The influence of the metal net charge of non-metallocene early transition metal catalyst on the ethylene polymerization activity  

作　　者：WU ChunHong LI HuaYi FENG YuQi HU YouLiang 

机构地区：[1]Department of Chemistry, Wuhan University, Wuhan 430072, China [2]Joint Laboratory of Polymer Science and Materials, and Key Laboratory of Engineering Plastics, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China

出　　处：《Chinese Science Bulletin》2008年第20期3164-3168,共5页

基　　金：the National Natural Science Foundation of China (Grant Nos. 20334030, 50703044 and 20734002)

摘　　要：The net charges on central metals of a serial non-metallocene early transition metal catalysts (FI catalyst) with similar steric hindrance were caculated with MM-QEq (molecular mechmism-charge equilibration) method and associated with ethylene polymerization activities of these FI catalyts. It was found that the activity increased with the net charge on metal if ignoring the influence of the steric hindrance. In other words, introduction of strong and/or more electron-withdrawing groups onto the ligand of FI catalyst would enhance the activity of the catalyst. This conculsion gave a direction to designing new FI catalyst with higher activity.The net charges on central metals of a serial non-metallocene early transition metal catalysts （FI catalyst） with similar steric hindrance were caculated with MM-QEq （molecular mechmism-charge equilibration） method and associated with ethylene polymerization activities of these FI catalyta. It was found that the activity increased with the net charge on metal if ignoring the influence of the steric hindrance. In other words, introduction of strong and/or more electron-withdrewing groups onto the Iigand of FI catalyst would enhance the activity of the catalyst. This conculsion gave a direction to designing new FI catalyst with higher activity.

关 键 词：乙烯 聚合活性 分子机制 电荷平衡 净电荷 催化剂 

分 类 号：O632.12[理学—高分子化学]