(1,3-Propanediyl)silylene-bis(1-indenyl)dichlorozirconium. Synthesis and polymerization catalysis

Article abstract of DOI:10.1016/0022-328X(94)05075-M

Reaction of indenyllithium with 1,1-dichlorosilacyclobutane gave a mixture of diastereomeric isomers of 1,1-bis(1-indenyl)-1-silacyclobutane (1), and the product was in turn converted into diastereomeric (1,3-propanediyl)silylene-bis(1-indenyl)dichlorozirconium complexes (2) in a 5:2 racemic:meso ratio.Complex 2 was activated with either methyl aluminoxane (MAO) or Ph3CB(C6F5)4 to perform ethylene and propylene polymerizations over a very broad range of temperature of polymerization (-55 deg C <*> T_p <*> 85 deg C).Variations of the polymerization activity (A) and molecular weight (MW) with T_p were investigated as well as the isotactic yield (IY) in the case of propylene polymerizations.Comparisons of those results with other closely related ansa-zirconocene precursors were also made. Keywords: Zirconocene; Homogeneous polymerization; α-olefin; Isospecific polymerization