This award, made in the Inorganic, Bioinorganic and Organometallic Chemistry Program, deals with transition metal complexes of carbon dioxide and offers the prospect of CO2 reduction to methanol or formaldehyde. Heterobimetallic carboxylates will be prepared either by reaction of nucleophilic metal carboxylates with metallo-Lewis acids or by CO2 insertion into metal-metal bonds. In either case, the metals chosen will have a "push-pull" effect which will stabilize the bound CO2. The metal pairs selected will generally be an electron rich transition metal (Fe, Ru) and an oxophilic early-metal (Zr,Hf,W). Supporting ligands on the metal pairs will be selected to optimize CO2 insertion and stabilize the bridged heterobimetallic complexes. Structures and reactivities of the CO2 complexes and their intermediates will be determined along the synthetic route. Reduction of bound CO2 will be effected by means of zirconium or silicon hydrides. %%% Transition metal-CO2 chemistry is an important research area which is relevant to fundamental processes such as photosynthesis. It also serves as a model for important, commercial, heterogeneously-catalyzed processes such as methanol and formaldehyde synthesis.
