Amine

In chemistry, amines (, UK also ) are organic compounds that contain carbon–nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of electrons. Amines can also exist as heterocyclic compounds. Aniline ( C 6 H 7 N {\displaystyle {\ce {C6H7N}}} ) is the simplest aromatic amine, consisting of a benzene ring bonded to an amino ( − NH 2 {\displaystyle {\ce {-NH2}}} ) group. Amines are classified into three types: primary (1°), secondary (2°), and tertiary (3°) amines. Primary amines (1°) contain one alkyl or aryl substituent and have the general formula RNH 2 {\displaystyle {\ce {RNH2}}} . Secondary amines (2°) have two alkyl or aryl groups attached to the nitrogen atom, with the general formula R 2 NH {\displaystyle {\ce {R2NH}}} . Tertiary amines (3°) contain three substituent groups bonded to the nitrogen atom, and are represented by the formula R 3 N {\displaystyle {\ce {R3N}}} . The functional group −NH2 present in primary amines is called the amino group.