Abstract
The expanding field surface organometallic chemistry (referred to as SOMC, or by its French acronym, COMS) offers new possibilities to heterogeneous catalysis. The basic philosophy of this new area of heterogeneous catalysis is based on the concept that the supported catalyst is a kind of molecular entity. Ideally, one ceases to speak of “the immobilization of a catalyst” or of “the modification of a surface” but rather one considers the entire continuum - support, metal, and ligands - as a quasi-molecular species responding to both the fundamental rules derived from organometallic chemistry and to the rules of surface science. Surface organometallic chemistry preserves some of the advantages of traditional supported catalysis such as the ease of separation of the catalyst from the substrate/product and the heightened stability with respect to homogeneous analogs. As with traditional techniques, one can vary such parameters as the surface area, porosity, and electrophilicity of the support, and the identity of the metal. Surface organometallic chemistry offers much more precise control of other metal-centered factors such as the oxidation state and coordination geometry of the catalytic site. The stoichiometric nature of COMS synthesis often leads to catalytic systems with very high percentages of relatively well defined active catalytic sites.