文献类型：期刊文献

英文题名：ansa-Metallocene (R-Ph)₂(Cp)(Ind)MCl₂ with electron withdrawing substituents on phenyl groups for olefin polymerization

作者：Yang, XX; Zhang, Y; Huang, JL

机构：[1]E China Univ Sci & Technol, Organomet Chem Lab, Shanghai 200237, Peoples R China

年份：2006

卷号：250

期号：1-2

起止页码：145

外文期刊名：JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000237318000025)】；

语种：英文

外文关键词：zirconocene; substituent; ethylene polymerization; copolymerization

摘要：The new ansa-complexes (R-Ph)(2)C(Cp)(Ind)MCl2 (R = CF3, F, CI; M = Ti, Zr or Hf) were synthesized from the reaction of dilithium salt of the corresponding ligands with appropriate group 4 metal halides. They were tested for ethylene homopolymerization and copolymerization in the presence of methylaluminoxane (MAO) at various ethylene pressures and temperatures. In the case of zirconocenes, complexes 2 (R = CF3) and 8 (R = Cl) demonstrated much higher catalytic activity than complexes 10 (Ph2C(Cp)(Ind)ZrCl2) and 5 (R = F) in ethylene polymerization. The same trend was observed in titanocenes and hafnocenes. The electronic and geometric effects of substituents at the phenyl group on the polymerization activity were easily noticed. For the ethylene/1-hexene or 1-octene copolymerization, 2 also showed the highest catalytic activity, and the copolymers from complex 8 possessed the highest 1-hexene and 1-octene contents. (c) 2006 Elsevier B.V. All rights reserved.