Diazonium Salts

Aromatic amines, treated with NaNO2 + HCl (nitrous acid generated in situ), give diazonium salts, Ar-N2+X-. These salts are stable only for a short time and so are used immediately after preparation, without being isolated. Representative examples are benzenediazonium chloride (C6H5-N2+Cl-), p-toluenediazonium bromide (a methyl-substituted ring with -N2+Br-), and p-nitrobenzenediazonium tetrafluoroborate (a nitro-substituted ring with -N2+BF4-) -- illustrating that both the ring substituent an …