The oxidation of mono- and diiodo- and -bromo-substituted polymethylbenzenes (mesitylene and durene) in the system PbO₂–CF₃COOH–CH₂Cl₂ at room temperature (2–70 h) leads mainly to the formation of iodo- and bromobenzyl alcohols as result of oxidation of methyl group. The reaction involves intermediate formation of haloarene radical cations. ESR study of these radical cations made it possible to determine the structure of their singly occupied molecular orbitals a₂ or b₁ and interpret their reactivity.