METALLOCENE DICHLORIDES BEARING ACENAPHTHYL SUBSTITUTED CYCLOPENTADIENYL RINGS - PREPARATION AND POLYMERIZATION BEHAVIOR

The unbridged complex eta(5)-7,9-diphenylcyclopenta[a]acenaphthadienyl )] zirconium dichloride (8) and two asymmetric ethylene bridged metall ocenes 9-diphenylcyclopenta[a]acenaphthadienyl)-1-phenyl] ethane} zirc onium dichloride (9) and acenaphthadienyl)-2-phenyl-2-(eta(5)-9-fluore nyl)] ethane} zirconium dichloride (10) were prepared and used as cata lysts for ethene and propene homopolymerization after activation with MAO. Whereas zirconocenes 8 and 9, that bear two acenaphthyl substitut ed Cp-rings, have only moderate activity, 10 produces polyethene with high activity and high molecular weight. Ln propene polymerization onl y atactic polymer was formed and the chain termination occurred mainly via P-methyl elimination. The solid state structures of compounds 8, 9 and 10 were determined by means of X-ray diffraction analysis. (C) 1 997 Elsevier Science S.A.