Regarding the intricate directing effects and reaction conditions in the direct electrophilic haloge — Haloalkanes and Haloarenes Chemistry Question
Question
Regarding the intricate directing effects and reaction conditions in the direct electrophilic halogenation of substituted arenes, which of the following statements are chemically accurate?
💡 Solution & Explanation
A) True. In non-polar solvents, phenol reacts slowly to give monobromination. In water, phenol ionizes to the highly activated phenoxide ion, causing rapid polybromination. B) True. The strong electronegativity of halogens withdraws electron density overall (deactivating), but their lone pairs can donate via resonance to stabilize adjacent positive charges, specifically directing ortho/para. C) True. $-NO_2$ is a powerful electron-withdrawing group that severely deactivates the ring toward electrophiles, directing the substitution to the meta position where the destabilizing positive charge is minimized. D) False. Alkyl groups are electron-donating via hyperconjugation and +I effects, making them activating and ortho/para-directing.