Reaction of 2-Mono- and 2,2-Disubstituted 1,3-Dioxolanes with 1-Ethyl-3-hexylaluminacyclopentane

Reaction of 2-mono- and 2,2-disubstituted 1,3-dioxolanes with 1-ethyl-3-hexylaluminacyclopentane involves cleavage of the Al-C bond of the metal cycle and formation, after hydrolysis, ethylene glycol monoethers. Catalytic amounts of ZrCl4 or Ni(acac)₂ drive the reaction with 2-monosubstituted 1,3-dioxolanes.     

Dielectric relaxation studies of 1-hexanol and 1,2-hexanediol in heptane

Solutions of 1-hexanol and 1,2-hexanediol in heptane have been investigated tigated by means of dielectric time domain spectroscopy (TDS). The permittivity spectrum of 1-hexanol in heptane is characterized by a model function containing a sum of three elementary Debye dispersions, while 1,2-hexanediol in heptane is best described by a Cole-Davidson model function. It is shown that dilute solutions of 1-hexanol in heptane have a completely different behavior to that of 1,2-hexanediol. For the diol, the relaxation time levels off at a high value indicating an existence of higher hydrogen bonded complexes. It is possible to quantify the relative amount of monomeric 1-alcohol molecules from the dielectric spectrum. The monomerization rate for 1-hexanol upon dilution with heptane is initially low, but increases rapidly for mole fractions of heptane exceeding 0.4.     

Synthesis of the C2 Symmetric 1,3-Dicyclohexyl-1,3-Propanediol and Diamine Enantiomers

The parent C₂-symmetric (R,R)- and (S,S)-1,3-dicyclohexyl-1,3-propanediols and diamines are readily obtained from the corresponding diphenyldiol precursors.     

Dielectric Properties of Low-Polarity Substances and Their Description Taking into Account Intermolecular Interactions

Optical and dielectric properties of low-polarity liquids (benzene, xylene, toluene, carbon tetrachloride, carbon disulfide) are considered. A generalized equation of dielectric polarization is suggested to describe these properties; its specific feature is the correction for the kind and intensity of intermolecular interaction. This correction is determined on the basis of the model of the molecular electronic shell expanding owing to cross self-polarization of molecules. A material equation improving the agreement of the calculated quantities with the experiment is obtained.     

Study of Intermolecular Interaction in Dimethylsulphoxide + 1-Alkanols (1-Butanol, 1-Hexanol, 1-Octanol) At 303.15 K

Abstract

The ultrasonic velocity, u, viscosity, η, and density, ρ of dimethylsulphoxide (DMSO), 1-butanol, 1-hexanol, 1-octanol, and of their binary mixtures, where DMSO is common component, have been measured at 303.15 K. From the experimental data, excess isentropic compressibility, K ^E _s, excess intermolecular free length, L^E _f, excess velocity, u ^E, excess acoustic impedance, Z ^E, excess viscosity, η^E, excess free energy of activation of viscous flow, G?^E, and excess rheochore, [R ^E] have been calculated. The behaviours of excess functions with composition of the mixtures suggest that the structure-breaking effect dominates over the interaction effect between the component molecules. Furthermore, the experimental values of u and η were fitted by empirical equations stating their dependence on composition of the mixtures. The experimental values of u have been compared with those calculated by using Nomoto and Van Dael relations.     

Studies on Intermolecular Interactions in Liquid Mixtures of Alkoxyalkanols and Branched Alcohols by Volumetric and Acoustic Measurements at Different Temperatures

Densities and speeds of sound for binary mixtures of diethylene glycol monomethyl ether and triethylene glycol monomethyl ether with 3-methyl-1-butanol and 2-methyl-2-butanol were measured at 288.15, 298.15 and 308.15 K, over the entire range of compositions at atmospheric pressure, using an Anton Paar DSA 5000 density meter. The experimental densities and speeds of sound have been used to calculate excess molar volumes and excess molar isentropic compressibilities. The speed of sound data are compared with theoretical speeds of sound calculated using several approaches.     

Dielectric properties of binary mixtures of three butanediols with 1,4-dioxane and 2-ethyl-1-hexanol at T = 298.2 K

Experimental results of dielectric investigations for solutions of the three butanediols {2,3-butanediol (2,3BD), 1,3-butanediol (1,3BD), and 1,4-butanediol (1,4BD)}, in 1,4-dioxane (1,4DX) are reported for various mole fractions at T = 298.2 K. Values of relative permittivity were measured at 100 kHz. The molecular dipole moments were determined using Guggenheim method. The variations of effective dipole moment and correlation factor, g, with mole fraction in these materials were investigated using Kirkwood–Frohlich equation. Dielectric measurements were also carried out on binary polar mixtures of the butanediols with 2-ethyl-1-hexanol (2EH) for various concentrations at T = 298.2 K. The Kirkwood correlation factor, the Bruggeman factor, and the excess permittivity were determined.     

1H-ANTA二聚体分子间相互作用的密度泛函理论研究

在DFT-B3LYP/6-311＋＋G**水平上求得1H-3-硝基-5-氨基-1,2,4-三唑(1H-ANTA)二聚体势能面上5种优化构型和电子结构. 经基组叠加误差(BSSE)和零点能(ZPE)校正, 求得分子间最大结合能为70.63 kJ/mol. 二聚体的形成使电荷向三唑环转移. 由氢键强弱推断二聚体稳定性的顺序与结合能顺序相一致, 氢键是二聚体的主要作用形式. 对优化构型进行振动分析, 并基于统计热力学求得200.0～800.0 K温度范围内单体形成二聚体的热力学性质变化. 发现在该温度范围所有二聚过程均能自发进行.     

Dielectric Relaxation and Thermodynamic Studies of Binary Mixtures of 2-Nitrotoluene with Primary and Secondary Alcohols at Different Temperatures

The dielectric complex spectra of 2-nitrotoluene with primary or secondary alcohol binary mixtures were studied over the frequency range of 10 MHz to 20 GHz for the whole solute mole fraction range at four different temperatures. An unusual suppression phenomenon was observed in the real and imaginary parts of the mixture complex spectrum, which are smaller than those for the pure alcohols, at low solute concentrations. The dielectric constant and dielectric relaxation time values were obtained by fitting the complex dielectric spectrum data to the single Debye model using a non-linear least squares method. The dielectric constant of mixtures decrease with the increasing mole fraction of 2NT in both the primary alcohols and secondary alcohols; the dielectric relaxation time decreases for all the five binary systems. Using the dielectric data, derived dielectric parameters, namely: the excess dielectric constant, excess inverse relaxation time, effective Kirkwood correlation factor, molar activation enthalpy and molar activation entropy, were calculated. The non-linear variation of permittivity (?₀) reveals the change in size and shape of hetero-molecular complex due to intermolecular H-bond interaction. The negative variation of the excess permittivity constant confirms that the dipoles form multimer structures with anti-parallel ordering of unlike dipoles. The molar activation enthalpy was found to be higher at 0.2 mol fraction of 2NT for primary alcohol binary system. To confirm the molecular function group interaction, a FT-IR spectroscopy study was carried out at 298 K. The FT-IR analysis confirmed the formation of hydrogen bonds between the hydrogen atom of hydroxyl groups of the alcohols and the oxygen atom of nitro groups of 2NT in the binary mixtures.     

Transformations of 2-Ethyl-2-methyl-2,3-dihydro-1H-indole at the 3-Position

Russian Journal of Organic Chemistry - The oxidation of N-acetyl-2-ethyl-2-methyl-2,3-dihydro-1H-indole with pyridinium chlorochromate, CrO3 · 2 Py, or CrO3 gave...     

Interactions of Diglycine in Aqueous Saccharide Solutions at Varying Temperatures: A Volumetric,Ultrasonic and Viscometric Study

Densities, viscosities and speeds of sound were measured for ternary mixtures of diglycine (0.05 to 0.30 mol⋅kg⁻¹) in 2, 4 and 6 mass-% aqueous xylose, L(-)arabinose, and D(-)ribose solutions at 288.15, 298.15 and 308.15 K and at atmospheric pressures, using a DSA 5000 instrument. The limiting apparent molar volume, limiting apparent molar adiabatic compressibility and their corresponding slopes were computed using the density and speed of sound data. Corresponding transfer functions have also been determined. The viscosity data have been analyzed on the basis of the Jones-Dole equation. The viscosity B-coefficient and Gibbs energy of activation of viscous flow per mole of solvent and solute have been evaluated. Hydration numbers, pairwise and triplet interaction coefficients have also been evaluated from these data. The variations of these parameters with concentration and temperature clearly suggest the roles of diglycine and saccharides in solute–solvent interactions.     

Intermolecular 1,3-dipolar cycloaddition of benzonitrile oxide to 2H-1,3-benzothiazines and hexahydro-4H-1,3-benzothiazine

The thermal [3 + 2] intermolecular cycloaddition of benzonitrile oxide to 2H-1,3-benzothiazines 1a-g and hexahydro-4H-1,3-benzothiazine ( 5 ) gives new types of tricyclic angularly and linearly condensed 1,2,4-oxadiazolo-1,3-benzothiazine-fused nitrogen-bridgehead ring systems 2a-g, 6 .     

Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Difluoroamine Complex

Introduction　　ApplicationsofabinitiocalculationstointermolecularinteractionsincludingeitherweakvanderWaalsorstrongerhydrogenbondinghavedrawnmuchattentioninthepastdecadesbecausetheyareimportantinawiderangeofphysical,chemicalandbiologicalfields .1 5Inre centyears ,wehaveappliedtheintermolecularinteractionstoenergeticsystemsandobtainedsomemeaningfulinfor mationthatisvaluableforthestudyofenergeticmateri als .6 14 Thebehaviorofmolecularcomplexesisusuallybe tweentwoextremes :thegasphaseandthecrys…     

Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Nitroamine Dimers

Ab initio self-consistent field(SCF) and Mφller-Plesset correlation correction methods employing 6-31G^** basis set have been applied to the optimizations of nitroamine dimers.The binding energies have been corrected for the basis set superposition error (BSSE) and the zero-point energy.Theree optimized dimers have been obtained.The BSSE corrected binding energy of the most stable dimer is predicted to be -31.85kJ/mol at the MP4/6-31G^**//MP2/6-31G^** level.The energy barriers of the Walden conversion for -NH2 group are 19.7kJ/mol and 18.3kJ/mol for monomer and the most stable dimer,respectively.The molecular interaction makes the internal rotation around N1-N2 even more difficult.The thermodynamic properties of nitroamine and its dimers at different temperatures have been calculated on the basis of vibrational analyses.The change of the Gibbs free energy for the aggregation from monomer to the most stable dimer at standard pressure and 298.2 K is predicted to be 14.05kJ/mol.     

Theoretical Study on Intermolecular Interactions and Thermodynamic Properties of Dimethylnitroamine Clusters

Ab initio SCF and Mφller-Plesset correlation correction methods in combination with counterpose procedure for BSSE correction have been applied to the theroetical studying of dimethylnitroamine and its dimers and trimers.Three optimized stable dimers and two trimers have been obtained.The corrected binding energies of the most stable dimer and trimer were predicted to be -24.68kJ/mol and -47.27kJ/mol,respectively at the MP2/6-31G^*//HF/6-31G^* level.The proportion of correlated interation energies to their total interaction energies for all clusters was at least 29.3 percent,and the BSSE of ΔE(MP2) was at least 10.0kJ/mol.Dispersion and/or electrostatic force were dominant in all clusters.There exist cooperative effects in both the chain and the cyclic trimers.The vibrational frequencies associated with N-O stretches or wags exhibit slight red shifts,but the modes associated with the motion of hydrogen atoms of the methyl group show somewhat blue shifts with respect to those of monomer.Thermodynamic properties of dimethylnitroamine and its clusters at different temperatures have been calculated on the basis of vibrational analyses.The changes of the Gibbs free energies for the aggregation from monomer to the most stable dimer and trimer were predicted to be 14.37kJ/mol and 30.40kJ/mol,respectively,at 1 atm and 298.15K.     

Dielectric data of binary mixtures of 1,2-butanediol with 2-ethyl-1-hexanol and 1,4-dioxane at T = (298.2, 308.2, and 318.2) K

Relative permittivity measurements were made on binary mixtures of (1,2-butanediol + 2-ethyl-1-hexanol) and (1,2-butanediol + 1,4-dioxane) for various concentrations at T = (298.2, 308.2, and 318.2) K. The molecular dipole moments were determined using Guggenheim–Debye method in the temperature range of (298.2 to 318.2) K. The variations of effective dipole moment and correlation factor, g, with the mole fraction in these materials were investigated using Kirkwood–Frohlich equation. The pure compounds showed a negative and small temperature coefficient of effective dipole moment. In order to obtain valuable information about heterogeneous interaction (interactions between the unlike molecules), the Kirkwood correlation factor, the Bruggeman dielectric factor and the excess permittivity were calculated. In addition, in order to predict the permittivity data of polar-apolar binary mixtures, five mixing rules were applied.     

3-硝基-1,2,4-三唑-5-酮与NH3及H2O分子间相互作用的理论研究

在DFT—B3LYP／6—311 G^**水平上,求得3-硝基-1,2,4-三唑-5-酮(NTO)／NH3和NTO／H2O两种超分子体系势能面上5种全优化构型．经基组叠加误差(BSSE)和零点能(ZPE)校正,求得NTO与NH3和H2O的分子间最大相互作用能依次为-37．58和-30．14kJ／mol,表明NTO与NH3的分子问相互作用强于与H2O的作用．超分子体系中电子均由NH3或H2O向NTO转移,相互作用能主要由强氢键所贡献,由自然键轨道分析揭示了相瓦作用的本质．对优化构型进行振动分析,并基于统计热力学求得200．0～800．0K温度范围从单体形成超分子的热力学性质变化．发现由NTO和NH3形成超分子Ⅱ和Ⅲ在常温下可自发进行;而NTO和H2O只在低温下才能自发形成Ⅳ,Ⅴ和Ⅵ超分子．     

Intermolecular reaction of 1-vinylimidazqle with 1-vinyl-2-pyrrolidone

Conclusions Using the IR spectroscopy method it was shown that 1-vinylimidazole exhibits intermolecular reaction with 1-vinyl-2-pyrrolidone to give the 11 associate.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1378–1379, June, 1979.     

A Study of the Kinetics of the Sulfation of 2-Octanol by Sulfamic Acid

The kinetics of the sulfation of 2-octanol by sulfamic acid in dimetylformamide were studied. The rate of disappearance of sulfamic acid obeys the rate equation: Rate=k[SA] where [SA] is the concentration of sulfamic acid. The energy and entropy of activation are 3.1 ± 0.6 kcal/mol and 15±2eu A possible mechanism is as follows: The sulfamic acid reacts with DMF to form DMF·SO₃ which then reacts rapidly with 2-octanol to form ammonium sec-octyl sulfate. The kinetics of the sulfation of 2-octanol by sulfamic acid in dimethyl sulfoxide were also studied. The reaction is described by a similar first-order equation. The energy and entropy of activation are 33.7±1.0 kcal/mol and 17±3eu.