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

Four new mixed‐ring zirconium completes, [CH 2 = CH(CH 2 ) n ‐C 5 H 4 ](RC 5 H 4 )ZrCl 2 [n = l, R = CH 3 OCH 2 CH 2 (3); n = 2, R = CH 3 OCH 2 CH 2 (4); n = 2, R=Me 3 Si (5); n = 2, R = allyl (6)], have been prepared by the reaction of CH 2 = CH(CH 2 ) n C 5 H 4 ZrCl 3 , DME[ n = l (1); n = 2 (2)] with RC 5 H 4 Li. 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 Cp 2 ZrCl 2 . 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 ( M η) on the Al/Zr ratio, the polymerization time ( t P ), polymerization temperature ( T P ) and the polymerization solvent volume (V) was investigated.