Electronic structure of two heterotrinuclear metal complexes [Ru<inf>2</inf>Co(μ<inf>3</inf>-O)(μ-CH<inf>3</inf>CO<inf>2</inf>)<inf>6</inf>L<inf>3</inf>] (L = H<inf>2</inf>O, Py)

Two μ3-oxo carboxylate-bridged heterotrinuclear (ruthenium, cobalt) [Ru2Co(μ3-O)(μ,-CH3CO2)6L3] (L = H2O, Py) complexes have been prepared. EPR studies at 77 K show that there is no interaction between the ruthenium and cobalt ions. The ground state of high-spin cobalt is a spin doublet and the two ruthenium ions are antiferromagnetically coupled. IR data show two different types of acetate groups bridging the trinuclear system and the absence of threefold symmetry. ESCA results reveal that the central μ3-oxo bridge is highly covalent and there is no interaction between the ruthenium and cobalt ions.