Highly <i>cis</i>-1,4 Selective Polymerization of Dienes with Homogeneous Ziegler−Natta Catalysts Based on NCN-Pincer Rare Earth Metal Dichloride Precursors
作者:Wei Gao、Dongmei Cui
DOI:10.1021/ja711146t
日期:2008.4.1
coordinating THF molecules, where the pincer ligand coordinates to the central metal ion in a kappaC:kappaN:kappaN' tridentate mode, adopting a meridional geometry. Complexes 1-6, 9-11, and 13 combined with aluminum tris(alkyl)s and [Ph3C][B(C6F5)4] established a homogeneous Ziegler-Natta catalyst system, which exhibited high activities and excellent cis-1,4 selectivities for the polymerizations of butadiene
第一个芳基二亚胺NCN-钳式连接稀土金属二氯化物(2,6-(2,6-C6H3R2N=CH)2-C6H3)LnCl2(THF)2 (Ln = Y, R = Me (1), Et (2) , iPr (3); R = Et, Ln = La (4), Nd (5), Gd (6), Sm (7), Eu (8), Tb (9), Dy (10), Ho (11) )、Yb (12)、Lu (13)) 通过 2,6-(2,6-C6H3-R2N=CH)2-C6H3Li 和 LnCl3(THF)(1-3.5) 之间的金属转移成功合成。这些配合物是具有两个配位 THF 分子的同构单体,其中钳形配体以 kappaC:kappaN:kappaN' 三齿模式与中心金属离子配位,采用子午几何。配合物 1-6、9-11 和 13 与三(烷基)铝和 [Ph3C][B(C6F5)4] 结合建立了均相齐格勒-纳塔催化剂体系,表现出高活性和优异的顺式