Chlorine azide

Chlorine azide
Names
IUPAC name
Chlorine azide
Identifiers
3D model (JSmol)
ChemSpider
  • InChI=1S/ClN3/c1-3-4-2
    Key: ZGNIYAPHJAPRMA-UHFFFAOYSA-N
  • [N-]=[N+]=NCl
Properties
ClN3
Molar mass 77.4731 g/mol
Appearance Yellow-orange liquid; colorless gas
Melting point −100 °C (−148 °F; 173 K)
Boiling point −15 °C (5 °F; 258 K)
Solubility Soluble[vague] in butane, pentane, benzene, methanol, ethanol, diethyl ether, acetone, chloroform, carbon tetrachloride, and carbon disulfide; slightly soluble in water
Structure
orthorhombic
Cmc 21, No. 36
Explosive data
Shock sensitivity Extreme
Friction sensitivity Extreme
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
 Extremely sensitive explosive
NFPA 704 (fire diamond)
NFPA 704 four-colored diamondHealth (blue): no hazard codeFlammability 0: Will not burn. E.g. waterInstability 4: Readily capable of detonation or explosive decomposition at normal temperatures and pressures. E.g. nitroglycerinSpecial hazards (white): no code
0
4
Related compounds
Related compounds
 Hydrazoic acid
Fluorine azide
Bromine azide
Iodine azide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkYX markN ?)

Chlorine azide (ClN3) is an inorganic compound that was discovered in 1908 by Friedrich Raschig. Concentrated ClN3 is notoriously unstable and may spontaneously detonate at any temperature.

Preparation and reactions

Chlorine azide is prepared by passing chlorine gas over silver azide, or by an addition of acetic acid to a solution of sodium hypochlorite and sodium azide.

Chlorine azide further reacts with silver azide to produce a very unstable allotrope of nitrogen, hexanitrogen (N6), which decomposes to dinitrogen above 80 K (−193.2 °C; −315.7 °F).

Explosive characteristics

Chlorine azide is extremely sensitive. It may explode, sometimes even without apparent provocation; it is thus too sensitive to be used commercially unless first diluted in solution. Chlorine azide reacts explosively with 1,3-butadiene, ethane, ethene, methane, propane, phosphorus, silver azide, and sodium. On contact with acid, chlorine azide decomposes, evolving toxic and corrosive hydrogen chloride gas.

Regulatory information

Its shipment is subject to strict reporting requirements and regulations by the US Department of Transportation.

References

  1. ↑ Lyhs, Benjamin; Bläser, Dieter; Wölper, Christoph; Schulz, Stephan; Jansen, Georg (2012). "A Comparison of the Solid-State Structures of Halogen Azides XN3 (X=Cl, Br, I)". Angewandte Chemie International Edition. 51 (51): 12859–12863. doi:10.1002/anie.201206028. PMID 23143850.
  2. ↑ Frierson, W. J.; Browne, A. W. (1943). "Chlorine Azide. II. Interaction of Chlorine Azide and Silver Azide. Azino Silver Chloride, N3AgCl". Journal of the American Chemical Society. 65 (9): 1698–1700. Bibcode:1943JAChS..65.1698F. doi:10.1021/ja01249a013.
  3. ↑ Frierson, W. J.; Kronrad, J.; Browne, A. W. (1943). "Chlorine Azide, ClN3. I.". Journal of the American Chemical Society. 65 (9): 1696–1698. Bibcode:1943JAChS..65.1696F. doi:10.1021/ja01249a012.
  4. ↑ Raschig, F. (1908). "Über Chlorazid N3Cl". Berichte der Deutschen Chemischen Gesellschaft. 41 (3): 4194–4195. doi:10.1002/cber.190804103130.
  5. ↑ Qian, Weiyu; Mardyukov, Artur; Schreiner, Peter R. (2025). "Preparation of a neutral nitrogen allotrope hexanitrogen C2h-N6". Nature. 642 (8067): 356–360. doi:10.1038/s41586-025-09032-9. ISSN 0028-0836. PMC 12158757. PMID 40500322.
  6. ↑ CID 61708 from PubChem