title: Cu3V10O28.24H2O and CuNa4V10O28.23H2O.
abstract: The crystal structures of tricopper decavanadate tetracosahydrate, (I), and copper tetrasodium decavanadate tricosahydrate, (II), have been determined by single-crystal X-ray diffraction. Both compounds exhibit a catenary structure consisting of [V10O28](6-) anions linked by Cu2+ cations in (I) or by Na+ cations in (II). Compound (II) also contains a polymeric linear array of edge-sharing [Na(OH2)6](+) and [Cu(OH2)6](2+) octahedra. In both compounds, the [V10O28](6-) ions lie about inversion centres and the Cu2+ ions in (I) also lie about inversion centers.
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, 2-12-1 O-okayama, Meguro-ku, Tokyo 152-8551, Japan.
authors.forename: Akifumi
authors.initials: A
authors.lastname: Iida
authors.forename: Tomoji
authors.initials: T
authors.lastname: Ozeki