SURFACE ORGANOMETALLIC CHEMISTRY - A MOLECULAR APPROACH TO SURFACE CATALYSIS

The study of the reactions of organometallic complexes with the surfac es of inorganic oxides, zeolites and metals constitutes a new aspect o f the coordination chemistry of organometallic compounds. We will demo nstrate that the basic rules of organometallic chemistry are often val id when applied to surfaces, using as an example the chemistry of bis( allyl)rhodium grafted onto silica. In addition, concepts can be develo ped which are new both in molecular chemistry and in surface science ( unusual oxidation state, coordination number and electron count). Thes e new concepts allow the design of a new generation of catalysts with unexpected activity and/or selectivity. Two examples will be presented : the low temperature activation of the C-H and C-C bonds of alkanes b y a zirconium hydride supported on silica, and the regioselective hydr ogenation of citral to geraniol with a metallic surface of Rh covered with alkyltin fragments.