摘要: Precise, efficient copolymerizations of ethylene with cyclic olefins [norbornene (NBE), cyclopentene (CPE)] using nonbridged half-titanocenes of type, Cp,TiCl2(L) (Cp, = cyclopentadienyl group, L = aryloxo, ketimide)-MAO catalyst systems have been summarized. CpTiCl2(N＝CtBu2) exhibited both remarkable catalytic activity and efficient NBE incorporation for ethylene/NBE copolymerization: the NBE incorporation by CpTiCl2(X) (X = N＝CtBu2, O-2,6-iPr2C6H3; Cp,＝Cp, C5Me5, indenyl) was related to the calculated coordination energy after ethylene insertion. (tBuC5H4)TiCl2(N＝CtBu) exhibited significant catalytic activities with efficient CPE incorporations in ethylene/CPE copolymerization in the presence of MAO. The polymerization proceeded with exclusive 1,2-CPE incorporation, affording high molecular weight (alternating) copolymers with uniform distributions. Therefore, the cyclopentadienyl fragment (Cp) plays an essential role in terms of both the activity and the efficient cyclic olefin incorporation.