Photoreduction of carbonate in a copper(I) complex

The photolysis of (prophos)CuI(CO3)CuI(prophos) with prophos = 1,3-bis(diphenylphosphino)-propane in homogeneous solution leads to the reduction of carbonate according to a simple overall stoichiometry (CO2 + prophos → CO + prophos monoxide). It is suggested that this reaction is initiated by a image MLCT state.