Nitrogen tribromide is a chemical compound with the formula NBr
3. It is extremely explosive in its pure form, even at −100 °C, and was not isolated until 1975.
It is a deep-red and volatile solid.
Preparation
NBr
3 was first prepared by reaction of bistrimethylsilylbromamine (
bis(trimethylsilyl)amine bromide) with
bromine monochloride
Bromine monochloride, also called bromine(I) chloride, bromochloride, and bromine chloride, is an interhalogen inorganic compound with chemical formula BrCl. It is a very reactive golden yellow gas with boiling point 5 °C and melting point � ...
(with
trimethylsilyl chloride
Trimethylsilyl chloride, also known as chlorotrimethylsilane is an organosilicon compound (silyl halide), with the formula (CH3)3SiCl, often abbreviated Me3SiCl or TMSCl. It is a colourless volatile liquid that is stable in the absence of water. I ...
as byproduct) at −87 °C according to the following equation:
:(Me
3Si)
2NBr + 2 BrCl → NBr
3 + 2
where "Me" is a
methyl group
In organic chemistry, a methyl group is an alkyl derived from methane, containing one carbon atom bonded to three hydrogen atoms, having chemical formula . In formulas, the group is often abbreviated as Me. This hydrocarbon group occurs in ma ...
.
Reactions
Nitrogen tribromide reacts instantly with
ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous ...
in
dichloromethane
Dichloromethane (DCM or methylene chloride, methylene bichloride) is an organochlorine compound with the formula . This colorless, volatile liquid with a chloroform-like, sweet odour is widely used as a solvent. Although it is not miscible wit ...
solution at −87 °C to yield
NBrH2.
:NBr
3 + 2 NH
3 → 3 NH
2Br
It also reacts with
iodine
Iodine is a chemical element with the Symbol (chemistry), symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , ...
in
dichloromethane
Dichloromethane (DCM or methylene chloride, methylene bichloride) is an organochlorine compound with the formula . This colorless, volatile liquid with a chloroform-like, sweet odour is widely used as a solvent. Although it is not miscible wit ...
solution at −87 °C to produce NBr
2I, which is a red-brown solid that stable up to -20 °C.
:NBr
3 + I
2 → NBr
2I + IBr
References
{{Nitrides
Inorganic amines
Bromides
Nitrogen halides
Substances discovered in the 1970s
Bromine(I) compounds