Transition metal–Schiff's base complexes. Part IV. Investigations of some iron(II) and manganese(II) systems

Abstract

The iron(II) complexes of the quadridentate ligand NN′-ethylenobis(salicylideneimine) and its 5-methyl, 5-nitro-, 5-chloro-, 4-chloro-, and 3-nitro-derivatives are high-spin, and have magnetic moments which vary little with temperature. Their moments are lower than commonly found for high-spin iron(II) systems presumably because of distortion and delocalisation effects. Failure to realise the air-sensitivity of these iron(II) compounds has in the past led to incorrect interpretations of magnetic and spectral data. The iron(II) complexes of the bidentate ligands N-phenyl- and N-methyl-salicylideneimine are also high-spin.The reduced magnetic moment of NN′-ethylenebis(salicylideneiminato)manganese(II) has been shown to arise from magnetic exchange. It is oxidised by nitric oxide to a high-spin manganese(III) compound.