Sponsor Area

Haloalkanes And Haloarenes

Question
CBSEENCH12010155

Chlorobenzene is extremely less reactive towards a nucleophilic substitution reaction. Give two reasons for the same?

Solution

1) Resonance effect: The electron pair on chlorine atom is in conjugation with the  electrons of the benzene ring which results in the following resonance structures:

 
This results in delocalization of the electrons of C- Cl bond and a partial double bond character develop in the bond, which makes it difficult for the nucleophile to cleave the C- Cl bond.

 2) The nucleophile suffers repulsion from the increased electron density on the benzene ring, as a result, the nucleophile is unable to make a close approach for the attack on the molecule.