Sr5(VIVOF5)3F(H2O)3 refined from a non-merohedrally twinned crystal

Abstract

The title compound, pentastrontium tris[pentafluoridooxidovanadate(IV)] fluoride trihydrate, was obtained under hydrothermal conditions. Its crystal structure has been refined from intensity data of a non-merohedrally twinned crystal. Two domains in almost equal proportions are related by a −180° rotation along the reciprocal [101]* vector. The structure may be considered as a derivative of the fluorite structure type, adopted here by SrF2. In the title compound, fluorite-like large rods are recognized, built up from a group of 16 Sr atoms of which 6 are substituted by V atoms, leading to [Sr10V6]∞ units. These rods extend infinitely along the b axis and are interconnected by the three water molecules. Each of the water molecules is shared by two different Sr atoms belonging to two different rods. The rods are also interconnected by an `independent' F atom in a distorted triangular [FSr3] coordination and by hydrogen-bonding interactions via donor water molecules. The acceptors are either F atoms or the O atoms of the vanadyl ion, VO2+, that is part of the [VOF5] isolated octahedron.