Excess enthalpies of ketone+methyl methylthiomethyl sulfoxide or +dimethyl sulfoxide at 298.15 k

Excess enthalpies of sixteen binary mixtures between one each of methyl methylthiomethyl sulfoxide (MMTSO) and dimethyl sulfoxide (DMSO) and one of ketone {CH₃CO(CH₂)_nCH₃, n=0 to 6 and CH₃COC₆H₅} have been determined at 298.15 K. All the mixtures showed positive excess enthalpies over the whole range of mole fractions. Excess enthalpies of ketone+MMTSO or DMSO increased with increasing the number of methylene radicals in the methyl alkyl ketone molecules. Excess enthalpies of MMTSO+ketone are smaller than those of DMSO+ketone for the same ketone mixtures. The limiting excess partial molar enthalpies of the ketone, H ₁ ^E,∞, in all the mixtures with MMTSO were smaller than those of DMSO. Linear relationships were obtained between limiting excess partial molar enthalpies and the number of methylene groups except 2-propanone.     

Deuterium Isotope Effect on Excess Enthalpies of Methanol or Ethanol and Their Deuterium Derivatives at 298.15 K

Excess enthalpies of six binary mixtures of CH₃ OD+CH₃ OH, CH₃ OD+CD₃ OD, CD₃ OD+CH₃ OH, C₂ D₅ OD+C₂ H₅ OH, C₂ D₅ OD+C₂ H₅ OD, C₂ H₅ OD+C₂ H₅ OH have been determined over the whole range of mole fractions at 298.15 K in order to know the isotopic effect on hydrogen-bonding accurately, although there are many reports on the differences in the strength of hydrogen-bonding between OH and OD. All excess enthalpies measured are very small and endothermic. The mixtures of CH₃ OD+ CH₃ OH, and C₂ D₅ OD+C₂ H₅ OH showed the largest excess enthalpies among each methanol and ethanol mixtures. The difference of intermolecular interaction between OH and OD in methanol and ethanol was almost same value of (1.82±0.04) J mol^-1 Excess enthalpies of 1,4-dimethylbenzene+1,3-dimethylbenzene and 1,4-dimethylbenzene+1,2-methylbenzene were measured by three different principle calorimeters at 298.15 K in order to know the precision of calorimetry for a small enthalpy change. This revised version was published online in July 2006 with corrections to the Cover Date.     

Thermodynamic study of 2-methyl-tetrahydrofuran with isomeric chlorobutanes

Excess molar volumes, V^E, isentropic compressibility deviations, Δκ_S, and excess molar enthalpies, H^E, for the binary mixtures 2-methyl-tetrahydrofuran with 1-chlorobutane, 2-chlorobutane, 2-methyl-1-chloropropane and 2-methyl-2-chloropropane have been determined at temperatures 298.15 and 313.15 K, excess molar enthalpies were only measured at 298.15 K. We have applied the Prigogine-Flory-Patterson (PFP) theory to these mixtures at 298.15 K.     

Excess enthalpies of alkane-1-amines {CnH2n+1NH2, n = 3-8} + methyl methylthiomethyl sulfoxide and +dimethyl sulfoxide at 298.15 K

Excess enthalpies of binary mixtures between each of alkane-1-amines {C_nH_2n+1NH₂, n=3-8} and methyl methylthiomethyl sulfoxide (MMTSO) or dimethyl sulfoxide (DMSO) have been determined at 298.15 K. All mixtures showed positive enthalpy changes over the whole range of mole fractions.The limiting excess partial molar enthalpies of the aliphatic amines, H₁^E,∞, of all the mixtures with MMTSO or DMSO studied were smaller than those of MMTSO or DMSO, H₂^E,∞, respectively. Linear relations are obtained between limiting excess partial molar enthalpies and number of methylene groups.     

Excess molar enthalpies of binary mixtures for (tributyl phosphate+methanol/ethanol) at 298.15 K

Excess molar enthalpies of binary mixtures for tributyl phosphate (TBP)+methanol/ethanol were measured with a TAM air Isothermal calorimeter at 298.15 K and ambient. The results for xTBP+(1–x)CH₃OH are negative in the whole range of composition, while the values for xTBP+(1–x)C₂H₅OH change from positive values at low x to small negative values at high x. The experimental results have been correlated with the Redlich–Kister polynomial. IR spectra of the mixtures were measured to investigate the effect of hydrogen bonding in the mixture.     

Densities and excess volumes of the ternary system butyl ethanoate + n-decane + 1-chlorobutane at 298.15 K

Excess molar volumes at 298.15 K and atmospheric pressure were measured for {x₁ CH₃CO₂(CH₂)₃CH₃ + x₂ C₁₀H₂₂ + (1 − x₁ − x₂) Cl(CH₂)₃CH₃} and the corresponding binary mixtures, with an Anton Paar densimeter. All the experimental values were compared with the results obtained by different prediction methods.     

Excess enthalpies and excess volumes of 1-nitropropane +, and 2-nitro-propane +, each of several non-polar liquids

Excess molar enthalpies H_m^E and excess molar volumes V_m^E have been measured for xC₃H₇NO₂ + (1 ? x)c-C₆H₁₂ at 298.15 and 318.15 K; +(1 ? x)CCl₄ at 298.15 and 318.15 K; +(1 ? x)C₆H₆ at 298.15 and 318.15 K; +(1 ? x)C₆H₁₄ (V_m^E only) at 298.15 K; +(1 ? x)p-C₆H₄(CH₃)₂ at 298.15 K; and for xCH₃CH(NO₂)CH₃ + (1 ? x)c-C₆H₁₂ at 298.15 and 318.15 K; +(1 ? x)CCl₄ at 298.15 and 318.15 K; +(1 ? x)C₆H₆ at 298.15 K; +(1 ? x)C₆H₁₄ at 298.15 K; +(1 ? x)(CH₃)₂CHCH(CH₃)₂ for H_m^E at 318.15 K and for V_m^E at 298.15 K; and +(1 ? x)C₁₆H₃₄ at 298.15 K. The H_m^E′s were determined with an isothermal dilution calorimeter and the V_m^E′s with a continuous-dilution dilatometer. Particular attention was paid to the region dilute in nitroalkane. In general H_m^E is large and positive for (a nitropropane + an alkane), less positive for (a nitropropane + tetrachloromethane), and small for (a nitropropane + benzene) and for (a nitropropane + 1,4-dimethylbenzene). The mixture with hexadecane shows phase separation. V_m^E is large and positive for (1-nitropropane + cyclohexane), less positive for (1-nitropropane + hexane), and S-shaped for (1-nitropropane + tetrachloromethane) with negative values in the 1-nitropropane-rich region. For (1-nitropropane + benzene) and for (1-nitropropane + 1,4-dimethylbenzene) V_m^E is negative. For mixtures with 2-nitropropane the results are similar except that for benzene V_m^E is S-shaped with positive values in the 2-nitropropane-rich region.     

Excess molar enthalpies of the ternary mixtures (1-hexene + tetrahydrofuran or 2-methyltetrahydrofuran + methyl tert-butyl ether) at the temperature 298.15 K

Microcalorimetric measurements of excess enthalpies at the temperature T = 298.15 K are reported for the binary mixture, (x₁C₆H₁₂ + x₂C₄H₈O) and the two ternary mixtures {x₁C₆H₁₂ + x₂(C₄H₈O or C₅H₁₀O) + x₃(C₅H₁₂O)}. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that good estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.     

Excess enthalpies of binary mixtures of 2-, 3-, 4-picoline+n-alkane (C6H14-C10H22) at 298.15 K. Comparison with theory

The molar excess enthalpies measured for binary mixtures of 2-, 3-, 4-picoline +n-alkane (C₆H₁₄-C₁₀H₂₂) at 298.15 K have been compared with the Prigogine-Flory-Patterson theory and the Extended Real Associated Solution model estimations.

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Zusammenfassung Die bei 298.15 K gemessenen molaren Zusatzenthalpien binärer Mischungen aus 2-,3-,4-Picolin und einemn-Alkan (C₆H₁₄-C₁₀H₂₂) wurden mit den nach der Prigonine-Flory-Patterson-Theorie und den nach dem erweiterten Modell real assoziierter Lösungen (ERAS) berechneten Weiten verglichen.

     

Excess enthalpies and molecular interactions in solutions of 1-fluoroalkanes in alkanes,benzene or tetrachloromethane. A group contribution (DISQUAC) study

Molar excess enthalpies H ^E at 298.15 K and atmospheric pressure were determined for 12 binary liquid mixtures, 1-fluoropentane, 1-fluorohexane, or 1-fluorononane + a non-polar solvent (hexane, cyclohexane, benzene, or tetrachloromethane) and were interpreted by the DISQUAC group contribution model. 1-Fluoroalkane + n-alkane mixtures are characterized by two types of groups or contact surfaces, fluorine (F) and alkane (CH₃, CH₂), the remaining mixtures by the additional contact surfaces of the solvents (C₆H₁₂ C₆H₆, or CCl₄). The interchange energies, entirely dispersive, of the alkane-solvent contacts were determined independently from the study of solvent-alkane mixtures. The dispersive F-alkane parameters were assumed to equal the parameters of perfluoroalkanes + n-alkanes. The shape of the H ^E curves of 1-fluorolkane + polarizable solvent (C₆H₆, CCl₄) mixtures are best reproduced by the model when the quasi-chemical F-solvent parameters are assumed to equal zero. The quasi-chemical F-alkane (the same for n-alkanes and cyclohexane) and the dispersive F-solvent parameters were estimated in this work. The 1-fluoroalkane solutions in C₆H₆ or CCl₄ exhibit the characteristic features of polar solute + polarizable solvent mixtures, viz., the deviations from the ideality are less positive than in alkanes and the experimental H ^E curves are strongly asymmetrical.     

Excess molar volumes and viscosities of mixtures of some n-alkoxyethanols with dialkyl carbonates at 298.15 K

Excess molar volumes V_m^E and viscosities η have been measured as a function of composition at atmospheric pressure and 298.15 K for nine {an alkoxyethanol+dimethyl carbonate (C₃H₆O₃), diethyl carbonate (C₅H₁₀O₃), or propylene carbonate (C₄H₆O₃)} mixtures. The alkoxyethanols were 2-methoxyethanol (CH₃OCH₂CH₂OH), 2-(2-methoxyethoxy)ethanol {CH₃(OCH₂CH₂)₂OH}, and 2-{2-(2-methoxyethoxy)ethoxy}ethanol {CH₃(OCH₂CH₂)₃OH}. The V_m^E for each of the carbonate mixtures studied decrease in magnitude as the polar head group of the alkoxyethanol increases. From the experimental results, deviation in the viscosity (Δlnη) have been calculated. The experimental results have been correlated using the Redlich–Kister equation to estimate the coefficients and standard errors. The experimental and calculated quantities are used to discuss the mixing behaviour of the components.     

Excess enthalpies of some aromatic aldehydes in n-hexane, n-heptane and benzene

Calorimetric measurements of molar excess enthalpies, H^E, at 298.15 K, of mixtures containing aromatic aldehydes of general formula C₆H₅(CH₂)_mCHO (with m = 0, 1 and 2) + n-hexane, n-heptane or benzene are reported, together with the values of H^E at equimolar composition compared with the corresponding values of H^E for the aromatic ketones in the same solvents. The experimental results clearly indicate that the intermolecular interactions between the carbonyl groups (CHO) are influenced by the intramolecular interactions between the carbonyl and phenyl groups, particularly for the mixtures containing benzaldehyde.     

Excess enthalpies of binary mixtures of n-octane with each of the hexane isomers at 298.15 K

Excess molar enthalpies, measured at 298.15 K in a flow microcalorimeter, are reported for the five binary systems formed by mixing n-octane with n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane and 2,3-dimethylbutane. The results for equimolar mixtures, together with similar data for other n-alkane + hexane isomer mixtures, are correlated in terms of the acentric factors of the n-alkanes.     

Excess molar enthalpies for ternary mixtures of (methanol or ethanol + water + tributyl phosphate) at <Emphasis Type="Italic">T</Emphasis> = 298.15 K

Excess molar enthalpies for two ternary mixtures of {x ₁ tributylphosphate (TBP) + x ₂ water + x ₃ methanol/ethanol} were measured at T = 298.15 K and atmospheric pressure using a TAM Air isothermal calorimeter, by mixing methanol or ethanol with binary mixtures of (water + TBP). Excess enthalpies for initial binary mixtures of (water + TBP) were also measured under the same conditions, which showed phase separation at low molar fraction of TBP. Experimental results of the ternary mixtures were expressed with constant excess molar enthalpy contours on Roozeboon diagrams.     

Excess molar enthalpies of the ternary mixtures: (tetrahydrofuran or 2-methyltetrahydrofuran + methyl tert-butyl ether + n-octane) at the temperature 298.15 K

Microcalorimetric measurements of excess enthalpies at the temperature T = 298.15 K are reported for the two ternary mixtures {x₁(C₄H₈O or C₅H₁₀O) + x₂C₅H₁₂O + x₃C₈H₁₈}. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that good estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.     

Standard molar enthalpies of formation of Ln(C9H6NO)2(C2H3O2) (Ln: Nd, Sm)

Using an on-line solution-reaction isoperibol calorimeter, the standard molar enthalpies of reaction for the general thermochemical reaction: LnCl₃·6H₂O(s) + 2C₉H₇NO(s) + CH₃COONa(s) = Ln(C₉H₆NO)₂(C₂H₃O₂)(s) + NaCl(s) + 2HCl(g) + 6H₂O(l) (Ln: Nd, Sm), were determined at T=298.15 K, as  kJ mol^−l, respectively. From the mentioned standard molar enthalpies of reaction and other auxiliary thermodynamic quantities, the standard molar enthalpies of formation of Ln(C₉H₆NO)₂(C₂H₃O₂)(s) (Ln: Nd, Sm), at T=298.15 K, have been derived to be: −(1494.7±3.3) and −(1501.5±3.4) kJ mol^−l, respectively.     

希土元素异硫氰酸盐与苄胺配合物的制备、性质及标准生成焓的测定

制备了Pr、Yb两种希土元素异硫氰酸(?)与苄胺的固体配合物.并对其进行了组成分析、红外光谱分析、X射线衍射物相分析和热重分析.测量了298.15K时两种固体配合物RE(NCS)_3·4C_6H_5CH_2NH_2在HCl水溶液中的反应热和相应的两种希土元素异硫氰酸盐水合物RE(NCS)_3·n_1H_2O(RE为Pr时,n_1=7;RE为Yb时,n_1=6)在C_6H_5CH_2NH_2-HCl-H_2O溶液中的积分溶解热以及苄胺C_6H_5CH_2NH_2在HCl水溶液中的反应热.藉助本文所设计的热化学循环,求得了这两种配合物的标准生成焓,还计算了它们的晶格能.     

希土元素异硫氰酸盐与苄胺配合物的制备、性质及标准生成焓的测定

制备了Pr、Yb两种希土元素异硫氰酸盐与苄胺的固体配合物.并对其进行了组成分析、红外光谱分析、X射线衍射物相分析和热重分析.测量了298.15K时两种固体配合物RE(NCS)₃·4C₆H₅CH₂NH₂在HCl水溶液中的反应热和相应的两种希土元素异硫氰酸盐水合物RE(NCS)₃·n₁H₂O(RE为Pr时,n₁=7;RE为Yb时,n₁=6)在C₆H₅CH₂NH₂-HCl^-H₂O溶液中的积分溶解热以及苄胺C₆H₅CH₂NH₂在HCl水溶液中的反应热.藉助本文所设计的热化学循环,求得了这两种配合物的标准生成焓,还计算了它们的晶格能.     

Excess enthalpies of the ternary mixtures: tetrahydrofuran + (diisopropyl ether or 2-methyltetrahydrofuran) + n-heptane at 298.15 K

Excess molar enthalpies, measured at 298.15 K in a flow microcalorimeter, are reported for the ternary mixtures (tetrahydrofuran + diisopropyl ether + n-heptane) and (tetrahydrofuran + 2-methyltetrahydrofuran + n-heptane). Smooth representations of the results are described and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. The latter are compared with diagrams obtained when the model of Liebermann and Fried is used to estimate the excess enthalpies of the ternary mixtures from the physical properties of the components and their binary mixtures.     

Determination of the standard molar enthalpy of formation of the ternary complex of neodymium with vitamin B3 and 8-hydroxylquinoline by microcalorimetry

A novel solid ternary complex, [Nd(C₆H₄NO₂)₂·C₉H₆NO·2H₂O], was synthesized in a water bath (333.15 K) by three kinds of reagents: neodymium chloride, vitamin B3 (C₆H₅NO₂), and 8-hydroxylquinoline (C₉H₇NO). Its composition and structure were characterized by elemental analysis, IR spectra, UV spectra, molar conductance, and thermogravimetric analysis. During the process of coordination, C₆H₅NO₂ was bidentate-coordinated with Nd³⁺ in the form of an acidic group by removing the proton; hydroxyl oxygen atom and heterocyclic nitrogen atom of C₉H₇NO formed a chelate ring. Particularly, in this article, a thermochemical cycle in the calorimetric solvent (V _HCl:V _DMF:V _EtOH = 3:1:1) was designed on the basis of Hess’s law. At 298.15 K, the dissolution enthalpies of the reactants and products were determined by a advanced solution–reaction isoperibol microcalorimeter, respectively. According to the above results and relevant literature data, the standard molar enthalpy of formation of [Nd(C₆H₄NO₂)₂·C₉H₆NO·2H₂O], was estimated to be $ \Updelta_{f} H_{m}^{\Uptheta} $ [[Nd(C₆H₄NO₂)₂·C₉H₆NO·2H₂O(s)], 298.15 K] = ?(2,129.1 ± 2.5) kJ mol^?1.