Benzene-carbon Tetrachloride Research Articles

Anionic synthesis of poly(epichlorohydrin- g-styrene) and chemical modification of polyepichlorohydrin

Poly(epichlorohydrin- g-styrene) copolymers, P(ECH- g-S)s, have been prepared in solution by two different methods of coupling polyepichlorohydrin, PECH, with polystyrene, PS, containing a functional end group. In the first method, polystyryl carboxylic acid, PSCOOH, prepared from living polystyrene, was converted to the corresponding potassium salt which was coupled with PECH in dimethyl formamide solution usually at 60°C. In the second method, polystyryl potassium, PS −K +, in tetrahydrofuran solution was end-capped with propylene sulphide to form PSCH 2CH(CH 3)S −K + which was coupled directly with PECH in tetrahydrofuran at 40°C. Grafting by the first reaction was relatively slow but occurred without significant adverse side reactions. The grafting by the second reaction was relatively fast, but side reactions occurred resulting in a cleavage of the graft copolymer. The graft copolymers were purified by fractional precipitation and extraction procedures and were characterized by infra-red and ultra-violet spectroscopy, microanalysis, gel permeation chromatography, differential scanning calorimetry, solution viscometry, dynamic mechanical testing, and electron microscopy. Solution properties of the graft copolymers in benzene-carbon tetrachloride and toluene-cyclohexane mixtures were studied. There was evidence of micelle formation in dilute solutions of the mixed solvents and microphase separation of components in the solid state. Nucleophilic substitution of chlorine atoms in PECH by phenyl acetate (C 6H 5 CH 2COO-) and thiophenoxide (C 6H 5S-) groups was performed.

Use of packed thermal diffusion columns to determine the soret coefficient in a benzene-carbon tetrachloride mixture

Experimental results of the determination of the Soret coefficient of a benzene-carbon tetrachloride mixture in a packed column with reservoirs at the ends are presented.

The state of dissolved benzene in aqueous solution

Henry's law constants for benzene in water have been measured by bringing water layers into equilibrium with solutions of benzene in carbon tetrachloride or in cyclohexane. The mole fraction of benzene in the aqueous layer was determined by ultraviolet absorption spectrophotometry, and its fugacity was taken as equal to that in the nonaqueous phase, reliable data for the C6H6−CCl4 and C6H6−c−C6H12 systems being available in the literature. Measurements were made at 5o intervals from 10 to 30°C inclusive, at mole fractions down to from 10% to 20% of saturation. In no case did Henry's law constant depart significantly from constancy, and it was in reasonable agreement with some representative literature values based on saturated solubility. The constancy and the magnitudes of our Kh values indicate that appreciable dimerization does not occur in the temperature range examined here. This conclusion contrasts with the suggestion of Reid, Quickenden, and Franks that their calorimetrically measured heat of solution of benzene in water is different enough from the van't Hoff heat to imply possible dimerization of the solute; it also contrasts with the hydrophobic-bond-forming tendency which Ben-Naim, Wilf, and Yaacobi ascribe to benzene on the basis of their studies of the solubilities of benzene and biphenyl. The results of the latter study, when combined with the known second virial coefficient of benzene vapor, predict that more than 20% of the benzene in saturated aqueous solution at 25°C should be present as dimer, in clear contradiction to the results of the present work.

The Henry's law constants of water in the binary mixtures of benzene, carbon tetrachloride, and cyclohexane at 25�C

The solubilities of water in each of the three binary mixtures benzene-carbon tetrachloride, benzene-cyclohexane, and carbon tetrachloride-cyclohexane were determined as a function of solvent composition at 25°C. It was found that, as with the pure solvents, water in the 0.50 mole fraction binary mixtures of these solvents obeyed Henry's law up to saturation. The experimentally determined solubilities were converted to Henry's law constants of water for the entire range of solvent compositions. These values for the Henry's law constants were compared with theoretically calculated values. The comparisons indicated that water in the benzene-cyclohexane and in the benzene-carbon tetrachloride mixtures was preferentially solvated by benzene. Preferential solvation of water was not indicated for the carbon tetrachloride-cyclohexane mixtures.

Extraction of phenol from water with mixed solvents

AbstractDistribution coefficient data ate presented for phenol at 25°C between water and nine mixed solvents. The binary solvent mixtures were n‐octane with n‐hexanol‐l, n‐octanol‐l and n‐decanol‐l; n‐octanol‐l with benzene carbontetrachloride, cyclo‐hexane, kerosene and butyl acetate; and n‐butyl acetate with benzene. All alcohol mixtures exhibited a positive deviation from linearity in distribution co‐efficient, maxima being obtained for mixtures of n‐octanol‐l with n‐butyl acetate and benzene. The data are correlated empirically and the nature of the chemical associations discussed. Practical implications are that esteralcohol mixtures may be the preferred solvents for phenol extraction from water since these mixtures have distribution coefficients significantly greater than either pure solvent.

Extraction of phenol from water with mixed solvents

AbstractDistribution coefficient data ate presented for phenol at 25°C between water and nine mixed solvents. The binary solvent mixtures were n‐octane with n‐hexanol‐l, n‐octanol‐l and n‐decanol‐l; n‐octanol‐l with benzene carbontetrachloride, cyclo‐hexane, kerosene and butyl acetate; and n‐butyl acetate with benzene. All alcohol mixtures exhibited a positive deviation from linearity in distribution co‐efficient, maxima being obtained for mixtures of n‐octanol‐l with n‐butyl acetate and benzene. The data are correlated empirically and the nature of the chemical associations discussed. Practical implications are that esteralcohol mixtures may be the preferred solvents for phenol extraction from water since these mixtures have distribution coefficients significantly greater than either pure solvent.

Thermodynamics of solutions. Excess volumes of benzene, carbon tetrachloride, and mesitylene mixtures

The thermodynamic properties of a number of binary mixtures, differing from hard sphere nature, have been investigated (72) by utilizing a rigid sphere model first proposed by Longuet-Higgins and Widom (5). Values of excess Gibbs energy for equimolar mixtures are usually forced to agree with experimental values at one temperature to fix necessary parameters. In principle, the precise measurement of excess volume can provide a more direct and possibly more acceptable procedure for determining the fitting parameters involved in the hard sphere model considered. In addition, the excess volume is readily measured. From this point of view, the determination of the excess volumes for three binary mixtures was carried out. The results of the measurements for the systems benzene-mesitylene, benzene-carbon tetrachloride, and carbon tetrachloridemesitylene at 27 and 40°C are given along with a description of a simple method for the determination of excess volumes.

Transient Response of a Distillation Column Plate. Part III. Model Evaluation from Concentration Pulse Data on a Plate for the Benzene–Carbon Tetrachloride System

Abstract A 3-plate distillation column was operated with the benzene–carbon tetrachloride system. The liquid composition entering the second plate was pulsed by direct injection of liquid into the downcomer. The output compositions of the two downcomers below the input were monitored. Vapor and liquid flow rates from 400 to 1000 ml/min were used, with the column at total reflux. The column was a 6-in. diameter column with one glass bubble cap tray on each plate. The composition–time data were numerically Laplace transformed, and the frequency response form was statistically fit to four models; (1) perfectly mixed; (2) plug flow; (3) perfectly mixed with downcomer delay; and (4) dispersion. The composition–time data for each model were reconstructed using the best fit parameters, and are compared with experimental data. The statistically best model was the dispersion model. A satisfactory model which is much simpler is the perfectly mixed tray with delay in the downcomer.

Use of a new cell to measure diffusion coefficients for the systems benzene-carbon tetrachloride and sucrose-water at 25.deg.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTUse of a new cell to measure diffusion coefficients for the systems benzene-carbon tetrachloride and sucrose-water at 25.deg.Graham R. Staker and Peter J. DunlopCite this: J. Chem. Eng. Data 1973, 18, 1, 61–63Publication Date (Print):January 1, 1973Publication History Published online1 May 2002Published inissue 1 January 1973https://doi.org/10.1021/je60056a006RIGHTS & PERMISSIONSArticle Views32Altmetric-Citations3LEARN 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 (314 KB) Get e-Alerts Get e-Alerts

THE HALOGEN REARRANGEMENT OF 1β-BROMO-AND 1β-CHLORO-5β-CHOLESTAN-2-ONE TO THE α′-POSITION

Abstract A new phenomenon of an α-haloketone having a halogen on its secondary carbon atom in which the halogen rearranges to the α′-position occupied by a secondary carbon atom was found in the reaction of 1β-bromo-and 1β-chloro-5β-cholestan-2-one with the following reagents: i) hydrogen bromide / acetic acid, ii) hydrogen chloride / acetic acid, iii) acetic acid, iv) acetic acid / dioxane, v) boron trifluoride etherate / dioxane, vi) perchloric acid-acetic anhydride / benzene-carbon tetrachloride, vii) potassium acetate / acetic acid.

Proton spin‐lattice relaxation study of polymer solutions

AbstractProton spin‐lattice relaxation times of solvent molecules were measured on ternary mixtures of a polymer and two solvents by the adiabatic rapid‐passage method. The selective adsorption of a good solvent was verified by this experimental technique for the systems benzene—cyclohexane—polystyrene(PS), benzene—carbon tetrachloride—poly(methyl methacrylate)(PMMA), and chloroform—carbon tetrachloride—PMMA. The number of molecules of adsorbed benzene per monomeric unit of PS was estimated to be about four, which is almost identical with that determined previously by thermodynamic measurements. The number of molecules of benzene and chloroform adsorbed on PMMA were also determined to be about five and four, respectively. It was found that the interaction between chloroform and PMMA has the greatest effect on the molecular motion of the solvent, whereas the benzene—PS interaction is weak.

Separation of Some Anthracene Derivatives by Thin Layer Chromatography

Abstract A thin layer chromatographic procedure has been developed for the rapid detection of anthracene photooxidation products. Thus anthracene, anthraquinone, alizarin, quinizarin, and chrysazine were separated by the 1 ppm level by ascending T. L. C. on silica gel with benzene-carbon tetrachloride - acetic acid (50:75:0.8) as the solvent system.

Nuclear magnetic resonance spectra of adamantyl-substituted phenols and solvent-induced shifts of sterically hindered protons

The n.m.r. spectra of 2,6-di-1-adamantyl-4-alkylphenols (alkyl = Me, Et, Pri, But, or 1-adamantyl) have been recorded for dilute solutions in [2H]chloroform, carbon disulphide, carbon tetrachloride, hexane, and [2H6]benzene. The internally referenced chemical shifts of the ring and phenolic protons are presented. The resonance of the sterically hindered 3- and 5-protons is shifted, relative to solutions in carbon tetrachloride or hexane, downfield in [2H6]benzene and in [2H]chloroform, and upfield in carbon disulphide. These internally referenced solvent shifts become larger as steric hindrance of the protons increases, except in the case of solutions in [2H]chloroform, for which the shift, relative to hexane solution, becomes smaller as the steric hindrance of the protons increases. Comparison with data for the corresponding 2,6-di-t-butylphenols reveals that the adamantyl group causes shielding of neighbouring protons. The chemical shifts of the sterically hindered phenolic protons of 2,4,6-tri-t-butylphenol and 2,6-di-1-adamantyl-4-t-butylphenol have been obtained for solutions in carbon tetrachloride–benzene over the whole range of mixture concentrations. The factors causing solvent shifts for the sterically hindered protons in these substituted phenols are discussed.

Thermodynamics of the system benzene-carbon tetrachloride

Abstract The thermodynamic behavior of benzene-carbon tetrachloride solutions at temperatures between 30 and 70°C and over the entire concentration range has been examined in terms of the Maron theory of nonelectrolyte solutions. The interaction parameter calculated from vapor pressure data has been found to be independent of concentration and to be linearly dependent on temperature. Use of this parameter in the equations given by the theory allows complete correlation of the available heats, entropies, and heat capacities of mixing for this system. For all these properties very good agreement has been obtained between the calculated and observed quantities.

Intensity Enhancement of Forbidden Electronic Transitions by Weak Intermolecular Interactions

This paper discusses the phenomenon where an originally ``forbidden'' electronic transition in a molecule (M) becomes strikingly enhanced through weak interactions with a neighboring perturber (P). The purpose of the paper is to present a general mechanism by which both symmetry-forbidden and multiplicity-forbidden transitions of a molecule in a perturbing environment can gain intensity. The mechanism for intensity enhancement is based on perturbation theory, diagrams being introduced in order to simplify the discussion. The paper emphasizes the fact that the enhanced transition moment may be gained not only from strong transitions in the molecule itself, but also from transitions in the perturbing environment. A number of examples of intensity enhancement are presented and analyzed. The so-called Ham bands of benzene in carbon tetrachloride, for example, are shown to arise from intensity borrowed from the solvent. In spin-forbidden transitions a requirement for enhancement is that either P is paramagnetic (O2 effect) or that strong spin—orbit coupling in the excited states of P exists (external heavy-atom effect). Besides spin-forbidden and symmetry-forbidden transitions, double and multiple transitions made allowed through weak intermolecular interactions are discussed. Double transitions in molecular oxygen are analyzed, and it is concluded that intensity is borrowed from the Schuman—Runge band system. In this case an intermolecular interaction energy of only 5 cm−1 is required to give the observed intensity, so the transition can hardly be thought of as being due to the ``O4 molecule.'' A study of these weak interactions allows knowledge to be gained about molecular eigenfunctions in the important but often neglected regions of intermolecular space.

Significant-Structure Theory of Binary Mixtures. II

The significant-structure theory has been successfully applied to the three binary systems involving carbon tetrachloride, benzene, and cyclohexane. In the first paper, the system carbon tetrachloride—cyclohexane was discussed. In this paper the other two systems, carbon tetrachloride—benzene and cyclohexane—benzene, are considered. The excess properties have been calculated on mixing at constant pressure as well as on mixing at constant volume. By taking account of the fact that the parameters in our theory are concentration dependent, a partition function for mixtures can be formulated in a similar way to those for single liquids.

Approximate Theory of Transport in Simple Dense Fluid Mixtures

The theory of transport proposed by Rice and Kirkwood is extended to the case of multicomponent systems. As in the previous case, the intermolecular force contributions to the shear and bulk viscosities and the thermal conductance are displayed as functions of the diffusion coefficient and the thermodynamic properties of the mixture. The self-diffusion coefficient is related to the intermolecular forces and molecular distribution function, thereby completing the molecular basis of the computation. Formulas are also given for the thermal diffusion factor and the heat of transport. The reader is referred to Eqs. (91), (104), (106), and (109). The theory presented predicts a form of volume fraction mixing. For example, the shear viscosity becomes η=(ν1*/ν)2η1*+(ν2*/ν)2η2*+2(ν1*ν2*/ν2)η12*,with v1* and v2* the volume of N1 molecules of component one and of N2 molecules of component two, respectively, at the same temperature and pressure as the mixture. The quantities η1*, η2*, η12* are composition dependent so that the predicted mixing law is not pure volume fraction mixing except in the case of an ideal solution. The theory is compared with experimental measurements of the viscosity of benzene—carbon tetrachloride mixtures, and good agreement is found. The agreement between theory and experiment is discussed with reference to the mechanism of irreversibility.

Time Spectra of Positrons Annihilating in Organic Liquids Containing Halogens

Measurements have been made of the mean life τ2, and the percent I2, of positrons forming triplet positronium in propyl halides and in benzene-carbon tetrachloride solutions. The experimental variations of I2 in the propyl halides can be predicted assuming a semiempirical equation of the form 100–4/3I2=AN1+2.4N2, where A is the annihilation factor of the parent molecule and N1 and N2 are the percent volumes of the parent and halide, respectively. A equal to 0.36 is needed for the propyl parent. This equation also predicts correctly the experimental values for the benzyl halides if A equal to 0.53 is used as the benzyl annihilation factor. The quenching of I2 in the benzene-carbon tetrachloride solutions is much greater than that computed by the equation and the variation in quenching closely resembles that obtained in aqueous nitrate-ion solutions.

The absorption spectrum of benzene in carbon tetrachloride at 77°K

The absorption spectrum of benzene has been studied in carbon tetrachloride solutions of various concentrations at 77°K and in 10 per cent solution at various temperatures from 30°C to 77°K. The so-called crystalline spectrum appeared strongly at low temperature and its occurrence was ascribed to the deformation of benzene due to crystal forces of the carbon tetrachloride matrix.

Composition Dependence of the Thermal Conductivity of Regular Solutions

It is demonstrated from the statistical mechanics of transport processes that the product κη of the coefficients of thermal conductivity and viscosity may be expected to be independent of composition in regular solutions. This conclusion is verified for the system benzene-carbon tetrachloride.