Arrange the following compounds in decreasing order of their reactivity towards nucleophilic aromatic substitution ( S_NAr ): (I) (II) (III)

Step-by-step solution

The reactivity of aryl halides towards nucleophilic aromatic substitution ( S_NAr ) depends on the stability of the carbanion intermediate formed during the reaction. Electron-withdrawing groups stabilize this intermediate and increase the rate of reaction. A nitro group at the ortho or para position with respect to the leaving group stabilizes the intermediate strongly through both resonance ( -M ) and inductive ( -I ) effects. A nitro group at the meta position stabilizes the intermediate only through the weaker