Bimetallic Nickel Complexes that Bear Diamine-Bis(Benzotriazole Phenolate) Derivatives as Efficient Catalysts for the Copolymerization of Carbon Dioxide with Epoxides

Abstract We report the facile synthesis and structural characterization of efficient bimetallic nickel catalysts that bear diamine‐bis(benzotriazole phenolate) derivatives for the copolymerization of CO 2 and epoxides. Thermally robust di‐nickel 2 is an effective catalyst for the alternating copolymerization of cyclohexene oxide (CHO) with CO 2 to give turnover numbers of up to >4000 and turnover frequencies of up to >400 h −1 . Ni catalyst 2 leads to not only controlled CO 2 /CHO coupling, but it has also been applied to catalyze the copolymerization of 4‐vinyl‐1,2‐cyclohexene oxide (VCHO) and CO 2 to obtain the corresponding polycarbonate with the vinyl functionality on the side chains. This is the first example of a dinuclear Ni complex that is efficient for both CO 2 /VCHO copolymerization and the formation of a high‐molecular‐weight copolymer with a large amount of carbonate linkages.