Haloarenes are less reactive than haloalkanes. The low reactivity of haloarenes can be attributed to
- resonance effect
- `sp^2` hybridisation of C — X bond
- polarity of C — X bond
- instability of phenyl cation (formed by self-ionisation of haloarene)
- repulsion between the electron rich attacking nucleophiles and electron rich arenes.
Reactivity of haloarenes can be increased or decreased by the presence of certain groups at certain positions for example, nitro (-NO2) group at o/p positions increases the reactivity of haloarenes towards nucleophilc substitution reactions.
The reactivity of the compounds by `SN^2` reaction
(i) `MeBr`
`(ii) C_2H_5Br`
`(iii) CH_3CH(Br)CH_3`
`(iv) CH_3C(CH_3)_2Br`

Options

A. `(i)gt(ii)gt(iii)gt(iv)`
B. `(i)gt(ii)lt(iii)gt(iv)`
C. `(i)gt(ii)gt(iii)lt(iv)`
D. `(i)lt(ii)lt(iii)lt(iv)`

Answer

A