CNCl

CNCl, commonly known as cyanogen chloride, is a chemical compound with the formula ClCN. It is a volatile, colorless substance that is highly toxic and reactive. In addition to its historical notoriety as a chemical weapon, CNCl is used as a cyanating agent in organic synthesis to introduce the cyano group into substrates.

Hazards and reactivity: CNCl is a potent irritant to the eyes, skin, and respiratory tract. It reacts readily with water, undergoing hydrolysis to form hydrogen cyanide and hypochlorous acid (CNCl + H2O → HCN + HOCl). Because of its toxicity and reactivity, handling requires appropriate containment, ventilation, and protective equipment. Acute exposure can be rapidly dangerous or fatal; chronic exposure is also hazardous.

Production and handling: Industrially, cyanogen chloride is produced by chlorinating cyanogen or by reactions involving cyanogen with chlorine under controlled conditions. It is typically stored and transported under strict regulatory controls in corrosion-resistant vessels, often as a compressed gas or low-boiling liquid. Materials compatibility, moisture exclusion, and ignition source control are important considerations, given its reactivity and hazard profile.

Applications and regulation: In organic chemistry, CNCl serves as a cyanating agent to transfer the cyano group to substrates. It has limited contemporary industrial use due to its toxicity and the availability of safer alternatives, but remains of historical significance as a chemical reagent and, regrettably, as a chemical weapon precursor. Regulatory controls apply to its manufacture, storage, and transport under national and international safety and nonproliferation frameworks.

See also: cyanogen, hydrogen cyanide, phosgene.