A colorless, inflammable, poisonous gas, C2N2, with a peach-blossom odor, so called from its tendency to form blue compounds; obtained by heating ammonium oxalate, mercuric cyanide, etc. It is obtained in combination, forming an alkaline cyanide when nitrogen or a nitrogenous compound is strongly ignited with carbon and soda or potash. It conducts itself like a member of the halogen group of elements, and shows a tendency to form complex compounds. The name is also applied to the univalent radical, CN (the half molecule of cyanogen proper), which was one of the first compound radicals recognized.

a colorless toxic gas with a pungent almond odor; has been used in chemical warfare

a substance that induces cyanide production

a gas formed in some plasma aluminum etchers that combines with the water in the atmosphere to form poisonous hydrogen cyanide (HCN). Its bitter almond odor can be detected at levels below dangerous concentrations. [SEMATECH] Also see dry plasma etch.

Cyanogen is a chemical compound (CN)2. The CN entity behaves like a halogen. Cyanogen molecules consist of two CN groups (analogous to diatomic halogen molecules, such as F2, Cl2, Br2, or I2).