Dielectric Relaxation Study of Chloro Group with Associative Liquids. II. 1,2-Dichloroethane with Methanol, Ethanol, and 1-Propanol

Frequency spectra of the complex permittivity for 1,2-dichloroethane–alcohol binary mixtures have been determined over the frequency range 10 MHz to 20 GHz at 15, 25, 35, and 45°C, using the time-domain reflectometry (TDR) technique, for 11 compositions of each 1,2 dichloroethane–alcohol system. The alcohols used in the study were methanol, ethanol, and 1-propanol. The relaxation in these systems can be described by a single relaxation time using the Debye model. The static dielectric constant, relaxation time, the corresponding excess dielectric properties, Kirkwood correlation factor, and Bruggeman factor of the mixtures have been determined. The static dielectric constants for the mixtures have been fitted with the modified Bruggeman model.     

Temperature-Dependent Dielectric Relaxation of 2-Ethoxyethanol, Ethanol, and 1-Propanol in Dimethylformamide Solution Using the Time-Domain Technique

Complex reflection coefficients for 2-ethoxyethanol–dimethylformamide (DMF), ethanol–DMF, and 1-propanol–DMF mixtures at several temperatures from 20 to 50° and the frequency range 10 MHz to 10 GHz were determined by time-domain spectroscopy in reflection mode. Fourier transforms and least-squares fitting were used to obtain complex permittivity, static dielectric constant, and relaxation time. The excess dielectric parameters, Kirkwood correlation factors, and thermodynamic properties for the binary mixtures were also determined. The static dielectric constant for the mixtures was fitted well with the modified Bruggeman model.     

时域反射光谱法研究酰胺-醇混合物的介电驰豫

Using time domain reflectometry (TDR),dielectric relaxation studies were carried out on binary mixtures of amides (N-methylformamide (NMF) and N,N-dimethylformamide (DMF)) with alcohols (1-butanol,1-pentanol,1-hexanol,1-heptanol,1-octanol,and 1-decanol) for various concentrations over the frequency range from 10 MHz to 10 GHz at 303 K. The Kirkwood correlation factor and excess dielectric constant properties were determined and discussed to yield information on the molecular interactions of the systems. The relaxation time varied with the chain length of alcohols and substituted amides were noticed. The Bruggeman plot shows a deviation from linearity. This deviation was attributed to some sort of molecular interaction which may take place between the alcohols and substituted amides. The excess static permittivity and excess inverse relaxation time values varied from negative to positive for all the systems indicating that the solute-solvent interaction existed between alcohols and substituted amides for all the dynamics of the mixture.     

Apparent Dipole Moments of 1-Butanol, 1-Propanol, and Chlorobenzene in Cyclohexane or Benzene, and Excess Molar Volumes of (1-Propanol or Chlorobenzene + Cyclohexane or Benzene) at T = 298.15K

Apparent dipole moments and relative permittivities of {x1-butanol + (1 – x) cyclohexane}, {x1-propanol + (1 – x)cyclohexane or (1 – x)benzene} and {xchloro- benzene + (1 – x)cyclohexane or (1 – x)benzene} were determined for the mole fraction range of 0.0003 < x < 0.1 at a temperature of T = 298.15 K and at a frequency of f = 100 kHz. The apparent dipole moments were calculated using Frohlich equation. The molar excess volumes for {x1-propanol + (1 – x)cyclohexane or (1 – x) benzene} and {xchlorobenzene + (1 – x)cyclohexane} were determined by a vibrating-tube densimeter at T = 298.15 K.     

Dielectric Study of n-Butyl Acetate–Alcohol Mixtures by Time-Domain Reflectometry

Using picosecond time-domain reflectometry (TDR), dielectric relaxation studies have been carried out on binary mixtures of n-butyl acetate with methanol, ethanol, and 1-propanol, over the frequency range from 10 MHz to 20 GHz, at various concentrations and temperatures. The excess permittivity, excess inverse relaxation time, Kirkwood correlation factor, and thermodynamic parameters have been obtained. The excess permittivity for all the systems is negative. The values of static permittivity and relaxation time decrease with an increase in the percentage of n-butyl acetate in the mixtures.     

Osmotic and Activity Coefficients of Nonaqueous Electrolyte Solutions. 1. Lithium Perchlorate in the Protic Solvents Methanol, Ethanol, and 2-Propanol

Vapor pressure lowering by the addition of LiClO₄ to the protic solvents methanol (0.04–5.1 m), ethanol (0.03–1.5 m), and 2-propanol (0.05–1.5 m) was measured at 25°C with high precision. The experimental data of the corresponding osmotic coefficients are compared to those obtained by the use of Pitzer equations and chemical model calculations. Mean activity coefficients are derived from the osmotic coefficients.     

Studies on hydroxy inclusion complexes. I. Host-guest interaction of the molecular complexes of 9-hydroxy-9-(1-propynyl) fluorene and 1,1-Bis (2,4-dimethylphenyl)-2-butyn-1-ol with water,methanol, ethanol,andn-propanol

Molecular inclusion by hydroxy host systems (9-hydroxy-9-(1-propynyl)fluorene+guest and 1,1-bis(2,4-dimethylphenyl)-2-butyn-1-ol+guest) has been investigated by using an empirical potential function. Water, methanol, ethanol, andn-propanol have been employed as guest molecules and their relative stabilities are considered. Alcohol is found to be more suitable than water as a guest molecule in the two tested host molecules. It is also found that the nonbonded interaction is the most important factor in determining the relative stabilities of hydroxy host systems.