HYDROTHERMAL SYNTHESES AND PROPERTIES OF NEW LAYERED ALKALINE-EARTH MOLYBDATE(VI) HYDRATES - SINGLE-CRYSTAL STRUCTURE OF BAMO4O13-CENTER-DOT-2H(2)O

The hydrothermal synthesis, X-ray single crystal structure, and some properties of the new layered BaMo4O13. 2H(2)O are described. (Crystal data: BaMo4O13. 2H(2)O, M(r) = 765.11, orthorhombic, space group Pbna (No. 60), a = 7.680 (2) Angstrom, b = 15.756 (3) Angstrom, c = 19.689 (3) Angstrom, V = 2382.5 Angstrom(3), Z = 8, R(F) = 4.00%, R(W)(F) = 4.39% [3059 reflections with I > 3 sigma(I)].) BaMo4O13. 2H(2)O is the first well-characterized barium molybdate hydrate to be reported, and contains three distinct MoO6 units and an unusual, distorted, MoO5 group in its layer structure. The 9-coordinate Ba2+ cations and water molecules provide the interlayer packing between the [Mo4O13](2-) sheets. SrMo4O13. 2H(2)O has also been prepared, and is isostructural with BaMo4O13. 2H(2)O, on the basis of powder X-ray, TGA, and LR data. (C) 1995 Academic Press, Inc.