Bromine azide

Bromine azide

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Names
IUPAC name Bromine azide
Other names Bromine nitride, Nitrogen bromide, Azidobromide
Identifiers
CAS Number	13973-87-0
ChemSpider	24562
Jmol 3D model	Interactive image Interactive image
PubChem	26364
InChI InChI=1S/BrN3/c1-3-4-2 Key: KFCUPNHUPHDVJC-UHFFFAOYSA-N InChI=1/BrN3/c1-3-4-2 Key: KFCUPNHUPHDVJC-UHFFFAOYAE
SMILES [N-]=[N+]=N\Br [N-]=[N+]=NBr
Properties
Chemical formula	BrN3
Molar mass	121.924 g/mol
Appearance	Red liquid
Density	N/A
Melting point	-45 degrees C (-49 F°)
Boiling point	Explodes
Vapor pressure	{{{value}}}
Related compounds
Related compounds	Fluorine azide Chlorine azide Hydrazoic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Bromine azide is an explosive inorganic compound with the formula BrN₃. It has been described as a crystal or a red liquid at room temperature. It is extremely sensitive to small variations in temperature and pressure, thus extreme caution must be observed when working with this reagent. This property of bromine azide has led to difficulty in discerning its crystal structure, with explosions occurring at Δp ≥ 0.05 Torr and also upon crystallization. Despite this, a crystal structure of bromine azide has been obtained using a miniature zone-melting procedure with focused infrared laser radiation. In contrast to IN₃, which forms an endless chain-like structure upon crystallization, BrN₃ forms a helical structure.

Preparation

Bromine azide may be prepared by the reaction of sodium azide with Br₂. This reaction forms bromine azide and sodium bromide:

NaN₃ + Br₂ → BrN₃ + NaBr

Reactions

Bromium azide adds to alkenes both through ionic and free-radical addition, each giving an opposite orientation in the products. The ionic addition occurs stereospecifically in trans. Reactions involving bromine azide are difficult to work with. The molecule is very reactive and is known to explode easily. This makes it a key reagent in explosives. Photochemistry experiments with bromine azide has found that UV photolysis of a small sample of bromine azide resulted in dissociation of the entire sample, making it unstable. Similar samples with azide molecules did not show such an effect. This shows bromine azide's unstable tendencies in that even in the presence of sunlight, bromine azide will be a reactive molecule.

Safety

Great care must be taken when handling bromine azide as it is potentially toxic and is able to explode under various conditions. Concentrated solutions in organic solvents may also explode. The liquid explodes on contact with arsenic, sodium, silver foil, or phosphorus. When heated to decomposition it emits highly toxic fumes of bromine and explodes. The amount of compound used during experimentation should be limited to 2 mmol. It also poses a potential moderate fire hazard in the form of vapor by chemical reaction. It is also a powerful oxidant.

It has been banned from transport in the United States by the US Department of Transportation.