Département de chimie moléculaire

The 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 electrochem. and spectroelectrochem. Under an inert atm., monoredn. 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 chem.-electrochem. reactions at the first reduction step, leading to the formation of reduced CO2 derivatives The exptl. results obtained from IR, NIR and UV-Vis spectroelectrochem., as well as DFT calculations, demonstrate an electron-transfer reaction whose rate is ligand-dependent.