The molecular and electronic structure of [Fe III ₂ ( t-bu L ISQ ) ₄ (μ-O)]—a dinuclear ferric complex containing four, O,N-coordinated o-iminobenzosemiquinonate(1−) π radical anions

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, [FeIII2(μ-O)(t-buLISQ)4], is described; its electronic structure is best described as comprising two FeIII(LISQ)2 halves with S* = 3/2 (SFe = 5/2 coupled to two organic radicals) which are then intramolecularly antiferromagnetically coupled via the oxo group yielding the observed S = 0 ground state.