Question

Why is chlorobenzene resistant to nucleophilic substitution reaction?

Answer 1

1. In chlorobenzene, the halogen is attached to a highly electronegative sp² hybridised carbon atom, and its lone pair electrons are involved in resonance with the benzene ring, forming resonance structures.
2. This gives the C–Cl bond partial double-bond character, making it stronger and less reactive.
3. In nucleophilic substitution, the carbon attached to the leaving group usually develops a partial positive charge to attract the nucleophile.
4. In chlorobenzene, this carbon is stabilized by resonance, and there’s no significant positive character, making it less attractive to nucleophiles.