Oxidation by nitrogen dioxide

Owing to oxidation by nitrogen dioxide, 1,2-propanediol is transformed into hydroxyacetone and pyruvic acid. The authors report that no lactic acid is produced, which is evidence that in the first place the secondary alcohol groups are oxidized. 

Taylor, E.W., Fowler, W.F. Jr., McGee, P.A. and Kenyon, W.O. (1947) Investigation of the properties of cellulose oxidized by nitrogen dioxide. II. The evolution of carhon dioxide from uronic acids and polyuronides./. Am. Chem. Soc., 69, 342-47. 

The first time a catalyst was used in the chemical industry was in 1746 by J Roebuck, in the lead chamber process. The lead chamber process was the first approach to the industrial production of sulfuric acid. In it, sulfur dioxide is oxidized by nitrogen dioxide in the presence of water. This reaction was carried out in wooden chambers lined with lead. 

Isoxazole-3-carbaldehyde has been obtained as a minor product from the reaction of acetylene with a mixture of nitric oxide and nitrogen dioxide (61JOC2976). Although 3-aryl-4-formylisoxazoles have been synthesized in good yields from the reaction of benzonitrile Af-oxides with 3-(dimethylamino)-2-propen-l-one (71S433), the parent member of the series, isoxazole-4-carbaldehyde, has never been reported. It may possibly be obtained by the addition of fulminic acid to 3-(dimethylamino)-2-propen-l-one. 

A number of NMP processes have been reported where the nitroxide is formed in situ. Nitrones 1 and nitroso-compounds128 have been used as nitroxide precursors. Control of methacrylate polymerization by mixtures of nitric oxide and nitrogen dioxide has also been attributed to in situ formation of a nitroxide. 130... 

First prepd by Hofmann and Zedtwitz (Ref 1) by passing a mixt of nitric oxide and nitrogen dioxide into 72% perchloric acid. The acid was then evapd at 140°, and on cooling the hydrate, N0C104.H2O, crystd out. The product was dehydrated in vacuo over phosphorous pentoxide When heated below 100° it decomps (Ref 2) according to the equation ... 

Ponzio Reaction. The formation of phenyl-dinit romethane from benzaldoxime by oxidation with nitrogen dioxide in eth (Refs 1 2) CH=NOH CH(N02)2... 

In the manufacture of nitric acid by the oxidation of ammonia, the first product is nitric oxide, which is then oxidized to nitrogen dioxide. From the standard reaction enthalpies... 

Cueto, R. and Pryor, W.A. 1994. Cigarette smoke chemistry conversion of nitric oxide to nitrogen dioxide and reactions of nitrogen oxides with other smoke components as studied by fourier transform infrared... 

The reaction in water at pH 7.4 has been much studied since the discovery of the importance of nitric oxide. The products are as for the thermal and photochemical reactions, except that the final product is nitrite ion. This is to be expected since nitric oxide in aerated water at pH 7.4 also yields quantitatively nitrite ion25, by it is believed the series of equations 7-9, which involves oxidation to nitrogen dioxide, further reaction to give dinitrogen trioxide which, in mildly alkaline solution, is hydrolysed to nitrite ion. Under anaerobic conditions it is possible to detect nitric oxide directly from the decomposition of nitrosothiols using a NO-probe electrode system26. Solutions of nitrosothiols both in... 

Irradiation of mixtures of an olefin with nitric oxide and nitrogen dioxide in air shows that the nitrogen dioxide rises in concentration before it is eventually consumed by reaction. Since it is the photodissociation of the nitrogen dioxide that initiates the reaction, it would appear that a negative quantum yield results. More likely, the nitrogen dioxide is being formed by secondary reactions more rapidly than it is being photodissociated. 

Reactions 2-6 through 2-8 form a catalytic cycle, in that the hydroxyl radical that is used in Reaction 2-6 is r enerated in Reaction 2-8. The net results of this cycle are the oxidations of nitric oxide to nitrogen dioxide and carbon monoxide to carbon dioxide by the oxygen present in the air. 

The methyl radical rapidly (in 10 s) combines with oxygen to form the methylperoxy radical, CH3O3. A recent study has confirmed that nitric oxide is oxidized by methylperoxy, although the rate constant is still unknown. The meffioxy radical, CH3O, should then react predominantly with oxygen to form formaldehyde, CHjO, and hydroperoxy radical. The net result of this sequence is the oxidation of one molecule of nitric oxide to nitrogen dioxide and the conversion of an alkyl radical into a hydro-... 

Although the above reactions generate a few fi radicals, most of the oxidation of nitric oxide to nitrogen dioxide is carried out by the alkyl-peroxy, RO, and hydroperoxy radicals that are formed in later reactions involving reactive hydrocarbons, aldehydes, or even carbon monoxide. One such example is shown in Figure 2-7. There is still considerable uncertainty as to the mechanism of these secondary reactions. The modeling studies should be consulted for details. ... 

We have listed in Table 3-6 the relative rates of conversion of nitric oxide to nitrogen dioxide measored by Glasson and Tuesday and the amounts of aerosol formed, relative to cyclohexene, from data of Renzetti and Doyle, Prager et Groblicki and Nebel, Wilson et... 

Much evidence has been accumulated that the ozone-olefin reaction has a predominant role in aerosol formation from alkenes, cyclic olefins, diolefins, and other unsaturated compounds. Free radicals are formed in the reaction and can react further, along with nitric oxide and nitrogen dioxide, either with the various intermediates or with the olefin itself (see the recent review by Pitts and Finlayson ). 

The gas-phase reactivity of various terpenes has been measured. Stephens and Scott were the first to include two terpenes (pinene and a-phel-landrene) with their study of the relative reactivity of various hydrocar ns. Both monoterpenes showed the high reactivity predicted by their olefinic structure. Conversion of nitric oxide to nitrogen dioxide in e presence of isoprene is at a rate intermediate between those for ethylene and trans-2-butene, and Japar et al, reported rate constants for the a-pinene and terpinolene-ozone reactions. Grimsrud et a/. measured the rate con-... 

London. On the second day, the late afternoon peak exceeded 0.1 ppm. It is apparent that some conversion of nitric oxide to nitrogen dioxide was responsible for the ozone buildups, but it is not as clear a chemical pattern for London as it is for cities in the western United States. The paper did not mention the method of ozone measurement however, qualitative descriptions of the weather patterns suggest that the days of high ozone were characterized by light winds and considerable sunlight. 

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