Developments in bridged metallocenes as the catalysts for olefin polymerization

The two cyclopentadienyl groups in metallocence compexes can be linked by one or two bridging groups to form ansa-metallocence catalyst precursors.This article reviewed latest developments in ansa-metallocene complexes as olefin polymerization catalysts with respect to different bridging atoms.Stereospecific polymerization of propylene catalyzed by different ansa metallocenes were described in detail.The influences of structure of bridging groups and substituted group on their catalytic properties for propylene polymerization and stereoregularity of the obtained polymers were discussed.