Darstellung, Schwingungsspektrum und Kristallstruktur des Decabromo-μ-nitrido-ditantalats(V) Ta2NBr10 3-. Ein Komplex mit symmetrischer Ta=N = Ta-Brücke / Preparation, Vibrational Spectra and Crystal Structure of the Deca Bromo μ-Nitrido Ditantalate(V) Ta2NBr10 3-.A Complex with a Symmetrical Ta=N=Ta Bridge

Abstract

The salt (NH4)3Ta2NBr10 can be prepared from NH4Br und TaBr5 at 400 °C in a sealed glas ampoule. The greenish yellow substance, which is sensitive to moist air, crystallizes in the tetragonal space group P4/mnc with Z = 2. The crystal structure is closely related to that of K4M2OCl10 · H2O (M = Ru, Re). It is built up by NH4 + cations and Ta2NBr10 3-- anions. The anions possess the point symmetry D4h and therefore show a symmetrical Ta = N = Ta bridge. The Ta-N distances of 185 pm can be interpreted by double bonds.