Hydrothermal synthesis and structure of a three-dimensional trimetallic oxide, Na2[CuV2O2(H2O)2(O3PCH2PO3)2]

The hydrothermal reaction of Cu(II), Na3VO4, and methylenediphosphonic acid provided a trimetallic hybrid oxide, Na2[CuV2O2(H2O)2(O3PCH2PO3)2] (1). The structure consists of a three-dimensional View the MathML source{CuV2O2(H2O)2(O3PCH2PO3)2}n-2n framework with charge-compensating Na+ cations entrained within the void spaces. The compound is paramagnetic, and the temperature dependence of the magnetic susceptibility was fit to the Curie–Weiss law. The effective magnetic moment of 2.92 μB at room temperature is consistent with three weakly interacting S = 1/2 spins, corresponding to one Cu(II) and two V(IV) sites.