ClCN

ClCN, or cyanogen chloride, is a binary compound composed of chlorine and cyanogen, with the chemical formula ClCN. The molecule is typically described as linear, with a chlorine atom bonded to the carbon of a cyanide group (Cl–C≡N). It is a colorless, volatile, and highly toxic substance that has a sharp, acrid odor.

ClCN is reactive and prone to hydrolysis in water. When exposed to moisture, it readily decomposes to hydrogen cyanide (HCN) and hydrogen chloride (HCl). It also acts as a cyanogenating agent in certain organic reactions, enabling the transfer of the CN fragment to substrates under controlled conditions. Because of its reactivity, ClCN is handled carefully in well-equipped laboratories and is typically used only by trained personnel for specialized chemical synthesis.

Historically, cyanogen chloride has been associated with chemical warfare, where it was used as a choking agent. In modern contexts, its production and use are limited and subject to stringent safety and regulatory controls. It is primarily of interest in research and certain industrial applications as a reagent for cyanide transfer and the preparation of other cyanogen-derived compounds.

Safety and handling are of critical importance due to its acute toxicity. Exposure can irritate the eyes, skin, and respiratory tract and can be life-threatening at sufficient doses. It is incompatible with water and many common solvents, and it can react exothermically under certain conditions. Appropriate engineering controls, personal protective equipment, and good laboratory practices are essential when working with ClCN. Regulatory oversight for ClCN varies by country but generally falls under laws governing toxic chemicals and, in many jurisdictions, strict controls related to chemical weapons conventions.