to thank Messrs J. R. Sanders, W. E. Lindsell and M. G. Swanwick for helping to check the text and references and prepare indexes. Finally, I should like to thank my wife for the very considerable assis­ tance she has given me in the writing and production of this book. M. L. H. G. Contents Preface to the Third Edition, Volume Two Page v INTRODUCTION TO VOLUME TWO I Oassification I The IS-electron rule 2 (i) The basis of the I8-electron rule p. 4, (ii) Exceptions to the I8-electron rule p. 5 1. TWO-ELECTRON LIGANDS 7 A. Classification 7 B. The preparation of olefin-transition metal complexes 7 (a) Displacement of solvent ligands p. 9, (b) Preparations from metal carbonyls p. 9, (c) Less common preparative routes p. 11, Reductive olefination method p. 12 C. A molecular orbital description of the bonding in orga- metallic complexes 13 (a) General comments p. 13, (b) Symmetry considerations p. 13, (c) Energies of the molecular orbitals p. 14 D. A description of the bonding of 2-electron ligands to transition metals 14 E. General comments of 2-electron ligands 19 (a) Infrared studies p. 20, (b) Effect of olefin substituents p. 21, (c) The rotation of ethylene about the ligand-metal bond p. 22, (d) Chemical properties p. 23 F. Particular complexes of metals with 2-electron ligands 25 (a) Copper, silver and gold p. 25, Complexes with benzene p. 28, (b) Nickel, palladium and platinum p.

to Volume Two.- Classification.- The 18-electron rule.- (i) The basis of the 18-electron rule.- (ii) Exceptions to the 18-electron rule.- 1. Two-Electron Ligands.- A. Classification.- B. The preparation of olefin-transition metal complexes.- (a) Displacement of solvent ligands.- (b) Preparations from metal carbonyls.- (c) Less common preparative routes.- Reductive olefination method.- C. A molecular orbital description of the bonding in organo-metallic complexes.- (a) General comments.- (b) Symmetry considerations.- (c) Energies of the molecular orbitals.- D. A description of the bonding of 2-electron ligands to transition metals.- E. General comments of 2-electron ligands.- (a) Infrared studies.- (b) Effect of olefin substituents.- (d) The rotation of ethylene about the ligand-metal bond.- (d) Chemical properties.- F. Particular complexes of metals with 2-electron ligands.- (a) Copper silver and gold.- Complexes with benzene.- (b) Nickel palladium and platinum.- Trans effects.- (c) Rhodium iridium ruthenium osmium and rhenium.- (d) Miscellaneous.- 2. Three-Electron Ligands.- A. Preparation of ?-enyl complexes.- (a) From allyl Grignard reagents.- (b) From allyl halides and allyl alcohols.- (c) From olefins.- (d) From alienes.- B. The structure of ?-enyl complexes.- C. The ?-allyl metal bond.- D. Dynamic equilibria in allyl complexes.- E. The chemistry of particular ?-enyl complexes.- (a) Pure ?-allyl metal complexes.- (b) ?-Enyl complexes of nickel palladium and platinum.- (i) Cyclobutenyl complexes].- (ii) Cyclopentenylcomplexes.- (iii) Cyclo-propenyl complexes.- (c) ?-Enyl cobalt and rhodium complexes.- (d) Iron ?-enyl complexes.- (e) Miscellaneous.- 3. Four-Electron Ligands.- A. Some differences between unconjugated and conjugated olefin ligands.- B. The bonding of 4-electron ligands to transition metals.- (a) Cyclobutadiene complexes.- (b) Butadiene complexes.- C. Particular studies.- (a) Cyclobutadiene complexes.- (i) Preparation.- (ii) Properties.- (b) Cyclopentadiene complexes.- (c) Non-cyclic diene-metal complexes.- (d) Miscellaneous 4-electron ligands.- 4. Five-Electron Ligands.- A. Cyclopentadienyl metal complexes.- (a) Classification and nomenclature.- B. ?-Cyclopentadienyl transition metal complexes.- (a) Preparation.- (i) Reaction of alkali metal cyclopenta-dienides with metal complexes.- (ii) Reaction between cyclopentadiene and metal complexes.- (iii) Reaction between fulvenes and metal carbonyls.- (b) Bis-?-cyclo-pentadienyl transition metal complexes.- (i) Crystal structure.- (ii) Molecular structure.- (iii) Electronic structure.- (iv) The stability of bis-n-cyclopentadienyl complexes.- (v) The solubility properties of the cations [(?-C5H5) 2M]+.- (vi) Some chenical reactions of bis-n-cyclopentadienyl complexes.- (c) ?-Cyclopentadienyl complexes of uranium thorium and actinide metals.- C. Cyclopentadienide transition metal complexes.- (a) Manganocene.- (b) Ionic character in the bis-?-cyclo-pentadienyls.- (c) Rare earth cyclopentadienides.- D. The bonding in mono-?-cyclopentadienyl transition metal complexes.- (a) The bonding in metal-tricarbonyl groups.- E. ?-Cyclopentadienyl carbonyl complexes.- (a) Vanadium niobium and tantalum complexes.- (b) Complexes of chromium molybdenum and tungsten.- (c) Some ?-cyclopentadienyl iron carbonyl chemistry.- (d) Cobalt and rhodium complexes.- (e) Complexes of nickel and platinum.- (f) Ligand substitution reactions of ?-cyclopentadienyl manganese tricarbonyl.- F. ?-Cyclopentadienyl nitrosyl complexes.- G. Brief notes on binuclear ?-cyclopentadienyl complexes containing bridging ligands.- H. ?-Cyclopentadienyl hydride complexes.- I. ?-Cyclopentadienyl halides and oxides.- (a) ?-Cyclopentadienyl titanium halide chemistry and related topics.- (b) Vanadium niobium and tantalum complexes.- (c) Chromium molybdenum and tungsten complexes.- J. Other 5-electron ligands.- (a) ?-Cyclohexadienyl complexes.- (b) ?-Cyclohepta-dienyl complexes.- (c) Pentadienyl complexes.- K. The organic chemistry of ?-cyclopentadienyl transition metal complexes.- (a) Electronic effects in ferrocene.- (b) The participation of the iron atom in the chemistry of ferrocenes.- (i) Some mechanisms of electrophilic and radical substitution reactions.- (ii) The interaction of the iron atom with ring substituents 142: ?-Carbonium ion stabilization.- ?-Carbonium ion stabilization.- Weak hydrogen bonding by the iron atom.- (e) Trends in the chemistry of ferrocene ruthenocene and osmocene.- L. Some particular reactions.- (a) Acylation.- (b) Alkylation reactions.- (c) Aryla-tion reactions.- (d) Halogenation.- (e) Hydroxyl compounds.- (f) Metallation studies.- (g) Nitration and sulphonation.- (h) Amine derivatives.- (i) Carboxylic acid derivatives.- (j) Carboxaldehyde derivatives.- 5. Six-Electron Ligands.- A. Arene transition metal complexes.- (a) Preparation.- (i) Fischer's reducing Friedel-Crafts method.- (ii) Cyclic polymerization of disubstituted acetylenes.- (iii) From aryl Grignard reagents.- (iv) From metal carbonyls.- (v) From substituted metal car-bonyls.- (b) Structural studies.- (c) The bonding in bis-?-arene complexes.- (d) The stability of bis-?-arene complexes.- (e) Some chemistry of bis-?-arene complexes.- (f) The stereochemistry of some arene metal carbonyls.- (g) Some reactions of arene metal carbonyls.- (h) Polynuclear complexes of the Group IV and Group V metals.- B. Olefin 6-electron ligands.- C. Transition metal complexes containing ?-bonded heterocyclic ligands.- 6. Seven-Electron Ligands Mixed Sandwich Complexes Related Azulene Derivatives and Cyclo-Octatetraene Complexes.- A. 7-Electron ligands.- (a) Preparation of ?-cycloheptatrienyl complexes.- (b) Structure.- (c) The chemistry of ?-cycloheptatrienyl complexes.- Ring contraction and expansion reactions.- B. Mixed sandwich complexes.- C. Metal complexes formed from azulenes.- D. Cyclo-octatetraene complexes.- 7. One-Electron Ligands.- I.1. Hydrocarbon alkyl and aryl complexes.- A. General preparative methods.- (a) From Grignard reagents and organoalkali metal derivatives.- (b) From complex metal anions and organic halides.- (c) From metal hydrides.- (d) Miscellaneous.- B. General chemical properties.- (a) Stability.- (b) Cleavage reactions of the metal-carbon bond.- (c) Insertion reactions.- C. The nature of interactions between transition metals and o-bonded organic substituents.- (a) Transition metal-?-interactions.- Metal carbene complexes.- (b) Transition metal-?-interactions.- (c) The possible nature of the ?-effect.- D. The bonding of 1-electro…