An Equilibrium in Catalyst Optimisation and Development ?

The themes of the Eighth International Conference of the Chemistry of the Platinum Group Metals (PGM8), held at the University of Southampton, from 7th to 12th July 2002, covered a broad spectrum from the chemistry of these fascinating elements, ranging through Organometallic chemistry Coordination and supramolecular chemistry Biological and medicinal chemistry Surfaces, materials and crystal engineering Photochemistry and electrochemistry 9 Catalysis and organic syntheses, to Theoretical chemistry and physical methods. The attendees also found time to cruise down Southampton Water (in mist and rain), visit Stonehenge and Salisbury (only a little rain), walk through in the New Forest (totally dry!), and dine under Kmg Arthur’s Round Table in the Great Hall in Winchester. But the open and challenging atmosphere was the most apparent hallmark of PGM8. Scientists with a breadth of approaches shared their differing experience and targets around common chemical foci, and these can be exemplified by an overview of the reports of the invited speakers. The wel-established antitumour activity of cisplatin and carboplatin, and the onset of tumour resistance to them, was discussed by Lloyd Kelland (St. George’s Hospital Medical School, London, U.K.); and here there siill remain many important targets. Phase I trials of a ruthenium(I1I) complex were reported by Gianni Sava (University of Trieste, Italy), and these show promise for a selective effect on lung metastases. Indeed, ruthenium complexes occupied a significantly important position in the biological and medicinal chemistry theme, with Jackie Barton (Caltech, U.S.A.) using them to monitor electron transfer ranges and identify the effect of oxidative damage on the conductivity of DNA. Peter Sader (University of Edinburgh, U.K) described how his work on coordination spheres interacted with DNA bases is being extended to organometallic centres. Control and exploitation of coordination spheres was preeminent in the programme. Many examples were elegant, such as the helicate complexes of open chain tetraand hexa-dentate phosphines (Bruce Wild, Australian National University, Canberra) and osmabenzenes and fused osma-aromatics (Warren Roper, University of Auckland, New Zealand), while others challenged conventional thinking, such as the careful design of complexes with monodentate phosphines acting as bridgmg ligands (Helmut Werner, University of Wiirzburg, Germany). Probably the ‘simplest’ hgand sets were presented by Gary Schrobdgen (McMaster University, Canada) who compared the htgh oxidation states of osmium and xenon (these elements have the widest +8 oxidation state chemistry). The simplicity of the formulae belied the technical challenges of unravelling this chemical frontier. For the most part, ligand sets were chosen to engender attractive physicochemical properties. These included the luminescent properties of terpyridyl complexes of iridium and ruthenium (Gareth Williams, University of Durham, U.K), and the non-linear optical materials based upon dendrimeric oligomers of rutheniumQI) bipyridyls (Hubert Le Bozec, Universitt de Rennes 1, France). Dendrimers and other polymeric architectures (rings, chains and helices) have been synthesised with impressive control by Shgetoshi Takahashi (Osaka University, Japan), and Ian Manners (University of Toronto, Canada) described his control over the synthesis of different types of ferrocenyl polymers. Catalysis was one of the recurring reasons for ligand design, with Duncan b Bruce (Univertsity of Exeter, U.K) demonstrating that metallorganic