轴性捐赠配体:一种用于晚期过渡金属烯聚合催化剂的新战略
Dennis H Leung1, Joseph W Ziller, Zhibin Guan
1Department of Chemistry, University of California, 1102 Natural Sciences 2, Irvine, California 92697-2025, USA.
Journal of the American Chemical Society
|May 23, 2008
概括
一种新型的胺联体与胺基组使得高活性后期金属催化剂用于乙烯聚合,产生线性高分子量聚乙烯. 与基于的对照剂相比,这种氨酸连接体显著提高了催化剂性能.
科学领域:
- 聚合物化学 聚合物化学
- 有机金属化学 有机金属化学
- 催化剂是一种催化剂.
背景情况:
- 为生产先进的聚合物材料,开发高效的烯酸聚合催化剂至关重要.
- 晚金属催化剂为聚合提供了独特的反应性概况.
- 阿尔法二胺联体是调整催化剂性能的多功能平台.
研究的目的:
- 合成和表征一种新型的α-二胺联体,其特征是带有轴性皮里丁组.
- 为了评估这个配体在乙烯聚合中的和复合物的性能.
- 研究二烯部分和共催化剂在催化剂活性和聚合物特性中的作用.
主要方法:
- 合成的α-二胺联体 (1) 与一个胺基组.
- (例如1-NiBr2) 和 (例如1-PdMeCl) 复合物的制备.
- 使用这些复合物的乙烯聚合实验与AlMe2Cl共催化剂.
- 使用凝透色谱 (GPC) 和NMR光谱分析聚合物分子量 (Mn) 和分支.
主要成果:
- 和复合物中的含有的配体 (1) 呈现出高活性乙烯聚合.
- 生产了高分子量线性聚乙烯 (PE),含量高达109,224 g/mol (Ni) 和880,379 g/mol (Pd).
- 使用联体的对照催化剂只产生了低分子量分支的寡合体,突出显示了氨酸组的有效性.
结论:
- 阿尔法二胺联体中的轴性皮里丁组是实现高活性和产生线性高分子量PE的关键.
- 协催化剂AlMe2Cl在激活基于的复合物方面发挥着特定的作用,可能是通过双金属相互作用.
- 化物部分抑制β-化物消除,导致减少链转移和增强聚合物线性.
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