Nitrate activity

The resolution was carried out by means of d-bromo-camphor-sulphonie acid. The salts of the bromo-series are more easily resolved on account of the great difference between the isomeric d-bromo-camphor sulphonates. In both series the d-bromo-eamphor sulphonate of the d-isomer is more sparingly soluble. These active compounds are very stable, and aqueous solutions of the bromides of the bromo-ammine series may be kept for a considerable time at ordinary temperatures, and even on heating to boiling racemisation does not occur. If the bromine in the complex be removed by means of silver nitrate activity... 

Other mixtures consist of ammonium nitrate activated with ammonium dichromate, for instance, plus a combustible ingredient also acting as a binder. 

Pinck [53] examined the nitrating activity of such a mixture, and obtained nitrocellulose with various nitrogen contents, rising to 13.36%, when nitric arid containing 15% N204 mixed with 95% sulphuric acid was used. 

According to Yerma et al. [35] the mechanism of the reaction may be rationalized as involving (3-oxygenation of the bismuth(III) nitrate activated chalcone enolate, which may then undergo a Michael addition to a second a, 3-unsaturated ketone (Scheme 4.52) to form a 1,5-diketone enolate adduct 180. Subsequent heteroannulation with o-PDA via condensation and retro-aldol disproportionation may form 2-hydroxy-1,2,4,6-tetraaryl-1,2,3,4-tetrahydro-pyridine derivatives 181, which may undergo dehydration to yield 1,2,4,6-tetraaryl-1,4-dihydropyridines 177. 

Ca2+ calcium di-(/i-octylphenyl) phosphate (active material) NO ammonium tetradecylammonium nitrate (active material)... 

In the U.S.S.R., the D.V.S. is often named the coefficient of dehydration and a slightly different way of calculating the nitric composition of sulphuric acid mixtures is in use there. This is

sulphuric acid in the mixture when the nitric acid is converted into the equivalent quantity of water. 

It is not advisable to use a high value of the factor of nitrating activity 0 for economic reasons. Nor should low 0, be applied as this leads to incomplete utilization of the nitric acid in the nitrating mixture. 

Fig. 57. Influence of the factor (nitrating activity) on the yield of m- nitrotoluene (Orlova [2a]).

The nitrate ion activities shown in Figure 13 were measured using a special nitrate electrode standardization technique for samples with a high hydrogen ion concentration or acidity. Pure samples of known HN03 concentration and nitrate activity were analyzed with the nitrate... 

One way of correcting for this H+ diffusion effect is to evaluate the reference voltage for each nitrate activity and measured electrode potential and make the reference voltage functionally dependent on the concentration of the H+ ions in the solution. Thus, through careful calibration with pure HN03 solutions and a knowledge of the H+ concentration of the sample, the reference voltage can be calculated and nitrate ion electrode can be used to determine the nitrate ion activity of the sample. The individual calibration corresponds to a series of experimental nitrate... 

Nitric Acid and Nitrate Activation. The reactions of HNO3, nitrates, and nitrogen oxides with lignocellulosic materials have been a subject of numerous publications. The specific transformations can be subdivided into acid reactions, oxidation reactions, and nitration-esterification reactions. With HNO3 and more acidic salts the acid reactions predominate at higher dilutions, and parallel those of aqueous solutions of H2SO4 and other similar acids. Oxidation of cellulose results primarily in oxidation of primary hydroxyls to carboxyls, with the secondary hydroxyls oxidized less. Nitration leads... 

The addition of mercury(II) nitrate activated alkenes to amides follows the rule of Maikovnikov. Subsequent NaBH4 demercuriation leads to more highly substituted amides in moderate to good yields. ... 

Figure 1. Evolution of nitration activity conducted in the vapor phase flow reactor at 150 C illustrating the induction period observed for all the zeolite catalysts.

Wendkos has proposed an "Orthostatic Electrocardiographic Index" in an attempt to demonstrate nitrate activity.This study is hardly conclusive as it was carried out on four schizophrenics without demonstrable organic heart disease. Wendkos recently reported that nitroglycerin and isosorbide dinitrate abolished ECG signs of ischemia provoked by l.v. administration of ergot alkaloids to anginal patients. ... 

No further work was done with N(V) nitration however, on the basis of these observations, we assert that nitric acid itself does not nitrate pyrene in methylene chloride. This finding can be contrasted with the results of Grosjean et al. (3), who concluded in atmospheric pollutant studies that the opposite view is correct. Specifically, their results from vapor-phase experiments suggested that N02 was not active in nitration of filter-deposited PAHs, whereas nitric acid was necessary for nitration. The differences in conditions must be considered when comparing these data with those from this work. Nonetheless, it is difficult to refute the absence of nitration activity by N(V) under our conditions, and the important questions concerning the nitrating species in the environmental work remain. 

Danon points out that the data can also be described with a model where no cationic complexes are formed. The key conclusion of this study is that the uncharged complex Th(N03)4(aq) is predominant when the activity of the nitrate is about 0.5 M and that anionic complexes are formed at higher nitrate activities. In the analysis of the experimental data, Danon has not considered the variation of the activity coefficients of the thorium species participating in the reactions and there is no justification for this approximation. Because of this, the present review has not accepted the equilibrium constants proposed by Danon. It should be noted that the experimental mean-activity... 

At early times after dermal exposure of rabbits to plutonium-239 nitrate, activity in blood was uniformly distributed, but later changed to a nonuniform distribution (Khodyreva 1966). Distribution of plutonium was greatest to the skeleton followed by muscle tissue, liver, kidney, spleen, heart, and lungs (Khodyreva 1966). In an earlier study in rats, the absorption of plutonium through intact skin did not appear to result in distribution to the liver as compared to absorption through skin damaged by punctures or wounds where deposition in the liver was seen (Oakley and Thompson 1956). 

Table 2 summarizes the variation in porosity at various stages of treatment of oil fly ash. Acid treatment of oil fly ash removes the most of the inorganic matter from the surface and inside of fly ash particles and produces micro and mesopores. Heating of ash with acid leached out most of the metals in the form of phosphates, sulfates and nitrates. Activation of ash with acid produces more mesopores than raw ash (see Fig. 2). 

Silver nitrate activates the terminal carbon of a triple bond to be attacked by the nucleophilic a-carbon of a carbonyl (Scheme 9) (13TL847). This reaction provides 1,2-dihydropyridines in good yields. 

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