Vanadium(IV) and mixed-valence vanadium(IV/V) oxygen clusters with novel electronic properties, including the examples [V12As8O40(HCO2)]n–(n= 3 or 5)

Abstract

The mixed valence compounds [NHEt₃]₂[NH₂Me₂][V₁₂As₈O₄₀(HCO₂)]·2H₂O 1 and Na₅[V₁₂As₈O₄₀(HCO₂)]·18H₂O 2 containing isostructural V–O clusters with encapsulated formate ions and different electron populations, and their characterization are reported; in structurally related V–O clusters spin–spin coupling increases with increasing numbers of V^IV centres in a nearly continuous way.