Fan Zhang, Y. Mu, Jianhui Wang
Sep 15, 2000
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0
Influential Citations
19
Citations
Journal
Polyhedron
Abstract
Abstract Zirconocene complexes carrying sterically bulky tri-substituted cyclopentadienyl ligands, (η5-4-R-1,2-Ph2C5H2)2ZrCl2 [R=phenyl (3), cyclohexyl (4)], were synthesized by the reaction of ZrCl4 with lithio salt of 1,2,4-triphenylcyclopentadiene (1) or 4-cyclohexyl-1,2-diphenylcyclopentadiene (2), respectively. The single-crystal X-ray structure analysis reveals that both complexes crystallize in C2-symmetric conformation in solid state. When activated with methylaluminoxane (MAO), complexes 3 and 4 polymerize ethylene with moderate activities to produce ultra-high-molecular-weight polyethylenes with high melting transition temperatures at low Al/Zr ratios. Under ambient conditions, both systems of 3–MAO and 4–MAO show relatively high activities in propylene oligomerization. The molecular weight of the polypropylene produced from the 3–MAO system is lower than that from the 4–MAO system. In comparison with 4, complex 3 is more active in both ethylene and propylene polymerization.