Which group on a benzene ring is deactivating yet directs incoming electrophiles to ortho and para positions? (Hard)
Answer and explanation
Correct answer: D. Chloro group (-Cl)
- Step 1: Halogens (-Cl, -Br) possess strong electronegativity, withdrawing electron density inductively (-I effect), making the ring deactivated toward electrophiles. Step 2. However, their lone pairs can donate into the ring by resonance (+R effect), stabilizing ortho and para arenium ions, resulting in ortho/para direction. Answer: Chloro group (-Cl). Why not the others: Nitro is deactivating and meta-directing; Methyl is activating and ortho/para-directing; Methoxy is strongly activating and ortho/para-directing.
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