Redetermination of the crystal structure of NbF4

Abstract

Single crystals of NbF4, niobium(IV) tetrafluoride, were synthesized by disproportionation of Nb2F5at 1273 K in a sealed niobium tube, extracted and studied by single-crystal X-ray diffraction. Previous reports on the crystal structure of NbF4were based on X-ray powder diffraction data and the observed isotypicity to SnF4[Gortsema & Didchenko (1965).Inorg. Chem.4, 182–186; Schäferet al.(1965).J. Less Common Met.9, 95–104]. The data obtained from a single-crystal X-ray diffraction study meant the atomic coordinates could now be refined as well as their anisotropic displacement parameters, leading to a significant improvement of the structural model of NbF4. In the structure, the Nb atom is octahedron-like surrounded by six F atoms of which four are bridging to other NbF6octahedra, leading to a layer structure extending parallel to theabplane.