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The Organometallic Chemistry of the Transition Metals THE ORGANOMETALLIC CHEMISTRY OF THE TRANSITION METALS THE ORGANOMETALLIC CHEMISTRY OF THE TRANSITION METALS Sixth Edition ROBERT H. CRABTREE Yale University, New Haven, Connecticut Copyright © 2014 by John Wiley & Sons, Inc. All rights reserved. Published by John Wiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions. Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com. Library of Congress Cataloging-in-Publication Data: Crabtree, Robert H., 1948– The organometallic chemistry of the transition metals / by Robert H. Crabtree.— Sixth edition. pages cm Includes bibliographical references and index. ISBN 978-1-118-13807-6 (cloth) 1. Organometallic chemistry. 2. Organotransition metal compounds. I. Title. QD411.8.T73C73 2014 547′.056–dc23 2013046043 Printed in the United States of America ISBN: 9781118138076 10 9 8 7 6 5 4 3 2 1 CONTENTS Preface xi List of Abbreviations xiii 1 Introduction 1 1.1 Why Study Organometallic Chemistry?, 1 1.2 Coordination Chemistry, 3 1.3 Werner Complexes, 4 1.4 The Trans Effect, 9 1.5 Soft versus Hard Ligands, 10 1.6 The Crystal Field, 11 1.7 The Ligand Field, 19 1.8 The sdn Model and Hypervalency, 21 1.9 Back Bonding, 23 1.10 Electroneutrality, 27 1.11 Types of Ligand, 29 References, 37 Problems, 38 2 Making Sense of Organometallic Complexes 40 2.1 The 18-Electron Rule, 40 2.2 Limitations of the 18-Electron Rule, 48 2.3 Electron Counting in Reactions, 50 2.4 Oxidation State, 51 v vi COnTEnTS 2.5 Coordination Number and Geometry, 57 2.6 Effects of Complexation, 60 2.7 Differences between Metals, 63 References, 66 Problems, 67 3 Alkyls and Hydrides 69 3.1 Alkyls and Aryls, 69 3.2 Other σ-Bonded Ligands, 84 3.3 Metal Hydrides, 86 3.4 Sigma Complexes, 89 3.5 Bond Strengths, 92 References, 95 Problems, 96 4 Carbonyls, Phosphines, and Substitution 98 4.1 Metal Carbonyls, 98 4.2 Phosphines, 109 4.3 n-Heterocyclic Carbenes (nHCs), 113 4.4 Dissociative Substitution, 115 4.5 Associative Substitution, 120 4.6 Redox Effects and Interchange Substitution, 122 4.7 Photochemical Substitution, 124 4.8 Counterions and Solvents in Substitution, 127 References, 129 Problems, 131 5 Pi-Complexes 134 5.1 Alkene and Alkyne Complexes, 134 5.2 Allyls, 140 5.3 Diene Complexes, 144 5.4 Cyclopentadienyl Complexes, 147 5.5 Arenes and Other Alicyclic Ligands, 154 5.6 Isolobal Replacement and Metalacycles, 158 5.7 Stability of Polyene and Polyenyl Complexes, 159 References, 160 Problems, 161 6 Oxidative Addition and Reductive Elimination 163 6.1 Introduction, 163 6.2 Concerted Additions, 166 COnTEnTS vii 6.3 Sn2 Pathways, 168 6.4 Radical Mechanisms, 170 6.5 Ionic Mechanisms, 172 6.6 Reductive Elimination, 173 6.7 σ-Bond Metathesis, 179 6.8 Oxidative Coupling and Reductive Fragmentation, 180 References, 182 Problems, 182 7 Insertion and Elimination 185 7.1 Introduction, 185 7.2 CO Insertion, 187 7.3 Alkene Insertion, 192 7.4 Outer Sphere Insertions, 197 7.5 α, β, γ, and δ Elimination, 198 References, 201 Problems, 201 8 Addition and Abstraction 204 8.1 Introduction, 204 8.2 nucleophilic Addition to CO, 207 8.3 nucleophilic Addition to Polyenes and Polyenyls, 208 8.4 nucleophilic Abstraction in Hydrides, Alkyls, and Acyls, 215 8.5 Electrophilic Addition and Abstraction, 216 8.6 Single-Electron Transfer and Radical Reactions, 219 References, 221 Problems, 222 9 Homogeneous Catalysis 224 9.1 Catalytic Cycles, 224 9.2 Alkene Isomerization, 231 9.3 Hydrogenation, 233 9.4 Alkene Hydroformylation, 242 9.5 Alkene Hydrocyanation, 245 9.6 Alkene Hydrosilylation and Hydroboration, 246 9.7 Coupling Reactions, 248 9.8 Organometallic Oxidation Catalysis, 250 9.9 Surface, Supported, and Cooperative Catalysis, 251 References, 253 Problems, 256 viii COnTEnTS 10 Physical Methods 259 10.1 Isolation, 259 10.2 1H NMR Spectroscopy, 260 10.3 13C NMR Spectroscopy, 264 10.4 31P NMR Spectroscopy, 266 10.5 Dynamic NMR, 268 10.6 Spin Saturation Transfer, 271 10.7 T1 and the Nuclear Overhauser Effect, 272 10.8 IR Spectroscopy, 276 10.9 Crystallography, 279 10.10 Electrochemistry and EPR, 281 10.11 Computation, 283 10.12 Other Methods, 285 References, 287 Problems, 288 11 M–L Multiple Bonds 290 11.1 Carbenes, 290 11.2 Carbynes, 302 11.3 Bridging Carbenes and Carbynes, 305 11.4 N-Heterocyclic Carbenes, 306 11.5 Multiple Bonds to Heteroatoms, 310 References, 313 Problems, 315 12 Applications 317 12.1 Alkene Metathesis, 317 12.2 Dimerization, Oligomerization, and Polymerization of Alkenes, 324 12.3 Activation of CO and CO2, 332 12.4 C–H Activation, 336 12.5 Green Chemistry, 343 12.6 Energy Chemistry, 344 References, 347 Problems, 349 13 Clusters, Nanoparticles, Materials, and Surfaces 353 13.1 Cluster Structures, 354 13.2 The Isolobal Analogy, 364 13.3 nanoparticles, 368 COnTEnTS ix 13.4 Organometallic Materials, 371 References, 379 Problems, 381 14 Organic Applications 383 14.1 Carbon–Carbon Coupling, 384 14.2 Metathesis, 391 14.3 Cyclopropanation and C–H Insertion, 393 14.4 Hydrogenation, 394 14.5 Carbonylation, 396 14.6 Oxidation, 399 14.7 C–H Activation, 401 14.8 Click Chemistry, 405 References, 406 Problems, 408 15 Paramagnetic and High Oxidation-State Complexes 411 15.1 Magnetism and Spin States, 413 15.2 Polyalkyls and Polyhydrides, 420 15.3 Cyclopentadienyl Complexes, 425 15.4 f-Block Complexes, 426 References, 433 Problems, 435 16 Bioorganometallic Chemistry 436 16.1 Introduction, 437 16.2 Coenzyme B12, 442 16.3 nitrogen Fixation, 449 16.4 nickel Enzymes, 457 16.5 Biomedical and Biocatalytic Applications, 463 References, 465 Problems, 467 Appendix A: Useful Texts on Allied Topics 469 Appendix B: Major Reaction Types and Hints on Problem Solving 472 Solutions to Problems 475 Index 493 PREFACE This book is a study of the logic of organometallic chemistry as well as some of its leading applications. It should give starting scholars every- thing they need to set out on this field and develop their own approaches and ideas. I would again like to thank the many colleagues and readers who kindly pointed out errors in the fifth edition or otherwise contrib- uted: Professors Pat Holland, Jack Faller, Yao Fu, Lin Pu, Samuel Johnson, Odile Eisenstein, Ann Valentine, Gary Brudvig, Alan Goldman, Ulrich Hintermair, and Nilay Hazari, as well as students Liam Sharn- inghausen, Nathan Schley, Jason Rowley, William Howard, Joshua Hummel, Meng Zhou, Jonathan Graeupner, Oana Luca, Alexandra Schatz, and Kari Young. I also thank the Department of Energy for funding our work in this area. Robert H. Crabtree New Haven, Connecticut August 2013 xi LIST OF ABBREVIATIONS [ ] Encloses complex molecules or ions □ Vacant site or labile ligand ° Degrees Celsius 1°, 2°, 3° . Primary, secondary, tertiary A Associative substitution (Section 4.5) acac Acetylacetonate AO Atomic orbital at. Pressure in atmospheres bipy 2,2′-Bipyridyl Bu Butyl ca. about cata Catalyst CIDNP Chemically induced dynamic nuclear polarization (Section 6.4) CN Coordination number cod 1,5-Cyclooctadiene coe Cyclooctene cot Cyclooctatetraene Cp, Cp* C5H5, C5Me5 Cy Cyclohexyl D Dissociative substitution mechanism (Section 4.4) D-C Dewar–Chatt model of M(C=C) bonding involving weak back donation (Section 5.1) n d Electron configuration (Section 1.4) dσ, dπ σ-Acceptor and π-donor metal orbitals (see Section 1.4) diars Me2AsCH2CH2AsMe2 dmf Dimethylformamide dmg Dimethyl glyoximate dmpe Me2PCH2CH2PMe2 DMSO Dimethyl sulfoxide dpe or dppe Ph2PCH2CH2PPh2 xiii xiv LISt Of ABBrEVIAtIONS e Electron, as in 18e rule E, E+ Generalized electrophile such as H+ e.e. Enantiomeric excess (Section 9.3) en H2NCH2CH2NH2 EPr Electron paramagnetic resonance eq Equivalent
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