Facile photochemical synthesis of main-chain-type semifluorinated alternating copolymers catalyzed by conventional amines or halide salts

In this work, we report a much simple and low-cost method to prepare main-chain-type semifluorinated alternating copolymers by the formation of halogen bond (XB) complex between α,ω-diiodoperfluoroalkanes and amines/halide salts. It is interesting that the terminal iodine functional group of the polymer chains are easily lost in the amine-promoted system, while the loss can be significantly reduced by adding a small amount of water. Importantly, the system promoted by halide salts can ensure the complete retention of iodine functional group. Overall, the establishment of this method provides a new strategy for designing smart fluoropolymer materials in a green and environmentally friendly facile manner under irradiation with visible light at room temperature.