The increasing order of the reactivity of the following compounds towards electrophilic aromatic…

The increasing order of the reactivity of the following compounds towards electrophilic aromatic substitution reactions is:

1. $\mathrm{I}\mathrm{I}<\mathrm{I}<\mathrm{I}\mathrm{I}\mathrm{I}$
2. $\mathrm{I}\mathrm{I}\mathrm{I}<\mathrm{I}\mathrm{I}<\mathrm{I}$
3. $\mathrm{I}\mathrm{I}\mathrm{I}<\mathrm{I}<\mathrm{I}\mathrm{I}$
4. $\mathrm{I}<\mathrm{I}\mathrm{I}\mathrm{I}<\mathrm{I}\mathrm{I}$

Solution

Rate of ${\mathrm{E}}^{+}$ substitution reaction $\propto -\mathrm{v}\mathrm{e}$ charge density on benzene ring
Electron releasing group; increasing the rate of $\mathrm{E}\mathrm{S}\mathrm{R}$ ; halogen has $-\mathrm{I}>+\mathrm{M}$ so deactivating group & but show $+\mathrm{M}$ but show $-\mathrm{M}>-\mathrm{I}$ so less deactivating group only

Reactivity order is:

Asked in: JEE Main 2019 (10 Apr Shift 1)

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