High cis‐1,4 polyisoprene or cis‐1,4/3,4 binary polyisoprene synthesized using 2‐(benzimidazolyl)‐6‐(1‐(arylimino)ethyl)pyridine cobalt(II) dichlorides
High cis‐1,4 polyisoprene or cis‐1,4/3,4 binary polyisoprene synthesized using 2‐(benzimidazolyl)‐6‐(1‐(arylimino)ethyl)pyridine cobalt(II) dichlorides
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DOI：
10.1002/pi.4490
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发表时间：
2013-12
影响因子：
3.2
通讯作者：
Aihua He;Genglin Wang;Weizhen Zhao;Xiubo Jiang;Wei Yao;Wen‐Hua Sun
中科院分区：
文献类型：
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作者：
Aihua He;Genglin Wang;Weizhen Zhao;Xiubo Jiang;Wei Yao;Wen‐Hua Sun
采用钴系在甲苯中合成了具有高顺式-1,4（高达95%）或顺式-1,4/3,4二元结构的聚异戊二烯（PI）。该钴体系具有较高的活性（高达3.50 × 106 g PI (mol Co)−1 h−1），包含一系列2-（苯并咪唑）-6-（1-（芳基）乙基）吡啶钴（II）二氯化合物，并被倍氯乙基铝活化。配体的性质和反应条件对钴配合物的催化性能和产物的结构都有显著影响。异戊二烯的立体定向聚合可以通过改变助催化剂或溶剂来调节：例如，在二乙基氯化铝存在的情况下，在庚烷中可以增加3,4 PI的含量（高达36.6%）。13C核磁共振分析表明，PI链上的3,4个单元是随机分布的。©2013化工学会
Polyisoprene (PI) with a high content of cis-1,4 (up to 95%) or cis-1,4/3,4 binary structures was synthesized using a cobalt system in toluene. The cobalt system, which exhibited high activities (up to 3.50 × 106 g PI (mol Co)−1 h−1), contained a series of 2-(benzimidazolyl)-6-(1-(arylimino)ethyl)pyridine cobalt(II) dichlorides activated with ethylaluminium sesquichloride. The nature of the ligands and the reaction conditions significantly affected both the catalytic performance of the cobalt complexes as well as the structures of the resultant PI. The stereospecific polymerization of isoprene could be tuned via changing either the co-catalyst or solvent: for example, increased content of 3,4 PI (up to 36.6%) was achievable in heptane in the presence of diethylaluminium chloride. Sequence distribution analysis by 13C NMR spectroscopy indicated that most 3,4 units occurred randomly in the PI chains. © 2013 Society of Chemical Industry