A reaction of aryl diazonium salts that does not involved loss of nitrogen takes place when they react with phenol and aromatic amines. Aryl diazonium ion relatively is weak electrophile but has sufficient reactivity to attack strongly activated aromatic ring. The reaction is known as azo coupling. The coupling of diazonium ions with phenols or other electron rich aromatic compounds is useful commercial reaction as azo compounds are highly coloured and many of them are used as dyes.
Which of the folllowing is responsible for the colour of diazo compounds ?

Options

A. Benzene ring
B. `-N = N-`group
C. `-OH` group
D. `-NH_(2)` group

Answer

B

Explanation

`-N=N-` group