立体选择环膨胀转化聚合与阴离子基基N-异环碳素复合物
Patrick Probst1, Jonas Groos1, Dongren Wang1
1Institute of Polymer Chemistry, Pfaffenwaldring 55, D-70569 Stuttgart, Germany.
Journal of the American Chemical Society
|March 14, 2024
概括
催化剂使循环烯的环扩张转化聚合 (REMP) 成为循环聚合物. 定制的催化剂在功能性norbornenes的聚合过程中实现了高立体选择性.
科学领域:
- 有机金属化学
- 聚合物化学
- 催化剂
背景情况:
- 含有N-异环碳素 (NHC) 连接体的基复合物被用于聚合.
- 环膨胀转化聚合 (REMP) 是合成循环聚合物的一种方法.
- 控制聚合物分子重量和立体化学对于先进的材料特性至关重要.
研究的目的:
- 研究新型-NHC复合物的循环烯的REMP效果.
- 在norbornene聚合中实现高分子量循环聚合物和控制立体化学.
- 使用计算方法阐明REMP过程的机制细节.
主要方法:
- 基NHC复合物的合成和表征.
- 环扩张转化聚合 (REMP) 的cis-cyclooctene (cCOE) 和功能性norbornenes.
- 聚合物分子重量 (MALDI-TOF) 和立体化学分析 (NMR光谱).
- 密度函数理论 (DFT) 计算用于机械洞察.
主要成果:
- -NHC催化剂从cCOE产生循环聚合物,其分子量可通过单体度控制.
- 采用REMP后的技术来增加循环多重体的分子量.
- 功能性norbornenes的立体选择性REMP产生了高达99%的立体选择性聚合物 (cis-isotactic,cis-syndiotactic,trans-isotactic).
结论:
- -NHC复合物是REMP的有效催化剂,可以合成循环聚合物.
- 催化剂和添加剂设计允许精确控制聚合物立体化学.
- DFT计算为观察到的聚合行为提供了有价值的机械学理解.
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