New oxyfluorotellurates(IV):: MTeO3F (M = FeIII, GaIII and CrIII)

The crystal structures of the new isomorphous compounds iron(III) oxyfluorotellurate(IV), FeTeO3F, gallium(III) oxyfluorotellurate(IV), GaTeO3F, and chromium(III) oxyfluorotellurate(IV), CrTeO3F, consist of zigzag chains of MO4F2 distorted octahedra alternately sharing O-O and F-F edges and connected via TeO3 trigonal pyramids. A full O/F anionic ordering is observed and the electronic lone pair of the Te-IV cation is stereochemically active.