Organometallic chemistry is an integral part of every chemistry curriculum the world over, primarily because it bridges two main sub-disciplines of chemistry—inorganic and organic chemistry. Basic Organometallic Chemistry: Concepts, Syntheses and Applications, Second Edition
B D Gupta (Late) was professor, Department of chemistry, IIT Kanpur. After completing his Ph D from Flinders University, Australia, he worked as a post-doctoral researcher at the University College, London. After a one-year teaching stint at Roorkee University (now IIT Roorkee), he joined IIT Kanpur where he taught undergraduate, graduate and postgraduate students for over 30 years. He taught undergraduate classes for many years at various universities in the USA and Japan. He has published more than 90 research papers in international journals of repute in the area of organometallic chemistry of cobalt compounds.
Anil J Elias is professor, Department of chemistry, IIT Delhi. After completing his Ph D in inorganic chemistry from IIT Madras, he gained further experience as an Alexander von Humboldt fellow in Germany and later at the Fluorine Research Laboratories of the University of Idaho, USA. He has been teaching undergraduate, graduate and postgraduate students at IIT Kanpur and IIT Delhi for over 20 years. His research interests are in the area of organometallic and main group chemistry. He has authored the book General Chemistry Experiments: An interesting Collection (Universities Press) and published more than 55 research papers in reputed international journals. Prof. Elias is the recipient of the INSA teacher’s award instituted by the Indian National Science Academy for excellence in teaching science.
Chapter 1 Introduction 1.1 What is organometallic chemistry? 1.2 A brief history of organometallic chemistry 1.3 Importance of organometallic compounds 1.3.1 Organometallic compounds as reagents 1.3.2 Organometallic compounds as additives 1.3.3 Organometallic compounds as catalysts Supplementary reading Chapter 2 The 18 Valence Electron Rule 2.1 Introduction 2.2 The 18 electron rule 2.3 Counting of electrons and finding metal–metal bonds 2.4 Compliance and violation of the 18 electron rule Problems and exercises Supplementary reading Chapter 3 Metal Carbonyls 3.1 Structure, p-bonding and infrared spectroscopy 3.2 Bonding modes of CO 3.3 Symmetry of metal carbonyls 3.4 Syntheses of metal carbonyls 3.4.1 Direct carbonylation 3.4.2 Reductive carbonylation 3.5 Reactions of metal carbonyls 3.5.1 Activation of metal carbonyls 3.5.2 Disproportionation 3.5.3 Nucleophilic addition to CO 3.5.4 Electrophilic addition to the carbonyl oxygen 3.5.5 Carbonyl anions, cations and hydrides 3.5.6 Collman’s reagent 3.5.7 Migratory insertion of carbonyls 3.5.8 Oxidative decarbonylation 3.5.9 Photochemical substitution 3.5.10 Microwave assisted substitution 3.6 Metal nitrosyls Problems and exercises Supplementary reading Chapter 4 Neutral Spectator Ligands: Phosphines and N-heterocyclic Carbenes 4.1 Phosphines: steric and electronic parameters 4.2 Basicity of phosphines 4.3 Monodentate phosphines 4.4 Multidentate phosphines 4.5 N-Heterocyclic carbenes 4.5.1 Synthesis of NHCs Problems and exercises Supplementary reading Chapter 5 Alkenes and Alkynes as Ligands 5.1 Models of ethylene–metal bonding 5.2 Synthesis of metal-alkene complexes 5.3 Reactions of metal bound alkenes: The concept of Umpolung 5.4 Alkynes: modes of bonding to metals 5.5 Reactions of metal complexes of alkenes and alkynes 5.5.1 Pauson–Khand reaction Problems and exercises Supplementary reading Chapter 6 Carbenes and Carbynes: Complexes with Metal–Carbon Double and Triple Bonds 6.1 Metal carbenes 6.1.1 Synthesis of Fischer carbene complexes 6.1.2 Synthesis of Schrock carbene complexes 6.1.3 Tebbe’s reagent 6.1.4 Carbenes that are intermediate between the Fischer and Schrock types 6.2 Metal carbynes 6.2.1 Synthesis of metal–carbyne complexes 6.2.2 Reactions of metal–carbyne complexes Problems and exercises Supplementary reading Chapter 7 Alkyl, Aryl and Ligands with Higher Hapticity 7.1 s bonded alkyl groups as ligands 7.1.1 Synthesis of metal–alkyl compounds 7.1.2 ß-Hydride elimination 7.1.3 s bonded ?1-aryl ligands 7.2 Cyclic and acyclic polyenyl p bonded ligands 7.2.1 Cyclopentadienyl (Cp–) 7.2.2 Synthesis of Cp based sandwich compounds 7.2.3 Structure and properties of MCp2 complexes 7.2.4 Ferrocene: The first metal-sandwich compound 7.2.5 Reactions of metal-sandwich compounds 7.2.6 Bent sandwich compounds 7.2.7 Schwartz’s reagent and hydrozirconation 7.2.8 Chemistry of Cp* 7.2.9 Chemistry of arene sandwich compounds 7.2.10 Allyl groups as ligands 7.2.11 1,3-Butadiene complexes 7.2.12 Cyclobutadiene complexes 7.2.13 Cycloheptatriene and cyclooctatetraene as ligands 7.3 Davies–Green–Mingos (DGM) rules Problems and exercises Supplementary reading Chapter 8 Unique Reactions in Organometallic Chemistry 8.1 Oxidative addition and oxidative coupling 8.1.1 Oxidative addition involving C–X bonds 8.1.2 Prelude to cyclometallation: Agostic and anagostic interactions 8.1.3 Oxidative addition involving C–H bonds and cyclometallation 8.1.4 Orthometallation 8.1.5 Oxidative addition involving C–C bonds 8.1.6 Oxidative addition of ligands with p systems (Oxidative coupling) 8.2 Reductive elimination 8.2.1 Mononuclear systems 8.2.2 Binuclear systems 8.3 Migratory insertion reactions 8.3.1 Lewis acid acceleration 8.3.2 Redox acceleration 8.3.3 Migration versus insertion 8.3.4 Insertion of alkenes 8.3.5 ß-Hydrogen elimination versus reductive elimination Problems and exercises Supplementary reading Chapter 9 Ligand Substitution Reactions and Fluxionality in Organometallic Compounds 9.1 Types of ligand substitution reactions 9.1.1 Activation entropy and activation volume 9.1.2 Factors affecting substitution reactions 9.2 Associative substitutions 9.2.1 Hapticity change in mulitdentate ligands 9.3 Dissociative substitutions 9.4 Interchange mechanisms 9.4.1 Associative interchange 9.4.2 Dissociative interchange 9.5 Stereochemical non-rigidity in organometallic compounds 9.5.1 Ring whizzing in ?1-Cp complexes 9.5.2 Interchange of ?1- and ?5-Cp rings 9.5.3 Allyl complexes 9.5.4 Allene complexes 9.5.5 Scrambling of carbonyl groups in metal carbonyls Problems and exercises Supplementary reading Chapter 10 Metal Clusters 10.1 Introduction 10.2 Dinuclear clusters 10.2.1 A five fold bonded organometallic compound 10.3 Multinuclear carbonyl clusters 10.3.1 Low nuclearity carbonyl clusters 10.3.2 High nuclearity carbonyl clusters (HNCC) 10.3.3 Electron counting schemes for high nuclearity clusters 10.3.4 Capping rules 10.3.5 Limitations and exceptions 10.3.6 Polyhedral skeletal electron pair approach or Mingo’s rules 10.3.7 Carbide clusters 10.4 The isolobal analogy 10.4.1 Clusters having interstitial main group elements 10.5 Synthesis of metal carbonyl clusters 10.6 Reactions of metal carbonyl clusters Problems and exercises Supplementary reading Chapter 11 Homogeneous Catalysis Using Organometallic Compounds 11.1 Catalysis 11.2 Terminology in catalysis 11.2.1 Turnover 11.2.2 Turnover number (TON) 11.2.3 Turnover frequency (TOF) or turnover rate 11.3 Sequences involved in a catalysed reaction 11.4 Other important terminology used in catalysis 11.5 Asymmetric synthesis using a catalyst 11.6 Heterogeneous catalysis 11.6.1 Catalytic converters in automobiles 11.7 Feedstock for the chemical industry Problems and exercises Supplementary reading Chapter 12 Catalytic Hydrogenation of Alkenes and Related Reactions 12.1 Hydrogenation catalysts 12.1.1 Classification of hydrogenation catalysts 12.1.2 Catalytic cycle of Wilkinson’s catalyst 12.1.3 Catalytic cycles of iridium and ruthenium based catalysts 12.1.4 Directing effects in catalytic hydrogenation 12.1.5 Hydrogenation by lanthanide organometallic compounds 12.2 Catalytic asymmetric synthesis 12.2.1 The first industrial catalytic asymmetric hydrogenation 12.2.2 The mechanism of asymmetric hydrogenation using a chiral catalyst 12.2.3 Asymmetric hydrogenation of ketones and isomerisation 12.2.4 Asymmetric hydrogen transfer 12.3 Hydrocyanation of alkenes 12.4 Hydrosilylation of alkenes Problems and exercises Supplementary reading Chapter 13 Hydroformylation 13.1 Importance of hydroformylation 13.2 Cobalt catalysts for hydroformylation 13.3 Phosphine modified cobalt catalysts 13.4 Rhodium–phosphine catalysts 13.5 Factors affecting the n/iso ratio of hydroformylation products 13.6 Enantioselective hydroformylation 13.7 Carboalkoxylation of olefins Problems and exercises Supplementary reading Chapter 14 Methanol Carbonylation and Olefin Oxidation: Monsanto, Cativa and Wacker Processes 14.1 History of methanol carbonylation 14.2 The Monsanto process 14.2.1 Problems with the Monsanto process 14.3 Celanese process using LiI modified rhodium catalyst 14.4 Tennessee Eastman acetic anhydride process 14.5 British Petroleum’s Cativa process 14.6 The Wacker process Problems and exercises Supplementary reading Chapter 15 Olefin Metathesis 15.1 Olefin metathesis as a synthetic tool 15.2 Well known olefin metathesis catalysts and their properties 15.3 Synthesis of Grubbs’ and Schrock catalysts 15.4 Mechanism of olefin metathesis 15.4.1 Ring opening metathesis (ROM) 15.4.2 Cross metathesis (CM) 15.4.3 Ring closing metathesis (RCM) 15.4.4 Ring opening metathesis polymerisation (ROMP) 15.4.5 Acyclic diene metathesis polymerisation (ADMET) 15.4.6 Enyne metathesis (EM) 15.5 Comparison of catalysts 15.6 Metathesis of hindered olefins 15.7 Applications of catalytic olefin metathesis 15.8 Alkyne metathesis Problems and exercises Supplementary reading Chapter 16 Palladium Catalysed C–C and C–N Cross Coupling Reactions 16.1 Discovery of palladium based cross coupling reactions 16.2 Industrial applications of cross coupling reactions 16.3 The cross coupling catalyst 16.4 The Heck reaction 16.5 Suzuki–Miyaura coupling 16.6 Sonogashira coupling 16.7 Stille coupling 16.8 Kumada coupling 16.9 Negishi coupling 16.10 Hiyama coupling 16.11 Buchwald–Hartwig C–N cross coupling 16.12 Cross coupling reactions in aqueous media with functional group tolerance 16.13 Cross coupling reactions of organohalides with non-organometallic and non-heteroatom based reagents Problems and exercises Supplementary reading Chapter 17 Olefin Polymerisation and Oligomerisation Reactions 17.1 Catalysts for olefin polymerisation 17.2 Types of polyethylene and polypropylene 17.2.1 Polyethylene 17.2.2 Polypropylene 17.3 The Ziegler–Natta catalyst 17.4 Site control and chain end control mechanisms 17.5 Metallocene based catalysts 17.5.1 Polypropylenes using metallocenes 17.5.2 The mechanism of propylene polymerisation by metallocenes 17.5.3 Polypropylene and stereochemistry 17.5.4 Stereo-block polypropylene 17.5.5 Constrained geometry catalysts 17.6 Post-metallocene catalysts 17.6.1 The Brookhart catalysts 17.6.2 Fenokishi Imin (FI) and related ligand based metal catalysts 17.7 Olefin oligomerisation reactions 17.7.1 Shell’s higher olefin process Problems and exercises Supplementary reading Chapter 18 Ferrocene: Structure, Bonding and Reactions 18.1 Structure and bonding of ferrocene 18.2 The reactions of ferrocene and its derivatives 18.2.1 Basic chemical reactions of ferrocene 18.2.2 Reactions of acetyl ferrocene and formyl ferrocene 18.2.3 Lithiated ferrocenes and their reactions 18.2.4 (Dimethylaminomethyl)ferrocene and its methiodide salt 18.2.5 Ferrocene boronic acid and haloferrocenes 18.3 Ferrocene derivatives in asymmetric catalysis 18.3.1 Chirality in ferrocene derivatives 18.3.2 Synthesis of chiral ferrocene based compounds Problems and exercises Supplementary reading Chapter 19 Organometallic Polymers 19.1 Polymers with organometallic moieties as pendant groups 19.2 Polymers with organometallic moieties in the main chain 19.2.1 Ferrocene based condensation polymers 19.2.2 Condensation polymers based on rigid rod polyynes 19.2.3 Polymers prepared by ring opening polymerisation process 19.3 Organometallic dendrimers 19.3.1 Synthesis of dendrimers: Divergent and convergent methods Problems and exercises Supplementary reading Chapter 20 Bioorganometallic Chemistry 20.1 Introduction 20.2 Organometallic enzymes and coenzymes 20.2.1 Vitamin B12 coenzyme: ‘Nature’s most beautiful cofactor’ 20.2.2 Nomenclature and structure 20.2.3 Correnoid dependant enzymatic reactions 20.2.4 Vitamin B12 model compounds 20.3 Role of organometallics in heavy metal poisoning 20.3.1 Heavy metal toxicity: Mercury related cases 20.3.2 Arsenic poisoning 20.4 Organometallic compounds as drugs 20.4.1 ?6-Aryl–ruthenium compounds as general anticancer drugs 20.4.2 Ferroquine as antimalarial drug 20.4.3 Ferrocifen as breast cancer drug 20.5 Organometallics as radiopharmaceuticals, tracers, ionophores and sensors 20.5.1 Radiopharmaceuticals 20.5.2 Organometallic tracers 20.5.3 Organometallics as ionophores 20.5.4 Organometallic compounds as sensors Problems and exercises Supplementary reading Appendix 1: Solutions to problems and exercises Appendix 2: Quick revision questions