Abstract Stereospecific cis-1,4 polymerization of 1,3 butadiene is carried out by using CpTiCl3/MAO and Cp*TiCl3/MAO catalysts in solvents (mesitylene, toluene, benzene, chlorobenzene, m-chlorobenzene, hexafluorobenzene) having different nucleophilicity. The influence of nucleophilicity of used solvent on activity and selectivity of the two considered catalytic systems is evaluated. Catalyst activity is strongly affected by used solvent, while polymer microstructure remains almost unchanged. The formation of a labile specie anti-η3-π-butenyl-Ti coordinated to solvent molecule, able to increase the rate of polymerization reaction, is hypothesized. The effect of two different external electron donors, N(C2H5)3 and P(C6H5)3, in the polymerization environment on activity and selectivity of the two considered catalytic systems is also investigated. Both N(C2H5)3 and P(C6H5)3 induce a sweeping decrease of catalyst activity, but do not cause changes in polymer microstructures.

中文翻译：

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环戊二烯基三氯化钛 (CpTiCl3)/甲基铝氧烷 (MAO) 和五甲基环戊二烯基三氯化钛 (Cp*TiCl3)/MAO 催化剂在 1,3-丁二烯聚合中的溶剂效应

摘要 在具有不同亲核性的溶剂（均三甲苯、甲苯、苯、氯苯、间氯苯、六氟苯）中，使用CpTiCl3/MAO和Cp*TiCl3/MAO催化剂，进行1,3丁二烯的立体定向顺1,4聚合。评估了所用溶剂的亲核性对两种考虑的催化体系的活性和选择性的影响。催化剂活性受所用溶剂的强烈影响，而聚合物微观结构几乎保持不变。假设形成与溶剂分子配位的不稳定物质抗-η3-π-丁烯基-Ti，能够提高聚合反应速率。还研究了聚合环境中两种不同的外部电子给体 N(C2H5)3 和 P(C6H5)3 对两种考虑的催化体系的活性和选择性的影响。