Pernitric acid

Den Hertog and Overhoff - observed that when pyridine in sulfuric acid is added to molten potassium sodium nitrate the 3-nitro derivative is formed at 300°C, whereas at 450°C 2-nitropyridme is the main product. The latter is probably a free-radical process. Schorigin and Toptschiew obtained 7-nitroquinoline by the action of nitrogen peroxide on quinoline at 100°C, possibly through the homolytic addition of NOa. Laville and Waters reported that during the decomposition of pernitrous acid in aqueous acetic acid, quinoline is nitrated in the 6- and 7-positions. They considered that the reaction proceeds as shown in Scheme 3. 

Halfpenny, E. and Robinson, P.L. (1952). Pernitrous acid. The reaction between hydrogen peroxide and nitrous acid and the properties of an intermediate product. J. Chem. Soc. 928-938. 

Pernitric acid, in smog, 39 Peroxides, in aerosols, 69 Peroxyacetylnitrate (PAN) as a fumigant, 454 concentration of, 183-84 damage to biologic systems from, 34 effect of, on plants, 10, 268 climate conditions influencing, 477, 480... 

Pernitrous acid (aq. NaN02-H202-H2S04) with quinoline at 0 °C gives low yields of 5-,... 

The 0-0 bond in peroxides and hydroperoxides is often rather weak. Pernitrous acid already decomposes readily at room temperature (see below), and the decomposition of peroxodisulfate at 70 °C is used in technical processes, but H202... 

Nitration with pernitrous acid. The first investigations into the nitration of benzene with per-nitrous acid were performed by Trifonov [166], In 1922 he found o- nitrophenol to be the reaction product and suggested the application of the reaction for detecting benzene and other aromatic hydrocarbons. His results were confirmed by the experiments of Halfpenny and P. L. Robinson [170],... 

Oxygen exchange between hydrogen peroxide and nitrate ion probably involves nitrogen pentoxide, with formation of pernitric acid HOO.NO2. 

When hydrogen peroxide reacts with nitrite, pernitrous acid forms as an intermediate of appreciable stability. The rates of its formation have been examined for solutions buffered to pH 4-6 (phosphates) and without buffers. 

A recent study of the rates of formation of pernitrous acid reveals the rate law... 

Alcock et a/. have shown that there is ambiguity in studying the rates ot formation and decay of such an intermediate by spectrophotometry if the rate coefficients and also the extinction coefficients have to be deduced from the measurements. This ambiguity may be removed in the present case. The rates of decay of pernitrous acid are given by... 

Table 9-9 includes similar data for the association products of N02 with peroxy radicals. Peroxyacetyl nitrate (PAN) is thermally the most stable of these adducts. It is important in all regions of the troposphere. Pernitric acid and methylperoxy nitrate are less stable but may become significant in the upper troposphere where temperatures are low. Model calculations by Logan et al. (1981) suggest that as much as 50% of N02 may be present as H00N02 at higher altitudes. Observational data are lacking, however, so that the real contribution of these addition products to the total reservoir of N02 in the troposphere remains to be established. 

Post-irradiation reduction of cerium (IV) in concentrated sodium nitrate solutions was previously reported by Pikaev, Glazunov, and Yakubovich (20) in pulsed electron irradiations of 0.8IV sulfuric acid containing 0.5M sodium nitrate and 2 X 10"4M cerium (IV). They attributed the post-irradiation reaction to intermediate formation of pernitric acid, originally suggested by Allen (1) as an intermediate in the radiolysis of nitric acid solutions. Furthermore, they ruled out nitrous acid since it has been shown previously that the non-radiolytic reaction between cerium (IV) and nitrous acid goes to completion very quickly under the same conditions. However, they presented no evidence to refute the... 

We assume that OH and N02 radicals do not react with each other to reform water and nitrate ion since that would result in no inhibition of water reformation by nitrate ion. Let us consider the formation of pernitrous acid... 

Mahoney, L. R. (1970). Evidence for the formation of hydroxyl radicals in the isomerization of pernitrous acid to nitric oxide in aqueous solution. J. Am. Chem. Soc. 92,5262-5263. 

Study of the interaction of toluene, nitrobenzene, dimethylaniline, phenol, anisole, and chlorobenzene with pernitrous acid (HOONO) at 8-98 C enabled formulation of the reaction mechanism [22]. HOONO is an important intermediate in the interconversion of nitrogen-containing species [23]. It forms upon reaction between hydrogen peroxide and nitrous acid. HOONO undergoes homolytic detachment ... 

Sulphurous acid Trademark of zeolite 1 -hydroxybenzotriazole Hydrogen chloride Hyperfine coupling Hyperfine interaction Hexafluoropropylene Hyperfine splitting Hexamethylbenzene Nitrous acid Nitric acid Pernitrous acid Sulphurous acid anion Trademark of zeolite Ionisation energie(s)... 

Graham, R. A., Winer, A. M., Pitts, J. N., Jr., "Temperature Dependence of the Uni-molecular Decomposition of Pernitric Acid and Its Atmospheric Implications," Chem. Phys. Lett. (1978) in press. 

The decay of pernitric acid, HO2NO2, follows first-order kinetics and yields mainly nitrite ion at pH values above 5. The rate-determining step at high pH seems to be reaction (16), while below pH 3-4 it is reaction (17). 

Mackay, D., W.Y. Shin, and K.C. Ma (1995), Illustrated Handbook of Physical-Chemical Properties and Environmental Fate of Organic Chemicals, Lewis Publishers, Boca Raton. Mac Leod, H., G.P. Smith, and D.M. Golden (1988), Photodissociation of pernitric acid (HO2NO2) at 248 nm, J. Geophys. Res., 93, 3813-3823. 

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