Synthesis, structure and magnetic properties of the polyoxovanadate cluster [Zn2(NH2(CH2)2NH2)5][{Zn(NH2(CH2)2NH2)2}2{V18O42(H2O)}]× xH2O (x ~ 12), possessing a layered structure

A hydrothermal reaction of a mixture of ZnCl2, V2O5, ethylenediamine and water gave rise to a layered poly oxovanadate material [Zn2(NH2(CH2)2NH2)5][{Zn(NH2(CH2)2NH2)2}2{V18O42(H2O)}]xH2O (x ~ 12) (I) consisting of [V18O42]12– clusters. These clusters, with all the vanadium ions in the +4 state, are connected together through Zn(NH2(CH2)2NH2)2 linkers forming a two-dimensional structure. The layers are also separated by distorted trigonal bipyramidal [Zn2(NH2(CH2)2NH2)5] complexes. The structure, thus, presents a dual role for the Zn-ethylenediamine complex. The magnetic susceptibility studies indicate that the interactions between the V centres in I are predominantly antiferromagnetic in nature and the compound shows highly frustrated behaviour. The magnetic properties are compared to the theoretical calculations based on the Heisenberg model, in addition to correlating to the structure. Crystal data for the complexes are presented.