What is a diazonium salt? Explain with suitable examples.

(N/A) The diazonium salts have the general formula $RN_{2}^{+} X^{-}$,where $R$ stands for an aryl group and $X^{-}$ ion may be $Cl^{-}, Br^{-}, HSO_{4}^{-}, BF_{4}^{-}$,etc.
They are named by suffixing 'diazonium' to the name of the parent hydrocarbon from which they are formed,followed by the name of the anion such as chloride,hydrogensulphate,etc. For example,$C_{6}H_{5}N_{2}^{+}Cl^{-}$ is called benzenediazonium chloride.
The $-N_{2}^{+} (-N^{+} \equiv N)$ group is called the diazonium group.
Primary aliphatic amines form highly unstable alkyldiazonium salts. Primary aromatic amines form arenediazonium salts,which are stable for a short time in solution at low temperatures $(273-278 \ K)$. The stability of the arenediazonium ion is explained on the basis of resonance,as shown in the structure below:
(Resonance structures of benzenediazonium ion involve the delocalization of the positive charge over the benzene ring).