AQUEOUS PEROXYNITRIC ACID (HOONO2) - A NOVEL SYNTHESIS AND SOME CHEMICAL AND SPECTROSCOPIC PROPERTIES

Peroxynitric acid, HOONO2, can be prepared in aqueous solution by the reaction of nitrous acid with a greater-than-2-fold excess of hydrogen peroxide at or below 0 degrees C. Under optimum conditions, concentra tions in excess of 1.5 M can be obtained. In acid solution at room tem perature, the compound has a ca. 30 min half-life for decomposition; i n alkaline solution, decomposition is very rapid, yielding nitrite ion and oxygen. The aqueous acid is a potent oxidizing agent, reacting ra pidly with I-, Br-, Cl-, N-3(-), and VO2+. Raman, UV, and N-15 NMR spe ctra of the aqueous acid have been obtained. The Raman spectra reveal three new fundamental vibrations of the peroxynitric acid molecule, le aving only two that have yet to be positively identified. The UV spect rum shows a monotonic rise in absorbance between 290 and 230 Mn; the N -15 NMR resonance has a chemical shift of -28.3 ppm relative to dilute nitric acid.