After graduating from Imperial College with a PhD Geoffrey Wilkinson moved to Canada to join the Chalk River project. Later, he moved to Berkeley, California. At that time, he claimed to have made more elemental isotopes than anyone else on earth. He moved to MIT then Harvard where he noticed a paper in which bis cyclopentadienyl iron had been made. When he saw the proposed structure with 2 cyclopentadienyl groups sigma bound to FeII he thought to himself “Jesus Christ, it can’t be that!”1
After a few experiments such as measuring the dipole moment and the infra-red spectrum, he proposed the now well-known sandwich structure of ferrocene.1 This started a life-long devotion to the chemistry of metals containing carbon based ligands or organometallic chemistry as the new discipline soon became called. In 1973 he shared the Nobel Prize for Chemistry with E.O Fischer for “for their pioneering work, performed independently, on the chemistry of the organometallic, so called sandwich compounds”.
Arguably, Wilkinson could have been awarded at least two other Nobel prizes. Indeed two avenues of work that he started have led to Nobel prizes for others. His work on complexes containing phosphorus based ligands led to the discovery of [RhCl(PPh3)3] in 1966.2 Now known as Wilkinson’s catalyst, this was the first phosphine containing complex to show catalytic activity, in this case hydrogenation of alkenes under exceptionally mild conditions (1 bar ambient temperature). Developments of this kind of rhodium phosphine complexes led to the development of the first catalysts for asymmetric hydrogenation and the Nobel Prize for chemistry in 2001 for W. S. Knowles3 and R. Noyori4 (shared with K. B. Sharpless for asymmetric oxidation).
In the early seventies Wilkinson studied the simplest organometallic compounds – those with only methyl groups attached to the metal. The isolation of hexamethyltungsten (WMe6)5 led to an outburst In studies of these simple complexes and eventually to R.R. Schrock’s demonstration that when trying to make pentakis(neopentyl)tantalum, a-hydrogen abstraction occurred to give the first alkylidene (non-stabilised carbene).6 Schrock’s further work in this area led him to discover low temperature homogeneous metathesis catalysts7 for which he shared the 2005 Nobel prize with R. Grubbs.8
Wilkinson’s work on hydrides and amides attached to transition metals was also seminal. Part of the hydride work led to the development of [RhH(CO)(PPh3)3], the first homogeneous rhodium based hydroformylation catalyst.9 This catalyst worked under unprecedentedly mild conditions and gave very high selectivity to linear aldehydes. It was commercialised by Union Carbide and is in use throughout the world for the hydroformylation of propene to give butanal as part of a route to the plasticiser 2-ethylhexanol. It has also been commercialised by Sasol in South Africa for the hydroformylation of long chain alkenes.
In addition to his many scientific publications and patents, Sir Geoffrey Wilkinson is probably best, known for his text books Advanced Inorganic Chemistry, Wiley (Editions 1-5 with his former PhD student, F. A. Cotton and 6 with additionally C. A. Murillo and M. Bochmann and Basic Inorganic Chemistry, Wiley, Editions 1-2 with F. A. Cotton and 3 additionally with P. L. Gaus. These textbooks were the bedrock of tertiary education in chemistry from the 1970s to 2000s. Wilkinson finished the last corrections of his sections of the 6th Edition of Advanced Inorganic Chemistry only a few days before he died.
- G. Wilkinson, J. Organomet. Chem., 1975, 100, 273.
- J. A. Osborn, F. H. Jardine, J. F. Young and G. Wilkinson, J. Chem. Soc. A, 1966, 1711.
- W. S. Knowles and M. J. Sabacky, Chem. Commun., 1968, 1445.
- A. Miyashita, A. Yasuda, H. Takaya, K. Toriumi, T. Ito, T. Souchi and R. Noyori, J. Am. Chem. Soc., 1980, 102, 7932.
- A. J. Shortland and Wilkinson.G, J. Chem. Soc., Dalton Trans., 1973, 872.
- R. R. Schrock, J. Am. Chem. Soc., 1974, 96, 6796.
- R. R. Schrock, J. Organomet. Chem., 1986, 300, 249.
- E. L. Dias, S. T. Nguyen and R. H. Grubbs, J. Am. Chem. Soc., 1997, 119, 3887.
- D. Evans, J. A. Osborn and G. Wilkinson, J. Chem. Soc. A, 1968, 3133.