Although Cl is electron withdrawing group yet it is ortho para directing towards electrophilic reactions. Why
Dear student,
The resonance effect tends to oppose the inductive effect for the attack at ortho- and para- positions and hence makes the deactivation less for ortho- and para- attack.
The -I effect of chlorine is stronger than its +R effect, hence chlorine causes net deactivation.
Therefore, in electrophilic substitution reactions of chlorobenzene, the ortho/ para directing ability of chlorine is due to the positive resonance effect.
Regards
The resonance effect tends to oppose the inductive effect for the attack at ortho- and para- positions and hence makes the deactivation less for ortho- and para- attack.
The -I effect of chlorine is stronger than its +R effect, hence chlorine causes net deactivation.
Therefore, in electrophilic substitution reactions of chlorobenzene, the ortho/ para directing ability of chlorine is due to the positive resonance effect.
Regards