Oxynitric acid

A great number of reaction pathways are known that oxidize these ions to sulfate, SC, but only three of them appear to be most important in clouds, namely, the reactions with ozone, with hydrogen peroxide, and with per-oxynitric acid. 

What Dalton calls oxynitric acid, here formulated as NOj, is formed by mixing nitrous... 

What Dalton calls oxynitric acid, here formulated as NO3, is formed by mixing nitrous gas with excess of oxygen Diary, 2 November 1806, where it is formulated N2O6 Roscoeand Harden, 75. 

Benzene and some of its derivatives react with solutions of mercuric nitrate in concentrated nitric acid to give nitrophenols. These reactions, known as oxynitrations may proceed by mercuration followed by nitroso-demercuration the resulting nitroso compound becomes a diazonium compound and then a phenol, which is nitrated. ... 

Dissolve 100 g of (+)-tartaric acid in 400 ml of water and add 8.5 g of bismuth oxynitrate. Shake for 1 hour, add 200 ml of a 40% w/v solution of KI and shake well Allow to stand for 24 hours and filter. Store and protect from light. 

Nitric acid in the presence of catalytic amounts of mercury (II) nitrate reacts with some substrates, under certain conditions, to give substimted polynitrophenols. The first example, reported by Boeters and Wolffenstein and known as oxynitration , involved treating benzene with 50-55 % nitric acid in the presence of mercury (II) nitrate. The product is a mixture of unreacted benzene, nitrobenzene, m-dinitrobenzene, 2,4-dinitrophenol and picric acid, from which the latter can be isolated by steam distillation of this crude mixture followed by recrystallization of the residue from hot water. 

The mechanism of oxynitration is generally accepted to involve the formation of phenyl mercuric nitrate which reacts with nitrogen oxides in the nitric acid to form a nitroso compound and then a diazonium salt the latter forms a phenol under the aqueous conditions which is then further nitrated. The use of more concentrated nitric acid favours a process of mercuration-nitration and suppresses the formation of phenols. ... 

Other examples of oxynitration include the formation of (1) 2,4,6-trinitro-m-cresol from toluene, (2) 2,4-dinitronaphth-l-ol from naphthalene, (3) 3-chloro-2,4,6-trinitrophenol from chlorobenzene and (4) 3-hydroxy-2,4,6-trinitrobenzoic acid from benzoic acid. ... 

Bismuth oxynitrate is prepared by hydrolysis of bismuth nitrate using either water or sodium bicarbonate solution under mild heating (between 30 to 70°C) and stirring. The composition of the product formed can vary depending on the strength of nitric acid and the quantity of water used. 

Zakharov found oxynitration to proceed best at 60% concentration of nitric acid. 

Davis and his co-workers [127,128] found chlorobenzene also undergoes oxynitration by action of 65% nitric acid, with formation of trinitro-m-chlorophenol along with chlo-ronitrobenzenes, while naphthalene when nitrated with more dilute acid, for example, at a concentration of 65%, yielded 2,4-dinitro-a-naphthol besides 2-nitro-a-naphthol. 

It seems to be certain that the oxynitration reaction in the presence of mercury salts proceeds through the formation of phenylmercuric nitrate. The isolation of phenylmercuric nitrate from a reaction mixture in dilute nitric acid by several authors (Carmack and his co-workers [135], Titov and Laptev [71], and also Bro-ders [124]) favours this view. If an intermediate nitroso compound is formed in the reaction its formation should be ascribed to the reaction between phenylmercuric nitrate and nitrous acid. This view, based on earlier experiments of Baeyer [136], Bamberger [137], Smith and Taylor [137a], has since been confirmed by Westheimer, Segel and Schramm [138], who considered the nitroso compound formed from an organo-mercuric compound to be the principal intermediate product in the Wolffenstein and Boters reaction. 

Numerous industrial studies have been carried out to investigate the possibility of using the oxynitration method for the commercial production of picric acid. However, they have failed to provide a reliable method for industrial application. Particulars on some experiments on the industrial scale are dealt with in the chapter on nitro derivatives of phenol. 

Phenol is liable to undergo extensive oxidation during nitration so that carefully controlled conditions are required it forms 40% o- and 13% p-nitrophenolA solvent like chloroform or acetic acid is recommended. The nitration of p-cresol is carried out in benzene and acetic acid solution at 0°, the product being 3-nitro-4-hydroxytoluene (77%). The nitration of ra-cresol is discussed under method 491. Benzene is oxidized and nitrated (oxynitration) to 2,4-dinitrophenoI (72%) or to picric acid (2,4,6-trinitrophenol) by the action of mercuric nitrate in nitric acid. Aromatic alcohols like / -phenylethanol are nitrated as the esters to avoid oxidation products... 

Zirconium oxychloride (or zirconium oxynitrate) was mixed with urea, nitric acid and water in an evaporating dish, and then thermolyzed in a muffle furnace at a fixed temperature about 10 minutes. This led to samples with a foam structure. The samples were then characterized by physical adsorption of N at 77K (ASAP-2000), TEM (H-600II) and XRD (D/max-yA). 

If mercury salts are added, the oxidizing action of dilute nitric acid can be elegantly utilized for simultaneous introduction of hydroxyl and several nitro groups. This oxynitration , discovered by Wolffenstein and Boters,103 permits the one-step conversion of, e.g., benzene into picric acid in about 50% yield104 and of benzoic acid into 3-hydroxy-2,4,6-trinitrobenzoic acid, although in less good yield in the latter case105 (for the mechanism see West-heimer et a/.106). 

Zr02 zirconium oxynitrate NP5 -1- NP9 (2 l)/cyclohexane/ oxalic acid 295-559 50 Support material 60... 

Ox3mitration. An interesting reaction occurs between benzene and approximately 50 per cent nitric acid containing 0.2 molar mercuric nitrate which yields up to 85 per cent dinitrophenol and picric acid. This process is known as oxynitration. It has been shown by Westheimer and coworkers that this reaction occurs in the following steps ... 

Bismuth oxynitrate BiONO, 10361-46-3 286.986 wh powder 260 dec 4.93 i EIjO, EtOEl s acid... 

The first report of catalytic nitration via mercuration was a patent issued to Wolffenstein and Boeters (136] at the beginning of the century. They reported a procedure for the synthesis of dinitrophenol and picric add via oxynitration of benzene with mercuric nitrate and 50-55% nitric acid. The mechanism of oxynitration was delineated by Wesiheimer ei al. (137]. 

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