Protonation of nitric acid and formation of NO2+. An Ab initio study

Abstract

The molecular structures and relative stabilities of nitric acid and its protonated species have been determined by SCF calculations. Protonation takes place preferentially at the hydroxylic oxygen atom, giving a complex of NO₂⁺ and H₂O. The dissociation energy [22 kcal mol^–1(92 KJ mol^–1) at 6-31 G**//44-31 G level] confirms that the production of NO₂⁺ could constitute the rate-determining step in aromatic nitration reactions.