高活性二元催化剂系统的设计用于CO2 /氧化物共聚合:聚合物选择性,酶选择性和立体化学控制
Xiao-Bing Lu1, Lei Shi, Yi-Ming Wang
1State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116012, People's Republic of China. lxb-1999@163.com
Journal of the American Chemical Society
|February 2, 2006
概括
化催化剂使二氧化碳和环氧化物的不对称共聚合成为聚碳酸盐. 这种二进制系统在温和条件下实现了高选择性和反选择性.
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
- 绿色化学 绿色化学
背景情况:
- 二氧化碳 (CO2) 的利用对于可持续化学至关重要.
- 对于先进的材料来说,受控的环氧化物聚合是必不可少的.
- 为二氧化碳和环氧化物共聚合开发高效的催化剂仍然是一个挑战.
研究的目的:
- 开发一种有效的二元催化剂系统,用于不对称,区域和立体选择性的二氧化碳和赛米亚利法性环氧化物交替共聚化.
- 研究催化剂结构对聚合物特性的影响.
- 为了实现高的选性和对聚合物微观结构的控制.
主要方法:
- 采用了一种二元催化剂系统,其中包括一种性四牙希夫基复合物 (电爱体) 和一种有机盐或强有机基 (核爱体).
- 研究了替代剂组对电友和核友性质的影响.
- 采用电子喷雾电离质谱和动力学研究来阐明反应机制.
主要成果:
- 在温和的温度和压力下实现有效的共聚合.
- 确定了一个理想的催化剂系统 ([SalcyCo(III) X]电和庞大的核),产生高达95%的头到尾连接性和高达99%的碳酸链接的聚碳酸盐.
- 证明催化剂组件结构显著影响活性,选择性和酶选择性.
- 观察到快速的共聚合率与催化剂度的增加.
- 阐明了电友对单体激活和核友对链增长的机制.
结论:
- 开发的二进制催化剂系统提供了一种高效的途径,用于从二氧化碳和环氧化物中合成聚碳酸.
- 催化剂设计,包括电友和核友的固体和电子特性,对于控制立体化学和聚合物特性至关重要.
- 该研究提供了关于异对称催化在异对称位点和聚合物链末端效应的合作效应的见解.
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