The first vanadium gallophosphates:: Hydrothermal synthesis and structure of Rb[(VO)(H2O)Ga(PO4)2] and Cs[(VO)(H2O)Ga(PO4)2]

The first examples of vanadium gallophosphates, Rb[(VO)(H2O)Ga(PO4)(2)] and Cs[(VO)(H2O)Ga(PO4)(2)] have been synthesized using hydrothermal methods, from XVO3 (X = Rb, Cs), Ga2O3, H3PO4, H2PO3F, and an organic species. The phases are isostructural and have a three-dimensional anionic vanadium gallophosphate framework assembled from corner sharing PO4 and GaO4 tetrahedra and VO5(H2O) octahedra. The PO4 and GaO4 tetrahedra form chains which are crosslinked by the vanadium octahedra. Since the GaO4 tetrahedra and VO5(H2O) octahedra each share corners exclusively with PO4 tetrahedra, no Ga-O-V bonding is present in the framework. The anionic charge of the framework is compensated by the alkali cations, which lie in tunnels running along the y axis. Single-crystal data for Rb[(VO)(H2O)Ga(PO4)(2)]: monoclinic, space group P2(1)/c (No. 14) with a = 7.928(2) Angstrom, b = 8.049(2) Angstrom, c = 13.983(3) Angstrom, beta = 104.274(5)degrees, V = 864.8(4) Angstrom(3), Z = 4, D-calc = 3.303 g cm(-3); for Cs[(VO)(H2O)Ga(PO4)(2)]: monoclinic, space group P2(1)/c (No, 14) with a = 8.0423(5) Angstrom, b = 8.0661(5) Angstrom, c = 14.1284(8) Angstrom, beta = 105.094(1)degrees, V = 884.89(9) Angstrom(3), Z = 4, D-calc = 3.584 g/cm(-3). (C) 1999 Academic Press.