Development of Abraham model correlations for describing the transfer of molecular solutes into propanenitrile and butanenitrile from water and from the gas phase

Experimental solubilities were measured for 20 crystalline organic solutes dissolved in propanenitrile and for 13 crystalline organic solutes dissolved in butanenitrile at 298.15 K. Infinite dilution activity coefficient data for solutes dissolved in propanenitrile and butanenitrile have been compiled from the published chemical and engineering literature and converted into gas-to-liquid partition coefficients and water-to-organic solvent partition coefficients through standard thermodynamic relationships. Abraham model correlations were developed for describing solute transfer into both propanenitrile and butanenitrile by combining our measured solubility data with the partition coefficients that we calculated from the published activity coefficient data. The derived Abraham model correlations were found to back-calculate the observed partition coefficients and molar solubility data to within 0.14 log units.     

Abraham model ion-specific equation coefficients for the 1-butyl-2,3-dimethyimidazolium and 4-cyano-1-butylpyridinium cations calculated from measured gas-to-liquid partition coefficient data

Partition coefficient and gas solubility data have been assembled from the published chemical and engineering literature for solutes dissolved in anhydrous 1-butyl-3-methylimidazolium dicyanamide, 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)imide, and 4-cyano-1-butylpyrridinium bis(trifluoromethylsulfonyl)imide. More than 60 experimental data points were gathered for each IL solvent. The compiled experimental data were used to derive Abraham model correlations for describing the solute transfer properties into the three anhydrous IL solvents from both the gas phase and water. The derived mathematical correlations described the observed solute transfer properties, expressed as the logarithm of the water-to-IL partition coefficient and logarithm of the gas-to-IL solvent partition coefficient, to within standard deviations of 0.125 log units (or less). Abraham model ion-specific equation coefficients are also calculated for the 1-butyl-2,3-dimethylimidazolium and 4-cyano-1-butylpyridinium cations.     

Thermochemical Investigations of Tautomeric Equilibrium. Variation of the Calculated Equilibrium Constant with Binary Solvent Composition

Abstract

A conventional nonelectrolyte solution model which has led to successful predictive equations for solute solubility and infinite dilution chromatographic partition coefficients is extended to systems containing a tautomeric solute dissolved in a binary solvent mixture. The derived expression predicts that the tautomeric solute concentration in a binary solvent is a geometric average of the pure solvent ratios and permits calculation of solute-solvent association constants from variation of the stoichiometric tautomeric solute concentration ratios as a function of binary solvent composition. Experimental data for phenylazonaphthol dissolved in aqueous-ethanol and aqueous-acetone solvent mixtures is discussed in relation to the theoretical model.