Published online by Cambridge University Press: 26 January 2011
Four new compounds containing vanadosilicate clusters have been synthesized by hydrothermal reactions. The clusters are derived from the [V18O42] Keggin cluster by substitution of V=O caps by Si2O(O,OH)2 species. In Cs9[(V15Si6O46(OH)2Cl)(V2O4)](H2O)6.2, 1, the [V15Si6O46(OH)2] cluster shells are covalently interconnected by VO4 tetrahedra to form an infinite layer. In ((CH3)4N)4[V15Si6O42(OH)6(H2O)](H2O)20, 2, and ((CH3)4N)4(V(H2O)6)2/3 [V15Si6O42(OH)6 (H2O)](H2O), 3, separated [V15Si6O42(OH)6] cluster shells are interlinked by hydrogen bonds to form frameworks with wide channel systems. The separated cluster shell in ((CH3)4N)4((CH3)2NH2)((CH3)2NH) [V14Si8O42(OH)8(HCO2)] (H2O)4.7, 4, has four Si2O(OH)2 species in a tetrahedral configuration. The 2D structure of 1 and 0D structures of 2-4 complement the known 1D and 3D structures formed from such vanadosilicate shells.