Synthesis of Mixed-ring Zirconocene Complexes Containing Alkenyl Group and Ethylene Polymerization Catalyzed with Them

Synthesis of Mixed‐ring Zirconocene Complexes Containing Alkenyl Group and Ethylene Polymerization Catalyzed with Them

Four new mixed‐ring zirconium completes, [CH₂ = CH(CH₂)_n ‐C₅H₄](RC₅H₄)ZrCl₂ [n = l, R = CH₃OCH₂CH₂(3); n = 2, R = CH₃OCH₂CH₂ (4); n = 2, R=Me₃Si (5); n = 2, R = allyl (6)], have been prepared by the reaction of CH₂ = CH(CH₂)_n C₅H₄ZrCl₃, DME[n = l (1); n = 2 (2)] with RC₅H₄Li. When activated with methylaluminoxane (MAO), the catalytic activities of the above complexes in ethylene polymerization were tested. Complexes 5 and 6 show high activities similar to Cp₂ZrCl₂. Introduction of methoxyethyl group into Cp‐ligand dramatically decreases the catalytic activities of complexes 3 and 4, which can be overcome by increasing the amount of MAO. For complex 5, the dependence of activity and molecular weight (Mη) on the Al/Zr ratio, the polymerization time (t_P), polymerization temperature (T_P) and the polymerization solvent volume (V) was investigated.