β-NbBr5, eine neue Modifikation von Niobpentabromid mit einer eindimensionalen Lagenfehlordnung/ β-NbBr5, a New Modification of Niobium Pentabromide Having One-Dimensional Stacking Disorder

Ulrich Müller, Paul Klingelhöfer
1983 Zeitschrift für Naturforschung. B, A journal of chemical sciences  
While trying to react NbBr5 with sulfur in a closed tube, crystals of the new modification β-NbBr5 were obtained. Its X-ray diffraction patterns have sharp reflexions and diffuse streaks showing the presence of a one-dimensional disorder. From the sharp reflexions alone, a statistically averaged sub-structure results; it has the space group Ccmm and the lattice constants a0 = 644, b0 = 1867 and c0 = 615 pm. Taking into account the diffuse streaks, the true structure was deduced; its lattice
more » ... ed; its lattice constants are a = 2a0, c = Co, b indefinite due to the disorder. β-NbBr5 is isostructural to tantalum pentaiodide. It consists of layers of (NbBr5)2 molecules that are stacked with displacement faults in the direction of b. The bromine atoms have a hexagonal close-packing arrangement.
doi:10.1515/znb-1983-0506 fatcat:ua6huhyvsbd7pjcmwsxexrgwdu