The molecular and electronic structure of [FeIII2(t-buLISQ)4(μ-O)]—a dinuclear ferric complex containing four, O,N-coordinated o-iminobenzosemiquinonate(1−) π radical anions

Abstract

The synthesis and crystal structure of a dinuclear complex containing a μ-oxo(diferric) core and four O,N-coordinated o-iminobenzosemiquinonate(1−) π radical anions, [Fe^III₂(μ-O)(^t-buL^ISQ)₄], is described; its electronic structure is best described as comprising two Fe^III(L^ISQ)₂ halves with S* = 3/2 (S_Fe = 5/2 coupled to two organic radicals) which are then intramolecularly antiferromagnetically coupled via the oxo group yielding the observed S = 0 ground state.