Popis: |
Peroxynitrite ions were shown to be formed in aqueous alkaline solutions bythe action of O2 on hydroxylamine, chloramine and sodium nitrohydroxamate. An enhanced formation of peroxynitrite was observed when introducing hypochlorite to chloramine and hydroxylamine solutions, in the presence of oxygen; also upon mixing chloramine and hydroxylamine in the presence of oxygen. The formation of peroxynitrite was demonstrated by its ultraviolet absorption spectrum. A molar extinction coefficient at λmax = 302 mμ of 1300 M−1 cm−1 is estimated. The pK of peroxynitrous acid was found to be lower than six. A method for preparation of relatively stable peroxynitrite solutions is described. Nitroxyl (NO−) is suggested as the product of the first step in all six reactions, peroxynitrite being ultimately formed by the reaction NO− + O2 → ONO2−. |