Redetermination of the crystal structure of NbF(4)

Single crystals of NbF(4), niobium(IV) tetra­fluoride, were synthesized by disproportionation of Nb(2)F(5) at 1273 K in a sealed niobium tube, extracted and studied by single-crystal X-ray diffraction. Previous reports on the crystal structure of NbF(4) were based on X-ray powder diffraction data and the observed isotypicity to SnF(4) [Gortsema & Didchenko (1965 ▸). Inorg. Chem. 4, 182–186; Schäfer et 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 NbF(4). In the structure, the Nb atom is octahedron-like surrounded by six F atoms of which four are bridging to other NbF(6) octa­hedra, leading to a layer structure extending parallel to the ab plane.