Question

what is di azonium reaction

Answer 1

 R−N+
2X−
 where R can be any organic group, such as an alkyl or an aryl, and X is an inorganic or organic anion, such as a halogen. Diazonium salts, especially those where R is an aryl group, are important intermediates in the organic synthesis of azo dyes.[1]

Answer 2

Diazonium salts are important intermediates for the preparation of halides (Sandmeyer Reaction, Schiemann Reaction), and azo compounds. Diazonium salts can react as pseudohalide-type electrophiles, and can therefore be used in specific protocols for the Heck Reaction or Suzuki Coupling.