Nitrogen tribromide
Nitrogen tribromide molecule
IUPAC name
nitrogen tribromide
3D model (JSmol)
  • InChI=1S/3BrH.N/h3*1H;/p-3
  • N(Br)(Br)Br
Molar mass 253.7187 g/mol
Appearance Deep red solid
Melting point Explodes at -100 °C[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Nitrogen tribromide is a chemical compound with the formula NBr3. It is extremely explosive in its pure form, even at −100 °C, and was not isolated until 1975.[2] It is a deep-red and volatile solid.


NBr3 was first prepared by reaction of bistrimethylsilylbromamine (bis(trimethylsilyl)amine bromide) with bromine monochloride (with trimethylsilyl chloride as byproduct) at −87 °C according to the following equation:

(Me3Si)2NBr + 2 BrCl → NBr3 + 2 Me

where "Me" is a methyl group.

NBr3 can be produced by the reaction of bromine or hypobromite and ammonia in a dilute aqueous buffer solution.[3] It can also be prepared by the reaction of bromine and bromine azide.[4] Ammonia and bromine undergo glow discharge, and after treatment, red NBr3·6NH3 can be obtained.[5] Pure nitrogen NBr3 was only produced in 1975.[6]


Nitrogen tribromide reacts instantly with ammonia in dichloromethane solution at −87 °C to yield NBrH2.[7]

NBr3 + 2 NH3 → 3 NH2Br

It also reacts with iodine in dichloromethane solution at −87 °C to produce NBr2I, which is a red-brown solid that stable up to -20 °C.[7]

NBr3 + I2 → NBr2I + IBr


  1. ^ Lide, David R. (1998), Handbook of Chemistry and Physics (87 ed.), Boca Raton, Florida: CRC Press, pp. 4–73, ISBN 0-8493-0594-2
  2. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. p. 439. ISBN 978-0-08-037941-8.
  3. ^ Galal-Gorchev, Hend; Morris, J. Carrell (Jun 1965). "Formation and Stability of Bromamide, Bromimide, and Nitrogen Tribromide in Aqueous Solution". Inorganic Chemistry. 4 (6): 899–905. doi:10.1021/ic50028a029. ISSN 0020-1669.
  4. ^ Klapötke, Thomas M. (1997-01-01). "The reaction of bromine azide with bromine". Polyhedron. 16 (15): 2701–2704. doi:10.1016/S0277-5387(96)00586-4. ISSN 0277-5387.
  5. ^ Schmeisser, Martin (1941-05-07). "Über Bromstickstoff". Zeitschrift für anorganische und allgemeine Chemie. 246 (3): 284–302. doi:10.1002/zaac.19412460305. ISSN 0863-1786.
  6. ^ Jander, Jochen; Knackmuss, Jürgen; Thiedemann, Klaus-Ulrich (1975-06-01). "Notizen: Darstellung und Isolierung von Stickstofftribromid NBr3 und Stickstoffdibromidmonojodid NBr2J / Preparation and Isolation of Nitrogentribromide NBr3 and Nitrogendibromidemonoiodide NBr2I". Zeitschrift für Naturforschung B. 30 (5–6): 464–465. doi:10.1515/znb-1975-5-633. ISSN 1865-7117.
  7. ^ a b Matyáš, Robert; Pachman, Jiří. (2013). Primary explosives. Berlin: Springer. p. 294. ISBN 978-3-642-28436-6. OCLC 832350093.