Polymerization of Norbornene Using Chiral Bis(phenolate) Zirconium Catalysts

Norbornene is polymerized by employing zirconium catalysts with (OSSO)-type bis(phenolate) ligands. The racemic precatalyst rac-1 produces high molecular weight poly(norbornene) with slight optical activity. Enantiopure precatalysts (S, S)-1 and (R, R)-1 are used to study the optical induction in the poly(norbornene)s formed. To overcome the insolubility of poly(norbornene) s in common solvents, their microstructure is studied using copolymers with ethylene as well as hydrooligomers. The crystal structure of a norbornene tetramer is reported.