Syntheses and X-ray characterisation of novel tellurium-substituted lacunary polyoxotungstates containing VIV, CoII, NiII and ZnII as heteroatoms

Four novel examples of sandwich-type tungstotellurates are synthesised and characterised by X-ray diffraction. The compounds reported are: [(CH3)(4)N](2)Na-6[(Ni(H2O)(3))(2)(WO2)(Ni(H2O)(2))(TeW9O33)(2)].23 H2O (1), [(CH3)(4)N](2)Na-6[(Zn (H2O)(3))(2)(WO2)(1.5)(Zn(H2O)(2))(0.5)(TeW9O33)(2)].26 H2O, (2) K-8[(Co(H2O)(3))(2)(WO2)(Co(H2O)(2))(TeW9O33)(2)].30 H2O, (3) and K-7[(VO(H2O)(2))(1.5)(WO(H2O)(2))(0.5)(WO2)(0.5)(VO(H2O))(1.5)(TeW9O33)(2)].22 H2O, (4). The compounds 1-4 crystallise in the triclinic crystal system, space group P(1) over bar, with a = 12.512(3), b = 13.547(3), c = 16.959(3), alpha = 70.51(3)degrees, beta = 83.47(3)degrees, gamma = 64.59(3) (compound 1); a = 12.608(2), b = 13.642(2), c = 17.010(3), alpha = 70.74(2)degrees, beta = 83.72(2)degrees gamma = 64.49(2)degrees (compound 2); a = 12.329(4), b = 12.596(3), c = 16.199(4), alpha = 77.40(2)degrees, beta = 84.79(2)degrees and gamma = 81.87(2)degrees (compound 3) and a = 12.121(6), b = 12.393(6), c = 16.772(7), alpha = 71.32(3)degrees, beta = 74.91(3)degrees, gamma = 82.73(4) (compound 4). All isomorphous compounds are built up of two beta-B-TeW9O33 Keggin defect fragments which are connected via four MO6 octahedra. In these metal atom sites disorder of the metal atoms is observed. (C) 2003 Elsevier B.V. All rights reserved.