Nitrates of substances

The Autoxygen Company of New York, NY, during WW II, proposed a method of nitration of. substances which it claimed would eliminate the use of sulfuric acid, reduce the proportion of nitric acid to material nitrated, and eliminate the necessity for reworking spent acid... 

After Schmid s accidental death in 1930, Meissner extented the application of continuous method to nitration of substances like benzene, toluene, etc, The,FirmaMeissner", Koln,... 

Although these nitrations proceed smoothly, attempted nitration of an unidentified substance should always be carried out with extreme care, e.g., by working in a fume-cupboard and pointing the boiling-tube away from the operator. Many organic substances e.g., alcohols and phenols) react with great violence with a mixture of nitric and sulphuric acids. 

A brief account of aromatic substitution may be usefully given here as it will assist the student in predicting the orientation of disubstituted benzene derivatives produced in the different substitution reactions. For the nitration of nitrobenzene the substance must be heated with a mixture of fuming nitric acid and concentrated sulphuric acid the product is largely ni-dinitrobenzene (about 90 per cent.), accompanied by a little o-dinitrobenzene (about 5 per cent.) which is eliminated in the recrystallisation process. On the other hand phenol can be easily nitrated with dilute nitric acid to yield a mixture of ortho and para nitrophenols. It may be said, therefore, that orientation is meta with the... 

The reactivity of dibenzyl is similar to those of alkylbenzenes, and it is therefore most probable that the nitrations of the latter substances were also influenced by mixing. ... 

The data of table 4.1, column [a), do not suggest that nitration of the alkylbenzenes with nitronium tetrafluoroborate in sulpholan occurs upon encoimter mesitylene might be so reacting ( 3.3) but comparison with a more inherently reactive substance would be necessary before this possibility could be considered. 

The nitration of the 2-anilino-4-phenylselenazole (103) is much more complicated. Even careful nitration using the nitrate-sulfuric acid method leads to the formation of a mixture of variously nitrated compounds in an almost violent reaction. By the use of column chromatography as well as thin-layer chromatography a separation could be made, and the compounds could be partly identified by an independent synthesis. Scheme 33 shows a general view of the substances prepared. Ring fission was not obser ed under mild conditions. 

Ammonium nitrate is normally classified as an oxidizing agent. The pure salt is not classed as an explosive because it is difficult to detonate. Spark, flame, or friction do not cause detonation, and ammonium nitrate is relatively insensitive to shock. However, a variety of substances, such as chloride and oil, are known to sensitize the material, so manufacturers strive to eliminate such substances from their processes. 

Predict the major product(s) of nitration of the following substances. Which react faster than benzene, and which slower ... 

Since the nitrations of interest to us are exothermic reactions that produce expl substances it is obvious that safety is an important consideration in any laboratory nitration and even more so in an industrial nitration process, in the... 

Nitrogen tetioxide is also formed during the manuf of nitric acid and in the nitration of org substances... 

TNPEN was first prepd by Lewis (Ref 2), and subsequently by several other investigators (see Refs 3,4,5 7). Ficheroulle (Ref 7) prepd it in 1937 at the Leboratoire Central des Poudres, by the nitration of jS-(2,4-Dinitrophenoxy) ethanol, but the results were not published until 1948 (Ref 3). The substance was purified by pptn of the nitrated mixt with w, and crystn from acet... 

A total charge of 4.5 kC is passed through an electrolytic- cell. Determine the quantity of substance produced in each case (a) the mass (in grams) of bismuth metal from a bismuth nitrate solution (b) the volume (in liters at 273 K and 1.00 atm) of hydrogen gas from a sulfuric acid solution ... 

The first step of the reaction involves nitration of the aromatic skeleton of the substance to be detected. Then the aromatic nitro derivatives so produced are reduced with sodium dithionite, in acid medium, to the corresponding amines these are then diazotized and coupled with N-(l-naphthyl)-ethylenediamine to yield an azo dye (cf. Fig. 21). 

C03-0109. The following pairs of substances are quite different despite having similar names. Write correct formulas for each, (a) sodium nitrite and sodium nitrate (b) potassium carbonate and potassium hydrogen carbonate (c) iron(II) oxide and iron(IIt) oxide and (d) iodine and iodide ion. 

Nitrobenzoyl peroxide,2 as well as w-nitrobenzoyl peroxide2 and anisoyl peroxide,3 have been prepared in about 50 per cent yields from the acid chlorides and an acetone solution of hydrogen peroxide, in the presence of a basic substance such as pyridine, sodium acetate, or sodium hydroxide. w-Nitrobenzoyl peroxide has also been prepared by nitration of benzoyl peroxide with cold... 

The end points of precipitation titrations can be variously detected. An indicator exhibiting a pronounced colour change with the first excess of the titrant may be used. The Mohr method, involving the formation of red silver chromate with the appearance of an excess of silver ions, is an important example of this procedure, whilst the Volhard method, which uses the ferric thiocyanate colour as an indication of the presence of excess thiocyanate ions, is another. A series of indicators known as adsorption indicators have also been utilized. These consist of organic dyes such as fluorescein which are used in silver nitrate titrations. When the equivalence point is passed the excess silver ions are adsorbed on the precipitate to give a positively charged surface which attracts and adsorbs fluoresceinate ions. This adsorption is accompanied by the appearance of a red colour on the precipitate surface. Finally, the electroanalytical methods described in Chapter 6 may be used to scan the solution for metal ions. Table 5.12 includes some examples of substances determined by silver titrations and Table 5.13 some miscellaneous precipitation methods. Other examples have already been mentioned under complexometric titrations. 

Physical characteristics of photosmog include a yellow-brown haze, which reduces visibility, and the presence of substances which irritate the respiratory tract and cause eye-watering. The yellowish color is owed to NO2, whilst the irritant substances include ozone, aliphatic aldehydes, and organic nitrates. The four conditions necessary before photosmog can develop are ... 

According to the amount of substance taken add 60-90 mg. of finely powdered silver nitrate (it is best to add one and a half times the amount which corresponds to the expected halogen content). Then, if the substance is only slowly attacked by nitric acid in the cold, add 10-1-5 c.c. of red fuming nitric acid. In the case of substances which react vigorously with nitric acid in the cold, hold the Carius tube obliquely and add the acid in a small round-bottomed tube (length 6 cm., width 0-8 cm.), cautiously allowing it to slide to the bottom of the Carius tube and taking care that substance and acid do not come into contact with each other. 

When ethyl nitrate is rapidly heated, for example in a flame, it decomposes explosively it belongs to the same class of substances as nitroglycerine. Precautions should therefore be taken. Under the conditions employed ethyl alcohol is not oxidised by pure nitric acid but merely esterified. Oxidation sets in immediately if traces of nitrous acid are present. Since the nitric oxide which is thus produced from the nitrous acid is at once oxidised to NOz by the nitric acid, the oxidation, which is initially slight, becomes progressively greater, its velocity... 

Consequently, an ISE for nitrate for example, a strongly hydrophilic ion, must have a strongly hydrophobic ion-exchanger ion. This conclusion has been demonstrated experimentally for a series of NO3 ISEs based on tetra-alkyl-ammonium salts with long alkyl chains [161] (see fig. 7.2). It was found that, in the studied series of substances, the tetradodecylammonium ion which is... 

As a rather strongly hydrophilic anion, nitrate requires an ISE membrane containing a strongly hydrophobic cation, as described on p. 169. This function was fulfilled in the first nitrate electrode from Orion Research by cation V [180] in nitro-p-cymene 5. The electrode can be used in the pH range 4-7. In other commercial electrodes, the ion-exchanger ion is a tetra-alkylammonium salt, for example in the electrode from Coming Co., substance XIII in solvent 6 [27]. An ISE with a renewable membrane surface was found to be very useful (see section 4.1 and fig. 4.4), in which the ion-exchanger solution contains the nitrate of crystal violet VII dissolved in nitrobenzene [191]. The NOj ISE also responds to nitrites that can be removed by addition of aminosulphonic acid. 

The A-nitration of the furazan-based heterocycle (29) has been reported. The corresponding tetranitramine (30) is an unstable substance, but obtained on treating (29) with either trifluoroacetic anhydride (TFAA) in nitric acid or dinitrogen pentoxide in nitric acid. In this case the furazan rings stabilize the 1,4,5,8-tetraazadecalin structure and further reduce the basicity of the amidine amino groups. A number of other furazan and nitrogen-rich nitramines... 

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