In given electrophilic substitution reaction, why halogen attach to only ortho and para position? Why not to other carbon?
Dear Student,
Halo benzene will react but at a slower rate than unsubstituted benzene. The bromine is also not resonance donating/activating, but can stabilize the intermediate product through resonance donation.
In the resonance structures of halo benzene,the ortho and para positions are negatively charged i.e the electron density is relatively more.The halogen(Br,Cl) is an ortho/para director, because when halo benzene attacks a carbocation, the meta positions are formally positive, and through resonance donation, halogen can complete an octet in one of the resonance depictions.
Understand this with the help of this given below :
Regards
Halo benzene will react but at a slower rate than unsubstituted benzene. The bromine is also not resonance donating/activating, but can stabilize the intermediate product through resonance donation.
In the resonance structures of halo benzene,the ortho and para positions are negatively charged i.e the electron density is relatively more.The halogen(Br,Cl) is an ortho/para director, because when halo benzene attacks a carbocation, the meta positions are formally positive, and through resonance donation, halogen can complete an octet in one of the resonance depictions.
Understand this with the help of this given below :
Regards