Propene polymerization with rac-Me2Si(2-Me-Benz[e]Ind)2ZrX2 [X = Cl,Me] using different cation-generating reagents

Propene was polymerized with methylaluminoxane (MAO) and cationic activated rac-dimethylsilylene-2-methylbenze]indenylzirconocene MBI-Cl ₂] and MBI-Me ₂]. For cationic activation of the MBI-Me ₂ system tris(pentafluorophenyl)borane I], N,N-dimethylanilinium tetra(pentafluorophenyl)borate III] were used. The MAO-activated dimethyl complex showed higher activity with respect to the dichloride system using high catalyst concentrations and Al]/Zr] ratios. Most effective cationic activator for MBI-Me ₂ was N,N-dimethylanilinium tetra(pentafluorophenyl)borate II] in combination with Al(i-Bu₃). Using tris(pentafluorophenyl)borane I] at different polymerization conditions or N,N-dimethylanilinium tetra(pentafluorophenyl)borate II] in combination with Al(Et)₃ no propene polymerization was observed due to the occurrence of reduction of the catalytically active site.