| Peroxynitrite, ONOO--, is a powerful nucleophile and oxidant, and is implicated in numerous pathological conditions. Peroxynitrite is formed from the bimolecular reaction of nitric oxide and superoxide. This reaction occurs extremely fast, k = 6 x 109 M --1s--1, near the diffusion-controlled limit. The physiological roles of peroxynitrite have been studied extensively, yet few chemists have reported details on the basic chemistry and reactivity of peroxynitrite. Characterization of peroxynitrite and mechanistic investigations of its decomposition have been controversial due to the lack of pure peroxynitrite and by inadequate detection methods of the decomposition products.;A brief overview of the chemistry and biochemistry of nitric oxide, superoxide, and peroxynitrite is given in Chapter 1. In Chapter 2, the improved synthesis of pure Tet-amethylammonium peroxynitrite, the first solid salt of its kind, is described. In addition, the solid state vibrational characterization of the cis and trans-tetramethylammonium peroxynitrite via Raman and IR spectroscopies is reported.;The decomposition of peroxynitrite is shown to be enhanced by thiocyanate in Chapter 3. This is demonstrated through a series of kinetic experiments. Furthermore, the stoichiometry of the reaction between peroxynitrite and thiocyanate has been determined using Raman spectroscopy.;Chapter 4 describes the determination of the mechanism of boric acid-catalyzed decomposition of peroxynitrite. This was accomplished by determining the rate law and constant for this decomposition. Isotopic exchange studies with 18O labeled borate were then performed and monitored via Raman spectroscopy to determine the decomposition mechanism.;The final chapter discusses the decomposition of peroxynitrite in aqueous solution and catalyzed by carbon dioxide. Isotopic exchange studies with 18O carbonate were used to determine the decomposition mechanism in the presence of carbonate. In addition, the determination of nitrite and nitrate formation from the decomposition of tetramethylammonium peroxynitrite from Raman spectroscopy supported the mechanism of peroxynitrite decomposition deduced from other sources. |
