Aromatic Substituted Group 4 Metallocene Catalysts for the Polymerization of α-Olefins

Abstract

Six new group 4 metallocene complexes were synthesized as precursors for the polymerization of α-olefins. The phenyl-substituted precursors 2b − 4b when activated by methylaluminoxane (MAO) were highly active for the polymerization of ethylene but exhibited no activity for the polymerization of propylene. Bis(2-methylbenz[ e ]indenyl)zirconium dichloride ( 5b ) was activated with both MAO and triphenylcarbenium tetrakis(pentafluorophenyl)borate (trityl)/triisobutylaluminum producing polypropylene with varying molecular weight depending on polymerization temperature. The titanium precursor 6b had lower activity for ethylene as compared to the zirconium analog 5b and virtually no activity for propylene when activated with either MAO or trityl.