Dielectric properties of mixtures of acetylene tetrachloride with toluene and acetone

Relative permittivities are reported for binary liquid mixtures of acetylene tetrachloride (ATC) with toluene and acetone at 35°C. Measurements of refractive indices have also been made for the mixtures. The values of the quantity , the deviations of the relative permittivities of these mixtures from ideality, have been calculated. The negative values of obtained for ATC+ toluene mixtures may be explained as being due to a decrease in the degree of alignment of the molecular dipoles with changing composition of the mixture, whereas the positive values of obtained for ATC+acetone mixtures are attributed to the formation of molecular complex between acetone and CHCl₂CHCl₂. The values of the Kirkwood correlation parameter g for both sets of mixtures have been calculated using the relative permittivity data.     

Synthesis,characterization and crystal structure of a novel mononuclear peroxotungsten(VI) complex with an acetone peroxide ligand

A new mononuclear peroxo complex of tungsten of the formula (gu)₂[WO(O₂)₂CO(O)₂(CH₃)₂](CH₃)₂CO (where gu⁺ = guanidinium ion, CN₃H₆⁺ion) has been synthesized and characterized by infrared, Raman, and ¹H NMR spectroscopies. The crystal structure of (gu)₂[WO(O₂)₂CO(O)₂(CH₃)₂](CH₃)₂CO determined by X-ray diffraction indicates that the side-on peroxo groups and the bidentate acetone peroxide ligand bind the W(VI) centre leading to an hepta coordination mode. The guanidinium ion occurring as a counterion and the hydrogen-bound interactions stabilize the complexes. The stability of the complex in aqueous solution was determined by Raman and NMR spectroscopies.     

Electro-kinetic transport of acetone,water and their binary mixtures

Summary Electroosmosis of acetone, water and their binary mixtures through thorium oxide (ThO₂) plug membrane has been studied and the data analysed using non-equilibrium thermodynamics. The phenomenological coefficients,L ₁₁ andL ₁₂ have been found to vary nonlinearly with composition. Excess phenomenological coefficients have therefore been evaluated and the results explained in terms of the membrane permeant and permeant-permeant interactions. The results on the measurement of electrophoretic velocity of ThO₂ particles dispersed in acetone-water mixtures also lead to the conclusion that the components of the mixture interact appreciably.

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Zusammenfassung Die Elektroosmose von Aceton, Wasser and deren binären Gemische durch eine ThO₂-Pflock-Membran wurde untersucht; die Daten wurden mit Hilfe der Nichtgleich-gewichts-Thermodynamik analysiert. Die phänomenologischen KoeffizientenL ₁₁ undL ₁₂ ändern sich hiernach nichtlinear mit der Zusammensetzung. Es wurden daher Exzess-L ₁₁-und -L ₁₂-Werte berechnet; die Ergebnisse wurden auf Grund der Membran-Permeant- und Permeant-Permeant-Wechselwirkungen diskutiert. Aus der Messung der elektrophoretischen Geschwindigkeit von ThO₂-Teilchen, die in Aceton-Wasser-Gemischen dispergiert sind, folgt, daß eine merkliche Wechselwirkung zwischen den Komponenten der Mischung vorliegt.

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With 8 figures and 1 table     

Conformational changes of a polyelectrolyte in mixtures of water and acetone

Samples of a polyelectrolyte poly(methacryloylethyl trimethylammonium methylsulfate), PMETMMS, with molar masses M_w = 22−25 × 10⁶ were examined with viscosity, static light scattering, and conductivity measurements in a water–acetone solvent. Because acetone is a nonsolvent for this polymer the measurements were performed to determine the influence of the solvent composition, the polymer concentration, and the presence of added ions on the conformation of the polyelectrolyte in mixed solvents. The possible influence of a hydrodynamic field on the polymer conformation was also studied. The viscosity of the polymer solutions as a function of polymer concentration, as well as of the solvent composition, was studied using a broad range of shear rates. When the mass fraction of acetone in the solvent, γ, is below 0.5, the solutions show a usual polyelectrolyte behavior. When γ ≥ 0.80, the polymer adopts a compact conformation. This is observed as a decrease of the radius of gyration, R_g, second virial coefficient, A₂, the viscosity, and also as a change in the conductivity of the solution. The change in the polymer conformation may be induced also by dilution. When 0.60 ≤ γ < 0.80, a gradual decrease in the polymer concentration leads to a sudden decrease of the reduced viscosity, which indicates a decrease in the particle size. The values of M_w measured by static light scattering were constant in all experiments. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1107–1114, 1998     

Ion association of persulphates in water and water+acetone mixtures

Conductometric studies have been made for the persulphates of sodium, potassium, and ammonium in water and water+acetone (X_acetone=0.016, 0.033, 0.072, 0.117 and 0.171) mixtures at 298.15, 303.15, 308.15 and 313.15 K, using Shedlovsky and Fuoss–Kraus extrapolation techniques. The limiting molar conductance (Λ_o), association constant (K_A), Walden product (Λ_oη_o) and the thermodynamic functions for the process of ion-pair formation have been evaluated and discussed.     

Prediction of viscosities and COSMO-RS analyses in binary mixtures of N,N-dimethylformamide with acetone

Experimental viscosities, η, for pure N,N-dimethylformamide (DMF) and acetone (ACT) and their binary mixtures are measured over the whole composition range as a function of temperature between 298.15 and 313.15 K. The deviations in viscosity, ?η, Gibbs free energy of activation ?G, entropies ?S*, enthalpies ?H of activation of viscous flow have been calculated. The determination of excess molar volumes, Vη^E, was calculated from the experimental viscosities for the binary mixtures. The conductor-like screening model is applied to interpret the intermolecular forces. The σ-profile is computed for the N,N-DMF and ACT with conductor-like screening model for real solvents. The experimental results were found to be in good agreement with the theoretical predictions. Moreover, viscosity data were calculated from the theoretical equations of Grunberg and Nissan, Hind et al. and Wilke for the entire systems. All results obtained were averaged experimentally and theoretically in terms of average deviations.     

High-frequency electric conductivity of mixtures of water with acetone,dimethyl sulfoxide,and carbamide

The high-frequency (HF) electric conductivity (EC) of water-acetone, water-dimethyl sulfoxide (DMSO), and water-carbamide mixtures was analyzed. The limiting high-frequency conductivity decreased as the content of the organic component in the mixture increased. When the acetone and DMSO concentrations increased, the high-frequency conductivity passed through a maximum at 2450 MHz and increased with the carbamide concentration in its mixtures with water. The optimum conditions for the absorption of HF energy by the aqueous organic mixtures under study were determined.     

Thermometric titration of some amines in water—acetone mixtures

The enthalpies of protonation of some N-bases in H₂O—acetone, 0, 0.25, 0.5, 0.75 and 0.95 mole fraction at 298 K have been determined by calorimetry. Solutions of amines in each solvent system were titrated enthalpimetrically with HClO₄ solution. The bases studied were piperidine, n-butylamine, 2-amino-2-methyl-1,3-propanediol, (AMP), tris(hydroxymethyl) aminomethane, tris, 2,2-bis-(hydroxymethyl-2,2′,2″-nitrilotriethanol, (bis-tris) and pyridine.The results are discussed in terms of the preferential solvation of ions by two types of solvent molecules. The enthalpy of protonation of all the bases passes through a minimum at a solvent composition of 0.75 mole fraction of acetone.     

Determination of organic peracids and hydrogen peroxide in mixtures

A simple method for the determination of organic peracids and hydrogen peroxide in mixtures is presented. The method is based on the instantaneous reaction of peracids with neutral potassium iodide and on the formation of a stable complex between hydrogen peroxide and titanyl ions. This complex is decomposed with sodium fluoride and the ensuing reaction with iodide is accelerated with molybdic acid. The influence of the different additives on the analytical results has been studied.     

A kinetic analysis of the photolysis of mixtures of acetone and propylene

The photolysis of mixtures of acetone and propylene at 308 nm has been studied kinetically from approximately 300 K to 580 K. Rate constants were calculated for the reactions at total pressures ranging from 110 torr to 750 torr and for [C₃H₆]/[(CH₃)₂CO] ratios in the range 0.03 to 3.3. No dependence of the rate constants on total pressure or on this concentration ratio could be detected within this range of conditions. The temperature dependence of the rate constants is given by © 1994 John Wiley & Sons, Inc.     

On the evaluation of the Kirkwood-Buff integrals of aqueous acetone mixtures

The Kirkwood-Buff integrals of acetone-water mixtures are determined using two experimental techniques: small-angle neutron scattering and vapor pressure measurements, in order to test the precision and reliability that can be achieved. The data are then compared with those previously reported by different authors, which tend to show considerable variation between them. The various possible sources of inaccuracies are pointed out, both from experimental origins and from the numerical treatment of the data. Comparison with recent simulation results allows to critically compare different models and provide some information about the microstructure of the aqueous mixture.