Thermodynamics of aqueous solutions of nonelectrolytes. II. Enthalpies of transfer of 1-methyl-2-pyrrolidinone from water to many aqueous alcohols

Molar excess enthalpies were measured for 1-methyl-2-pyrrolidinone mixed with various pure alcohols and with aqueous alcohols at a low mole fraction of 1-methyl-2-pyrrolidinone at 298°K, using a LKB flow microcalorimeter. Enthalpies of transfer of 1-methyl-2-pyrrolidinone from water to the aqueous alcohol mixtures are estimated from the molar excess enthalpies. The results are discussed from the point of view of the effect of 1-methyl-2-pyrrolidinone on the structure of aqueous alcohol solutions.     

Structure and molecular interactions in {ethanol + (propan-1-ol/propan-2-ol)} mixtures at 303.15 K

In view of industrial importance of binary {ethyl alcohol + (propan-1-ol/propan-2-ol)} mixtures, the densities (ρ) and refractive indices (n _D ) of these alkanols mixtures were measured for different compositions at 303.15 K. Molar volumes (V _m) and excess molar volumes (V ^E) of these binary mixtures were calculated from experimental density data of pure solvents and solvents mixtures. The measured refractive index and density data was used to calculate specific refractions (R _D ), molar refractions (R _M) and apparent molar refractions (R _{φ, i} ) of binary mixtures. From mole fraction dependence of apparent molar refractions, the limiting apparent molar refractions (R _{φ, i} ^○ ) of propan-1-ol and propan-2-ol have been determined. The graphical values of R _{φ, i} ^○ for propan-1-ol and propan-2-ol were found to be 9.5664 and 7.405 cm³ mol^?1 respectively. Structural changes, geometrical fittings and molecular interactions in binary mixtures of these alkanols have been discussed.     

Reductive cleavage of C-OH bonds in allyl position-formation of gaseous products in the course of the cathodic reduction of some simple unsaturated alcohols

The problem of the reductive cleavage of C?OH bonds in allyl position has been considered starting from the literature data concerning the behaviour of allyl alcohol. The formation of hydrocarbons has been shown in the case of the electroreduction of crotyl alcohol, 2-butene-1,4-diol, propargyl alcohol, 2-butyne-1,4-diol and 1-butyne-3-ol. The composition of the gaseous products was analyzed, current efficiency values with respect to the hydrocarbon formation were calculated. Schemes for the reduction path were given.     

Enthalpic changes on mixing two couples of S- and R-enantiomers of heptane-2-ol, octane-2-ol, nonane-2-ol, 3-chloro-propane-1,2-diol, 2-methyl-1,4-butanediol at 298.15 K

Enthalpies of mixing of (R)- and (S)-enantiomers of liquid chiral compounds such as heptane-2-ol, octane-2-ol, nonane-2-ol, 3-chloro-propane-1,2-diol and 2-methyl-1,4-butanediol have been measured over a range of mole fractions at 298.15 K, albeit very small values. Mixing of heterochiral liquids of heptane-2-ol, octane-2-ol, nonane-2-ol, 3-chloro-propane-1,2-diol, realized enthalpic destabilization over the whole range of mole fractions, whereas that of 2-methyl-1,4-butanediol realized enthalpic stabilization over entire compositions. The maximum values of enthalpies of mixing and the intermolecular interaction of cohesive energy density and entropy of vaporization showed a linear correlation except for the compounds having two chiral centers and others.     

Physico-chemical and excess properties of the binary mixtures of methylcyclohexane + ethanol, + propan-1-ol, + propan-2-ol, + butan-1-ol, + 2-methyl-1-propanol,or 3-methyl-1-butanol at T = (298.15, 303.15, and 308.15) K

Physico-chemical properties viz., density, viscosity, and refractive index at temperatures = (298.15, 303.15, and 308.15) K and the speed of sound at T = 298.15 K are measured for the binary mixtures of methylcyclohexane with ethanol, propan1-ol, propan-2-ol, butan-1-ol, 2-methyl-1-propanol, and 3-methyl-1-butanol over the entire range of mixture composition. From these data, excess molar volume, deviations in viscosity, molar refraction, speed of sound, and isentropic compressibility have been calculated. These results are fitted to the polynomial equation to derive the coefficients and standard errors. The experimental and calculated quantities are used to study the nature of mixing behaviours between the mixture components.     

(Z)-1-三苯基锡基-3-对氯苯基-1-丁烯-3-醇及其卤代物的合成、表征和晶体结构

在氮气保护下,3-对氯苯基-1-丁炔-3-醇与三苯基氢化锡进行游离基加成反应,获得加成物(Z)-1-三苯基锡基-3-对氯苯基-1-丁烯-3-醇(1).加成物(1)与卤素反应后,与锡原子相连的苯基被取代,得到一卤代、二卤代和混合二卤代物(2-8).通过元素分析、¹HNMR和IR表征了化合物1～8的结构,并测定了加成物(1)、一溴代物(3)和二溴代物(5)的晶体结构.在加成物(1)的晶体结构中存在一对对映体,由于分子内存在较弱的O→Sn配位作用,构成以锡原子为中心的扭曲四面体构型.在化合物3和5分子中,存在分子内O→Sn配位键,构成以锡为中心的扭曲三角双锥构型.该系列化合物分子内的O→Sn配位能力和Lewis酸性强弱的顺序为:二卤化物>一卤化物>加成物;氯代物>溴代物>碘代物.     

Kinetics and mechanism of the hydration of the equilibrium mixture of 3-methyl-1-buten-3-ol and 3-methyl-2-buten-1-ol with isoprene in aqueous solutions of sulfuric acid

The kinetic relationships of the hydration of an equilibrium mixture of 3-methyl-1-buten-3-ol (dimethylvinylcarbinol, DMVC) and 3-methyl-2-buten-1-ol (dimethylallyl alcohol, DMAA) with isoprene (C₅H₈) were investigated in aqueous solutions of sulfuric acid from 24.9 to 49.7% at 25°C. Data were obtained on the mechanism of hydration of the equilibrium mixture of DMVC and DMAA with isoprene.Deceased.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1311–1314, June, 1992.     

Viscosity of Aqueous Solutions of Formamide,N-Methylformamide and N,N-Dimethylformamide

Abstract

Viscosities of aqueous solutions of formamide, N-methylformamide and N,N-dimethylformamide have been measured at temperatures 303.15, 308.15, 313.15, 318.15 and 323.15 K. For formamide + water system the viscosity increases exponentially with respect to the mole fraction of formamide. In contrast, N-methylformamide+water and N,N-dimethylformamide+water systems exhibit maxima in water-rich region, the maxima of the latter being higher and sharper than those of the former system. The excess viscosities of formamide+water system are positive at 323.15 K, which turn to negative values at 303.15 K, the magnitude of the values being very small irrespective of their sign. On the other hand, N-methylformamide+water and N,N-dimethylformaide+water systems show large positive excess viscosities for the whole range of composition. The viscosities and excess viscosities for the system formamide+water have been explained by assuming some complex formation between the components with the simultaneous disruption of water structures. For N-methylformamide+water and N,N-dimethylformamide+water systems, it has been assumed that cluster-like structure of water is formed around methyl group(s) attached to N-atom of the amides, which influences the viscosity behaviour of these systems strongly.     

Thermodynamics of aqueous solutions of nonelectrolytes. I. Enthalpies of transfer of 1-methyl-2-pyrrolidinone from water to aqueous methanol

Molar excess enthalpies were measured for 1-methyl-2-pyrrolidinone mixed with water and with methanol over the whole concentration range and with aqueous methanol at the low mole fraction of 1-methyl-2-pyrrolidinone at 298.15°K, using a LKB flow microcalorimeter. Enthalpies of transfer of 1-methyl-2-pyrrolidinone from water to aqueous methanol were estimated from the molar excess enthalpies. The result was qualitatively in agreement with the conclusion described by Arnett et al.     

Effect of physicochemical properties of water-propane-2-ol mixture and temperature on thermodynamics of Cu complexation with glycine

The stability constants of Cu²⁺ complexes with glycine are determined by potentiometric method in water-propane-2-ol mixture, i.e., [CuL]⁺, CuL₂ (L = Gly^–) (0.070, 0.167, 0.310 mole fraction of alcohol), and [CuHL]²⁺ (0.070 mole fraction of alcohol) at 298.15, 308.15, and 318.15 K. Thermodynamic characteristics of Cu²⁺ complexation with glycine and the Gibbs energy of transfer of complex species [CuL]⁺ and CuL₂ from water to a mixed solvent are calculated. The solvation-thermodynamic analysis of effects of water-propane-2-ol solvents and of separate solvation contributions of reagents to Cu²⁺ coordination with glycine is performed. The increasing stability of the [CuL]⁺ and CuL₂ complexes in water-propane-2-ol as compared to that in pure water is explained by the increasing energy of solvation of complex species [CuL]⁺ and CuL₂ and by the decreasing energy of solvation of Cu²⁺ and Gly^– ions.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 4, 2005, pp. 311–318.Original Russian Text Copyright © 2005 by Tsurko, Bondarev, Shikhova, Khrebto.     

Viscosity of Aqueous Solutions of n-butylamine,sec-butylamine and tert-butylamine

Abstract

Viscosities of the systems, water (W) + n-butylamine (NBA), W + sec-butylamine (SBA) and W + tert-butylamine (TBA) have been measured in the temperature range 298.15–323.15K. The viscosities (η) and excess viscosities (η^E) have been plotted against mole fraction of amines (X ₂). On addition of amines to water, viscosities first increase rapidly, then pass through maxima at 0.2 mole fraction of amines and then decline continuously as the addition of amines is continued. η^E show large positive values, with maxima also at 0.2 mole fraction of amines. The maxima of the curves of η and η^E vs. mole fraction of butylamines follow the order, W + TBA > W + SBA > W + NBA. The ascending part of the η vs. X ₂ curves in the water-rich region is explained by the hydrophobic hydration caused by the hydrocarbon tails and the hydrophilic effect due to — NH₂ group of amines. Following the maxima, amine - amine association is preferred, which accounts for the steady decrease of viscosity up to the pure state of amines.     

Heat capacity of aqueous mixtures of diethanolamine with 2-amino-2-methyl-l-propanol

Heat capacities of aqueous mixtures of diethanolamine (DEA) with 2-amino-2-methyl-1-propanol (AMP) were measured over the temperature from 30 to 80 °C with a differential scanning calorimeter (DSC). For mole fractions of water ranging from 0.2 to 0.8, 16 concentrations of the DEA + AMP + water systems were studied. The binary system DEA + AMP with nine various concentrations were also studied. The heat capacities of aqueous mixtures of DEA with AMP presented in this study are, in general, of sufficient accuracy for most engineering-design calculations.     

Effect of temperature and concentration on density,viscosity and ultrasonic velocity of the pentan-1-ol + nitrobenzene mixtures

Density, viscosity and ultrasonic velocity values for pentan-1-ol (1) + nitrobenzene (2) mixtures were measured at temperatures of 303.15 to 313.15 K. The new equations have been developed for viscosity and ultrasonic velocity by the use of statistical software Design Expert. The excess values like excess molar volume, viscosity deviation and ultrasonic velocity deviations have been calculated from density, viscosity and ultrasonic velocity respectively. The excess values were correlated using the Redlich-Kister polynomial equation to obtain their coefficients and standard deviations.     

手性邻二醇－－（2S，3R）－1，2，3－丁三醇－1－对甲苯磺酸酯的不对称合成

以（E）－2－丁烯－1－醇为原料经不对称环氧化反应合成2，3－环氧醇（1） 。该环氧醇的对甲苯磺酸酯对映选择性酸水解开环制备手性邻二醇（2）(95％ee)。     

Viscosities of Aqueous Solutions of Dimethylsulfoxide, 1,4-Dioxane and Tetrahydrofuran

Abstract

Viscosities of the systems, water(W) + dimethylsulfoxide(DMSO), W + 1,4-dioxane (DXN) and W + tetrahydrofuran(THF), are measured at temperatures ranging from 303.15–323.15K. Viscosities and excess viscosities are plotted against the mole fraction of the organic solutes. On addition of solutes to water, viscosities first increase rapidly, pass through maxima and then decline continuously until the pure state of solutes is reached. Excess viscosities are found to be positive and large in magnitude and their curves are similar to those of the viscosity curves. The ascending part of the viscosity curves in the water-rich region is accounted for by both the hydrophobic effect of forming cage structures around solutes and the hydrophilic effect forming H-bonds between water and organic solutes. The descending part of the viscosity curves is explained by the continuous destruction of cages formed. The maxima are thought to be due to competing processes of formation and destruction of cage structures.     

Viscosity of aqueous solutions of some diamines

Viscosities of the systems, ethylenediamine (ED) + water (W), 1,2-diaminopropane (DAP) + W, trimethylenediamine (TMD) + W and N,N-dimethyltrimethylenediamine (DMTMD) + W, have been measured for the whole range of composition at temperatures ranging from 303.15 to 323.15?K. The viscosities have been plotted against the mole fraction of diamines, showing some common characteristics for all the systems. On addition of diamines to water viscosities rise up very rapidly and pass through maxima. Following the maxima viscosities decline quite rapidly and monotonously up to about 0.6 mole fraction of diamines, which then fall down rather slowly. The hydrophobic and hydrophilic effects are considered responsible for the ascending part of viscosities in water-rich region, although the former is thought to be much more predominant than the latter. The height of viscosity maxima and their shifting to more water-rich region have been explained preferentially in terms of the hydrophobic effect. The declining part of viscosities is thought to be due to continuous destruction of cage structures formed by hydrophobic interaction. The excess viscosities have been calculated and plotted against mole fractions of diamines. The characteristics of excess viscosities have been explained by the same reasonings as used to explain viscosities.     

Effect of solvent on the kinetics of arylsulfonylation of N-alkylated anilines in a water-propan-2-ol system

The effect of the composition of a water-propan-2-ol solvent on the kinetics of arylsulfonylation of N-ethyl-, N-isopropyl-, and N-butylanilines with 3-nitrobenzenesulfonyl chloride at 298 K was studied. The reaction rate constant increases monotonically with an increase in the water fraction in the solvent from 5 to 30 wt.%. The apparent activation parameters of the reaction of N-butylaniline with 3-nitrobenzenesulfonyl chloride were calculated. No considerable changes in the activation parameters of the reaction were observed on going from pure propan-2-ol to a 10% aqueous solution, which indicates that the mechanism remains unchanged upon solvent change. Propan-2-ol with a water content of 5–30 wt.% can be used in the synthesis of arylsulfonylation products of the amines under study in 98–99% yield. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 937–939, June, 2006.     

Volumetric properties of (1-propoxypropan-2-ol + water) mixtures between (283 and 303) K: The effect of branching on alkoxyalcohols

Accurate density values are reported for aqueous binary mixtures of 1-propoxypropan-2-ol (1-PP-2-ol) over the whole composition range and temperatures between (283 and 303) K at intervals of 5 K. Excess molar volumes of the mixture, , apparent molar volumes of 1-PP-2-ol, V_φ,2, as well as excess partial molar volumes, , of both components were obtained over the entire composition and temperature ranges. Thermal expansibility effects on this (amphiphile + water) mixture are analysed in terms of excess molar isobaric expansions, , of the mixture and from the temperature dependence of limiting excess partial molar isobaric expansions, , for both chemical substances in the mixture. An analytical method based on Redlich−Kister fitting equations for as a function of the mole fraction has been used to obtain limiting excess partial molar volumes, . The excess properties are referred to a thermodynamically defined ideal liquid mixture. Interesting insights into the mixing process are gained from the visual impact of plots showing the composition and temperature dependence of different excess molar thermodynamic properties. The choice of 1-PP-2-ol was specially meant to highlight the role of branching in the alcohol versus alkoxy moieties. The present thermodynamic data are compared with that for isomeric 2-butoxyethanols, which are structural isomers of 1-PP-2-ol, and for 2-isopropoxyethanol. From this comparison an extended insight is gained into the role of branching and chain length on the mixing process and particularly in changes of local H-bond patterns of hydration water.     

Excess Molar Enthalpies and Excess Molar Volumes of (Water+Octan-1-ol or +Octan-2-ol) at 298.15 K

The excess molar enthalpies and volumes have been determined for the binary system (water+octan-1-ol or +octan-2-ol) by means of direct calorimetric and densimetric measurements in the miscibility range. The experimental data were described through a Redlich-Kister type equation. For excess enthalpies a sigmoidal shape is predicted,while excess volumes are negative except for a little positive queue observed for(water+octan-1-ol) system at very low water content. Also the partial molar enthalpies of solution and the partial molar volumes of water in the two isomeric octanols at infinite dilution have been evaluated and discussed. A comparison is made between excess enthalpies and excess free energies calculated by the UNIFAC method. This revised version was published online in July 2006 with corrections to the Cover Date.