HYDROTHERMAL SYNTHESIS AND STRUCTURE OF MN2VO(PO4)(2)CENTER-DOT-H2O

Manganese(II) vanadyl phosphate hydrate, Mn2VO(PO4)(2). H2O, has been prepared hydrothermally and characterized structurally from single cry stal-diffraction data. It crystallizes in space group P2(1)/c of the m onoclinic system with Z = 4 in a cell of dimensions a = 8.957(2) Angst rom, b = 8.806(2) Angstrom, c = 9.329(2) Angstrom, and beta = 100.95(1 )degrees. The outstanding feature of the structure is a tetrameric clu ster of Mn(1)O-5 polyhedra and VO6 octahedra. These clusters are linke d together by Mn(2)O-5 polyhedra and PO4 tetrahedra to yield the three -dimensional arrangement of the structure. The compound decomposes at 400 degrees C to afford a nominally dehydrated phase. Magnetic suscept ibility measurements confirm the assignment of the metal oxidation sta tes as Mn(II) and V(IV) in the title compound. (C) 1995 Academic Press , Inc.