Acid In Carbon Tetrachloride Research Articles

Proton Spin-Lattice Relaxation Studies of Intermolecular Interactions in Acetic Acid Solution

Abstract Proton spin-lattice relaxation measurements were carried out by the rapid-passage method on the hydroxyl and methyl protons of acetic acid in carbon tetrachloride, benzene-d6, and chloroform-d in order to investigate the effect of the self-association of acetic acid on the spin-lattice relaxation. It was found that there exists a maximum of the relaxation rate in carbon tetrachloride, and two maxima in benzene-d6 and chloroform-d, on dilution with a solvent. This relaxation behavior was attributed to the change in the self-association mechanism of acetic acid. We tried to keep the proton-density constant in all solution in order to avoid any ambiguity arising from the change in density by using the analogous deuterated compounds.

Nitration of aromatic hydrocarbons by anhydrous nitric acid in carbon tetrachloride

Kinetic studies with a 20-fold or greater excess of nitric acid over mesitylene in carbon tetrachloride show that nitration to the mono-substituted product is of the sixth order in nitric acid and of zeroth order in mesitylene. The nitration reaction has a negative temperature coefficient and the order in both reactants remains unchanged down to –23°, the lowest temperature studied.

Electrophilic aromatic substitution. Part V. Nitration by nitric acid in carbon tetrachloride

Nitration of some benzene homologues by anhydrous nitric acid in carbon tetrachloride is shown to have characteristics which indicate that the nitronium ion is the effective electrophile. The small increase in rate on lowering the temperature is attributed to the effect of the variation in temperature on the formation of aggregates of nitric acid molecules from which the nitronium ions are produced. It is suggested that the results of some previous work on this system were affected by a heterogeneous reaction.

Enol esters. VII. Isolation and rearrangement of terminal fatty oxirane esters

AbstractIsopropenyl esters of mono‐ and dibasic fatty acids were epoxidized with m‐chloroperbenzoic acid in carbon tetrachloride. The isolation of the resulting oxirane ester was difficult because of the spontaneous rearrangement to a hydroxyacetone ester. Rapid gel filtration was the only method that consistently afforded good yields of the oxiranes. The infrared spectra of these oxirane esters had many strong, sharp bands which were completely lacking in the rearranged product. The isomerization, carried out in several ways, could easily be followed spectrally and a qualitative estimate of purity made.

The volumetric and dielectric behaviour of acetic acid in mixtures with nonpolar liquids

Results for the volume change of mixing of acetic acid with carbon tetrachloride, benzene, and cyclohexane are given. Further, the dielectric constant has been determined for acetic acid in carbon tetrachloride from spectroscopic measurements of the association equilibrium. The volume changes are both positive and large. The dielectric behaviour of acetic acid in carbon tetrachloride parallels that of acetic acid in benzene and n-heptane previously reported. Our results taken together with published data indicate: (i) the dipole moment of acetic acid monomer in the gas phase is higher than has been previously reported, (ii) the dipole moment of acetic acid monomer in solutions rich in acetic acid is considerably greater than in the gas phase, possibly because of a contribution of the trans-configuration, and (iii) a strong attractive interaction exists between acetic acid monomer and acetic acid dimer.

An Analysis of the Proton Magnetic Resonance Spectra of Acrylic Acid in Solution: A Comparative Discussion of the Methods of the Analysis of ABC Spin Systems

Abstract In an attempt to examine various existing methods for the analysis of high-resolution NMR spectra, the statistical theory has been applied to the least-squares iteration method presented by Arata, Shimizu and Fujiwara. The standard errors of chemical shifts and spin-spin coupling constants, and the singularity in the normal equation, have been discussed. Two sets of parameters which are placed close together have a possibility of producing a singularity in the normal equation. A way of eliminating the singularity has been presented. The method thus presented has then been applied to an analysis of the vinyl proton spectra of acrylic acid in carbon tetrachloride and in aqueous solutions of various pH values. It has been found that the spin-spin coupling constants do not change beyond the range of experimental errors under the conditions of the present study. The change in chemical shifts has been discussed in terms of the possible conformations of the molecules.

Nuclear spin-lattice relaxation and molecular association in acetic acid

Spin-lattice relaxation times for solutions of acetic acid in carbon tetrachloride and carbon disulphide are presented. The experimental results cannot be explained only on the basis of considerations about the mutual viscosity of the solutions. This is caused by the presence of molecular associations due to the hydrogen bond and the discussion of the results has led to some information about the nature of the association.

The carboxyl proton chemical shift of trimethylacetic acid monomers in carbon tetrachloride

The carboxyl proton chemical shifts for trimethylacetic acid in carbon tetrachloride have been measured at 11°C, 21.5°C, 34°C, and 50°C. Previously reported equilibrium constants are used to calculate the monomer chemical shift. The previously reported findings of exceptionally high shieldings for the monomer, large decreases in shielding with increasing temperature, and higher shieldings in carbon tetrachloride solution than benzene solution are confirmed.

The Dimerization of Benzoic Acid in Carbon Tetrachloride and Chloroform

Abstract The dimerization equilibrium of benzoic acid has been studied by high resolution infrared spectroscopy over a wide range of acid concentrations. The concentrations of the monomer and the dimer fractions have been determined from the integrated intensities of the respective carbonyl-stretching vibration bands. The calculated equilibrium constant is 2300 l.mol−1for carbon tetrachloride and 400 1. mol−1 for chloroform, both values being considered more reliable than that determined by peak intensity measurements. A weak association of chloroform with benzoic acid has been suggested as occurring through hydrogen bonding to the monomer carbonyl.

Studies on the Preservatives in Foods (V)

In general, dehydroacetic acid in foodstuffs has been determined by ultraviolet spectrophotometry, or colorimetry with salicylaldehyde.In the present report, studies on the infrared spectrometric analysis of the acid are described.The results obtained are as follows:1. Characteristic absorption of dehydroacetic acid in carbon tetrachloride in IR-region provides an infrared spectrometric method of analysis of the acid.2. Carbonyl band 1, 750cm-1 are useful as key band for the quantitative analysis of the acid.3. The interfering effects of other food additives on this method have been investigated, and the detection of the acid was found to be possible, but its determination was found to be difficult.

Reaction of Salicylic Acid with N‐Bromosuccinimide

AbstractThe reaction of equimolar amounts of NBS with salicylic acid in carbon tetrachloride was found to give tribromophenol, 4‐bromo‐ and 4,6‐(not 4,5)‐dibromo‐salicylic acids, while the same reaction carried out in dioxane yielded only tribromophenol and 4‐bromosalicylic acid and addition of pyridine into the reaction mixture (in dioxane) decreased the yields of the products. The fact that no 4,6‐dibromosalicylic acid could be produced in a dioxane medium is a strong evidence showing that the bromination in dioxane takes place through dioxane dibromide as the intermediate.

Studies on the Preservatives in Foods (III)

Sorbic acid in foodstuffs has been determined UV-spectrometrically. However, the acid shows only one absorption band in UV region and its shift and being masked by interfering substances reduce the accuracy and precision of the analysis.In the present report, studies on the infrared spectrometric analysis of the acid are described. The results obtained are as follows:1. Characteristic absorption of sorbic acid in carbon tetrachloride in IR-region provides an IR spectrometric method of analysis of the acid.2. For the quantitative analysis, 1690cm-1 and 1000cm-1 are useful as key bands for the acid.3. The interfering effects of food additives and of natural substances on the analysis have, also, been investigated.

The determination of uranium in sea water by pulse polarography

A procedure is described for the determination of the uranium content of sea water. The uranium is first separated and concentrated from 4 litres of sea water by solvent extraction with di-(2-ethylhexyl)-phosphoric acid in carbon tetrachloride. A further purification of the uranium is carried out by the extraction, of uranyl nitrate into ethyl acetate, and the uranium concentration is found by pulse polarography using the peak from a perchloric acid-tartrate supporting electrolyte. Uranium-237 is employed as a radioactive tracer to measure the percentage recovery of uranium in the chemical separation processes. The value obtained for English Channel water is 3.37 ± 0.08 μg of uranium per litre.

The Dimerization of Acetic Acid in Carbon Tetrachloride and Chloroform

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Dimerization of Acetic Acid in Carbon Tetrachloride and ChloroformGordon M. Barrow and E. Anne YergerCite this: J. Am. Chem. Soc. 1954, 76, 20, 5248–5249Publication Date (Print):October 1, 1954Publication History Published online1 May 2002Published inissue 1 October 1954https://doi.org/10.1021/ja01649a093RIGHTS & PERMISSIONSArticle Views221Altmetric-Citations36LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (262 KB) Get e-Alerts Get e-Alerts

The kinetics of the addition of chlorine to olefins in carbon tetrachloride

For the interpretation of the rates of absorption of chlorine from air by solutions of olefins and iodine in carbon tetrachloride, it is necessary to know the kinetics of the addition of chlorine to the olefins under the conditions of the absorption. The rate of addition of chlorine to 2-ethyl hexene-1 and to oleic acid in carbon tetrachloride was found proportional to the concentration of the chlorine and to the concentration of the olefin. With excess cyclohexene, the rate of addition of chlorine to cyclohexene in carbon tetrachloride was found to be proportional to the second power of the chlorine concentration and independent of the concentration of cyclohexene.

The Addition of Hydrogen Bromide to Cinnamic Acid and the Oxygen Effect

Abstract The action of the mixture of hydrogen bromide and oxygen on cinnamic acid in carbon tetrachloride produces ω-bromoacetophenone together with α,β-dibromohydrocinnamic acid. It is concluded that the free radical C6H5\.{C}HCHBrCOOH is formed in the intermediate stage in accord with the expectation from theoretical considerations concerning the stability of radicals. The radical, owing to its stability, does not react with hydrogen bromide to give α-bromohydrocinnamic acid, but reacts, on one hand, with oxygen ultimately to give ω-bromoacetophenone after disrupture of carbon dioxide and, on the other hand, with bromine or hydrogen bromide, as detailed in the text, to give α, β-dibromohydrocinnamic acid.

The Addition of Hydrogen Bromide to Crotonic Acid in Carbon Tetrachloride Solution and the Oxygen Effect

Abstract (1) Hypotheses suggested to explain the orientation of hydrogen bromide in the addition to the ethenoid compound have been briefly reviewed and critisized. (2) Allowing the mixture of hydrogen bromide and oxygen to react with crotonic acid in carbon tetrachloride, three products, β-bromobutyric acid, crotonic acid dibromide and α-hydroxy-β-bromobutyric acid, have been isolated. (3) Oxygen has been found not to accelerate the addition of hydrogen bromide to crotonic acid in carbon tetrachloride solution in the dark. (4) It is concluded that in the addition of hydrogen bromide to crotonic acid in the presence of oxygen, this participates in the reaction producing free bromo-radical acid and bromine atoms, the latter being attached to the β-carbon atom of crotonic acid, but that the chains involving these cannot develop because of the ready reaction of the bromo radical acid with oxygen rather than with hydrogen bromide.

The Effects of Oxygen and Peroxides on the Rate of Addition of Bromine to Cinnamic Acid in Carbon Tetrachloride

Abstract (1) The relation between the extent of addition of bromine to cinnamic acid in carbon tetrachloride and the amount of oxygen present has been shown. (2) It has been indicated that hydrogen bromide is indifferent to the reaction of bromine with cinnamic acid in carbon tetrachloride either in presence or in absence of oxygen. (3) The accelerating effect of benzoyl peroxide on the addition of bromine to cinnamic acid in carbon tetrachloride has been demonstrated. (4) In all cases, namely in vacuum and in the presence of any of oxygen, benzoyl peroxide, and hydrogen bromide, the products separating out in crystals were cinnamic acid dibromide melting at 198°. (5) All the results mentioned above were obtained from the additions in the dark at room temperature.

The Effect of Oxygen on the Addition of Bromine to Cinnamic Acid in Carbon Tetrachloride

The Effect of Oxygen on the Addition of Bromine to Cinnamic Acid in Carbon Tetrachloride