This award in the Inorganic, Bioinorganic, and Organometallic Chemistry Program supports research on carbon dioxide by Dr. Donald J. Darensbourg of the Chemistry Department, Texas A&M University. The main focus of the research is on the fundamental processes occurring during copolymerization of carbon dioxide and epoxides to form polycarbonates. Information gleaned will be used to design more selective catalysts for those reactions. Tungsten, zinc, cadmium, and copper complexes will be used to probe the lability of alkoxide complexes, epoxide complexation and subseqent coupling with ligated carboxylates, and catalyst activity and selectivity. In addition, metal catalyzed copolymerization reactions of carbon dioxide and aziridines to form polyurethane will be explored, and reactivity of carbon dioxide with coordinatively and electronically unsaturated metal carbonyl derivatives that contain pi-donor ligands will be investigated. Biphasic catalysis and supercritical carbon dioxide will be used for catalyst separation from the substrate and the product in these homogeneous processes. Carbon dioxide is a potential source of carbon for various uses. Also, it can serve as an environmentally-benign replacement solvent for volatile organic compounds. In this study, catalysts will be designed for reactions in which carbon dioxide is used as a source material for synthesis of useful polymers. In addition, supercritical carbon dioxide will be tested as a solvent for some of the separations needed in the process.
