文献类型：期刊文献

英文题名：Zirconium complexes bearing bis(phenoxy-imine) ligands with bulky o-bis(aryl)methyl-substituted aniline groups: synthesis, characterization and ethylene polymerization behavior

作者：Li, Aike[1];Ma, Haiyan[1];Huang, Jiling[1]

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

年份：2013

卷号：27

期号：6

起止页码：341

外文期刊名：APPLIED ORGANOMETALLIC CHEMISTRY

收录：;EI(收录号：20132216386580);WOS:【SCI-EXPANDED(收录号:WOS:000319516500005)】；

基金：The authors are grateful for financial support from the key project of the Chinese Ministry of Education (No. 109064) and the National Natural Science Foundation of China (NSFC) (No. 21274041, 20774027).

语种：英文

外文关键词：zirconium; phenoxy-imine; polymerization; ethylene; polyethylene

摘要：A series of bis(phenoxy-imine) zirconium complexes bearing bulky o-bis(aryl)methyl-substituted aryl groups on the aniline moiety have been synthesized, characterized and tested as catalyst precursors for ethylene polymerization. 1H NMR spectroscopy suggests that these complexes exist as a single chiral C2-symmetric isomer in the solution. X-ray crystallographic analysis of the resulting biszwitterionic-type adduct complex C1 center dot 2HCl reveals that the phenoxy-imine groups function as a monodentate phenoxy ligand and the oxygen atoms are oriented trans to each other at the central metal atom. Using modified methylaluminoxane (MMAO) as co-catalyst, C1 center dot 2HCl, C2-C6 exclusively produce linear aluminium-terminated polyethylenes (Al-PEs) with high activity (up to 16.89x106 g PE (mol Zr h)-1, suggesting that chain transfer to aluminum is the predominant termination mechanism. It is noteworthy that the introduction of an excessively bulky o-bis(aryl)methyl substituent adjacent to the imine-N produces low molecular-weight Al-PEs (Mv 1.6-10.1x103) due to the enhanced rate of chain transfer to alkylaluminium groups during polymerization. Copyright (c) 2013 John Wiley & Sons, Ltd.