Award Address (Gabor A. Somorjai Award for Creative Research in Catalysis sponsored by the Gabor A. & Judith K. Somorjai Endowment Fund). Mechanistic studies of 1-alkene trimerization and polymerization with organotransition metal catalysts

Abstract

The evolution of our research group's research efforts to understand the fundamental steps of catalytic olefin polymn.: initiation, propagation, and chain transfer, beginning with the initial demonstration that Cp* ScR (R = H, alkyl) polymerizes ethylene, will be reviewed. The development of new stereoselective catalysts for propylene polymn., based on organoscandium, organoyttrium, and organozirconium complexes, revealed the basis for stereocontrol leading to isotactic, syndiotactic, or hemitactic microstructures. Recently the group has explored the mechanisms of ethylene and 1-alkene trimerization with organochromium and organotitanium precatalysts. We have demonstrated successful combination of trimerization with polymn. catalysis for tandem ethylene trimerization, followed by copolymn. of the so-produced 1-hexene with addnl. ethylene, to yield butyl-branched linear low d. polyethylene from an ethylene-only feed.