Iron(III) azide


Iron azide, also called ferric azide, is a chemical compound with the formula. It is an explosive, very unstable, hygroscopic dark brown solid. This compound is a reagent in organic chemistry. It forms red solutions in water.

Preparation

This compound is prepared by the reaction of sodium azide and iron sulfate in methanol:
Iron azide can also be formed by pulse gamma-irradiation of a mixture of iron perchlorate, sodium azide, and hydrogen peroxide. Under these conditions, a neutral N3 radical is formed, which oxidizes the iron to iron; the iron then promptly combines with azide ions.

Application in organic chemistry

In organic chemistry, ferric azide is a reagent in the one-pot conversion of alkenes to alkyl azide, such as n-butyl azide. The process begins with a hydroboration: an anti-Markovnikov addition of a borane to an alkene. Reaction of the alkylborane with iron azide in the presence of hydrogen peroxide then gives the alkyl azide.