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Nitrogen trichloride

Safety data
Other names Trichloramine
Nitrogen(III) chloride
CAS number 10025-85-1
RTECS number QW974000
Molecular formula NCl3
Molar mass 120.36 g/mol
Appearance yellow oily liquid
Density 1.635 g/mL, liquid
Melting point

-40 °C (233 K)

Boiling point

71 °C (344 K)

Solubility in water Immiscible
slowly decomposes
Viscosity  ? mPa·s at ? °C
Molecular shape trigonal pyramidal
Dipole moment 0.6 D
Std enthalpy of
+232 kJ/mol
Standard molar
 ? J.K−1.mol−1
EU classification not listed
NFPA 704
Related Compounds
Other anions Nitrogen trifluoride
Nitrogen tribromide
Nitrogen triiodide
Other cations Phosphorus trichloride
Arsenic trichloride
Related chloramines Chloramine
Related compounds Nitrosyl chloride
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)

Infobox disclaimer and references

Nitrogen trichloride, also known as trichloramine, is the chemical compound with the formula NCl3. This yellow, oily, pungent-smelling liquid, is most commonly encountered as a byproduct of chemical reactions between ammonia-derivatives and chlorine (for example, in swimming pools between disinfecting chlorine and urea in urine from bathers). In pure form, NCl3 is highly reactive. Nitrogen trichloride can form in small amounts when public water supplies are disinfected with monochloramine. Nitrogen trichloride was trademarked as Agene and used to artificially bleach and age flour. It has been used as a teargas.

Additional recommended knowledge


Preparation and structure

The compound is prepared by treatment of ammonium salts, such as ammonium nitrate with chlorine:

4 NH3 + 3 Cl2 → NCl3 + 3 NH4Cl

Intermediates in this coversion include chloramine and dichloramine, NH2Cl and NHCl2, respectively.

Like ammonia, NCl3 is a pyramidal molecule. The N-Cl distances are 1.76 Â, and the Cl-N-Cl angles are 107°.[1] The electronegativities are very similar for nitrogen (3.04) and chlorine (3.16).


Nitrogen trichloride is a dangerous explosive, being sensitive to light, heat, and organic compounds. Pierre Louis Dulong first prepared it in 1812, and lost two fingers and an eye in two separate explosions. An explosion from NCl3 blinded Sir Humphry Davy temporarily, inducing him to hire Michael Faraday as a coworker. Belgian researchers reported a possible link between NCl3 and rising numbers of childhood asthma cases.[2]


  1. ^ Holleman, A. F.; Wiberg, E. "Inorganic Chemistry" Academic Press: San Diego, 2001. ISBN 0-12-352651-5.
  2. ^ Bernard A, Carbonnelle S, de Burbure C, Michel O, Nickmilder M (2006). "Chlorinated pool attendance, atopy, and the risk of asthma during childhood". Environmental Health Perspectives 114 (10).

Further reading

  • Jander, J. (1976). Adv. Inorg. Chem. Radiochem. 19: 2.
  • P. Kovacic, M. K. Lowery, K. W. Field (1970). "Chemistry of N-bromamines and N-chloramines". Chemical Reviews 70 (6). doi:10.1021/cr60268a002.
  • Hartl, H.;, Schoner, J.; Jander, J.; Schulz, H. (1975). "Structure of Solide Nitrogen-Trichloride (-125°C)". Zeitschrift für Anorganische und Allgemeine Chemie 413 (1).
  • Cazzoli, G.; Favero, P. G.; Dalborgo, A. (1974). "Molecula-Structure, Nuclear-Quadruple Coupling-Constant and Dipole-Moment of Nitrogen Trichloride from Microwave Spectroscopy". Journal of Molecular Spectroscopy 50 (1-3).
  • Bayersdo, L.; Engelhar, U., Fischer, J.; Hohne, K.; Jander, J. (1969). "Nitrogen-chlorine compounds: Infrared spectra and Raman spectra of nitrogen trichloride". Zeitschrift für anorganische und allgemeine Chemie 366 (3-4).
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Nitrogen_trichloride". A list of authors is available in Wikipedia.
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