Remarkable Effects of Aluminum Cocatalyst and Comonomer in Ethylene Copolymerizations Catalyzed by (Arylimido)(aryloxo)vanadium Complexes: Efficient Synthesis of High Molecular Weight Ethylene/Norbornene Copolymer
Remarkable Effects of Aluminum Cocatalyst and Comonomer in Ethylene Copolymerizations Catalyzed by (Arylimido)(aryloxo)vanadium Complexes: Efficient Synthesis of High Molecular Weight Ethylene/Norbornene Copolymer
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DOI：
10.1021/ma050629s
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发表时间：
2005-06
期刊：
影响因子：
5.5
通讯作者：
W. W. and-W.;K. Nomura
中科院分区：
文献类型：
--
作者：
W. W. and-W.;K. Nomura
本文研究了VCl_2（N-2，6-Me_2C_6H_3）（OAr）[Ar = 2，6-Me_2C_6H_3（1），2，6-iPr_2C_6H_3（2），2，6-Ph_2C_6H_3（3）]型（芳酰亚氨基）（芳氧）钒（V）配合物与助催化剂[甲基铝氧烷（MAO）或Et_2AlCl]催化体系的乙烯与异戊二烯（NBE）、环戊烯（CPE）和1-己烯的共聚反应。这些配合物在Et 2AlCl助催化剂存在下对乙烯聚合表现出显著的催化活性，特别是由1制备的聚乙烯具有窄的分子量分布，Mn值随聚合物产率（TON值）的增加而线性增加。Al助催化剂在乙烯与NBE共聚反应中的催化活性、NBE的引入、主要的链转移反应以及共聚物的Mn值都与所用的Al助催化剂（MAO或Et 2AlCl）密切相关。1-Et 2AlCl催化剂体系表现出显著的催化活性，可用于制备高纯度的甲醇。
Copolymerizations of ethylene with norbornene (NBE), cyclopentene (CPE) and 1-hexene by (arylimido)(aryloxo)vanadium(V) complexes of the type VCl2(N-2,6-Me2C6H3)(OAr) [Ar = 2,6-Me2C6H3 (1), 2,6-iPr2C6H3 (2), 2,6-Ph2C6H3 (3)] with cocatalyst [methylaluminoxane (MAO) or Et2AlCl] catalyst systems have been explored. These complexes exhibited remarkable catalytic activities for ethylene polymerization in the presence of Et2AlCl cocatalyst; in particular, the resultant polyethylene prepared by 1 possessed narrow molecular weight distributions and the Mn value increased linearly upon increasing the polymer yields (TON values). Notable effects of Al cocatalyst have been observed in the copolymerization of ethylene with NBE: the catalytic activities, the NBE incorporation, dominant chain transfer reactions, and the Mn values for resultant copolymers were highly dependent upon the Al cocatalyst employed (MAO or Et2AlCl). The 1−Et2AlCl catalyst system exhibited remarkable catalytic activities, affording ultrahigh ...