Question

In electrophilic aromatic substitution reactions of chlorobenzene, the ortho/para- directing ability of chlorine is due to its

• A. positive inductive effect (+I)
• B. negative inductive effect (-I)
• C. positive resonance effect (+R)
• D. negative resonance effect (-R )

Answer 1

Answer: (C)

In electrophilic aromatic substitution reaction of chlorobenzene, the ortho/para directing ability of chlorine is due to its $+R$-effect. The resonating structures of chlorobenzene are as follows :

Due to this effect, the electron density increases more at ortho and para-positions than at meta- position.