HYDROTHERMAL SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF A NEW VANADYL(IV) ARSENATE - BAVO(ASO4)(H2ASO4).H2O

A new vanadyl(IV) arsenate, BaVO(AsO4)(H2AsO4).H2O, has been synthesised hydrothermally at 230-degrees-C and characterized by single-crystal X-ray diffraction, thermogravimetric analysis, and magnetic susceptibility. The compound crystallizes in the monoclinic space group P2(1)/n with a = 11.222(2), b = 6.570(2), c = 11.540(3) angstrom, beta = 102.87(2)-degrees, Z = 4 and R = 0.0297. The structure consists of layers of corner-sharing VO6, AsO4 and H2AsO4 polyhedra, extending parallel to the (1 01 ) crystallographic plane with the Ba atoms and H2O molecules between the layers. The connectivity formula for a layer is infinity 2[(VOO2/2O3/2)(AsOO3/2){As(OH)2O2/2)]2-. The adjacent layers are linked by O-Ba-O bonds and hydrogen bonding.