循环烯的环开转化聚合由 (Arylimido) ((V) -Alkylidenes:高活性,热强的Cis特异性聚合
Xiaohua Hou1, Kotohiro Nomura1
1Department of Chemistry, Faculty of Science and Engineering, Tokyo Metropolitan University , 1-1 Minami Osawa, Hachioji, Tokyo 192-0397, Japan.
Journal of the American Chemical Society
|August 20, 2016
概括
新的催化剂有效地进行循环烯的环开转化聚合 (ROMP). 这些催化剂显示出高活性和对聚合物特性的控制,进步了烯酸聚合研究.
科学领域:
- 有机金属化学
- 聚合物科学
- 催化剂
背景情况:
- 环开转化聚合 (ROMP) 是从循环烯合成聚合物的关键方法.
- 基于的催化剂在ROMP中表现有前途,但实现高活性和选择性仍然是积极研究的领域.
- 开发高效和选择性的催化剂是扩大ROMP在材料科学中的应用的关键.
研究的目的:
- 在ROMP中探索三种 (arylimido) (V) 化合物的催化活性.
- 研究催化剂结构和反应条件对各种循环烯的ROMP的影响.
- 评估这些催化剂对特定聚合物结构的受控聚合和合成的潜力.
主要方法:
- 三种新型 (arylimido) (V) -基催化剂的合成和表征
- 使用诺伯 (NBE) 和环氧作为单体的ROMP实验.
- 动力学研究以确定催化活性 (周转频率,TOF) 和选择性 (cis-选择性).
- 研究反应参数,包括温度,添加剂 (PMe3) 和链传递剂 (1-hexene).
主要成果:
- 复合物3对NBEROMP具有非常高的催化活性 (TOF=603,000h-1).
- 化酒类相应物 (6, 7) 实现了高活性的NBE的cis特异性活ROMP (TOF=125,000157,000h-1在25°C).
- 在较高的温度和PMe3添加时,催化剂活性增加,保持高的cis选择性 (98%).
- 通过链转移显示出受控的分子重量 (Mn),这表明催化剂在交叉转移中的有效性.
- 对于各种诺波衍生物和环烯ROMP,二甲类类似物 (3, 7) 是有效的,在较高的温度下活性增加.
结论:
- 研究的 (arylimido) (V) 催化剂,特别是复合物3,6和7,对ROMP具有高度活性和选择性.
- 这些催化剂可对聚合物进行调节控制,使得具有所需性质的聚合物能够合成.
- 这些发现代表了开发高效的催化剂的重大进展.
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