A trinuclear anionic trifluoroacetato derivative of iron(II) containing a central O(-I) ligand

The reaction of Fe(CO)5 with CF3COOH/(CF3CO)2O, or with CF3COOH, in DMF at about 140 °C produces [Fe(DMF)6][Fe3(μ3-O)(CF3COO)6(DMF)3]2, characterized by a triangular disposition of the three iron atoms, the central substantially coplanar oxygen atom being formulated as a singly charged anion O(-I) stabilized by complexation to iron(II).