Acta Cryst. (2006). E62, i201-i203  [ doi:10.1107/S1600536806034362 ]

K₂NaH[GeW₁₂O₄₀]·7H₂O, with a Keggin-type heteropolyoxoanion

Q.-X. Han, J.-P. Wang and L.-H. Song

Abstract: During experiments aimed at the crystal growth of tetrapotassium dodecatungstogermanate, K₄[GeW₁₂O₄₀].xH₂O, the title compound, dipotassium sodium hydrogen dodecatungstogermanate heptahydrate, K₂NaH[GeW₁₂O₄₀]·7H₂O, (I), was obtained serendipitously. The [GeW₁₂O₄₀]^4- units in (I) are interconnected by K⁺ cations to establish a three-dimensional network, with large channels running along the c axis. Disordered Na⁺ cations and water molecules reside on the outside of these channels, leaving empty pores with a diameter of ca 9.2 Å. The heteropolyoxoanion is of the Keggin-type, with a central Ge atom situated on a position with 222 symmetry.

Online 6 September 2006

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