Ultrasound-assisted synthesis of a stable Co (II) coordination polymer as heterogeneous catalyst for CO2 transformation

Abstract A stable benzimidazole-containing Co (II) coordination polymer namely [Co(L)0.5(oba)]n (1) (H2oba = 4,4′-oxybis(benzoate), L = 1,6-bis(5,6-Dimethylbenzimidazolyl) hexane) was successfully synthesized by ultrasonic technique under mild conditions. In especial, the effects of initial reagent concentration, irradiation time and ultrasonic power on the morphology and size of micron scale 1 were discussed in detail. Micron scale 1 appeared exceptional solvent and pH stabilities. Further, as a heterogeneous Lewis catalyst, 1 exhibited a highly activity and recyclability for CO2 transformation by cycloaddition with epoxide under room temperature.