Cyanogen chloride is a toxic chemical compound with the formula NCCl. This linear, triatomic pseudohalogen is an easily condensed colorless gas. More commonly encountered in the laboratory is the related compound cyanogen bromide, a room-temperature solid that is widely used in biochemical analysis and preparation.
|Preferred IUPAC name
|Systematic IUPAC name
3D model (JSmol)
|Molar mass||61.470 g mol−1|
|Density||2.7683 mg mL−1 (at 0 °C, 101.325 kPa)|
|Melting point||−6.55 °C (20.21 °F; 266.60 K)|
|Boiling point||13 °C (55 °F; 286 K)|
|Solubility||soluble in ethanol, ether|
|Vapor pressure||1.987 MPa (at 21.1 °C)|
|236.33 J K−1 mol−1|
Std enthalpy of
|137.95 kJ mol−1|
|Main hazards||Highly toxic; forms cyanide in the body|
|Safety data sheet||inchem.org|
|Flash point||nonflammable |
|US health exposure limits (NIOSH):|
|C 0.3 ppm (0.6 mg/m3)|
IDLH (Immediate danger)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
|what is ?)(|
Synthesis, basic properties, structureEdit
Cyanogen chloride is a molecule with the connectivity ClCN. Carbon and chlorine are linked by a single bond, and carbon and nitrogen by a triple bond. It is a linear molecule, as are the related cyanogen halides (NCF, NCBr, NCI). Cyanogen chloride is produced by the oxidation of sodium cyanide with chlorine. This reaction proceeds via the intermediate cyanogen ((CN)2).
- NaCN + Cl2 → ClCN + NaCl
Cyanogen chloride is slowly hydrolyzed by water to release cyanate and chloride ions
- ClCN + H2O → NCO− + Cl− + 2H+
- at neutral pH
Applications in synthesisEdit
Also known as CK, cyanogen chloride is a highly toxic blood agent, and was once proposed for use in chemical warfare. It causes immediate injury upon contact with the eyes or respiratory organs. Symptoms of exposure may include drowsiness, rhinorrhea (runny nose), sore throat, coughing, confusion, nausea, vomiting, edema, loss of consciousness, convulsions, paralysis, and death. It is especially dangerous because it is capable of penetrating the filters in gas masks, according to United States analysts. CK is unstable due to polymerization, sometimes with explosive violence.
By 1945, the U.S. Army's Chemical Warfare Service developed chemical warfare rockets intended for the new M9 and M9A1 Bazookas. An M26 Gas Rocket was adapted to fire cyanogen chloride-filled warheads for these rocket launchers. As it was capable of penetrating the protective filter barriers in some gas masks, it was seen as an effective agent against Japanese forces (particularly those hiding in caves or bunkers) because their standard issues gas masks lacked the barriers that would provide protection against cyanogen chloride. The US added the weapon to its arsenal but the CK rocket was never deployed or issued to combat personnel.
- Lide, David R., ed. (2006). CRC Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0487-3.
- "CYANOGEN CHLORIDE (CK)". The Emergency Response Safety and Health Database. NIOSH.
- "NIOSH Pocket Guide to Chemical Hazards #0162". National Institute for Occupational Safety and Health (NIOSH).
- Coleman, G. H.; Leeper, R. W.; Schulze, C. C. (1946). "Cyanogen Chloride". Inorganic Syntheses. 2: 90–94. doi:10.1002/9780470132333.ch25.
- Vrijland, M. S. A. (1977). "Sulfonyl Cyanides: Methanesulfonyl Cyanide" (PDF). Organic Syntheses. 57: 88.; Collective Volume, 6, p. 727
- Graf, R. (1966). "Chlorosulfonyl Isocyanate" (PDF). Organic Syntheses. 46: 23.; Collective Volume, 5, p. 226
- FM 3-8 Chemical Reference Handbook. US Army. 1967.
- "Schedule 3". www.opcw.org. Retrieved 16 March 2018.
- Smart, Jeffrey (1997), "2", History of Chemical and Biological Warfare: An American Perspective, Aberdeen, MD, USA: Army Chemical and Biological Defense Command, p. 32.
- "Characteristics and Employment of Ground Chemical Munitions", Field Manual 3-5, Washington, DC: War Department, 1946, pp. 108–19.
- Skates, John R (2000), The Invasion of Japan: Alternative to the Bomb, University of South Carolina Press, pp. 93–96, ISBN 978-1-57003-354-4
- Murphy-Lavoie, H. (2011). "Cyanogen Chloride Poisoning". eMedicine. MedScape.
- "National Pollutant Inventory – Cyanide compounds fact sheet". Australian Government.
- "NIOSH Pocket Guide to Chemical Hazards". Centers for Disease Control and Prevention.