Mn2+ substitution within the {V14As8} polyoxovanadate archetype results in {Mn2V12As8} shells with trans‐positioned heterometal positions

Abstract

AbstractSolvothermal exploration of the As, V, Mn reaction system in the presence of aqueous diethylenetriamine (=dien) solution led to the discovery of [MnII4VIV12AsIII8O40(dien)4(H2O)] ⋅ 3.5H2O, containing the first arsenato‐polyoxovanadate featuring a {Mn2V12As8O40} cluster shell. In comparison to its parental {V14As8O42} archetype, two vanadyl (VO2+) units at opposite ends of the polyoxovanadate shell here are substituted by Mn2+ centers. In the solid state, these {Mn2V12As8O40} units are joined into rods by sharing common Mn−O−V linkages. Expansion of the cluster shell by two further Mn2+ sites via Mn−O=V bridges generates a {Mn4V12As8O40} moiety. Three Mn2+ cations are joined by monodentate‐coordinating dien ligands, which link the rods into layers. The dien ligands here coexist in three different coordination modes: monodentate, bidentate and tridentate, which is rarely observed. Magnetic susceptibility measurements show the expected significant antiferromagnetic coupling interactions between all spin centers present in the title compound, namely the isotropic spin‐5/2 Mn2+ centers and the isotropic spin‐1/2 vanadyl groups, in line with most other heterometal‐substituted arsenato‐polyoxovanadate(IV) clusters.