Synthesis and powder data for [Mn(H2O)]0.25(VO)0.75PO4·2H2O

Abstract

A new compound [Mn(H2O)]0.25(VO)0.75PO4·2H2O was prepared by the reaction of V2O5 with the boiling aqueous solution of H3PO4 and KMnO4. The reaction product is a yellow-brown powder, stable in air. The tetragonal unit-cell parameters (298 K) are a = 6.2034(2)Å, c = 13.814(1)Å, V = 531.59Å3, Z = 4, Mr = 194.94, Dx = 2.493 g/cm3, Dexp = 2.52 g/cm3. X-ray (CoKα radiation) powder diffraction data (35 lines) are reported. The compound's structure is probably derived from the VOPO4·2H2O layered lattice by substitution of [Mn(H2O)]3+ ions for a quarter of the vanadyl groups VO3+. Practically the same powder data and unit-cell parameters were found for [Mn(H2O)]x(VO)1−xPO4·2H2O, where x ranges from 0.185 to 0.25.