A Barium Vanadium(v) Selenite Hydrate, Ba(VO2)(2)(SeO3)(2)center dot H2O: A Novel 3D Polymer of Cross-Linked Sheets with Embedded center dot center dot center dot V-O-V center dot center dot center dot 2(1) Helices

摘要

The characterisation, by a single-crystal X-ray study at similar to 150 K, of brown acicular crystals of barium(II) bis(dioxovanadium(v)) bis(selenite(IV)) monohydrate, BaSe2V2O10 center dot H2O, obtained as a minor product of the synthesis of the previously reported Ba(VO)(2)(SeO3)(2)(HSeO3)(2)', is recorded. Crystals are monoclinic, P2(1)/c, a = 10.803(2), b = 5.1126(8), c = 17.905(3) angstrom, beta = 92.048(2)degrees, V = 988.3(3)angstrom(3), 2456 independent diffractometer reflections refining to R1 = 0.032, wR2 = 0.084. A single BaV2Se2O11H2 formula unit, devoid of crystallographic symmetry, comprises the asymmetric unit of the structure, which is a three-dimensional polymer, with component sheets parallel to the crystallographic b axis, containing pentavalent vanadium atoms, one five-, the other six-coordinate, linked by selenite pyramids.