Ferrocene in Radical Coordination Polymerization of Vinyl Chloride: a DFT Study
摘要
Metal complexes have a variety of current applications, including radical-initiated polymerization in the presence of metallocenes, which form active centers of coordination chain propagation. Recently, only styrene and methyl methacrylate radical coordination polymerization have been studied. A DFT study of all potential elementary acts of the radical polymerization vinyl chloride in the presence of ferrocene demonstrates that growth radicals (R•) are bound to a ferrocene cyclopentadienyl ligand to form a metal-centered radical (C5H5R)Fe•Cp with a free vacancy on an iron atom. The sequential addition of growth radicals and monomers to intermediate (C5H5R)Fe•Cp leads to the formation of the following coordination chain growth active centers types: (C5H5R)FeR(M)Cp, R2(M)Fe•Cp, and (R)M2FeCp. The chain propagation proceeds in these active centers without radicals, leading to the formation of a regular “head-to-tail” polymer structure. Notably, this process occurs without chain termination and radicals, a characteristic that allows it to be described as radical coordination polymerization.