Research Interests
My research encompasses synthetic and mechanistic organometallic chemistry and catalysis, with emphasis on the invention, synthesis, and study of new late-transition metal catalysts for olefin dimerization and polymerization reactions. Insights gained from extensive fundamental studies of migratory insertion reactions have provided guidelines for design and development of numerous new catalytic systems. Examples include cobalt(III) alkyl complexes for living polymerization of ethylene, rhodium(III) catalysts for selective acrylate dimerizations, and palladium(II) complexes for living, alternating copolymerization of CO and olefins. Most recently my group, using specially crafted ligands, developed highly active palladium and nickel catalysts that polymerize ethylene to new forms of highly branched polyethylene, convert alpha-olefins to polymers with unique microstructures and copolymerize polar and nonpolar olefins. Low-temperature nuclear magnetic resonance studies were used to map out the catalytic cycles. Branching was shown to occur by migration of the metal along the polymer chain in competition with monomer insertion. My laboratory has also investigated the interaction of carbon-hydrogen bonds with transition metal centers and constructed catalysts that incorporate a carbon-hydrogen bond activation step in the catalytic cycle. For example, catalysts have been developed that add C-H bonds of various substrates across carbon-carbon double bonds.
Membership Type
Member
Election Year
2001
Primary Section
Section 14: Chemistry