Mg2Na2V10O28•20H2O and Mg3V10O28•28H2O

The crystal structures of dimagnesium disodium decavanadate icosahydrate, Mg2Na2V10O28.20H(2)O, (I), and trimagnesium decavanadate octacosahydrate, Mg3V10O28.28H(2)O, (II), have been determined by single-crystal X-ray diffraction. They crystallize with monoclinic (C2/c) and triclinic (P(1) over bar) symmetry, respectively. All the Mg2+ cations in (I) and (II) are octahedrally coordinated by six water molecules. The Na+ cations in (I) are coordinated by three water molecules and three O atoms of the decavanadate anions, and link the latter into a three-dimensional network. The decavanadate anions in (II) are not linked to one another.