Structure and reactivity of 3-hydroxypyridine N-oxide

It has been established by UV spectroscopy that 3-hydroxypyridine N-oxide in aqueous and acid solutions exists in the form of the conjugate acid, and in an alkaline medium in the anionic form; no bipolar form has been detected in aqueous solution. Using Huckel's MO LCAO method the indices of the -electronic structure have been calculated for various forms of 3-hydroxypyridine N-oxide. The values of the localization energies L _r ⁺ obtained agree with the experimentally observed sequence of electrophilic substitution in 3-hydroxypyridine N-oxide in acid and alkaline media.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 92–95, January, 1974.