Imide

Imide in organic chemistry
In organic chemistry, imide is a functional group consisting of two carbonyl groups bound to a primary amine or ammonia. Imides are generally prepared directly from ammonia or the primary amine, and either carboxylic acid(s) or acid anhydrides. The structure of the imide moiety is as shown to the left.



In chemical industry, many imides are monomers used to make polyimides. The imides most commonly used for this are based on aromatic dicarboxylic acids of moderately high molecular weight. Such imides contain a heterocyclic ring, shown to the right.



Another important imide is phthalimide, the heterocyclic imide of phthalic acid. It is an intermediate in the preparation of phthalocyanine dyes. Some phthalimides have luminescent qualities.

The imide functionality is present in the RNA nucleotide uracil and the DNA nucleotide thymine, and participates in Watson-Crick hydrogen bonding, where the carbonyl oxygens act as hydrogen-bond acceptors and the imide nitrogen acts as a hydrogen-bond donor.

Imides can be prepared in the isoimide to imide Mumm rearrangement.

Imide in inorganic chemistry
Imide may also refer to the diatomic ion NH2-, which is a powerful base and will turn into ammonia in the presence of water.