The early days of research were in the field of synthesis and reactions of organotransition metal compounds and covered the period 1958– 2000. In 1990 research commenced on heterogeneous catalysis and was focused towards hydrocarbon reactions. And in 1993 a completely new area of research into carbon nanotubes started. The highlights of the discoveries made in these areas are listed below in chronological order. Key references are given in the text, often together with citation numbers presented as C. xxx (these were taken from the Web of Science on January 24th 2006). Those given in bold are particularly noteworthy.
Fundamental reactions of transition metal alkyl and carbene systems
The first demonstration of β-hydrogen abstraction from a metal-alkyl system, its reversibility, and its role as a model for the mechanism of metal catalysed olefin isomerisation. (12, 15, C. 186) The reversible β-elimination reaction is widely available to transition metal alkyls with β-hydrogens.
The first demonstration of a reversible alpha-elimination of a metal-methyl giving a transition metal-methylene-hydride.(112 C. 97, 159 C. 109) The reversible α-elimination reaction is widely available to transition metal alkyls with α-hydrogens.
The first systematic synthesis of metallacyclobutanes and that their decomposition occurred with carbon-carbon bond cleavage, as previously proposed for the olefin metathesis reaction mechanism. (125 C. 111 129, C. 61, 133, C. 87)
The discovery of a general route to the synthesis of hydroxycarbene derivatives of transition metals: the second paper on transition metals carbene systems. (62 C. 107)
Pioneering studies of the activation of carbon-hydrogen G-H bonds in aromatic and aliphatic hydrocarbons by transition metal compounds
A.E Shilov first showed that platinum metal systems could catalyse the H/D exchange beterrn deuterium and alkanes and made kinetuc studies, However no proposed alkyl-hydride compounds were isolated. The first demonstrations for the isolation of stable alkyl- and aryl-hydrides was made by Green, He showed the insertions of a transition metal centers into C-H bonds of both aromatic and saturated C-H aliphatic bonds. Both photochemical and thermal activation processes were used. (88 C. 78, 162 C.77, 259 C. 125)
The synthesis of the first zerovalent compounds of the early, refractory transition metal via the development of the electron-gun metal vapour synthesis experiment
Metal vapour synthesis was first shown by Peter Timms. The first demonstration of the electron gun furnace method for metal vapour synthesis, and its use for the synthesis of the first examples of zerovalent bis-eta-benzene compounds of titanium, zirconium, hafnium, niobium and tantalum. The synthesis of bis-benzenetungsten on a large scale (5-10 g) and many other metal atom reactions.(96 C. 67, 117 . 62, 186 C. 116, 255, 56, 171 C. 60, 234, C. 69)
Commercialization of equipment for Metal Vapour Synthesis by G.V. Planer Ltd.
The formulation of general rules for the sterospecificity of nucleophilic addition to organometalliccations (with D.M.P. Mingos and S.G. Davies) (148 C. 298)
The formulation of a stimulating and accepted mechanism for Ziegler-Nattacatalysedpolymerisation of olefins. (156 C. 239)
The development of the field of organometallic solid state chemistry
There are several areas which essentially established this new field of research activity. (303, 305)
The synthesis of the first organometallic compound with a large second order non-linear optical behaviour. (286 C. 266)
The studies on synthesis and properties of organometallic intercalation compounds. (121, 143, 152, C.50, 160 ,282, 285, 290, 325, 351, 389, 398)
Studies on redox-active organometallic “soft salts”(287, 350)
There are now many active groups in this area. There were 53 recent articles cited under WoS search Organometallic Materials, the most highly cited of which was a review of organometallic non-linear optical materials (> 230 citations).
Pioneering studies on transition metal-hydrogen compounds
The first hydrides of tantalum and related tungsten and molybdenum compounds (with Wilkinson). (9, C.226)
The synthesis of the first stable nickel-hydride compounds – such systems had long been proposed following the discovery of nickel catalysed hydrogenation reactions by Paul Sabatier in 1913.(43) This work was one of the earliest demonstrations of the use of a bulky tertiary phosphineligands to achieve increased thermal stability, now a widely exploited strategy.
The development of M-H-C agostic bonds
The discovery of the agostic-ethyl and -methyl titanium compounds which unambiguously demonstrated the existence of the agostic M-H-C bond. (194, C.110, 216 C. 92, 251 C. 115)
There is now appreciation of the widespread role of agostic bonds as intermediates in many key metal-hydrocarbon reactions. (218 C. 68, 222 C. 1064, 302 C. 653)
A 2014 search for the word agostic using Web of Science gave 1,549 articles published by others using this term since the concept “agostic bond” was proposed in 1983. The word “agostic” has been included in the recent edition of the Oxford English Dictionary. (222 C. 1064, 302 C. 653)