Black, with varying air sensitivity, depending on preparative conditions. Almost completely resistant to H2O and dilute acids. Decomposed by concentrated H2SO4 and HNO3. Insoluble in organic solvents. It can be sublimed in a high vacuum (10-4 mm) at about 400°C. Thermal decomposition into NbBr5 and Nb begins at 900°C. The TaBr3 and the TaBr2 can be obtained in the same manner as NbBr3, starting from TaBr5 and H2 at 700°C; however, the purity and the yield are lower.
