X-Ray crystal structures and electronic aspects of two mononuclear iron(III) complexes of the class FeIIILL′ with the quadridentate ligand L = salen or nta and the bidendate ligand L′= oxalate [salen = bis(salicylidene)ethylenediamine anion, H3nta =N,N-bis(carboxymethylglycine)]

Abstract

The X-ray crystal structures of two mixed-ligand six-co-ordinate iron(III) complexes, [Fe^III(salen)(ox)]pipH (1) and [Fe^III(nta)(ox)](dabcoH)₂(2)(ox = oxalate, pipH = piperidinium cation, dabcoH = 1,4-diazabicyclo [2.2.2]octane cation) are characterized by a distorted octahedral co-ordination; the resulting ligand field rhombicity and spin–orbit coupling provide significant quantum mixing of the S= 5/2 ground state as revealed by magnetic properties studies.