how does Cl donate electrons if it slightly deactivates the benzene ring by withdrawing electrons through its strong electronegativity?

@jOeCHEM

2 жыл бұрын

Hi Womannequin Reviews! So in my mind, the two most likely scenarios you encounter with directing groups are: EDG: the directing group, via resonance, pumps electrons INTO the benzene ring--activating the benzene ring for faster EAS reactions. When drawing the resonance out, the ortho/para gain negative charges, causing EAS reactions to add groups ortho/para. EWG: the directing group, via resonance, sucks electrons OUT of the benzene ring--deactivating the benzene ring for slower EAS reactions. When drawing the resonance out, the ortho/para gain postivie charges, causing EAS reactions to add groups meta to avoid the partially positive ortho/para locations. The halogens are weird, because they have a foot in each of the two buckets above: Halogens (EDG that directs groups ortho/para, but slightly deactivates the ring): Because the halogens are so electronegative and hate sharing their electrons, they inductively "withdraw" a bit of electron density from a benzene ring, making EAS reactions slower. HOWEVER, they still enable resonance structures to be drawn, and those resonance structures show the ortho/para gain negative charges, causing EAS reactions to add groups ortho/para. I know it's a weird thing to rectify in your mind, but does that make sense?