Photoresponsive Palladium and Nickel Catalysts for Ethylene Polymerization and Copolymerization
Photoresponsive Palladium and Nickel Catalysts for Ethylene Polymerization and Copolymerization
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用于乙烯聚合和共聚的光响应钯和镍催化剂
DOI：
10.1002/anie.202107883
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发表时间：
2021-09-02
影响因子：
16.6
通讯作者：
Chen, Changle
中科院分区：
文献类型：
--
作者：
Peng, Dan;Chen, Changle
在这方面的贡献，我们安装一个偶氮苯功能的烯烃聚合催化剂，并使用光调制其性能通过光诱导的反-顺异构化的偶氮苯部分。最初靶向的偶氮苯官能化的α-二亚胺钯和镍催化剂不是光响应性的。为了解决这个问题，制备并研究了具有与金属中心中断的共轭的亚胺-胺系统和在远离金属中心的共价位置处具有偶氮苯单元的α-二亚胺系统。我们证明，光可以用来调整其在乙烯聚合和与极性共聚单体共聚的性能，使光诱导的聚合过程，聚合物的微观结构和聚合物的性能的控制。更有趣的是，光介导的性质的变化归因于配体的电子效应在一个系统和配体的空间效应在其他。
In this contribution, we install an azobenzene functionality in olefin polymerization catalysts and use light to modulate their properties via photoinduced trans-cis isomerization of the azobenzene moiety. The initially targeted azobenzene-functionalized alpha-diimine palladium and nickel catalysts are not photoresponsive. To address this issue, an imine-amine system bearing interrupted conjugation with the metal center, and a sandwich-type alpha-diimine system bearing an azobenzene unit at a position covalently far from the metal center were prepared and studied. We demonstrate that light can be used to tune their properties in ethylene polymerization and copolymerization with polar comonomers, enabling light-induced control of the polymerization processes, polymer microstructures and polymer properties. More interestingly, the light-mediated property changes were attributed to ligand electronic effects in one system and ligand steric effects in the other.