Tungsten(V) bromide is the inorganic compound with the empirical formula WBr<sub>5</sub>. The compound consists of bioctahedral structure, with two bridging bromide ligands, so its molecular formula is W<sub>2</sub>Br<sub>10</sub>.
Tungsten(V) bromide is prepared by treating tungsten powder with bromine in the temperature range 650-1000 ðC. The product is often contaminated with tungsten hexabromide.
According to X-ray diffraction, the structure for tungsten pentabromide consists of an edge-shared bioctahedron.
Tungsten(V) bromide is the precursor to other tungsten compounds by reduction reactions. For example, tungsten(IV) bromide can be prepared by reduction with aluminium or tungsten. The WBr<sub>4</sub> can be purified by chemical vapor transport.
Excess tungsten pentabromide and aluminum tribromide are then removed by sublimation at 240 ðC.
Tungsten(II) bromide can then be obtained heating the tetrabromide. At 450-500 ðC, gaseous pentabromide is evolved leaving yellow-green residue of WBr<sub>2</sub>. An analogous method can also be applied to the synthesis of tungsten(II) chloride.
Because it is relatively easy to reduce tungsten pentahalides, they can be used as alternative synthetic routes to tungsten (IV) halide adducts. For example, reaction of WBr<sub>5</sub> with pyridine gives WBr<sub>4</sub>(py)<sub>2</sub>.