Highly Efficient Ethylene/Cyclopentene Copolymerization with Exclusive 1,2-Cyclopentene Incorporation by (Cyclopentadienyl)-(ketimide)titanium(IY) Complex-MAO Catalysts

摘要

The (cyclopentadienyl)-(ketimide)titanium(IV) complex (t-BuC5H4)TiCl2 [N=C(t-Bu)2] exhibited remarkable catalytic activities (1.99-3.16 x10~4 kg polymer/mol Ti-h) with efficient cyclopentene incorporation in ethylene/cyclo-pentene copolymerization in the presence of meth-ylaluminoxane (MAO). The polymerization took place with exclusive 1,2-cyclopentene incorporation, affording high molecular weight (alternating) copolymers (cyclopentene < 43.6 mol %) with uniform distributions. The effect of the cyclopentadienyl fragment (Cp') in the copolymerization using Cp'TiCl2[N=C(t-Bu)2] [Cp' = indenyl, t-BuC5H4, C5Me5 (Cp*), C5H5 (Cp)] has been explored in the presence of MAO; the Cp' plays an important key role in terms of both activity and efficient cyclopentene incorporation.