Final answer:
Benzene diazonium chloride reacts with compounds having nucleophilic centers such as phenol and aniline. These centers allow coupling reactions due to their electron-donating properties through resonance, making the benzene ring more electron-rich and nucleophilic. Compounds like benzene and chlorobenzene without activating groups are less likely to undergo such reactions.
Step-by-step explanation:
The coupling reactions of benzene diazonium chloride require compounds that have nucleophilic centers, such as phenol and aniline. These nucleophilic centers are typically electron-rich atoms or groups that are capable of donating electrons to form a bond with the electron-deficient diazonium ion. While benzene itself and chlorobenzene lack such activating groups, aniline has an amino group that makes it very reactive in coupling reactions. Furthermore, substituents like -OH in phenol make the benzene ring more nucleophilic by donating electrons through resonance.
For example, aniline, with its amino group (-NH2), provides a highly reactive site for the coupling due to the lone pair of electrons on the nitrogen atom. The -OH group in phenol has a similar effect, making it highly reactive towards the diazonium salt through resonance stabilization. However, compounds like benzene and chlorobenzene without such activating groups are less likely to undergo coupling reactions with diazonium salts under normal conditions.
Therefore, for successful coupling with benzene diazonium chloride, compounds generally need to have activating groups like -OH or -NH2 that can engage in resonance to make the phenyl ring more electron-rich and thus more nucleophilic.