Acta Cryst. (2008). E64, i13-i14  [ doi:10.1107/S1600536808001608 ]

The dehydrated copper silicate Na₂[Cu₂Si₄O₁₁]: a three-dimensional microporous framework with a linear Si-O-Si linkage

L. Cunha-Silva, P. Brandão, J. Rocha and F. A. Almeida Paz

Abstract: The structure of the title dehydrated copper silicate, disodium dicopper undecaoxide tetrasilicate, Na₂(Cu₂O₁₁Si₄), was determined by single-crystal X-ray diffraction from a non-merohedral twin. It exhibits an effective three-dimensional microporous framework with the major channels, in which the Na⁺ cations are placed, running along the a-axis direction and smaller channels observed along the b-axis direction. The structure is unusual in that it contains a symmetry-constrained Si-O-Si angle of 180°. The Cu centre is coordinated to five O atoms, exhibiting a slightly distorted square-pyramidal coordination geometry. The Na cation is interacting with five neighbouring O atoms, exhibiting an uncharacteristic coordination environment.

Online 23 January 2008

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