AbstractThe polymerization of propylene using a variety of fluorinated bis(phenoxyimine)titanium complexes is reported. The synthesis of ten complexes containing varying fluorinated N‐aryl substituents is described. X‐ray structural and solution NMR data indicate that these complexes are C2‐symmetric in the solid state, although in some cases C1‐symmetric isomers are observed in solution. When activated with methylalumoxane, all complexes formed syndiotactic polypropylene. Catalysts with ortho‐fluorine substituents formed polymers with very narrow molecular weight distributions, indicative of a living polymerization. Catalysts with fluorine in at least the ortho and para positions exhibited the highest syndio‐specificities. Catalysts with meta‐ or para‐fluorine‐containing substituents were more active for propylene polymerization than the corresponding non‐fluorinated catalyst.
摘要 报道了使用各种
氟化双(苯氧
亚胺)
钛络合物聚合
丙烯的情况。文中介绍了含有不同
氟化 N-芳基取代基的十种络合物的合成过程。X 射线结构和溶液核磁共振数据表明,这些络合物在固态下是 C2 对称的,但在某些情况下,在溶液中也能观察到 C1 对称的异构体。当用甲基铝氧烷活化时,所有配合物都会形成对位聚
丙烯。带有正
氟取代基的催化剂形成的聚合物分子量分布非常窄,表明是活聚合。至少在正位和对位含有
氟的催化剂具有最高的联合特异性。与相应的非含
氟催化剂相比,含偏
氟或对位
氟取代基的催化剂对
丙烯聚合的活性更高。