Write the importance of diazonium salts in the synthesis of aromatic compounds.

(N/A) Diazonium salts serve as versatile intermediates for introducing various functional groups such as $-F, -Cl, -Br, -I, -CN, -OH,$ and $-NO_2$ into an aromatic ring.
$1.$ Aryl fluorides and iodides cannot be prepared via direct halogenation of benzene.
$2.$ The cyano group $(-CN)$ cannot be introduced through direct nucleophilic substitution of chlorine in chlorobenzene,whereas cyanobenzene is easily synthesized from diazonium salts.
$3.$ Diazonium salts allow for the synthesis of substituted aromatic compounds that are otherwise difficult or impossible to prepare through direct electrophilic substitution reactions on benzene or substituted benzene rings.