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.