Mehmood Andleeb, Xu Xiaowei, Raza Waseem, Kim Ki-Hyun, Luo Yi
State Key Laboratory of Fine Chemicals, School of Chemical Engineering, Dalian University of Technology, Dalian 116024, China.
Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul 04763, Korea.
Polymers (Basel). 2020 Oct 19;12(10):2401. doi: 10.3390/polym12102401.
The mechanism of ethylene with vinyl ether (VE, CH=CHOEt) copolymerization catalyzed by phosphine-sulfonate palladium complex () was investigated by density functional theory (DFT) calculation. On achieving an agreement between theory and experiment, it is found that the favorable 1,2-selective insertion of VE into the complex originates from stronger hydrogen interaction between the oxygen atom of VE and the ancillary ligand of catalyst . Additionally, VE insertion is easier into the ethylene pre-inserted intermediate than that into the catalyst to form the resultant copolymers with the major units of OEt in chain and minor units of OEt at the chain end. The effect of -OEt and -H elimination was explored to elucidate chain termination and the molecular weight of copolymers. Furthermore, a family of cationic catalysts has been demonstrated to copolymerize ethylene with VE along with our modified cationic complex with higher incorporation of VE and reactivity in comparison with complex , which was modelled computationally by increasing the strong interactions between the catalyst and monomer moiety. Other than VE, the activity of cationic complex for copolymerization of vinyl chloride and methacrylate is also computed successfully.
通过密度泛函理论（DFT）计算研究了膦磺酸钯配合物（）催化乙烯与乙烯基醚（VE，CH=CHOEt）共聚的机理。在理论与实验达成一致后发现，VE在配合物中有利的1,2-选择性插入源于VE的氧原子与催化剂的辅助配体之间更强的氢键相互作用。此外，VE插入乙烯预插入中间体比插入催化剂更容易，从而形成链中主要单元为OEt且链端为OEt次要单元的共聚物。研究了-OEt和-H消除的影响以阐明链终止和共聚物的分子量。此外，已证明一类阳离子催化剂可使乙烯与VE共聚，以及我们改性的阳离子配合物，与配合物相比，其VE的掺入量更高且反应活性更高，通过增加催化剂与单体部分之间的强相互作用对其进行了计算建模。除了VE，还成功计算了阳离子配合物对氯乙烯和甲基丙烯酸酯共聚的活性。
