Which of the following substituents are classified as meta-directors and strongly deactivating group — Aromatic Hydrocarbons Chemistry Question

💡 Solution & Explanation

Meta-directing groups withdraw electron density from the aromatic ring, significantly destabilizing the arenium ion transition state (especially for ortho/para attack). $-SO_3H$, $-CF_3$, and $-CN$ are all powerful electron-withdrawing groups (via $-M$ or strong $-I$). $-NHCOCH_3$ is an ortho/para director and a moderate activator due to the nitrogen lone pair.