Cyanogen

Cyanogen is the chemical compound with the formula (CN)₂. Its structure is N≡C−C≡N. The simplest stable carbon nitride, it is a colorless and highly toxic gas with a pungent odor. The molecule is a pseudohalogen. Cyanogen molecules are linear, and consist of two CN groups ‒ analogous to diatomic halogen molecules, such as Cl₂, but far less oxidizing. The two cyano groups are bonded together at their carbon atoms, though other isomers have been detected. The name is also used for the CN radical, and hence is used for compounds such as cyanogen bromide (Br−C≡N) (but see also Cyano radical). When burned at increased pressure with oxygen, it is possible to get a blue tinted flame, the temperature of which is about 4800°C (a higher temperature is possible with ozone). It is as such regarded as the gas with the second highest temperature of burning (after dicyanoacetylene).

Cyanogen is the anhydride of oxamide:

H₂N−C(=O)−C(=O)−NH₂ → N≡C−C≡N + 2 H₂O

though oxamide is manufactured from cyanogen by hydrolysis:

N≡C−C≡N + 2 H₂O → H₂N−C(=O)−C(=O)−NH₂