2691. Cyanogen

Nomenclature

CAS number: 460-19-5
Ethanedinitrile; dicyan; oxalic acid dinitrile.
C2N2; mol wt 52.03.
C 46.17%, N 53.84%.
N≡C‐C≡N.

Description and references

Prepn by adding an aq soln of sodium or potassium cyanide to an aq soln of copper(II) sulfate or chloride: Janz, Inorg. Synth. 5, 43 (1957); from HCN by the use of CuO: Fierce, Millikan, US 2841472 (1958 to Pure Oil); from HCN and NO2: Fierce, Sander, Ind. Eng. Chem. 53, 985 (1961). Review: Brotherton, Lynn, Chem. Rev. 59, 841-883 (1959). Review of toxicology and human exposure: Toxicological Profile for Cyanide (PB98-101207, 1997) 291 pp.

Properties

Gas with almond-like odor, acrid and pungent when in lethal concns. Burns with pink flame having a bluish border. mp -27.9° (also reported as -34.4°). bp -21.17°. d4-21.17 0.9537. Poisonous, flammable. Heat of vaporization (liquid) 5.778 kcal/mole. Above 500° polymerizes to insol paracyanogen (CN)n. One vol of water dissolves about 4 vols of cyanogen gas. Also sol in alcohol, ether. Slowly hydrolyzed in aq soln giving oxalic acid and ammonia.

Caution

Potential symptoms of overexposure are irritation of eyes, nose, upper respiratory system; lacrimation; cherry red lips; tachypnea, hyperpnea, bradycardia; headache, vertigo, convulsions; dizziness, loss of appetite, weight loss. Direct contact with liquid may cause frostbite. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 82.