Multicomponent polyanions. 52. Crystal structure of hexacaesium monohydrogen decamolybdo(VI)divanado(IV)phosphate(7-) dihydrate

The structure of the title compound, (Cs6HPMo10V2O40)-V-VI-O-IV. 2H(2)O has been determined by a single-crystal X-ray diffraction method. The compound crystallises in two different space groups. Crystal A: monoclinic P2(1), a = 10.988(3), b = 10.615(3), c = 17.472(2) Angstrom, beta = 91.55(1)degrees , V = 2037(7) Angstrom(3) and Z = 2. Crystal B: monoclinic, Pn, a = 10.982( 2), b = 10.614(3), c = 17.487(3) Angstrom, beta = 91.64(1)degrees, V = 2037 (7) Angstrom(3) and Z = 2. The R-values based on F were 0.0487 for A and 0. 0485 for B for 4491 (A) and 4464 (B) reflections with F-o > 4.0 sigma (F-o) and 353 parameters, and S = 1.048 (A) and 1.026 (B). The polyanion has a s o-called alpha-Keggin structure in each crystal. The two vanadium atoms are delocalised in the 12 addenda atom positions in the anion.