Redetermination of Fe2[BP3O12]

Abstract

Explorations of phases in the quaternary FeIII-B III-PV-O system prepared by the high temperature solution growth (HTSG) method led to single-crystal growth of anhydrous diiron(III) borotriphosphate, Fe2[BP3O12]. This phase has been synthesized previously as a microcrystalline material and its structure refined in space group P3 from powder X-ray diffraction data using the Rietveld method [Chen et al. (2004). J. Inorg. Mater. 19, 429-432]. In the current single-crystal study, it was shown that the correct space group is P6 3/m. The three-dimensional structure of the title compound is built up from FeO6 octa-hedra (3.. symmetry), trigonal-planar BO 3 groups (6 symmetry) and PO4 tetra-hedra (m.. symmetry). Two FeO6 octa-hedra form Fe2O9 dimers via face-sharing, while the anionic BO3 and PO4 groups are connected via corner-sharing to build up the [BP3O12] 6- anion. Both units are inter-connected via corner-sharing.