20 Smith, G. M., 128 Smith, G. P., 409 Smith, J. G., 408, 428, 439 Smith, J. N., 75 Smith, M. B., 200 Smith, P. W., 7, 45 Smith, R. A., 201, 369 Smith, S. E., 462 Smith, T. D., 9 Smith, W. E., 5,42, 271 Smith, W. L., 268 Smith, W. N., Jun., 51 Smirnova, V. G., 163 Sneeden, R. P. A., 88,115 Snezho, N. I., 457 Snow, M. R., 226, 258, 315, 426 Snyder, R. V., 332 So, H., 50 Soboleva, M. S., 384 Sobota, P.,210 Sobry, R., 475 Soderquist, R., 315, 322 Sofue, A,, 70 Soga, T., 469 Soignet, D. M., 99, 111 Sokol, V. I., 34 Sokolova, M. P., 178 Sokol’skii, D. V., 19, 44 Soliev, L., 17 Solodar, A. J., 235 Solomakha, V. N., 161,453 Solov’ev, E. A., 110 Solovkin, A. S.,33

Solovykh,T. P., 389 Solozhenkin, P. M., 95, 148 Sommerville, P., 189 Somoano, R. B., 138 Sonderegger, J. L., 120 SQndergaard-Sqirensen, B., 376 Songstad, J., 433 Soni, R. N., 162, 33~1,477 Sonoda,N., 441 Sordo, J., 84 Sorensen, A. M., 262 Sorensen, C. S., 264 Sorokina, L. D., 375, 423,424 Sorpkin, I. D., 28 Sorriso, S., 202 Soto, R., 293 Sdtofte, I., 384 Souchay, P., 113,163 Sovago, I., 332 Soylemez, Z., 446 Spacu, P., 149 Spaskii, S. S., 22 Spaulding, L., 420 S p a , A. N., 9, 111, 194, 195, 314 Specker, H., 218 Spence, J. T., 145, 148, 149 Spencer, A., 343 Spencer, C. T., 237 Spendjian, H.K., 188 Sperati, C. R., 99 Spevak, V. N., 423 Speza, N. N., 455 Spickett, J. T., 21 Spiegel, H. J., 211 Spindler, H., 305 Spinney, H. G., 3,78 Spiridinov, V. P., 153 Spiridonova, N. N., 59 Spiro, T. G., 220 Spitsbergen, U., 15 Spitsyn, V. I., 35, 65, 68, 139, 161, 165, 175, 177,457, 471 Spivak, B., 150 Spofford, W. A., 300 Springer, C. S., jun., 461 Springer, J. M., jun., 70 Sprout, G. D., 222 Srinivasan, T. K. K., 192 Srivastava, K. P., 105, 225, 226,245,313,331:477 Srivastava, L. N., 110, 280, 310,432 Srivastava, M. N., 35, 56, 331, 332,458 Srivastava, P. C., 34 Srivastava, R., 96 Srivastava, R. C., 317 Srivastava, R. D., 49, 158 Srivastava, S. C., 407

Author Index Srivastava, S. K., 34, 332 Srivastava, T. S., 171, 356 Stadelmann, W., 107 Stainbank, R. E., 385 Stalick,,J. H., 299 Stalick, J. K., 246 Stamper, P. J., 88 Stampfli, R., 456 Stanescu, D., 165 Staniforth, M. L., 462 Stanko, J. A., 352 Staples, P. J., 422 Starikova, L. P., 6 Starks, D. F., 472 Starysh, M. P., 261 Statsenko, V. P., 164 Steadman, R., 151 Steele, D. F., 141, 364 Steele, J. C. H., 286 Steenb$l, P., 376 Steger, H. F., 331, 438 Steggerda, J. J., 262 Steiner, E., 111 Stelzer, O., 285 Stepanenko, 0. N., 267 Stepanov, A. V., 456 Stephen, W. I., 396 Stephens, F. S., 210 Stephenson, N. C., 31 Stephenson, R. F., 149 Stephenson, T. A., 141, 341, 351, 364,415 Stepin, B. D., 193 Stetsenko, A. I., 414, 418 Stevels, J. M., 158 Stevens, J. R., 357, 359 Stevenson, J. N., 464 Stevenson, K. L., 101 Stewart, B. V., 63 Stewart, C. P., 60 Stewart, D. J., 79, 82 Stewart, J. J. P., 2, 161 Stewart, J. M., 90, 228 Stewart, R.P., 88, 172, 199, 201 Stiefel, E. I., 120, 145 Stiubianu, G., 202 Stobart, S. R., 186, 202 Stoessiger, R., 7 Stokely, J. R., 466 Stoklosa, H. J., 52, 57, 313 Stomberg, R., 163 Stone, F. G. A., 200, 337, 338, 349, 359, 388,406 Stone, M. E., 280 Stone, R. E., 465 Stoope, D., 123 Storhoff, B. N., 167 Stork-Blaisse, B. A., 218 Storms, E. K., 97 Strange, R. S., 381

Stratton, S., 452 Streba, E., 5, 202 Streit, G., 98 Streitweiser, A., 472 Strekalovskii, V. N., 30 Strelin, S. G., 414, 418 Strickland, R. W., 100 Strissel, E., 419 Strizhev, E. F., 424 Strope, D., 201 Strouse, C. E., 465 Struchkov, Yu. T., 39, 48, 70, 146,200,314 Stubata, S., 153 Stubbs, M. E., 431 Stuckey, G. D., 191, 301 Stuckey, J. E., 244 Stucki, H., 191 Stucky, G. D., 98, 222 Stunzi, H., 427 Stuermer, D. H., 346 Stuhr, A., 446,451 Stukan, R. A., 227 Stynes, D. V., 268, 368 Stynes, H. C., 268 su, c.-c.,53 Suarez Cardeso, J. M., 113 Subbotina, N. A,, 139, 177 Subrahmanya, R. S., 332 Subramanian, S., 246 Sucha, L., 17 Sudarikov, B. N., 76,480 Sugihara, J. M., 308 Sukhanovskaya, A. I., 110 Sukup, J. L., 144 Suleimanov, D. M., 4 Suliman, M. R., 6, 13 Sumarokova, T. A., 18 Sun, P., 35 Sunar, 0. P., 35,335,457 Sundararajan, S., 305 Sunder, W. A., 42 Suoninen, E., 4 Suprunenko, P.A., 305, 306 Surana, S. S. L., 354 Surat, L. L., 59 Surles, T., 273 Sutton, D., 198, 202, 388, 392 Sutton, G. J., 213, 360 Suvorov, A. L., 19,22 Suvorov, A. V., 18,84 Suzuki, M., 254 Svarichevskaya, S. I., 98 Sveshnikova, L. B., 373 Swaddle, T. W., 104 Swamy, S. V. J., 164 Swank, D. D., 304 Swanson, B. I., 87, 197 Swarnakov, R. D., 178 Swartz, W. E., 271

Swift, D. R., 325 Swinehart, J. H., 58 Swingler, D. L., 459 Switkes, E. S., 341 Syamal, A., 55, 316, 317 Sych, A. M., 17 Sykes, A. G., 5, 113, 114,268 Sylvester, G., 234 Symons, M. C. R., 185, 212, 340 Syrtsova, G. P., 261, 374, 375 Tabacchi, R., 24 Tabak, S., 438 Tabuteau, A., 161 Tachez, M., 43 Tandon, J. P., 332 Taft, R. W., 410 Tagawa, H., 466 Tak, S., 457 Takada, T., 42,228 Takagi, T., 136 Takahashi, M., 5 Takahashi, S., 235, 265 Takahashi, T., 108, 153 Takahashi, Y., 196, 438 Takaya, H., 269 Takayanagi, T., 50 Takemoto, J., 9 Takemoto, S., 31 Takenaka, A,, 322 Taketatsu, T., 457 Takuma, T., 136 Talipov, Sh. T., 19 Tamaki, M., 287 Tanaka, K., 256,400 Tanaka, M., 302, 332 Tanaka, N., 272 Tanaka, T., 319,400,441 Tanakina, T. N., 15 Tananaev, N. N., 457 Tandon, J. P., 56, 68, 457 Tandon, S. P., 354 Taneja, A. D., 105, 225, 331, 477 Tang, S. C., 110 Tani, B., 454 Tani, M. E. V., 266,406 Tappmeyer, W. P., 225 Taqui-Khan, M. M., 331 Tarasov, V. P.,77 Tarasova, Z. A., 211 Tardy, M., 309 Tarli, F., 296 Tarte, P., 103, 154 Tashiro, N., 300, 430 Tasker, P. A., 291, 325 Tatarinov, V. A., 104 Tatlow, J. C., 252 Tatsch, C. E., 314 Tatsuno, Y.. 366

509

Author Index Taube, H., 344,346, 348, 357 Tausik, G. R., 260 Tauher, G., 247,268 Tayim, H. A., 225 Taylor, D., 139 Taylor, D. W., 237 Taylor, F. B., 9 Taylor, J. C., 465 Taylor, L. T., 237, 250, 321 Taylor, M. D., 459 Taylor, N. J., 78 Taylor, R., 253 Taylor, R. C., 247,403 Taylor, S. H., 132 Tebbe, F. N., 2, 69 Tebelev, L. G., 456 Tedesco, P. H., 104, 332 Telegus, V. S., 98 Tel’noi, V. I., 84 Tel’nykh, T. F., 156 Temple, T. B., 227 Temyakov, E. D., 106 Tennant, W. C., 227 Teo, S. M., 315 Teotia, M. P., 107 Terao, N., 103 Tereshkina, R. I., 161 Ternovaya, T. V., 457 Terzaghi, G., 120 Terzis, A., 220, 306 Teterin, E. G., 33 Tetyukhina, L. F., 160 Teuben, J. H., 10 Tewari, R. C., 35, 56, 317, 331,458 Teze, A., 163 Thackeray, J. R., 48, 56 Thackeray, M. M., 225,436 Thakre, 0. B., 82, 157 ThC, K. I., 239 Theobald, F., 43 ThCophanides, T., 99,419 Theriot, L. J., 55,250,316,317 Thewalt, H., 269 Thewalt, U., 327 Thickett, G. W., 227 Thiele, G., 142, 254 Thiele, K. H., 24, 29, 68, 145 Thierr-Sorel, A., 46 Thiers, G. F., 438 Thistlethwaite, R. J., 459 Thomas, F. D., 318 Thomas, G., 287 Thomas, J. L., 127 Thomas, K. M., 340, 361, 408,409, 418,428,439 Thomas, P., 53, 305 Thomas, T. W., 411 Thompson, D. T., 38 Thompson, D. W., 20 Thompson, S., 460

Thomson, A. J., 69 Thomson, J., 285 Thornton, D. A., 299, 351 Thornton, P., 46, 241, 275 Thynne, J. C. J., 136 Tiethof, J. A., 299 Tikhonov, G. P., 110 Tikhonova, G. A., 64, 157 Tille, D., 100 Tilloca, G., 83 Timchenko, T. I., 156 Timms, P. L., 93, 191 Timofeeva, E. G., 112 Timofeeva, E. N., 158 Timofeeva, N. I., 33 Tindall, G. W., 7 Ting-I Li, 332 Ting Po I, 332 Tinker, H. B., 364, 365 Tipton, D. L , 131 Tiripicchio, A., 195 Tirouflet, J., 2, 26 Tishchenko, M. A,, 454 Tishchenko, R. P., 68 Tisley, D. G., 175, 176, 199, 247, 366,370,458 Tissier, A., 36 Titcomb, C. G., 73 Titov, V. A., 84 Titus, D. D., 304 Tkachenko, E.V., 64, 157 Tkachev, V. V., 162 Tkacheva, V. Ya., 112 Tkachuk, G. M., 65 Tobinaga, K., 321 Todorova-Naidenova, T., 427 Toftgard, B., 333 Toftlund, H., 101, 256 Tokareva, T. P., 95 Tokii, T., 317, 319 Tokonami, M., 42 Tokunov, 0. I., 156 Tolmachev, V. N., 36 Tolman, C. A., 271 Toma, H. E., 211 Tomat, G., 468,474 Tomicka, B., 332 Tomita, I., 104 Tomlinson, A. A. G., 273 Tomlinson, C. H., 93, 191 Tomlonovic, B., 243 Tong, H. W., 236,254 Tong, S. B., 358 Toogood, G. E., 109, 198 Topol, L. E., 222 Toppen, D., 143,173 Topping, R. L., 313 Toptygina, G. M., 35 Torchenkova, E. A., 165 Tordjman, Torri, G., 20

Tosi, L., 95 Tossidis, I., 236 Tossidis, J. A., 21 Toth, L. M., 118 Touboul, M., 63 Tourne, C., 50,165 Tourne, F., 165 Towers, C., 189 Towns, R. L. R., 48 Traggeim, E. N., 83 Traverse, J. P., 83, 103 Trefonas, L. M., 241 Treichel, P. M., 167, 186, 189, 190,205,409 Treindl, L., 331 Trendafelov, D., 224 Tret’yakov, Yu. D., 15, 82, 108 Tridot, G., 59 Tripathy, K. K., 446 Trivedi, C. P., 35, 332,457 Trofimenko, S., 239 Trofimov, V. A., 267,408 Trogu, E. F., 402 Troitskaya, A. D., 95, 245, 286,407,427 Trotter, J., 91, 126, 189, 199, 235, 310 Troup, J. M., 31 Troyanov, S. I., 28 Trtanj, M. I., 31 Trunov, V. K., 156, 158, 160, 161 Trusov, V. I., 84 Trusova, K. M., 427 Truter, M. R., 302, 311 Tsay, F.-D., 133 Tsevina, A. V., 56 Tsintsadze, G. V., 37 Tsirel’nikov, V. I., 28 Tsivadze, A. Yu., 480 Tsuchiya, R., 254, 273 Tsuda, T., 310 Tsutsui, M., 25, 171, 356,465, 47 1 Tsvetkov, A. A., 480 Tsvetkova, M. P., 19 Tsyashchenko, Yu. P., 154 Tsyganok, L. P., 164 Tsyganova, I. A., 138 Tucker, E. E., 433 Tucker, P. M., 96 Tudo, J., 43, 46, 64 Tuenge, R. T., 72 Tukhtaev, S. S., 254 Tully, M. E., 171, 173 Turchaninov, A. M., 7 Turco, A., 375 Turlakov, V. N., 15 Turner, J. J., 89, 270, 358, 420

510 Turta, K. I., 224,227 Tvanov, V. A., 332 Twigg, M. W., 169 Tylkina, M. A., 138 Tytko, K.-H., 122 Tyvoll, J. R., 309 Ubozhenko, 0. D., 48,51 Uchida, I., 34 Uden, P. C., 396 Uchida, Y., 18, 271, 393 Udovenko, A. A., 480 Udovenko, V. V., 255, 267, 327

Udupa, M. R.,250, 396,436 Udy, D. J., 15, 16 Uebel, J. J., 451, 462 Uehara, A., 273 Ueno, A., 156 Ueno, K., 55, 166, 242, 243, 282, 311, 319, 395,459

Ugarov, V. V., 158, 180 Uggla, R., 304, 309 Ugo, R.,248 Uguagliati, P., 364 Uhlemann, E., 251, 332 Ul’ko, N. V., 148 Ullbricht, W., 51 Ulmer, S. W., 123 Ulrich, S. E., 254 Umanskii, Ya. S., 71 Umbreit, M. A., 137 Umland, F., 164 Umova, I. E., 110 Underhill, A. E., 41 1 Underhill, M., 356 Ungurenasu, C., 5,202 Uno, T., 331 Urbach, F. L., 292 Urban, W., 64 Urland, W., 411 Urushiyama, A., 106 Uryu, N., 107 Usatenko, Yu. I., 85 Ushakova, N. I., 119 Ushakovskii, V. T., 137 Ushida, Y., 270 Ushijama, T., 55, 319 Usmanov, Z. I., 117, 147 Uson, R.,24 Ustynyuk, N. A., 146 Utkina, E. A., 133 Uttley, M. F., 342, 346, 384 Uvarova, K. A., 85 Vaisbein, Z. Y., 401 Valenti, V., 248 Valikhanova, N. Kh., 59 Vallarino, L. M., 191, 275, 294

Valueva, N. A., 73

Author Index Van, K. V., 299 van Ammon, R., 460 Van Dam, P. B., 137 Van Den Heuvel, G. P. M., 79 Vanderheim, D. B., 105 Van Der Helm, D., 314 Van der Linden, J. G. M., 300,

440 van der Meer, H., 300 van der Veer, M. C., 288 Van der Voorst, P. H., 193 Van de Velde, G. M. H., 15 Van Hecke, G. R., 99 Van Landuyt, J., 72 Van Leeuwen, H. P., 176 Van Loon, C. J. J., 191 Vannerberg, N. G., 223 Vanni, A., 332 Van Oven, H. O., 1 Van Poucke, L. C., 332,438 Van Tamelen, E. E., 210 Van Tamelen, J. A., 120 Van Vugt, N., 453 Varfolomeev, M. B., 83, 453, 4s 5

Varga, L. P.,467 Vargas, J. I., 36 Varhelfi, C., 261, 294 Varshavskii, Yu. S., 365 Varshney, K. G., 16 Vashman, A. A., 243 Vasil’kova, I. V., 6, 142 Vasilev, Khr., 137 Vasil’ev, V. P.,13, 83, 309 Vasil’eva, G. A., 27 Vast, P., 117 Vatulescu, R., 16 Vaughan, D. H., 371 Vavilova, V. V., 71 Veal, J. T., 106 Vedrine, A., 101 Velichko, A. V., 180,453 Velikodnyi, Yu. A., 156 Venanzi, L. M., 429 Venkappayya, D., 101 Venkataraman, B., 57 Venkatesan, K., 450 Venskovskii, N. U., 423 Verani, G., 402 Vereshchagina, T. Y., 243 Verheijdt, P. L., 193 Verkade, J. G., 207 Verma, J. R., 56 Verschoor, G. C., 191,218 Vertes, A., 219 Viard, B., 13, 18 Vicat, J., 16 Vicedomini, M., 332 Vicentini, G., 452,456 Vickova, J., 309

Vidali, M., 475,478 Vidulich, G. A., 34, 454 Vieles, P., 112 Vigato, A., 397 Vigato, P.A., 475, 478 Vigee, G. S., 332 Viglino, P., 402 Vijayaraghavan, V. R., 260 Vinarov, I. V., 36 Vince, D., 249 Vince, D. G., 324 Vincents, F., 109 Vining, R. F. W., 70 Vinogradov, I. V., 177 Vinogradov, V. S., 180 Vinogradova, S. M., 24 Vinogradova, V. N., 127 Vinokurov, V. A., 156, 160 Viossat, B., 66 Viranovskaya, N. N., 22 Vishinskaya, L. I., 29 Vitali, D., 169 Vite, L. W. G., 265 Vitzhum, G., 194 Vladimirova, Z. A., 31, 34 Vlaskina, R. Ya., 66 Vlasova, N. N., 21 Vlasova, R. A., 408 Vlasse, M., 77 Vleck, A. A., 236 Vodop’yanova, V. P., 64,65 Volter, J., 409 Voitlander, J., 100 Volfovsky, C., 66 Volkov, S. V., 280 Volkov, V. L., 59,64, 156, 157 Volkov, V. M., 344, 352,400 Volkova, A. I., 84 Volkova, A. N., 1 1 Y Volkova, L. M., 160 Volkova, V. P., 228 Volokh, T. N., 262 Voloshina, T. D., 64 Vol’pin, M. E., 342 Volponi, L., 476 Volshtein, L. M., 412 Volz, W. B., 467 Von Angerer, E., 91 Von der Miihl, R., 102 Von Dreele, R. B., 53 Von Hodenberg, R., 63 Von Meyenburg, U., 107 Von Zelewsky, A., 239 Vorob’ev, P. N., 13 Voronkov, A. A., 15, 32 Voronkov, M. G., 66,112,166 Vorontsov, E. S., 13 Vorotnikova, V. N., 34 Voskov, V. S., 86 Votinov, M. P., 147

51 1

Author Index Vovkotrub, E. G., 75 Vowles, P. D., 292 Vozhdaeva, E. E., 144, 146 Vrieze, K., 366 Vu Hoang Kyi, 82 Vuillard, G., 31 VuletiC, N., 66, 75, 85 Vulliet, P., 36 Vyshinskaya, L. I., 27 Vyskubov, V. P., 64,83 Wada, H., 228 Wada, M., 390 Wada, Y., 108 Wade, R. S., 217 Wadier, C., 78 Wadley, L. G. B., 8,47 Wagner, B. E., 326 Wagner, K. P.,409 Wagner, M. R., 446 Wagner, S., 68 Wagner, W. F., 451 Wailes, P. C., 7, 10, 25, 27, 40 Wakita, H., 452 Waldmeier, P., 260 Waldron, B., 247 Waldron, R. W., 299, 397 Walker, F. A., 305, 332 Walker, I. M., 463 Walker, W. R.,309 Wallbridge, M. G. H., 39 Wallwork, S. C., 224 Walsh, D., 318 Walters, R. T., 102 Walther, B., 124 Walton, R. A., 175, 176, 199, 199,247, 366, 370,434, 458 Wan, C., 178 Wander, J. D., 462 Wang, F., 377 Wang, J. T., 285, 332 Wang, P. S.,352 Wang, R., 352 Wanklyn, B. M., 15 Ward, G. A,, 116 Ward, R. T., 153,176 Waring, J. L., 31, 156 Warnke, Z., 332 Warren, L. E., 323 Warzecha, W., 273 Wasfi, S. H., 165 Wasgestian, H. F., 114 Wasson, J. R., 52, 57, 313 Wasson, S. J. S., 451 Watanabe, E., 224 Watanabe, T., 322 Waters, T. N., 304, 306 Waters, W. A., 236 Watkins, C. L., 332 Watkins, D. D., 387

Watkins, D. M., 411 Watkins, N. T., 308 Watkins, P. M., 195, 284, 398 Watkins, S. F., 356 Watlon, R. A., 433 Watson, K. J., 258 Watson, W. H., 264 Watt, G. D., 344 Watt, G. W., 466,480 Watts, R. J., 389 Waugh, A. B., 169 Wayland, B. B., 9, 239 Waysbort, D., 352 Weakley, T. J. R., 165,245 Weaver, J., 230 Weaver, T. R.,389 Webb, G. A., 275,302 Webb, T. R., 140, 141 Weber, L., 406 Weeden, D. H., 463 Wehry, E. L., 305 Wei, C. H., 279, 309 Wei, R. M. C., 221,397 Weigel, D., 280 Weigel, F., 448,456 Weigold, H., 25, 40 Weil, J. A., 269 Weil, T., 420 Weininger, M. S., 300 Weinstein, G. N., 318 Weinstock, N., 166 Weiss, A., 4 Weiss, A. J., 26 Weiss, R., 30, 121, 141, 241, 318 Wekman, N., 205 Welch, A. J., 236, 241, 446, 45 1 Wells, P.R., 410 Wendling, E., 174 Wentworth, R. A. D., 144 Werbelow, L. G., 461 Werle, P., 42, 47 Werner, D., 130 Werner, H., 221 Werner, K., 278 Werner, K. V., 367, 368 Wertz, D. L., 309 Wessels, G. F. S., 464 West, B. O., 48, 186 West, D. X.,105, 194 Westin, L., 392 Westlake, D. G., 40 Westland, A. D., 109, 143 Whan, D. A., 137 Whang, Y.-A., 216 Wharton, R. K., 113 Wheatland, D. A., 299, 397 Wheatley, P. J., 185, 392 Whillans, F. D., 234 Whimp, P. O., 190

White, A. H., 139, 198, 263, 309 White, A. M., 284 White, D. A., 235 White, J. W., 173 White, W. B., 99 Whitesides, G. M., 39 Whiting, R., 298 Whitten, D. G., 347 Whittingham, M. S., 151 Whyman, R., 379 Wichmann, K., 213 Wiedemann, W., 218 Wiedermann, J., 243 Wiegerink, F. J., 104, 194 Wieghardt, K., 268 Wiese, G., 162, 164 Wiggins, R. A., 51 Wigmans, T., 453 Wilde, R. E., 192 Wilder, R. L., 110 Wilinski, J., 75 Wilke, G., 27 Wilkins, A. L., 82 Wilkins, J. D., 86, 144 Wilkins, T. A., 9 Wilkinson, G., 24, 116, 122, 148, 166,205,285, 338, 343, 347,365, 374,410,422 Wilkinson, J. G., 212, 340 Willcott, M. R. tert., 463 Willemse, J., 297, 313 Willett, R. D., 304 Willey, G. R.,21 Williams, D. R., 331,458 Williams, R. J., 451 Williamson, D. R., 439 Williams-Smith, D. L., 93 Willis, C. J., 52 Winkler, B., 269 Wilson, J. R., 43, 60,64 Wilson, M. F., 332 Wilson, P. W., 465, 479 Windgassen, N. R., 83 Windle, J. J., 316 Winfield, J. M., 136 Wingfield, J. N., 126, 235 Wing, R. M., 379,451,462 Winkler, T., 383 Winscom, C. J., 57 Winters, L. J., 195 Winterton, N., 104, 207 Wirth, G., 102 Wishnevsky, V., 448 Witiak, D., 254 Wohrmann, H., 144 Wojcicki, A., 185, 190, 209 Wojcicki, H., 167 Woldbye, F., 101,255 Wolf, W. R., 105 Wolters, A. P., 144

Author Index

512 Wong, C. H., 436 Wong, C. M., 8 Wong, H., 213 Wong, R. Y., 224 Wood, D. J., 16 Wood, J. S., 451 Wood, M. B., 7 Wood, M. H., 64 Woods, M., 269 Woodward, J. T., 36 Woodward, P., 201, 230, 338 Woolf, A. A., 423 Workman, M. O., 286 Wormald, J., 298 Worrell, W. L., 97 Worthington, J. M., 305 Wozniak, W. T., 168, 185 Wreford, S. S., 426 Wright, C. J., 173 Wrighton, M., 125, 168, 195, 262 Wu, K. K., 15 Wuesteneck, A., 44 Wunsch, J., 164 Wyatt, M., 462 Wyganowski, C., 195 Wyruboff, M. G., 474 Wysocki, J., 253 Yablokov, Yu. V., 107 Yablokova, Y. V., 245 Yadav, B. N., 22 Yakimov, M. A., 455 Yakovlev, I. P., 267, 408 Yamada, O., 108 Yamada, S., 114, 249, 264, 322 Yamagishi, T., 271 Yamaguchi, S., 228 Yamamoto, A., 5, 24, 299, 342 Yamamoto, O., 153 Yamamoto, T., 24 Yamamoto, Y., 209,214,422 Yamanouchi, K., 114,249 Yamasaki, K., 255 Yamazaki, H., 25 Yamazaki, S., 193 Yampol'skaya, V. V., 453 Yanagisawa, S., 253, 390 Yanai, M., 70 Yandle, J. R., 192 Yano, T., 55, 166, 319 Yanson, G. D., 82 Yanushkevich, T. N., 156 Yarkova, E. G., 18 Yashida, I., 267 Yastrebov, V. V., 18 Yasufuku, K., 25 Yatsimirskii, K. B., 67 Yavari, A., 98

Yavorskaya, E. V., 441 Yawney, D. B., 310 Yeh, C.-L., 128 Yeh, E. L., 128 Yeo, P. A., 331 Yesinowski, J. P., 339 Yoke, J. T., 237,300 Yokio, H., 456 Yoneda, H.. 101. 254. 376 Yoshida, I., 242, 282, 459 Yoshida, S., 457 Yoshida, Z., 224, 367 Yoshikawa, S., 256, 257, 263 Yoshikawa, Y., 255 Yoshimura, M., 147 Yoshimura, T., 468 Yoshino, N., 20 Yoshino, T., 20, 321 Yosim, S. J., 222 Young, C. H., 269 Young, J. E., 422 Yudelevich, I. G., 161 Yuen, J. M. C., 354 Yukhimenko, E. V., 138 Yushin, A. S., 70 Yvon, K., 44 Zaccai, G., 82 Zacharias, P. S., 243 Zachariasen, W. H., 448, 449 Zacheslavskaya, R. Kh., 139 Zadrodin, I. N., 17 Zagetova, R. G., 18 Zagorskaya, T. V., 398 Zahrobsky, R. F., 12 Zaitsev, B. E., 50, 119, 156, 308,423,452,454 Zaitsev, L. M., 33 Zaitsev, M. G., 456 Zaitseva, G. A., 83 Zaitseva, L. L., 177, 180, 453 Zaitseva, V. A., 308 Zalkin, A., 443 Zamanskii, V. Y., 331 Zanderighi, L., 120 Zanella, P., 470 Zapletnyak, V. M., 66 Zarli, B., 476 Zarnegar, P. P., 347 Zarurna, D., 166 Zasorin, E. Z., 153 Zatko, D. A., 436 Zavol'skii, V. A., 15, 82 Zayakina, T. A., 251 Zayan, S. E., 291 Zdunnek, P., 24 Zeinstra, J. D., 1 Zeiss, H. H., 88, 115 Zektar, J., 217 Zelenov, V. I., 441

Zelentsov, V. V., 48, 51, 57, 107, 139, 177, 193 Zelikman, A. N., 82 Zemlyanskii, N. I., 95, 148 Zetta, L., 24 Zevin, L. S., 160 Zharskii, I. M., 153 Zhebentyaev, A. I., 84 Zhelyazkova, B. G., 67 Zhemchuzhnikova, T. A., 107 Zhukov, A. N., 137 Zhukovskii, V. M., 156 Zhurba, T. V., 332 Ziegler, R. J., 102 Ziegler, U., 305 Zikmund, Z., 153 Zilkha, A., 393 Zinato, E., 106, 110 Zingales, F., 363 Zingde, M. D., 109, 284 Zink, J. I., 100, 252, 377, 460 Zinner, L. B., 456 Ziolkowski, J., 42, 158 Ziolo, R. F., 304 Zipperer, W. C., 95 Znekova, G. A., 160 Zolina, Z. K., 160 Zolotova, E. A., 15, 33, 157 Zolotareva, L. S., 161 Zolotavin, V. L., 64,65 Zommer, S., 68 Zorin, R. B., 7 ' Zotov, N. I., 372 Zsinka, L., 452 Zubankov, V. N., 30 Zubenko, V. V., 82 Zubieta, J. A., 200 Zubritskaya, D. I., 134 Zuech, E. A., 132 Zuika, I., 166 Zyuzya, L. A,, 68

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