Synthesis, Characterization, and Polymerization Studies of Ethylenebis(hexamethylindenyl) Complexes of Zirconium and Hafnium
作者:Paul Ransom、Andrew E. Ashley、N. David Brown、Amber L. Thompson、Dermot O’Hare
DOI:10.1021/om100986j
日期:2011.2.28
The chemistry of a series of ansa-bridged ethylene-bis(hexamethylindenyl)zirconium and hafnium complexes has been explored. Treatment of EBI*Li2·THF0.38 with MCl4·THF2 (M = Zr, Hf) gives rac-EBI*MCl2 (rac-2, rac-3) and meso-EBI*MCl2 (meso-2, meso-3) (M = Zr and Hf), respectively. The rac- and meso- isomers can be separated by fractional crystallization. meso-EBI*ZrMe2 (meso-4) can be prepared by alkylation
一系列的化学柄-bridged亚乙基-双(hexamethylindenyl)锆和铪配合物已探索。用MCl 4 ·THF 2(M = Zr,Hf)处理EBI * Li 2 ·THF 0.38(M = Zr,Hf)得到rac- EBI * MCl 2(rac -2,rac -3)和内消旋-EBI * MCl 2(meso -2,中观-3)(M = Zr和Hf)。外消旋和内消旋异构体可通过分步结晶分离。中观-EBI * ZrMe2(内消旋-4)可通过烷基化制备内消旋- 2用的MeLi·溴化锂。的分子结构外消旋-和内消旋-2和外消旋-和内消旋-3已经通过单晶X-射线晶体学测定。这些化合物与相关的ansa茂金属之间进行了全面的结构比较。外消旋-和内消旋-2和外消旋-和内消旋-3在改性甲基铝氧烷(MMAO)的存在下,是用于乙烯聚合的非常活跃的催化剂前体,可得到分子量(M w)在100000-220 000和多分散度(M