This award in the Inorganic, Bioinorganic, and Organometallic Program provides continued support for research by Dr. Robert G. Bergman of the Chemistry Department, University of California at Berkeley in the area of organometallic chemistry. Synthesis and reactions of heterobimetallic compounds composed of early-late transition metals linked by a variety of bridging groups will be studied. One of the investigations concerns soluble compounds with bridging methylene and alkylidene ligands and metals centers of tantalum and platinum or tantalum and cobalt, which have been found to act as catalysts for the hydrogenation, isomerization, and hydrosilation of alkenes, as well as for the coversion of carbon monoxide and hydrogen to methane and the conversion of methanol and carbon monoxide to acetic acid. The mechanism of these catalytic processes will be determined, particuarly with regard to stereochemistry, and the effectiveness of other combinations of metals tested. %%% The goal of the project is to develop methods for the systematic synthesis of new molecules containing two transition metal centers and to explore the details of their reactions with organic molecules. The two metals will be an early (e.g., Zr or Ta) and a late (e.g., Ir or Co) transition metal, and will have different electronic properties. They are connected by bridging groups containing carbon, oxygen, nitrogen, and sulfur, which can react with organic molecules in novel ways because of the influence of the bimetallic environment. The findings of this research are relevant to reactions in complicated multi-metal systems such as catalytic surfaces.
