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.     

Excess molar enthalpies of R-fenchone + propan-1-ol or +propan-2-ol. Modeling with COSMO-RS and UNIFAC

In this paper, experimental excess molar enthalpies for the binary mixtures of R-fenchone with propan-1-ol or propan-2-ol, at four temperatures (283.15, 298.15, 313.15 and 328.15) K and atmospheric pressure are reported over the entire composition range. They have been fitted to the Redlich–Kister equation at each temperature. Excess molar enthalpies are positive in all cases, being greater for the mixture with propan-2-ol than for the mixture with propan-1-ol. These positive values of the excess enthalpy suggest the predominance of the effect due to hydrogen bond breaking over the interaction between dissimilar molecules in the mixture. Finally UNIFAC (Dortmund) method and the Quantum Continuum Method COSMO-RS have been used to predict the excess molar enthalpies. Better predictions are obtained in the case of UNIFAC model.     

Enthalpies and entropies of vaporization of propan-2-ol-2-methylpropan-1-ol solutions

P-T-x dependences are measured for the solutions of a propan-2-ol-2-methylpropan-1-ol binary system and the enthalpies and entropies of vaporization are determined. Dimerization in propan-2-ol and 2-methylpropan-1-ol is rationalized and the contribution from energy introduced by isostructural methyl groups to the enthalpy of vaporization is determined. Structural and energy analyses of solutions with networks of specific interactions are performed. The formation of heterodimers in solutions and vapors with reduced hydrogen bond energies and specific interactions with the 2s ²(C) unshared electron pairs of the carbon atoms of terminal methyl groups in ethyl and propyl fragments of propan-2-ol and 2-methylpropan-1-ol, respectively, is substantiated. The hydrogen bond energy of heterodimers is estimated.     

CO2 laser-induced decomposition of propan-2-ol,butan-2-ol,pentan-2-ol,pentan-3-ol,and hexan-2-ol

The pulsed CO₂ laser-induced decompositions of propan-2-ol, butan-2-ol, pentan-2-ol, pentan-3-ol, and hexan-2-ol in the gas phase have been investigated. Like ethanol which we examined previously [1] the absorption cross section of propan-2-ol for pulsed 9R14 radiation increases with pressure at low pressures, an effect attributed to rotational hole-filling. In contrast the absorption cross section of butan-2-ol (10R24) has only a small pressure dependence and those of pentan-2-ol (9R26), pentan-3-ol (10R14), and hexan-2-ol (9P20) show little or no variation with pressure in the range 0.1–5.0 torr. Decomposition products have been investigated at low pressure where the excitation of the alkanols was essentially collision free. The observed products for all the alkanols can be rationalized on the basis of primary dehydration and C? C fission channels, with minor contributions from other molecular eliminations. © 1994 John Wiley & Sons, Inc.     

Catalytic conversion of propan-2-ol and butan-2-ol on carbon nanotubes with different carbon structures

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Ruthenium-catalyzed transfer hydrogenation of imines by propan-2-ol in benzene

Transfer hydrogenation of a variety of different imines to the corresponding amines by propan-2-ol in benzene catalyzed by [Ru2(CO)4(mu-H)(C4Ph4COHOCC4Ph4)] (1) has been studied. The reaction is highly efficient with turnover frequencies of over 800 per hour, and the product amines were obtained in excellent yields. A remarkable concentration dependence of propan-2-ol was observed when the reaction was run in benzene as cosolvent. An optimum was obtained at 24 equivalents of propan-2-ol to imine, and further increase of the propan-2-ol led to a dramatic decrease in rate. Also the use of polar cosolvents with 24 equivalents of propan-2-ol gave a low rate. It was found that ketimines react faster than aldimines and that electron-donating substituents on the imine increase the rate of the catalytic transfer hydrogenation. Electron-withdrawing substituents decreased the rate. An isomerization was observed with imines having an alpha-hydrogen at the N-alkyl substituent, which is in accordance with a mechanism involving a ruthenium-amine intermediate. It was demonstrated that the ruthenium-amine complex from alpha-methylbenzylamine, corresponding to the postulated intermediate, can replace 1 as catalyst in the transfer hydrogenation of imines. A primary deuterium isotope effect of kCH/CD = 2.7 +/- 0.25 was observed when 2-deuterio-propan-2-ol was used in place of propan-2-ol in the transfer hydrogenation of N-phenyl-(1-phenylethylidene)amine.     

Thermodynamic interactions in binary mixtures of anisole with ethanol, propan-1-ol, propan-2-ol, butan-1-ol, pentan-1-ol, and 3-methylbutan-1-ol at T = (298.15, 303.15, and 308.15) K

In this paper, excess thermodynamic functions have been computed from the measured values of density, viscosity, and refractive index at T = (298.15, 303.15, and 308.15) K, ultrasonic velocity at T = 298.15 K over the entire mixture composition range of (anisole with ethanol, propan-1-ol, propan-2-ol, butan-1-ol, pentan-1-ol, or 3-methyl butan-1-ol). Excess molar volume, V^E has been calculated from densities, whereas deviations in viscosity, Δη, were computed from the measured viscosities. From ultrasonic velocities, isentropic compressibilities were calculated, from which deviations in isentropic compressibility, Δk_s have been computed. Lorenz-Lorentz mixture rule was used to compute molar refractivity, R from refractivity index data and from these data, deviations in molar refractivity, ΔR have been computed. Computed thermodynamic quantities have been fitted to Redlich and Kister polynomial equation to derive the coefficients and standard errors between experimental and predicted quantities. Intermolecular interactions between anisole and alkanols have been studied based on the computed excess thermodynamic quantities.     

Non-catalytic and selective alkylation of phenol with propan-2-ol in supercritical water

Phenol can be alkylated with propan-2-ol without catalyst in supercritical water at 673 K with mainly ortho substituted alkylphenols being obtained and alkylation reaction rate increasing with increasing water density.     

One-pot synthesis of 1,3-bis(cytisinyl)propan-2-ol

Russian Journal of Organic Chemistry -     

1-氮杂环-2-(6-甲氧基萘-2-基)丙-2-醇的合成、表征与生物活性

6-甲氧基-2-萘基乙酮经硫酸单酯三甲锍环氧化和氮杂环开环反应, 合成了4种新的唑类化合物. 目标物经核磁共振和MS测定其结构; 分析目标物中萘环质子偶合分裂情况, 并确定萘环上各质子的归属. 生物活性测试结果表明, 部分新化合物具有杀菌活性.     

The study of modified zirconium catalysts for selective dehydration of propan-2-ol

Journal of Thermal Analysis and Calorimetry - X-ray amorphous precipitated zirconium hydrophosphate ZrP has been subjected to hydrothermal, microwave and mechanochemical modification. Modified...     

Studies on the pervaporation membrane of permeation water from methanol/water mixture

This investigation was performed to find if the nanometer SiO₂ added in the membranes can improve the pervaperation performance of the membranes. Acrylic acid (AA) and acrylonitrile (AN) were synthesized by solution polymerization with and without nanometer SiO₂. The copolymer solution was made into main body of the membranes, then composited with the polyvinyl alcohol (PVA) acetal membranes, to make the three-layer sandwich composite pervaporation membranes. The structure and the performance of the membranes were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG), dynamic themomechanical analysis apparatus (DMA) and mechanical property testing. Pervaporation experiments were carried out using these membranes to separate the mixtures of methanol/water over the complete concentration range 70–98%, and results showed that the selectivity of the membranes with nanometer SiO₂ had notable improvement. For the 98% mixture at 60 °C, the separate factor is up to 1458, which is improved more than 10 times compared to the membranes without nanometer SiO₂, the permeate flux is up to 325 g/(m² h). For the 70% mixture at 70 °C, the separate factor arrived at 12, the permeate flux is up to 7097 g/(m² h), which is improved more than 14 times compared to membranes without nanometer SiO₂. It was concluded that the pervaperation performance of the membranes can improve greatly by nanometer SiO₂.     

Chemistry of baker's yeast reduction products: Use of optically active (S)-(+)-1-(p-toluenesulfonyl)propan-2-ol and (S)-(+)-1-(phenylsulfonyl)propan-2-ol in synthesis.

The utility of the title compounds in the preparation of optically active lactones and alcohols is detailed.     

合成(R)-2-异戊氧基丙醇的新方法

以(R)-1,2-丙二醇为原料,经伯醇羟基保护、仲醇O-异戊基取代、脱羟基保护三步反应合成了手性醇(R)-2-异戊氧基丙醇,其结构经NMR和MS确证.     

Adsorption and oxidation of propan-2-ol on WO3/MgO

Magnesia-supported tungsta catalysts have been prepared by impregnation, with different tungsta contents and calcined at different temperatures in air. All samples are active for propan-2-ol dehydrogenation above 473 K, and selective towards acetone formation. At low W content, acetone is further oxidized. The behavior has been related to the W-containing phases existing in the samples.     

Preferential sorption and permeation of binary liquid mixtures in poly (vinyl chloride) membrane by pervaporation

Preferential sorptions and pervaporation selectivities in poly (vinyl chloride) (PVC) membrane for various binary liquid mixtures were investigated. Methanol/n-propanol, benzene/n-hexane, and ethanol/water mixtures were selected as the binary liquid mixture. In the methanol/n-propanol mixture, methanol was preferentially sorbed in the PVC membrane and predominantly permeated. In the benzene/n-hexane mixture, benzene was incorporated and permeated preferentially. In the ethanol/water mixture, ethanol was preferentially sorbed in the PVC membrane and water was preferentially permeated. The preferential sorptions were analyzed according to Mulder's model derived from Flory-Huggins thermodynamics. The pervaporation selectivity in these systems were discussed using a sorption selectivity and diffusion selectivity. © 1995 John Wiley & Sons, Inc.     

Coordinative flexibility of 1,2-bis[1,4,7-triazacyclonon-1-yl]propan-2-ol in mononuclear and binuclear Ni(II) complexes

Reaction of 1,2-bis[1,4,7-triazacyclonon-1-yl]propan-2-ol hexabromide (T(2)PrOH.6HBr) with Ni(ClO(4))(2)[middle dot]6H(2)O and adjustment of the pH to 7 resulted in the crystallization of pink and blue products from the one reaction mixture. The analytical data and X-ray structure determinations establish compositions corresponding to [Ni(T(2)PrOH)]Br(ClO(4))xH(2)O (pink crystals) and [Ni(2)(T(2)PrO)(OH(2))(3)Br]Br(ClO(4))x2H(2)O (blue crystals). A repeat synthesis of the latter yielded the diperchlorate monohydrate [Ni(2)(T(2)PrO)(OH(2))(3)Br](ClO(4))(2)xH(2)O. In the mononuclear complex, the 2-propanol group connecting the two 1,4,7-trizacyclononane (tacn) rings is protonated, the six nitrogen donors from the T(2)PrOH ligand coordinating to a single Ni(II) centre in a distorted octahedral geometry. In the binuclear complexes and, three coordination sites on each distorted octahedral Ni(II) centre are occupied fac by three nitrogen donors from the one tacn ring, the two metal centres being linked by an endogenous alkoxo bridge. A notable common feature of the two identical cations is that for one Ni(II) centre the remaining two sites are occupied by two water ligands, while in the other a bromo ligand replaces one ligated water. Similar binuclear systems have been recently defined [Zn(2)(T(2)PrO)X(H(2)O)(2)](ClO(4))(2)(X = Cl, Br), two complexes that exhibit coordination asymmetry with one pseudo-octahedral and one pseudo-square pyramidal Zn(ii) centre. The weak antiferromagnetic coupling in and is discussed and compared to di-phenoxo-bridged Ni(II) examples.