Toward the Design of Double Metal Cyanides for the Copolymerization of CO₂ and Epoxides

Abstract

Reaction of [KCpFe(CN)2PPh2(CH2)1.5]2 with zinc iodide results in the formation of a nonplanar diamond-shaped arrangement of [FeCNZn]2 with a bridging diphenyl-phosphinopropane, [CpFe(μ-CN)2ZnI(THF)]2-μ-dppp. This double metal cyanide (DMC) is found to mimic the reactivity of the heterogeneous DMC catalysts. That is, it serves to homogeneously catalyze the coupling of CO2 and cyclohexene oxide to afford cyclic cyclohexene carbonate and low molecular weight polycarbonate.