Question

chlorobenzene is extremely less reactive towards a nucleophillic substitution reaction?

Answer 1

because due to lone pair on chlorine , the bond with which it is directly attached to benzene ring has double bond character and harder to break ...

Answer 2

Hey !!

The two reasons are as follows:-

• The electron pair of chlorine atom is involved in conjugation with the π-electrons of the benzene ring. As a result, electrons of C ---- Cl bond get delocalized and a partial double bond character develops in the bond and hence, it becomes difficult for the nucleophile to cleave the C ----- Cl bond.
• INCREASED ELECTRON DENSITY :- A repulsion is suffered by the nucleophile, due to increased electron density on the benzene ring which prohibits the nucleophile to make a close access for the attack on the molecule.

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