Preparation, crystal structure and characterization of a novel iron(III) oxide cluster containing two different discrete [Fe3O] units

The preparation, X-ray crystal structure, Mössbauer spectra and magnetic properties of a novel iron(III) oxide cluster have been reported. The reaction of excess trans-2-butenoic acid with FeSO4·7H2O in the presence of NaOH gives the novel hexanuclear complex [Fe3O(O2CCHCH-CH3)6(H2O)3][Fe3O(O2CCHCH-CH3)7(H2O)2](HO2CCHCH-CH3)4(OH)(H2O). The X-ray analysis reveals that it is the first case that contains two different discrete trinuclear oxo-centered [Fe3O] units. The Mössbauer spectra of the complex are typical of high spin iron(III) complexes. The complex has been found to exhibit antiferromagnetic exchange interactions between the Fe(III) ions.