Hydrothermal synthesis and structure of a novel molybdenum phosphate: Na-4(H3O) [Na(HPO4)(2)(PO4)(4)Mo18O49]center dot 16H(2)O

The title compound (Na5H37PMo18O90)-Mo-6 1 (M-r = 1658) was synthesized und er hydrothermal condition and its crystal Structure was determined by X-ray diffraction. It crystallized in the monoclinic system, space group P2(1) w ith a = 14.957(1), b = 16.535(1), c = 16.159(1)Angstrom, beta = 108.586(2)d egrees, V = 3787.85 Angstrom (3), Dc =3.040 g/cm(3), Z = 2, mu (MoK alpha) = 3.17mm(-1), F(000) = 3242. The final R and wR are 0.0500 and 0.1535 for 6 643 observable reflections with I greater than or equal to2 sigma (I), resp ectively, The result of structure analysis indicates that [Na(HPO4)(2)(PO4) (4)-Mo-18 O49](5-) anions 2 in 1 has the symmetry of C-2V, in which each (M oO6)-O-VI octahedron is connected to adjacent PO4 tetrahedra through corner -sharing and to adjacent octahedra through edge-sharing or corner-sharing.