Ethylene and ethylene/1-hexene (co)polymerizations with 2,5-dimethylcyclopentadienyl ansa-titanocene and zirconocene complexes

C1-bridged titanocene complexes, [R(H)C(η5-C5H4)(η5-2,5-Me2C5H2)]TiCl2 have been prepared. The titanocene complexes activated with MAO show much higher activities than the corresponding ansa-zirconocene complex [Me(H)C(η5-C5H4)(η5-2,5-Me2C5H2)]ZrCl2 in ethylene polymerization and the molecular weights of the obtained polymers are significantly higher (Mw, ∼800 000).