SILYLENE-BRIDGED FLUORENYL-CONTAINING LIGANDS AND ZIRCONIUM COMPLEXES WITH C-1 AND C-S SYMMETRY - GENERAL-SYNTHESIS AND OLEFIN POLYMERIZATION CATALYSIS

A variety of new silylene-bridged fluorenyl-containing ligands has been synthesized with good yields via a convenient synthetic route. Two dimethylsilylene-bridged (eta(5)-indenyl)(eta(5)-fluorenyl) (1) and (eta(5)-cyclopentadienyl)(eta(5)-fluorenyl) (2) zirconocene dichlorides with C-1 and C, molecular symmetry have also been prepared. Upon activation with methyl aluminoxane, the former produced a polypropylene of high molecular weight, but with low activity and isotacticity. The latter catalyzed non-stereospecific propylene polymerization without any syndiotactic tendency, but with 40 and 20 times greater ethylene and propylene activity respectively than the former catalytic system.