Mono- and dinuclear FeIII complexes with the tridentate N-ethyl-N-(2-aminoethyl)salicylaldiminato ligand. X-ray structures, magnetic and spectroscopic properties

Three new FeIII complexes have been synthesized with the tridentate ligand salEen (salEen=N-ethyl-N-(2-aminoethyl)salicylaldiminate). Two of them are neutral dinuclear complexes and their structures have been resolved. Their formulae are [Fe(salEen)(Cl)(μ-CH3O)]2 and [Fe(salEen)(DBC)]2 (DBC=3,5 di-tert-butylcatecholate), respectively. These complexes exhibit a ‘diamond-core’ geometry with the ferric ions antiferromagnetically coupled by the bridging oxygens of the methoxy or DBC ligands, respectively. The last complex is a mononuclear one of formula [Fe(HsalEen)2Cl2]Cl, with the protonated ligand acting as a bidentate one. This compound is actually a mixture of two complexes with the same formula but with different coordination of the HsalEen fragments.