3H-diazirine

thumb|100px|A generic diazirine

In organic chemistry, a diazirine is an organic molecule consisting of a carbon bound to two nitrogen atoms, which are double-bonded to each other, forming a cyclopropene-like ring, 3H-diazirine (). Diazirines are isomeric with diazocarbon groups (), and like them can serve as precursors for carbenes by loss of a molecule of dinitrogen. For example, irradiation of diazirines with ultraviolet light leads to carbene insertion into various , , and bonds. Hence, diazirines have grown in popularity as small, photo-reactive, crosslinking reagents. They are often used in photoaffinity labeling studies to observe a variety of interactions, including ligand-receptor, ligand-enzyme, protein-protein, and protein-nucleic acid interactions.