带有非局部化酸盐结构的弱协调离子的合成,结构和反应性:对金属聚合催化剂中的离子效应的评估
J Zhou1, S J Lancaster, D A Walker
1School of Chemistry, University of Leeds, Leeds LS2 9JT, UK.
Journal of the American Chemical Society
|July 18, 2001
概括
从三和化物基联体合成了新的庞大,协调较弱的离子. 这些离子与conocene复合体具有独特的反应性,影响聚合催化和反应通路.
科学领域:
- 有机金属化学 有机金属化学
- 协调化学 协调化学
- 聚合物化学 聚合物化学
背景情况:
- 三 ((五二) 是弱协调离子的关键前体.
- 强烈协调的阳离子,如化物,可以被修改为形成重的,较少协调的物种.
- 基复合物被广泛用作聚合催化剂.
研究的目的:
- 为了合成和表征基于三 (pentafluorophenyl) 和化物配体的新型体积大,协调较弱的离子.
- 为了研究这些新离子与conocene二甲基复合物的反应性.
- 评估烯聚合物中衍生催化系统的性能.
主要方法:
- 新型基离子的合成和分离.
- 用X射线结晶学测定关键化合物的结构.
- 齐尔科诺复合物的反应性研究与合成的阴离子.
- 使用衍生催化系统进行乙烯和烯聚合实验.
主要成果:
- 成功合成了[CN[B[(C6F5) ]2](-) 和[M[CNB[(C6F5) ]4](2-) (M=Ni,Pd) 阳离子.
- 确定了这些离子的几个盐的晶体结构.
- 与齐尔科诺二甲基复合物的反应产生了双核甲基桥接离子.
- 由这些离子衍生的催化系统在乙烯和聚合过程中表现出高活性,具有不同的质量运输限制和活性顺序.
结论:
- 新的庞大,协调较弱的离子是基于conocene 的催化剂的有效对手.
- 阳离子结构和固体质量显著影响催化剂稳定性和聚合活性.
- 单体协调和位移很可能参与聚合的速度限制步骤.
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