Question

Why do aryl halides not show nucleophilic substitution reaction?

• A. The C--X bond has partial double bond character due to resonance.
• B. There is very high steric hindrance in the benzene ring.
• C. The size of the halogen atom is very small.
• D. Aryl carbocation is highly stable.

Hint:

Remember why aryl halides are less reactive: \[ \boxed{\text{Resonance} \Rightarrow \text{Partial double bond character}} \] Therefore, \[ \boxed{\text{Stronger C--X bond}} \] which resists nucleophilic substitution. This is one of the most frequently asked concepts in Haloarenes.

Answer 1

The Correct Option is A

In aryl halides, the lone pairs on the halogen are delocalized into the benzene ring through resonance, giving the $C-X$ bond partial double bond character. This makes the ipso carbon less electrophilic and the $C-X$ bond shorter and stronger than in alkyl halides, effectively preventing nucleophilic substitution under ordinary conditions.