乙烯/极性单体共聚化通过[N,P]Ti复合物:极性聚合物具有超高分子量
Jingjiao Liu1, Jiaojiao Zhang1, Min Sun2
1State Key Laboratory of Chemical Resource Engineering, Key Laboratory of Carbon Fiber and Functional Polymers, College of Material Science and Technology, Beijing University of Chemical Technology, Beijing 100029, P. R. China.
ACS omega
|April 8, 2024
概括
具有[N,P]连接体的新型复合物显示出高的聚合催化活性. 替代剂显著增强活性,产生超高分子量共聚合物,由DFT计算证实.
科学领域:
- 有机金属化学 有机金属化学
- 聚合物科学 聚合物科学
- 催化剂是一种催化剂.
背景情况:
- 复合物是聚合物的关键催化剂.
- 连接体设计显著影响催化剂性能.
- 了解替代物效应是优化聚合物的关键.
研究的目的:
- 用[N,P]连接体合成和表征新的复合物.
- 研究这些复杂物在聚合过程中的催化活性.
- 探索替代剂的电子和硬质效应对催化性能的影响.
主要方法:
- 合成和表征复合物 (2a-2e) 与[N,P]配体 (1a-1e) 的合成和表征.
- 使用在极性添加剂的存在下合成的复合物进行聚合实验.
- 密度函数理论 (DFT) 计算以研究聚合机制和替代剂效应.
主要成果:
- 合成的复合物表现出高的催化活性,达到高达1.04 × 10^6 g的聚合物 (mol·Ti) ^-1·h^-1.
- 产生了超高分子量 (高达1.37 × 10^6 g/mol) 的共聚物.
- 在氨酸环上提取电子的替代剂显著增强了催化活性,活性顺序为2e > 2d > 2c > 2b > 2a.
- DFT计算表明,连接体替代剂的电子效应控制了聚合行为,而不是硬质阻碍.
结论:
- 具有[N,P]连接体的新型复合物表现出良好的催化活性,并产生高分子量聚合物.
- 作为一个吸收电子的组,有效地促进过渡金属协调聚合.
- DFT计算与实验结果一致,验证了催化剂设计的理论方法.
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