Metallocene dichlorides bearing acenaphthyl substituted cyclopentadienyl rings: Preparation and polymerization behavior

Article abstract of DOI:10.1016/S0022-328X(97)00524-X

The unbridged complex [bis(η⁵-7,9-diphenylcyclopenta[a]acenaphthadienyl)] zirconium dichloride (8) and two asymmetric ethylene bridged metallocenes {bis[1,2-(η⁵-7,9-diphenylcyclopenta[a]acenaphthadienyl)-1-phenyl] ethane} zirconium dichloride (9) and {[1-(η⁵-7,9-diphenylcyclopenta[a]acenaphthadienyl)-2-phenyl-2-(η⁵-9-fluorenyl)] ethane} zirconium dichloride (10) were prepared and used as catalysts for ethene and propene homopolymerization after activation with MAO. Whereas zirconocenes 8 and 9, that bear two acenaphthyl substituted Cp-rings, have only moderate activity, 10 produces polyethene with high activity and high molecular weight. In propene polymerization only atactic polymer was formed and the chain termination occurred mainly via β-methyl elimination. The solid state structures of compounds 8, 9 and 10 were determined by means of X-ray diffraction analysis.