Diazo Compounds

the general name for organic substances that contain a group of two atoms of nitrogen bound to one carbon atom; essentially, the term “diazo compounds” applies to various classes of compounds. The structure of acyclic diazo compounds may be represented by the following formulas:

Acyclic diazo compounds decompose on heating, on exposure to ultraviolet radiation, in the presence of catalysts such as copper and its salts (which results in the formation of carbenes), and in the presence of acids. Diazomethane and ethyl diazoacetate are typical representatives of this class of compounds. Acyclic cyclodiazo compounds (diazirines),

, are more stable and less reactive than true

acyclic diazo compounds: they form carbenes upon pyrolysis or photolysis but do not react with acids or unsaturated compounds.

Another class of diazo compounds is represented by diazonium salts, which form upon diazotization of aromatic amines. Aromatic diazo compounds are unstable, and dry compounds are explosive; they enter into many reactions. Diazotates are formed in the presence of alkalies. Aromatic diazo compounds are intermediate products of the production of azo dyes and other organic substances. Photosensitive aromatic diazo compounds are used extensively in the diazo process.