Nitrous acid weak monobasic acid known only in solution and in the form of nitrite salts. Formula: HNO₂ Systematic name: dioxonitric(III) acid

Nitrous acid is used to make diazides from amines; this occurs by nucleophilic attack of the amine onto the nitrite, reprotonation by the surrounding solvent, and double elimination of water. The diazide can then be liberated as a carbene.

See also: nitric acid (HNO₃)

Chemical structure

O=N-O-H