Metal-Catalyzed Diene and Olefin Polymerizations: Mechanistic Studies and Catalyst Design

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This award in the Inorganic, Bioinorganic and Organometallic Chemistry Program supports research by Dr. Maurice Brookhart at the University of North Carolina at Chapel Hill to examine the mechanism of diene polymerization reactions by using naked allyl-Ni species and (diene)Ni(allyl)+ species. Both species are highly reactive at low temperature and are key intermediates in diene polymerizations. These Ni "ligandless" complexes along with monoligated complexes and Pd analogs will be used to polymerize butadiene and a series of substituted dienes and to fully elucidate the mechanistic details of these polymerizations so as to identify factors that allow control of the polydiene microstuctures. Living polymerizations will be sought in order to generate a series of copolymers incorporating functional groups with potential new structures and properties. The reactivity of these unique naked M(allyl)+ species will also be explored with other unsaturated molecules including olefins, strained cyclic olefins and alkynes. Other projects include (a) developing a direct synthesis of alkyl aldehydes through combining ethylene oligomerization with an oxidative chain transfer process using N2O and (b) a collaborative project with R. Broene of Bowdoin College to develop catalysts for dimerization of alpha-olefins to the linear alpha-olefin dimers. Through a long-established collaboration with DuPont, recent discoveries from this laboratory on new polymerization catalysts are being brought towards commercialization. Undergraduate students from underrepresented minorities in science will be brought into the research. Graduate students involved in the project are also actively involved in outreach to high schools through the UNC-sponsored "Saturday Academy".