(1,3-PROPANEDIYL)SILYLENE-BIS(1-INDENYL)DICHLOROZIRCONIUM - SYNTHESIS AND POLYMERIZATION CATALYSIS

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 Ph(3)CB(C6F5)(4) to perform ethylene and propylene polymerizations over a very broad range of temperature of polymerization (-55 degrees C less than or equal to T-p less than or equal to 85 degrees 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.