V2O2F4(H2O)2·H2O: a new V(4+) layer structure related to VOF3.

V(IV) oxyfluorides are of interest as frustrated magnets. The successful synthesis of two-dimensionally connected vanadium(IV) oxyfluoride structures generally requires the use of ionic liquids as solvents. During solvothermal synthesis experiments aimed at producing two- and three-dimensional vanadium(IV) selenites with triangular lattices, the title compound, diaquatetra-μ-fluorido-dioxidodivanadium(IV) monohydrate, V2O2F4(H2O)2·H2O, was discovered and features a new infinite V(4+)-containing two-dimensional layer comprised of fluorine-bridged corner- and edge-sharing VOF4(H2O) octahedral building units. The synthesis was carried out under solvothermal conditions. The V(4+) centre exhibits a typical off-centring, with a short V=O bond and an elongated trans-V-F bond. Hydrogen-bonded water molecules occur between the layers. The structure is related to previously reported vanadium oxyfluoride structures, in particular, the same layer topology is seen in VOF3.