Volume 1

Mechanisms of Inorganic and Organometallic Reactions

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Volume 1

Mechanisms of Inorganic and Organometallic Reactions

Edited by

M. V. Twigg Imperial Chemical Industries P. L. C. Billingham, United Kingdom

PLENUM PRESS • NEW YORK AND LONDON

Library of Congress Cataloging in Publication Data

Main entry under title:

Mechanisms of inorganic and organometallic reactions. Includes bibliographical references and index. I. Chemical reactions. 2. Chemistry, Inorganic. 2. Organometallic compounds. I.

Twigg, M .. V. QD50l.M426 1983 541.3'9 83-2140

ISBN 978-1-4615-7412-5 ISBN 978-1-4615-7410-1 (eBook) DOI 10.1007/978-1-4615-7410-1

© 1983 Plenum Press, New York Sof'tcover reprint of the hardcover I st edition 1983

A Division of Plenum Publishing Corporation 233 Spring Street, New York, N.Y. 10013

All rights reserved

No part of this book may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, microfilming, recording, or otherwise, without written permission from the Publisher

Contributors

Dr. 1. Burgess ter, U.K.

Chemistry Department, The University of Leicester, Leices-

Dr. 1. Coe Chemistry Department, Kings College, London University, The Strand, London WC2, U.K.

Dr. I.M. Davidson Dept. of Chemical Engineering, University of Edin-burgh, Kings Building, Edinburgh EH9 3JL, Scotland, U.K.

Dr. A.l. Deeming Chemistry Department, University College London, 20 Gordon Street, London WCIH OAJ, U.K.

Dr. M. Green Chemistry Department, The University of York, York, North Yorkshire, U.K.

Dr. D. Hague Chemical Laboratory, The University of Kent, Canterbury, Kent, U.K.

v

vi Contributors

Dr. M.N. Hughes Chemistry Department, Queen Elizabeth College, Uni-versity of London, London W8 7AH, U.K.

Dr. L.A.P. Kane-Maguire Chemistry Department, University College, Car-diff CFl IXL, Wales, U.K.

* Dr. A.G. Lappin Chemistry Department, University of Glasgow, Glasgow, Scotland, U.K.

Professor A. McAuley Department of Chemistry, University of Victoria, British Columbia, Canada

Dr. P. Moore Department of Chemistry and Molecular Sciences, University of Warwick, Coventry CV4 7AL, U.K.

*Presently: Department of Chemistry . University of Notre Dame. Notre Dame, Indiana46556, U.S.A.

Preface

During recent years a high level of interest has been maintained in the kinetics and mechanisms of inorganic compounds in solution, and there has also been a notable upsurge of literature concerned with reaction mechanisms of organo­transition metal compounds. The reviews of the primary literature previously provided by "Inorganic Reaction Mechanisms" (Royal Society of Chemistry) and "Reaction Mechanisms in Inorganic Chemistry" in "MTP International Re­views of Science" (Butterworths) continue to be of considerable value to those concerned with mechanistic studies, and it is unfortunate they are no longer published.

The objective of the present series is to provide a continuing critical review of literature dealing with mechanisms of inorganic and organometallic reactions in solution. The scope of potentially relevant work is very large, particularly in the field of organotransition metal chemistry, and papers for inclusion have been chosen that specifically probe mechanistic aspects, rather than those of a prep­arative nature. This volume covers the literature published during the period July 1979 to December 1980 inclusive. Material is arranged basically by type of reaction and type of compound along generally accepted lines. Numerical data are usually reported in the units used by the original authors, though the units of some results have been converted in order to make comparisons.

Many people, most of whom are members of the Inorganic Mechanisms Discussion Group (UK), were involved in establishing this series. Their help is gratefully acknowledged, as is the enthusiastic and prompt way in which con­tributions were prepared. Comments on this and future volumes will be wel­comed.

vii

Contents

Part 1. Electron Transfer Reactions

Chapter 1. General Redox Processes and Reactions between Two Complexes

A.G. Lappin

1.1. Introduction............................................ 3 1.2. General Background. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2. 1. General and Theoretical . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.2.2. Theoretical Developments ......................... 4 1.2.3. Optical Electron Transfer. . . . . . . . . . . . . . . . . . . . . . . . . . 5

1.3. Reaction Mechanisms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 11 1.3.1. Inner-Sphere and Outer-Sphere Reactions. . . . . . . . . . . .. 11 1.3.2. Solvent Effects in Electron Transfer Reactions. . . . . . . .. 30

1.4. Excited State Electron Transfer . . . . . . . . . . . . . . . . . . . . . . . . . . .. 31 1.5. Stereoselectivity in Electron Transfer. . . . . . . . . . . . . . . . . . . . . . .. 34 1.6. Metalloprotein Redox Reactions. . . . . . . . . . . . . . . . . . . . . . . . . . .. 34

Chapter 2. Metal-lon-Ligand Redox Reactions

A. McAuley

2.1. Introduction............................................ 37 2.2. Metal Complexes with Inorganic Substrates. . . . . . . . . . . . . . . . .. 38

2.2.1. Reactions of Hydrazine and Hydroxylamine. . . . . . . . . .. 38 2.2.2. Reactions of Nitrate and Nitrite. . . . . . . . . . . . . . . . . . . .. 39

ix

x Contents

2.2.3. Reactions of Thiocyanate. . . . . . . . . . . . . . . . . . . . . . . . .. 40 2.2.4. Reactions of Dithionite and Thiosulfate .............. 40 2.2.5. Reactions of Iodide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 41 2.2.6. Other Reductants ............................... " 42

2.3. Oxidation of Organic Substrates by Metal Ion Complexes. . . . . .. 43 2.3.1. Chromium(VI)................................... 44 2.3.2. Vanadium(V).................................... 46 2.3.3. Manganese(III) and Manganese(VII) . . . . . . . . . . . . . . . .. 46 2.3.4. Iron(III)........................................ 48 2.3.5. Thallium(III).................................... 49 2.3.6. Iridium(IV)..................................... 49 2.3.7. Cerium(IV)..................................... 50 2.3.8. Cobalt(III)...................................... 51 2.3.9. Bromate........................................ 52 2.3.10. Other Oxidizing Agents. . . . . . . . . . . . . . . . . . . . . . . . . .. 53

2.4. Oxidation of Metal Ion Complexes ......................... 54 2.4.1. Iron(lI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54 2.4.2. Chromium(II)................................... 56 2.4.3. Vanadium(II) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 57 2.4.4. Coba1t(II) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 58 2.4.5. Other Reductants. ................................ 59

2.5. Intramolecular Electron Transfer. . . . . . . . . . . . . . . . . . . . . . . . . .. 59

Part 2. Substitution and Related Reactions

Chapter 3. Reactions of Compounds of the Nonmetallic Elements

M.N. Hughes

3.1 . Introduction............................................ 65 3.2. Boron................................................. 65 3.3. Group IV Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 68

3.3.1. Carbon......................................... 68 3.3.2. Silicon......................................... 69 3.3.3. Germanium..................................... 70

3.4. Group V Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 71 3.4.1. Nitrogen........................................ 71 3.4.2. Phosphorus..................................... 76 3.4.3. Arsenic........................................ 80 3.4.4. Antimony....................................... 80

Contents xi

3.5. Group VI Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 80 3.5.1. Oxygen........................................ 80 3.5.2. Sulfur .......................................... 81 3.5.3. Selenium....................................... 84 3.5.4. Tellurium....................................... 84

3.6. Group VII Elements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 84 3.6.1. Fluorine........................................ 84 3.6.2. Chlorine........................................ 85 3.6.3. Bromine........................................ 85 3.6.4. Iodine.......................................... 86

Chapter 4. Substitution Reactions of Inert Metal Complexes­Coordination Numbers 4 and 5

J.S. Coe

4.1. Introduction............................................ 87 4.2. Square-Planar Complexes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 88

4.2.1. Platinum(II)..................................... 88 4.2.2. Palladium(II).................................... 93 4.2.3. Nickel(II) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 95 4.2.4. Gold(III)....................................... 98 4.2.5. Miscellaneous................................... 99 4.2.6. Isomerization .................................... 100

4.3. Tetrahedral Complexes ................................... 101 4.4. Five-Coordinate Complexes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 101

Chapter 5. Substitution Reactions of Inert Metal Complexes­Coordination Numbers 6 and Above

J. Burgess and P. Moore

5. 1. Introduction............................................ 103 5.2. Chromium ............................................. 105

5.2.1. Introduction ..................................... 105 5.2.2. Aquation and Solvolysis of Chromium(III) Complexes.. 105 5.2.3. Formation of Chromium(III) Complexes. . . . . . . . . . . . .. 117 5.2.4. Chromium(III) Photochemistry ..................... 124 5.2.5. Isomerization and Racemization Reactions. . . . . . . . . . .. 125 5.2.6. Base Hydrolysis ................................. 126 5.2.7. Solids .......................................... 126 5.2.8. Other Chromium Oxidation States. . . . . . . . . . . . . . . . . .. 127

xii Contents

5.3. Group VII Elements ..................................... 127 5.3.1. Technetium ..................................... 127 5.3.2. Rhenium....................................... 128

5.4. Iron ................................................... 128 5.4.1. Pentacyanoferrate(II) Complexes. . . . . . . . . . . . . . . . . . .. 129 5.4.2. Diimine Complexes .............................. 133 5.4.3. Other Low-Spin Iron(II) Complexes. . . . . . . . . . . . . . . .. 139 5.4.4. Iron(III) Complexes .............................. 140

5.5. Ruthenium ............................................. 141 5.5.1. Ruthenium(II) ................................... 141 5.5.2. Ruthenium (III) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 143 5.5.3. Ruthenium(IV) .................................. 145

5.6. Osmium ............................................... 145 5.7. Cobalt(III)............................................. 146

5.7.1. Aquation and Solvolysis. . . . . . . . . . . . . . . . . . . . . . . . . .. 146 5.7.2. Base Hydrolysis and Base Solvolysis ................ 154 5.7.3. CatalyzedAquation ............................... 157 5.7.4. Formation...................................... 160 5.7.5. Solvent and Ligand Exchange ...................... 164 5.7.6. Racemization and Isomerization .................... 167 5.7.7. Carbonate and Sulfite Complexes ................... 170 5.7.8. Bis(glyoximato) Complexes ........................ 172 5.7.9. f.L-Dicobalt(III) Complexes. . . . . . . . . . . . . . . . . . . . . . . .. 174 5.7.10. Photochemistry .................................. 176 5.7.11. Reactions of Coordinated Ligands. . . . . . . . . . . . . . . . . .. 177

5.8. Rhodium(III)........................................... 179 5.8.1. Aquation ....................................... 180 5.8.2. Base Hydrolysis ................................. 180 5.8.3. Catalyzed Aquation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 181 5.8.4. Formation ...................................... 181 5.8.5. Solvent and Ligand Exchange. . . . . . . . . . . . . . . . . . . . .. 182 5.8.6. Ring Opening and Closing. . . . . . . . . . . . . . . . . . . . . . . .. 182 5.8.7. Isomerization.................................... 183 5.8.8. Carbonate and Sulfite Complexes ................... 183 5.8.9. Bis(glyoximato) Complexes ........................ 186 5.8.10. Photochemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 186

5.9. Iridium ................................................ 188 5.9. 1. Iridium(III)..................................... 188 5.9.2. Iridium(IV) ..................................... 190

5.10. Platinum(lV) ........................................... 190 5.10.1. General ........................................ 190 5.10.2. Inversion at Coordinated Sulfur and Selenium ......... 190

Contents xiii

Chapter 6. Substitution Reactions of Labile Metal Complexes

D.N. Hague

6.1. Complex Formation Involving Unsubstituted Metal Ions with Unidentate Ligands and Solvent Exchange . . . . . . . . . . . . . . . . . .. 193 6.1.1. Univalent Ions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 193 6.1.2. Bivalent Ions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 193 6.1.3. Ions of Valency 3 and Higher. . . . . . . . . . . . . . . . . . . . .. 195

6.2. Complex Formation Involving Unsubstituted Metal Ions and Multidentate Ligands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 197 6.2.1. Univalent Ions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 197 6.2.2. Bivalent Ions .................................... 198 6.2.3. Ions of Valency 3 and Higher ...................... 202

6.3. The Effects of Bound Ligands ............................. 203 6.3 . 1. Reactions in Water . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 203 6.3.2. Reactions in Nonaqueous Solvents .................. 207

Part 3. Reactions of Organometallic Compounds

Chapter 7. Metal-Alkyl Bond Fission and Formation

M. Green

7.1. Introduction............................................ 211 7.2. Metal-Alkyl Bond Fission ................ . . . . . . . . . . . . . . .. 211 7.3. Miscellaneous Thermal Decompositions ..................... 216 7.4. Metal-Alkyl Bond Formation .............................. 217 7.5. Transalkylation ......................................... 219

Chapter 8. Substitution, Oxidative Addition-Reductive Elimination, and Migration-Insertion Reactions

M. Green

8.1. Introduction ............................................ 223 8.2. Substitution Reactions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 223

8.2.1. Reactions Involving Carbonyls or Carbon Monoxide .... 223 8.2.2. Reactions Involving Di- or Multihapto Ligands ........ 228

xiv Contents

8.3. Oxidative Addition and Reductive Elimination ................ 231 8.4. Migration-Insertion Reactions ............................. 243

Chapter 9. Rearrangements, Intramolecular Exchanges, and Isomerization of Organometallic Compounds

A.J. Deeming

9.1. Mononuclear Compounds ............................... " 249 9.1.1. Isomerizations and Intramolecular Exchanges. . . . . . . . .. 249 9.1.2. Simple Ligand Rotation at a Metal Center ............ 251 9.1. 3. Ligand Motion Involving Changes in Hapiticity. . . . . . .. 256 9.1.4. Metal Migration between Different Ligand Sites ....... 259 9.1.5. Hydrogen Migrations Involving Hydrogen Bound to

Carbon .......................................... 260 9.1.6. Alkyl Migration Reactions ......................... 263 9. 1.7. Intraligand Rotations and Rearrangements ............ 263

9.2. Dinuclear Compounds .................................... 264 9.2.1. Migration of CO and Related Ligands ............... 264 9.2.2. Hydrogen Migration Reactions ..................... 265 9.2.3. Motion Involving Bridging Organic Ligands .......... 266 9.2.4. Rotation about Metal-Metal Bonds .................. 268

9.3. Cluster Compounds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 268 9.3.1. Fluxional Metal Frameworks . . . . . . . . . . . . . . . . . . . . . .. 268 9.3.2. Migration of CO and Related Ligands ............... 268 9.3.3. Hydrogen Migration Reactions ..................... 270 9.3.4. Motion Involving Bridging Organic Ligands .......... 270

Chapter 10. Reactivity of Coordinated Hydrocarbons

L.A.P. Kane-Maguire

10.1. Introduction ............................................ 273 10.2. Nucleophilic Addition and Substitution. . . . . . . . . . . . . . . . . . . . .. 273

10.2.1. a-Bonded Hydrocarbons. . . . . . . . . . . . . . . . . . . . . . . . . .. 273 10.2.2. 1T-Bonded Hydrocarbons .......................... 276 10.2.3. Reactions at Side Chains and Exocyclic Carbocations ... 290 10.2.4. Attack at Carbonyl Ligands ........................ 292

10.3. Electrophilic Attack ...................................... 293

Contents

Chapter 11. Homogeneous Catalysis of Organic Reactions by Complexes of Metal Ions

1.M. Davidson

xv

11.1. Introduction............................................ 295 11. 1.1. Scope of the Review. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 295 11.1.2. Elementary Steps in Homogeneous Catalysis .......... 295

11.2. Reactions Catalyzed by Carbene Complexes .................. 296 11.2.1. Alkene Metathesis ................................ 296 11.2.2. Ring-Opening Polymerization by Metallocarbene

Complexes ...................................... 301 11.3. Hydrogenation .......................................... 301

11. 3. 1. Introduction..................................... 301 11.3.2. Hydrogenation of Alkenes ......................... 302 11.3.3. Asymmetric Hydrogenation ........................ 303 11.3.4. Hydrogenation of Aromatic Hydrocarbons ............ 306 11. 3.5. Hydrogen Transfer Hydrogenation. . . . . . . . . . . . . . . . . .. 307

11.4. Reactions of Carbon Monoxide .. . . . . . . . . . . . . . . . . . . . . . . . . .. 308 11.4.1. Hydroformylation ................................ 308 11.4.2. Carbonylation of Alcohols ......................... 308 11.4.3. The Homogeneous Water Gas Shift Reaction (WGSR) .. 311

11.5. Oxidation .............................................. 314

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 317

Author Index . .......................................... 351

General Subject Index. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... 367