Effects of Added Anions on the Reaction of Nitrous Acid with Hydrogen Peroxide

摘要

The reactions of nitrous acid with hydrogen peroxide in acidic aqueous solution in the presence of several added anions have been studied at 0∩ and pH 2-4 to investigate the nucleophilic catalysis of these anions. From the dependence of reaction rates on the anion concentrations, significant catalytic effects were found for Cl-, Br-, SCN-, in order of effect SCN- ≈ Br- > Cl-, while no observable effect was found for ClO4- and NO3-. These results support O-nitrosation reaction is the rate-determining step and NOX formed in the presence of an anion (X-) also acts as a nitrosating agent and accelerates the overall reaction rate. The order of reactivity was found to be NOCl > NOBr > NOSCN, which is consistent with the results of N-nitrosation and S-nitrosation reactions.