The syntheses and characterisation of a new family of isostructural mixed-metal selenites based on the zemannite-type framework are described. These BaM2(SeO3)3·3H2O phases are built up from three-dimensional networks of MO6 (M = Co, Ni, Mn, Mg) octahedra and SeO3 pyramids. The octahedral groups form isolated M2O9 face-sharing pairs, which are linked by the selenite anions into a three-dimensional anionic framework. The framework encapsulates one-dimensional 12-ring channels occupied by the barium cations and water molecules. There are two types of channels: in one, the cations and water molecules are well ordered, and the channels are fully occupied; in the other, the same species are disordered, and the channels are partially occupied. There is little if any evidence of zeolitic reversible de/rehydration and cation ion-exchange behaviour for these materials.
- open frameworks
- zeolite analogues
- ion exchange
Johnston, M. G., & Harrison, W. T. A. (2011). New BaM2(SeO3)3·nH2O (M = Co, Ni, Mn, Mg;n ≈3) Zemannite-type frameworks: single-crystal structures of BaCo2(SeO3)3·3H2O, BaMn2(SeO3)3·3H2O and BaMg2(SeO3)3·3H2O. European Journal of Inorganic Chemistry, 2011(19), 2967-2974. https://doi.org/10.1002/ejic.201100344