Molar Refractivity Data Research Articles

Constrained dipole oscillator strength distributions, sum rules, and dispersion coefficients for Br2 and BrCN

Dipole oscillator strength distributions for Br2 and BrCN are constructed from photoabsorption cross-sections combined with constraints provided by the Kuhn-Reiche-Thomas sum rule, the high-energy behavior of the dipole-oscillator-strength density and molar refractivity data when available. The distributions are used to predict dipole sum rules S(k), mean excitation energies I(k), and van der Waals C6 coefficients. Coupled-cluster calculations of the static dipole polarizabilities of Br2 and BrCN are reported for comparison with the values of S(-2) extracted from the distributions.

Constrained Dipole Oscillator Strength Distributions for CF4, CClF3, CCl2F2, CCl3F, CHF3, CH3F, CH3Cl, CH3Br, CH3I, C2F6, and CCl3CF3

Abstract Dipole oscillator strength distributions are constructed for CF4, CClF3, CCl2F2, CCl3F, CHF3, CH3F, CH3Cl, CH3Br, CH3I, C2F6, and CCl3CF3 from experimental and theoretical photoabsorption cross-sections combined with constraints provided by the Kuhn–Reiche–Thomas sum rule, the high-energy behavior of the dipole-oscillator-strength density, and either molar refractivity data or static dipole polarizabilities depending upon the availability of refractivities. The distributions are used to predict dipole sum rules S(k), mean excitation energies I(k), and van der Waals C 6 coefficients. Pseudospectral representations of the DOSDs are reported.

Dipole properties of PH3, PF3, PF5, PCl3, SiCl4, GeCl4, and SnCl4

ABSTRACTExperimental and theoretical photoabsorption cross sections combined with constraints provided by the Kuhn–Reiche–Thomas sum rule, the high-energy behaviour of the dipole oscillator strength density, static dipole polarisabilities, and molar refractivity data when available are used to construct dipole oscillator strength distributions for PH3, PF3, PF5, PCl3, SiCl4, GeCl4, and SnCl4. The distributions are used to predict dipole sum rules S(k), mean excitation energies I(k), and van der Waals C6 coefficients.

Molar Refraction and Polarizability of Antiemetic drug 4-amino-5-chloro-N-(2-(diethylamino)ethyl)-2 methoxybenzamide hydrochloride monohydrate in [Aqueous-Sodium or Lithium Chloride] Solutions at 30 and deg;C

Hematological and biochemical studies on Parquetina nigrescens root extract in albino ratsB.V. Owoyele, O.T. Oyelowo, S.A. Biliaminu, O.N. Alaran, S.A. Alimi, R.S. Saliu

Construction of Constrained Dipole Oscillator Strength Distributions

Abstract A brief review is given of how a constrained dipole oscillator strength distribution (DOSD) is constructed from experimental and possibly theoretical photoabsorption cross-sections with constraints provided by molar refractivity data and the Kuhn–Reiche–Thomas sum rule. Some recent refinements including the imposition of the correct high-energy behavior on the DOSD for homoatomic molecules are discussed and extended to the general molecular case. A sample application to pyridine is given.

Azeotrope breaking for the system ethyl tert-butyl ether (ETBE) + ethanol at 313.15 K and excess properties at 298.15 K for mixtures of ETBE and ethanol with phosphonium-based ionic liquids

Isothermal vapor–liquid equilibria for the ternary system {ethyl tert-butyl ether (ETBE)+ethanol+trihexyltetradecylphosphonium chloride ([P666,14][Cl]) or trihexyltetradecylphosphonium bis(2,2,4-trimethylpentyl)phosphinate ([P666,14][TMPP])} have been determined at 313.15K using headspace gas chromatography (HSGC). The addition of a small amount of ionic liquids (ILs) to the system ETBE+ethanol produced an important salting-out effect. The azeotrope disappeared by varying the mole fraction of ILs from 0.05 to 0.10. The experimental VLE data were correlated using the Wilson equation. In addition, excess molar volumes (VE) and deviations in molar refractivity ((R) data at 298.15K are reported for the binary systems {ETBE+[P666,14][Cl]}, {ETBE+[P666,14][TMPP]} and {ethanol+[P666,14][TMPP]} by a digital vibrating tube densimeter and a precision digital refractometer. The VE and (R were well correlated according to the Redlich–Kister equation.

Liquid–liquid equilibria and thermo physical properties for 1-methyl-2-pyrrolidinone + heterocyclic nitrogen compounds + hexadecane systems at 298.15 K

Liquid–liquid equilibrium data for {1-methyl-2-pyrrolidinone (NMP)+heterocyclic nitrogen compounds+hexadecane} systems were analytically determined at 298.15K and atmospheric pressure using stirred and thermo-regulated cell. The experimental data were modeled with the NRTL and UNIQUAC equations. Besides, the Bachman–Brown correlation was used to ascertain the reliability of the experimental data. Additionally, excess molar volumes (VE) and deviations in the molar refractivity (ΔR) data at 298.15K were determined for the {NMP+heterocyclic nitrogen compounds} binary systems using a digital vibrating-tube densimeter and a precision digital refractometer. The VE and ΔR data were modeled with the Redlich–Kister equation.

Ozone: Unresolved discrepancies for dipole oscillator strength distributions, dipole sums, and van der Waals coefficients

Dipole oscillator strength distributions (DOSDs) for ozone are constructed from experimental photoabsorption cross-sections combined with constraints provided by the Kuhn-Reiche-Thomas sum rule, the high-energy behavior of the dipole-oscillator-strength density, and molar refractivity data. A lack of photoabsorption data in the intermediate energy region from 24 to 524 eV necessitates the use of a mixture rule in that region. For this purpose, a DOSD for O(2) is constructed first. The dipole properties for O(2) are essentially the same as those obtained in earlier work even though most of the input data is from more recent experiments. A discrepancy is found between the refractivity data and photoabsorption data in the 10-20.6 eV range for ozone. A reliable ozone DOSD of the sort obtained for many other species remains out of reach. However, it is suggested that the true dipole properties of ozone lie between those predicted by two distributions that we present.

Vapor–liquid equilibria at 333.15 K and excess molar volumes and deviations in molar refractivity at 298.15 K for mixtures of diisopropyl ether, ethanol and ionic liquids

In this work, we have studied influence of ionic liquids (ILs) on the azeotrope composition for the system {diisopropyl ether (DIPE) + ethanol} using trihexyltetradecylphosphonium chloride ([P 666,14][Cl]) and trihexyltetradecylphosphonium bis(2,2,4-trimethylpentyl) phosphinate ([P 666,14][TMPP]). Isothermal vapor–liquid equilibrium data at 333.15 K are reported for the ternary systems {DIPE + ethanol + [P 666,14][Cl]} and {DIPE + ethanol + [P 666,14][TMPP]} with varying the mole fraction of ILs from 0.05 to 0.10. The experimental ternary VLE data were correlated using the Wilson equation. In addition, excess molar volumes ( V E) and deviations in molar refractivity (Δ R) data at 298.15 K are reported for the binary systems {DIPE + [P 666,14][Cl]} and {ethanol + [P 666,14][Cl]} by a digital vibrating tube densimeter and a precision digital refractometer. The V E and Δ R were correlated by the Redlich–Kister equation.

Isothermal vapor–liquid equilibrium at T = 333.15 K and excess volumes and molar refractivity deviation at T = 298.15 K for the ternary mixtures {di-methyl carbonate (DMC) + ethanol + benzene} and {DMC + ethanol + toluene}

Isothermal vapor–liquid equilibrium data at 333.15K are reported for the ternary systems {di-methyl carbonate (DMC)+ethanol+benzene} and {DMC+ethanol+toluene} as determined with headspace gas chromatography. The experimental ternary vapor–liquid equilibrium (VLE) data were correlated with different activity coefficient models. The excess volume (VE) and deviations in molar refractivity (ΔR) data are reported for the binary systems {DMC+benzene} and {DMC+toluene} and also for the ternary systems {DMC+ethanol+benzene} and {DMC+ethanol+toluene} at 298.15K. These VE and ΔR data were correlated with the Redlich–Kister equation for binary systems and the Cibulka equation for ternary systems.

Isothermal Vapor−Liquid Equilibrium Data at T = 333.15 K and Excess Molar Volumes and Refractive Indices at T = 298.15 K for the Dimethyl Carbonate + Methanol and Isopropanol + Water with Ionic Liquids

Isothermal vapor−liquid equilibrium (VLE) data at T = 333.15 K are reported for the four ternary systems dimethyl carbonate (DMC) + methanol + 1-ethyl-3-methylimidazolium ethyl sulfate (EMISE), DMC + methanol + 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF4]), isopropanol + water + EMISE, and isopropanol + water + [Bmim][BF4] by using headspace gas chromatography. The mole fraction of ionic liquids was varied from 0.05 to 0.2. The experimental binary VLE data were correlated using the Wilson, NRTL, and UNIQUAC equations. In addition, the excess volumes and deviations in molar refractivity data are reported at T = 298.15 K for the sub-binary pairs of the above-mentioned ternary systems. These properties are correlated with the Redlich−Kister equation. Finally, the ternary excess volumes and deviations in molar refractivity data were calculated from the Radojkovic equation using correlated binary Redlich−Kister parameters.

Dipole oscillator strength distributions with improved high-energy behavior: Dipole sum rules and dispersion coefficients for Ne, Ar, Kr, and Xe revisited

The construction of the dipole oscillator strength distribution (DOSD) from theoretical and experimental photoabsorption cross sections combined with constraints provided by the Kuhn-Reiche-Thomas sum rule and molar refractivity data is a well-established technique that has been successfully applied to more than 50 species. Such DOSDs are insufficiently accurate at large photon energies. A novel iterative procedure is developed that rectifies this deficiency by using the high-energy asymptotic behavior of the dipole oscillator strength density as an additional constraint. Pilot applications are made for the neon, argon, krypton, and xenon atoms. The resulting DOSDs improve the agreement of the predicted S(2) and S(1) sum rules with ab initio calculations while preserving the accuracy of the remainder of the moments. Our DOSDs exploit new and more accurate experimental data. Improved estimates of dipole properties for these four atoms and of dipole-dipole C(6) and triple-dipole C(9) dispersion coefficients for the interactions among them are reported.

QSPR studies on normal boiling points and molar refractivities of organic compounds by correlation-ranking-based PCR and PC–ANN analyses of new topological indices

The new topological indices (Sh indices) based on the distance sum and connectivity of a molecular graph, previously developed by our team, were extended to predict the two physicochemical properties, including normal boiling point (NBP) and molar refractivity (MR), of a large set of organic compounds consisting of alkanes, alkenes, ethers, amines, alcohols, alkylbenzenes, and alkylhalides. The sets of molecular descriptors were derived directly from the two-dimensional molecular structure of the compounds based on graph theory. Both linear and nonlinear modelings were implemented by using principal component regression (PCR) and principal component – artificial neural network (PC–ANN) with back-propagation learning algorithm, respectively. Eigenvalue and correlation-ranking procedures were used to rank the principal components and entered them into the models. Principal component analysis of Sh data matrix showed that the respective six and seven PCs could explain 97.49% and 99.22% of variances in the Sh indices. PCR analysis of the NBP and MR data demonstrated that the proposed Sh indices could explain about 97.52% and 99.52% of variations, while the variations explained by the PC–ANN modeling were more than 99.00% and 99.82%, respectively. The predictive ability of the models were evaluated using an external test set for NBP and MR of the molecules with the respective root-mean-square errors lower than 9.69 K and 0.660 cm3mol–1for the linear model and 6.17 K and 0.416 cm3mol–1for the nonlinear model.

Isothermal Vapor−Liquid Equilibrium at 333.15 K and Excess Volumes and Molar Refractivity Deviation at 298.15 K for Binary System Dibutyl Ether (DBE) + 2,2,4-Trimethylpentane and for Ternary System DBE + Ethanol + 2,2,4-Trimethylpentane

Isothermal vapor−liquid equilibrium (VLE) data are reported for the binary system dibutyl ether (DBE) + 2,2,4-trimethylpentane at 333.15 K, as well as for the ternary system DBE + ethanol + 2,2,4-trimethylpentane using headspace gas chromatography. The experimental binary and ternary VLE data are correlated with common activity coefficient models. Excess volumes and deviations in molar refractivity data are also reported for the same binary and ternary systems at 298.15 K. These properties are correlated with the Redlich−Kister equation for binary systems and the Cibulka equation for ternary systems, respectively. The ternary excess volumes and deviations in molar refractivity data are also compared with the estimated values from the binary contribution models of Radojkovič, Tsao−Smith, Kohler, and Rastogi.

Isothermal Vapor−Liquid Equilibrium at 333.15 K and Excess Molar Volumes, Refractive Indices, and Excess Molar Enthalpies at 303.15 K for the Binary and Ternary Mixtures of Di-isopropyl Ether, Ethanol, and 2,2,4-Trimethylpentane

Isothermal vapor−liquid equilibrium (VLE) data at 333.15 K are measured for the binary systems {di-isopropyl ether (DIPE) + ethanol} and {DIPE + 2,2,4-trimethylpentane} and for the ternary system {DIPE + ethanol + 2,2,4-trimethylpentane} by using headspace gas chromatography. The experimental VLE data were correlated with the GE model: Margules, van Laar, Wilson, nonrandom two-liquid, and UNIQUAC equations. The excess molar volume and deviations in molar refractivity data are reported for the binary systems {DIPE + ethanol}, {DIPE + 2,2,4-trimethylpentane}, and {ethanol + 2,2,4-trimethylpentane} at 303.15 K. In addition, excess molar enthalpies for two binaries, {DIPE + ethanol} and {DIPE + 2,2,4-trimethylpentane}, at 303.15 K are also reported. These data were correlated with the Redlich−Kister equation. The excess molar volume and deviations in molar refractivity data are also reported for the ternary system {DIPE + ethanol + 2,2,4-trimethylpentane} at 303.15 K. The ternary data were correlated with the...

Isothermal vapor–liquid equilibrium at 333.15 K, excess molar volumes and refractive indices at 298.15 K for mixtures of tert-amyl methyl ether + ethanol + 2,2,4-trimethylpentane

Isothermal vapor–liquid equilibrium data at 333.15 K are measured for the binary system tert-amyl methyl ether + ethanol and tert-amyl methyl ether + 2,2,4-trimethylpentane and for ternary system tert-amyl methyl ether + ethanol + 2,2,4-trimethylpentane by using headspace gas chromatography. The experimental vapor–liquid equilibrium data were correlated with G E models (Margules, van Laar, Wilson, NRTL, UNIQUAC) equations. The excess volume and deviations in molar refractivity data are also reported for the same binary and ternary systems at 298.15 K. These data were correlated with the Redlich–Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively. The experimental ternary excess volume and deviations in molar refractivity data, were also compared with the estimated values from the binary contribution models of Tsao–Smith, Kohler, Rastogi and Radojkovič.

Isothermal vapor–liquid equilibrium at 333.15 K and excess molar volumes and refractive indices at 298.15 K for the mixtures of di-methyl carbonate, ethanol and 2,2,4-trimethylpentane

Isothermal vapor–liquid equilibrium data at 333.15 K are measured for the binary system ethanol + 2,2,4-trimethylpentane and for ternary system di-methyl carbonate (DMC) + ethanol + 2,2,4-trimethylpentane by using headspace gas chromatography. The experimental binary and ternary vapor–liquid equilibrium data were correlated with different activity coefficient models. Excess volume and deviations in molar refractivity data are also reported for the binary systems DMC + ethanol and DMC + 2,2,4-trimethylpentane and the ternary system DMC + ethanol + 2,2,4-trimethylpentane at 298.15 K. These data were correlated with the Redlich-Kister equation for the binary systems and the Cibulka equation for the ternary system, respectively. The ternary excess volume and deviations in molar refractivity data were also compared with estimated values from the binary contribution models of Tsao–Smith, Kohler, Rastogi and Radojkovič.

Isothermal vapor–liquid equilibrium at 323.15 K and excess molar volumes and refractive indices at 298.15 K for the ternary system propyl vinyl ether + 1-propanol + benzene and its binary sub-systems

Isothermal vapor–liquid equilibrium data at 323.15 K are reported for the binary systems propyl vinyl ether + 1-propanol, PVE + benzene and 1-propanol + benzene and also for ternary system PVE + 1-propanol + benzene by using headspace gas chromatography. The experimental binary and ternary vapor–liquid equilibrium data were correlated with different activity coefficient models. The excess volumes and deviations in molar refractivity data are also reported for the same binary and ternary systems at 298.15 K. These properties are correlated with Redlich–Kister equation for binary systems, and with the Cibulka equation for the ternary system, respectively.

Dipole oscillator strength distributions, properties and dispersion energies for the dimethyl, diethyl and methyl–propyl ethers1

Isotropic dipole oscillator strength distributions (DOSDs) have been constructed for the dimethyl, diethyl and methyl–propyl ether molecules through the use of quantum mechanical constraint techniques and experimental dipole oscillator strength data. The constraints are furnished by molar refractivity data and the Thomas–Reiche–Kuhn sum rule. The DOSDs are used to obtain recommended values for a variety of isotropic dipole oscillator strength sums, logarithmic dipole oscillator strength sums, and mean excitation energies for the molecules. Pseudo-DOSDs for the ethers are also constructed and used to obtain reliable results for the isotropic dipole–dipole dispersion energy coefficients for all two-body interactions of the ethers with each other and with fifty other species. In addition reliable results are also obtained for the triple–dipole dispersion energy coefficients for all three-body interactions involving the ethers. 1Dedicated to Anthony Stone, an excellent scientist and friend, on the occasion of his 70th birthday.

Excess molar volumes and refractive indices at 298.15 K for the binary and ternary mixtures of diisopropyl ether + ethanol + 2,2,4-trimethylpentane

Excess molar volumes ( V E) and deviations in molar refractivity (Δ R) data at 298.15 K are reported for the binary systems diisopropyl ether + ethanol, diisopropyl ether + 2,2,4-trimethylpentane(isooctane) and ethanol + isooctane and also for ternary systems of diisopropyl ether + ethanol + isooctane by digital vibrating tube densimeter and a precision digital refractometer. The V E and Δ R were correlated with Redlich–Kister equation for binary systems and Cibulka equation for ternary system, respectively. Especially the ternary V E and Δ R were compared with the estimated values from the binary contribution model equations of Tsao–Smith, Kohler, Rastogi and Radojkovič.