Cycloaddition of CO2 to epoxides using di-nuclear transition metal complexes as catalysts

Abstract

Studies on the reaction and conversion of CO₂ to valuable products have made much progress in recent years, and the search for efficient catalysts is also expanding. Cycloaddition of CO₂ to epoxides was carried out selectively using di-nuclear Cu^II, Co^II and Ni^II complexes (C1, C2 and C3, respectively) as catalysts. The complexes were synthesized in good yield and characterized by various physical and spectroscopic methods. In all complexes the ligand L acted as a bidentate NO donor favouring distorted octahedral, tetrahedral or square planar geometry for C1, C2 and C3, respectively. Complex C2 in the presence of n-Bu₄NI as a cocatalyst showed the highest activity among the reported complexes in the cycloaddition reaction.