Development of Abraham model correlations for predicting enthalpies of solvation of nonionic solutes dissolved in formamide

Experimental enthalpy of solution data for 81 solutes dissolved in formamide have been compiled from the published literature and converted to enthalpies of solvation data using standard thermodynamic relationships. Abraham model correlations were derived from the compiled enthalpy of solvation data. The derived mathematical equations describe the observed experimental to within overall standard deviations of 2.3 kJ mol^?1. A principal component analysis based on the calculated equation coefficients, and the coefficients for water and 23 organic solvents previously determined, shows that formamide is both a hydrogen-bond acid and a hydrogen-bond base. Of the solvents that we have studied thus far, formamide is the closest to water in terms of enthalpies of solvation of dissolved solutes.     

Abraham model enthalpy of solvation correlations for solutes dissolved in dimethyl carbonate and diethyl carbonate

Experimental data have been compiled from the published chemical and engineering literature on the enthalpies of solvation for 80 different inorganic gases and organic vapours in diethyl carbonate and for 57 different gaseous compounds in dimethyl carbonate. The compiled data are used to derive mathematical correlations based on the Abraham solvation parameter model. The derived expressions describe the experimental solvation enthalpies in diethyl carbonate and dimethyl carbonate to within standard deviations of 2.1 and 2.7 kJ mol^?1, respectively.     

Development of Abraham model correlations for enthalpies of solvation of organic solutes dissolved in 1,3-dioxolane

Published excess enthalpy of mixing data has been assembled from the chemical literature for binary mixtures containing 1,3-dioxalane. The experimental data were converted into partial molar enthalpies of solution and enthalpies of solvation for solutes dissolved in 1,3-dioxolane using standard thermodynamic relationships. The compiled enthalpy of solvation data for 59 different organic solutes was used to derive mathematical correlations based on the Abraham solvation parameter model. The derived correlations describe the experimental enthalpy of solvation data in 1,3-dioxolane to within a standard deviation of 2.0 kJ mol^?1.     

Enthalpy of solvation correlations for gaseous solutes dissolved in chloroform and 1,2-dichloroethane based on the Abraham model

Enthalpy of solvation data have been compiled from the published literature for more than 80 solutes dissolved in chloroform and 1,2-dichloromethane. Mathematical correlations based on the Abraham general solvation parameter model are developed for describing the experimental solvation enthalpies to within standard deviations of 2.10 kJ/mol (chloroform) and 1.72 kJ/mol (1,2-dichloroethane). Division of the measured values into a training set and a test set shows that there is no bias in predictions, and that the estimative capability of the correlations is better than 2.5 kJ/mol.     

Updated Abraham model correlations for enthalpies of solvation of organic solutes dissolved in benzene and acetonitrile

A search of the published chemical and engineering literature found enthalpy of solution data for an additional 104 and 49 organic compounds dissolved in benzene and acetonitrile, respectively. Standard thermodynamic relationships were used to convert the experimental enthalpy of solution data, ΔH_solv, to enthalpies of solvation, ΔH_solv. Updated Abraham model correlations were derived for describing gas-to-benzene and gas-to-acetonitrile enthalpies of solvation by combining the 104 and 49 additional values to existing benzene and acetonitrile ΔH_solv databases. The updated Abraham model correlations for benzene and acetonitrile described the observed ΔH_solv values to within overall standard deviations of less than 3.4 kJ mol^?1.     

Ion-specific equation coefficient version of the Abraham model for ionic liquid solvents: determination of coefficients for tributylethylphosphonium, 1-butyl-1-methylmorpholinium, 1-allyl-3-methylimidazolium and octyltriethylammonium cations

Gas-to-ionic liquid partition coefficient data have been assembled from the published chemical literature for solutes dissolved in 1-allyl-3-methylimidazolium dicyanamide, 1-allyl-3-methylimidazolium bis(trifluoromethylsulphonyl)imide, octyltriethylammonium bis(trifluomethyl-sulphonyl)imide, tributylethylphosphonium diethylphosphate and 1-butyl-1-methylmorpholinium tricyanomethanide. The published experimental data were converted to water-to-ionic liquid partition coefficients using standard thermodynamic relationships. Both sets of partition coefficients were correlated with the Abraham solvation parameter model. The derived Abraham model correlations described the observed partition coefficient data to within 0.13 log units. Cation-specific equation coefficients were calculated for each of the cations present in the five ionic liquid solvents studied. The calculated cation-specific equation coefficients can be combined with previously reported ion-specific equation coefficients for 19 different anions to yield Abraham model correlations for predicting the partitioning the behaviour of solutes in 76 different anhydrous ionic liquid solvents.     

Experimental and predicted solubilities of 3,4-dichlorobenzoic acid in select organic solvents and in binary aqueous–ethanol mixtures

Experimental solubilities are reported for 3,4-dichlorobenzoic acid dissolved in methyl butyrate, and in 16 alcohol, 5 alkyl acetate, 5 alkoxyalcohol and 6 ether solvents. Solubilities were also measured in nine binary aqueous–ethanol solvent mixtures at 298.15?K. The measured solubility data were correlated with the Abraham solvation parameter model. Mathematical expressions based on the Abraham model predicted the observed molar solubilities to within 0.12 log units.     

Correlation and prediction of partition coefficient between the gas phase and water, and the solvents dry methyl acetate, dry and wet ethyl acetate, and dry and wet butyl acetate

Experimental partition coefficient data have been compiled from the published literature for the water/methyl acetate, water/ethyl acetate and water/butyl acetate partition systems, log P data, and for the gas/methyl acetate, gas/ethyl acetate and gas/butyl acetate partition systems, log K data. Application of the Abraham solvation parameter model to the sets of partition coefficients leads to equations that correlate the log P data and log K data to 0.18 log units for the three dry alkyl acetate solvents. Slightly larger deviations were noted for solute partition into both wet ethyl acetate and wet butyl acetate. The derived correlations were validated using training set and test set analyses.     

Nonelectrolyte Solvation in Aqueous Dimethyl Sulfoxide—A Calorimetric and Infrared Spectroscopic Study

We report enthalpies of solution of formamide, N,N-dimethylformamide,N,N-dimethylacetamide, acetic acid, methyl acetate, and acetonitrile in water +dimethylsulfoxide mixed solvents. These, along with literature data for additional solutes,are analyzed in terms of the extended coordination model of solvation. We alsoanalyze infrared data for several of these solutes. These analyses show thatN,N-dimethylformamide and N,N-dimethylacetamide are preferentially hydrated,while the other solutes appear to be preferentially solvated by dimethylsulfoxide.In all cases, the extent of preferential solvation is relatively small. It is also foundthat the degrees of preferential solvation recovered from analyses of the enthalpydata correspond closely to those recovered from the infrared data, although thelatter refer only to the polar chromophores on the solute molecules. It is foundthat the extent to which the solutes disrupt the solvent-solvent interactions variessystematically with the area of the nonpolar surfaces of the solute molecules.     

Calculating the solvation contributions from reagents to the change in enthalpy of silver(I) complexation with 18-crown-6 ether in binary methanol-acetonitrile solvents

The enthalpies of the transfer of silver(I) ions from methanol to mixed methanol-acetonitrile solvents are calculated using the literature data. An estimative calculation of the enthalpies of transfer of the reaction of formation of [Ag18C6]⁺ upon a change in the solvent composition MeOH → AN is performed on the basis of previously found laws of change in the thermodynamic characteristics of complexation and solvation of reagents. It is shown that the governing factor in the change in the energy of the reaction is the enhancement of the solvation of the central ion.     

Thermodynamics of protolytic equilibrium of nicotinic acid in water-ethanol solutions

The enthalpies of stepwise protonation of nicotinate ion (L⁻) in water-ethanol solvents were determined calorimetrically at 298.15 K. It was found that the reduced exothermicity of the reaction of nicotinate ion protonation upon an increase of the organic component content in solution is due mainly to increased solvation of the proton. The minor influence of solvent on the enthalpy of protonation of nicotinic acid (HL) is characterized by compensation from solvation of the proton, the ligand, and its protonated form (H₂L⁺).     

Characterization of the sorption of gaseous and organic solutes onto polydimethyl siloxane solid-phase microextraction surfaces using the Abraham model

Water-to-polydimethylsiloxane (PDMS) and gas-to-PDMS sorption coefficients have been compiled for 170 gaseous and organic solutes. Both sets of sorption coefficients were analyzed using the Abraham solvation parameter model. Correlations were obtained for both "dry" headspace solid-phase microextraction and conventional "wet" PDMS coated surfaces. The derived equations correlated the experimental water-to-PDMS and gas-to-PDMS data to better than 0.17 and 0.18 log units, respectively. In the case of the gas-to-PDMS sorption coefficients, the experimental values spanned a range of approximately 11 log units.