Electrochemically Driven Reduction of Carbon Dioxide Mediated by Mono‐Reduced Mo‐Diimine Tetracarbonyl Complexes: Electrochemical, Spectroelectrochemical and Theoretical Studies

Abstract

AbstractThe activation of carbon dioxide by three different Mo‐diimine complexes [Mo(CO)4(L)] (L=bipyridine (bpy), 1,10‐phenantroline (phen) or pyridylindolizine (py‐indz)) has been investigated by electrochemistry and spectroelectrochemistry. Under an inert atmosphere, monoreduction of the complexes is ligand‐centered and leads to tetracarbonyl [Mo(CO)4(L)].− species, whereas double reduction induces CO release. Under CO2, [Mo(CO)4(L)] complexes undergo unexpected coupled chemical‐electrochemical reactions at the first reduction step, leading to the formation of reduced CO2 derivatives. The experimental results obtained from IR, NIR and UV‐Vis spectroelectrochemistry, as well as DFT calculations, demonstrate an electron‐transfer reaction whose rate is ligand‐dependent.