The polynuclear iron-oxo/hydroxy complexes containing ketoacidoximate ligands described in this report are [Fe 3 6 (3) (dmso = dimethyl sulfoxide). 1-3 are isolated from the reaction of Fe(NO 3 ) 3 ·9H 2 O and in situ generated anions of ketoacidoximate ligand [(HO 2 C-C(R 1 ) = NOR 2 ), where R 1 = CH 3 , C 6 H 5 and CH 2 -C 6 H 5 ; R 2 = H or CH 3 ] in H 2 O, followed by crystallization in donor solvents. 1-3 undergo thermal decomposition above 200 8C and form crystalline a-Fe 2 O 3 at 600 8C.