Two novel oxo-centered trinuclear compounds, [M2M'O(C3H3O2)6(H2O)3]+ (M = Cr, M' = Cr, Fe) have been synthesized. The complexes were characterized by elemental analysis, infrared and electronic spectroscopy and thermogravimetric analysis (TGA). These complexes contain unsaturated carboxylate bridging ligands that cause them to have potential scopes for polymerization in the solid state by cross-linking of substituents. Bridging coordination modes for carboxylates were indicated by presence of nasym (M2M'O) vibrations in the infrared spectra.