Exchange interaction in polynuclear complexes. Part 2.—Antiferromagnetic coupling in binuclear oxo-bridged iron(III) complexes

Abstract

A previously described model for exchange interaction is applied to the study of antiferromagnetic coupling in binuclear oxo-bridged iron (III) complexes. The energies of the magnetic orbitals (singly occupied d orbitals of each transition ion, partially delocalized towards the ligands surrounding this ion), and of the m.o.s. built from these magnetic orbitals are calculated, using the Angular Overlap Model. The wavefunctions associated with the low lying terms are expressed in the form of H.L. functions and the relative energies of these terms are calculated from a one electron matrix, which couples the magnetic orbitals in such a way that its eigenfunctions an eigenvalues are the m.o.s. and their energies. An interpretation of the relative magnitudes of antiferromagnetic coupling in Fe^III—O—Fe^III and Cr^III—O—Cr^III dimers is proposed.