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. This particular 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.