Pulse Radiolysis of Nitric Oxide in Aqueous Solution

Abstract

Transient spectra observed on the pulse radiolysis of aqueous solutions of nitric oxide at pH 7.0 have been assigned to the species NO − , N 2 O 2 − , and N 3 O 3 − . In acid solution these species are protonated to form the corresponding acids, HNO, HN 2 O 2 , and HN 3 O 3 . Both the basic and acid forms undergo similar reactions, but at different rates, to form the products of radiolysis N 2 O and NO 2 − .[Formula: see text]The basic species decays more slowly than the corresponding acid species but both processes have appreciable activation energies of 15 and 10 kcals/mol, respectively. Computer calculations have been used in conjunction with the experimental data over a wide range of pH and NO concentration to deduce a reaction mechanism consistent with the observed results. Reaction rate constants, acid dissociation constants and extinction coefficients for the various species are presented and compared with earlier work.