An imine is a compound containing a carbon–nitrogen double bond, written R₂C=NR′. It is the nitrogen analogue of a carbonyl group (C=O), and is typically formed when an aldehyde or ketone reacts with a primary amine, with loss of water. Imines are named with the suffix '-imine'; the C=N double bond contrasts with the C=O of the carbonyl it resembles.

亚胺是含有碳氮双键的化合物,写作 R₂C=NR′。它是羰基(C=O)的氮类似物,通常由醛或酮与伯胺反应、脱去一分子水生成。亚胺以词尾“-imine(亚胺)”命名;其 C=N 双键与它所类似的羰基中的 C=O 形成对照。