Niobium(V) bromide is the inorganic compound with the formula Nb<sub>2</sub>Br<sub>10</sub>. Its name comes from the compound's empirical formula, NbBr<sub>5</sub>. It is a diamagnetic, orange solid that hydrolyses readily. The compound adopts an edge-shared bioctahedral structure, which means that two NbBr<sub>5</sub> units are joined by a pair of bromide bridges. There is no bond between the Nb centres. Niobium(V) chloride, niobium(V) iodide, tantalum(V) chloride, tantalum(V) bromide, and tantalum(V) iodide all share this structural motif.
Niobium(V) bromide can be prepared by the reaction of bromine with niobium metal at 230âÂÂ250 ðC in a tube furnace. It can also be produced from the more accessible oxide by metathesis using aluminium tribromide:
A challenge with the latter method is the occurrence of NbOBr<sub>3</sub> as an impurity.