Amine

Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are formally derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group.

Amines have the general formula NH_3−xR_x, where R = alkyl or aryl and x is the number of substituted groups.

Types

• Primary amines: One of the three hydrogen atoms in ammonia is replaced by an alkyl or aromatic. Examples: methylamine, isopropylamine, aniline, most aminoacids, etc.
• Secondary amines: Two hydrogen atoms in the ammonia are replaced by an alkyl or aromatic. Examples: N-Allylthiourea, etc.
• Tertiary amines: In tertiary amines, the nitrogen atom has three organic substituents. Examples: triethylamine, hexamine, EDTA, etc.
• Cyclic amines: Cyclic amines are secondary or tertiary amines, where the organic group forms a cycle to the nitrogen atom. Examples: pyridine, etc.
• Inorganic: Amines where the nitrogen atom is bounded to an inorganic group or another nitrogen atom, which may or may not be another amine. Examples: hydrazine and derivatives, hydroxylamine, chloramines, etc.

Properties

Amines are gaseous or liquid compounds, while high molecular weight amines are solids, as are aminoacids. Amines have an unpleasant smell, of fish or rotten fish/flesh.

Amines react with acids to form alkyl- or aryl-ammonium salts.

References

Relevant Sciencemadness threads

• Types of amine
• Primary Amine Methylation