polyamine

A polyamine is an organic compound having two or more primary amino groups -NH₂.

This class of compounds includes several synthetic substances that are important feedstocks for the chemical industry, such as ethylene diamine H2N-CH₂-CH₂-NH₂, 1,3-diaminopropane H₂N-(CH₂)₃-NH₂, and hexamethylenediamine H₂N-(CH₂)₆-NH₂. It also includes many substances that play important roles in both eukaryotic and prokaryotic cells, such as putrescine H₂N-(CH₂)₄-NH₂, cadaverine H₂N-(CH₂)₅-NH₂, spermidine H₂N-((CH₂)₄-NH-)₂-H, and spermine H₂N-((CH₂)₄-NH-)₃-H.

As of 2004, there had been no reports of any geminal diamine, a compound with two or more unsubstituted -NH₂ groups on the same carbon atom. However, substituted derivatives are known, such as tetraethylmethylenediamine, (C₂H₅)₂N-CH₂-N(C₂H₅)₂.

Cyclen is the main representative of a class of cyclic polyamines. Polyethylene amine is a polymer based on aziridine monomer.