Ethylene and vinyl halide (VX, X = F or Cl) copolymerization mechanism in the presence of catalysts A ((PO^OMe,OMe)PdMe, PO^OMe,OMe = {2(2-MeOC₆H₄)(2-SO₃-5-MeC₆H₃)P}) and A′ ((PO^Bp,OMe)PdMe, PO^Bp,OMe = {(2-MeOC₆H₄)(2-{2,6-(MeO)₂C₆H₃}C₆H₄)(2-SO₃-5-MeC₆H₃)P}) has been comparatively studied via density functional theory (DFT) calculations. The origin of different chain-end microstructures produced by A and A′ and the discrepancy due to VX insertion into Pd–X (X = F and Cl) species are disclosed. It is found that β-F elimination does not result in catalytic deactivation. –CH₂–CHF₂ as a major copolymer unit generated from catalyst A′ was mainly ascribed to a more positive charge of metal Pd assisting the β-F elimination and stronger H⋯OMe and C–H⋯π interactions. However, in the catalysis with A′, the same chain-end unit –CH₂–CHCl₂ was difficult to be generated with a high energy barrier and an apparent endergonic character, which was mainly attributed to the strong Pd–Cl bond and the higher tendency for the reversible β-Cl elimination.

中文翻译：

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膦-磺酸盐钯配合物催化乙烯/卤化乙烯共聚中不同链端微观结构的起源

在催化剂A（（PO ^OMe，OMe）PdMe，PO ^OMe，OMe = {2（2-MeOC ₆ H ₄）（2-SO ₃）的存在下乙烯和卤乙烯（VX，X = F或Cl）的共聚机理-5-MeC ₆ H ₃）P}）和A'（（PO ^Bp，OMe）PdMe，PO ^Bp，OMe = {（2-MeOC ₆ H ₄）（2- {2,6-（MeO）₂ C_对6 H ₃ } C ₆ H ₄）（2-SO ₃ -5-MeC ₆ H ₃）P}）进行了比较研究通过密度泛函理论（DFT）计算。揭示了由A和A'产生的不同链端微结构的起源以及由于VX插入Pd–X（X = F和Cl）物种而引起的差异。发现消除β-F不会导致催化失活。由催化剂A'生成的作为主要共聚物单元的-CH ₂ -CHF ₂主要归因于金属Pd的正电荷更多，有助于β-F的消除和更强的H⋯OMe和C-H⋯π相互作用。但是，在A'催化下，相同的链端单元–CH ₂ –CHCl ₂ 高能垒和明显的阴磁特性难以产生，这主要归因于强的Pd-Cl键和可逆的β-Cl消除趋势。