Diazirines are a class of organic molecules consisting of a carbon bound to two nitrogen atoms, which are double-bonded to each other, forming a cyclopropene

Cyclopropene

Cyclopropene is an organic compound with the formula 34. It is the simplest isolable cycloalkene. It has a triangular structure. Because the ring is highly strained, cyclopropene is both difficult to prepare and interesting to study. Like cyclopropane, the carbon ring of cyclopropene is planar...

-like ring. They are mainly used as carbene precursor and also in photoaffinity labelling studies of nucleic acids and proteins.

Reactions

Diazirines are unstable in the presence of light, decaying upon photolysis to form the corresponding carbene

Carbene

In chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The general formula is RR'C:, but the carbon can instead be double-bonded to one group. The term "carbene" may also merely refer to the compound H2C:, also called...

 and nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

 gas. This reaction can also be performed thermally.

Synthesis

Diazirines can be synthesized by the Graham reaction, from the corresponding amidine

Amidine

Amidines are a class of oxoacid derivatives.The oxoacid from which an amidine is derived must be of the form RnEOH, where R is a substituent...

 or by oxidation of a diaziridine

Diaziridine

Diaziridines are heterocyclic compounds containing two nitrogen atoms in a three-membered ring. They can be considered as strained hydrazines. Due to the ring strain, the nitrogen atoms are configuration stable leading to cis-trans isomers....

.