Bromine azide is an explosive

inorganic compound An inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as ''inorganic chemistry''. Inorgan ...

with the formula . It has been described as a crystal or a red liquid at room temperature. It is highly sensitive to small variations in temperature and pressure, with explosions occurring at Δp (pressure change) ≥ 0.05

Torr The torr (symbol: Torr) is a Pressure#Units, unit of pressure based on an absolute scale, defined as exactly of a standard atmosphere (unit), atmosphere (101325 Pa). Thus one torr is exactly (≈ ). Historically, one torr was intended to be ...

upon crystallization, thus extreme caution must be observed when working with this chemical.

Preparation

Bromine azide may be prepared by the reaction of

sodium azide Sodium azide is an inorganic compound with the formula . This colorless salt is the gas-forming component in some car airbag systems. It is used for the preparation of other azide compounds. It is highly soluble in water and is acutely poisonou ...

with . This reaction forms bromine azide and

sodium bromide Sodium bromide is an inorganic compound with the formula . It is a high-melting white, crystalline solid that resembles sodium chloride. It is a widely used source of the bromide ion and has many applications.Michael J. Dagani, Henry J. Barda, T ...

: :

Structure

The high sensitivity of bromine azide has led to difficulty in discerning its crystal structure. 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 , which forms an endless chain-like structure upon crystallization, forms a helical structure. Each molecule adopts a ''trans''-''bent'' structure, which is also found in the gas phase.

Reactions

Bromium azide adds to

alkene In organic chemistry, an alkene, or olefin, is a hydrocarbon containing a carbon–carbon double bond. The double bond may be internal or at the terminal position. Terminal alkenes are also known as Alpha-olefin, α-olefins. The Internationa ...

s both through

ion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convent ...

ic and

free-radical addition In organic chemistry, free-radical addition is an addition reaction which involves free radicals. These reactions can happen due to the free radicals having an unpaired electron in their valence shell, making them highly reactive. Radical addit ...

, 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 Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 Nanometre, nm), visible ligh ...

experiments with bromine azide have 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. Bromine azide further reacts with silver azide to produce a very unstable

allotrope Allotropy or allotropism () is the property of some chemical elements to exist in two or more different forms, in the same physical state, known as allotropes of the elements. Allotropes are different structural modifications of an element: the ...

nitrogen Nitrogen is a chemical element; it has Symbol (chemistry), symbol N and atomic number 7. Nitrogen is a Nonmetal (chemistry), nonmetal and the lightest member of pnictogen, group 15 of the periodic table, often called the Pnictogen, pnictogens. ...

, hexanitrogen (N₆), which decomposes to dinitrogen above .

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 Arsenic is a chemical element; it has Symbol (chemistry), symbol As and atomic number 33. It is a metalloid and one of the pnictogens, and therefore shares many properties with its group 15 neighbors phosphorus and antimony. Arsenic is not ...

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

, silver foil, or

phosphorus Phosphorus is a chemical element; it has Chemical symbol, symbol P and atomic number 15. All elemental forms of phosphorus are highly Reactivity (chemistry), reactive and are therefore never found in nature. They can nevertheless be prepared ar ...

. 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 The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

by the

US Department of Transportation The United States Department of Transportation (USDOT or DOT) is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the president of the United States a ...

References

{{Azides Bromine(I) compounds Azido compounds Explosive chemicals Pseudohalogens