Published gas-to-Leonardite humic acid partition coefficient data, measured at a relative humidity of 98% and at 278.15, 288.15, 298.15, 308.15, and 318.15 K, were correlated with the Abraham solvation parameter model. The five derived temperature-specific correlations described the observed partition coefficient data to within an overall standard deviation of 0.33 log units. A method was devised for combining experimental partition coefficients measured at different temperatures into a single regression correlation. The proposed method described the 664 experimental partition coefficients, which covered the 278.15-348.15 K temperature interval, to within a standard deviation of 0.33 log units.

Data have been assembled from the published literature on the enthalpies of solvation for more than 100 compounds dissolved in methanol, ethanol, and 1-butanol. It is shown that an Abraham solvation equation with five descriptors can be used to correlate the experimental enthalpies of solvation to within Standard Deviations (SDs) of 2.70 kJ/mol (methanol), 2.53 kJ/mol (ethanol), and 2.34 kJ/mol (1-butanol). The derived correlations provide very accurate mathematical descriptions of the measured enthalpy of solvation data at 298 K, which in the case of methanol span a range of about 105 kJ/mol. Division of the experimental values into a training set and a test set shows that there is no bias in predictions, and that the predictive capability of the correlations is better than 3.0 kJ/mol.

Data have been assembled from the published literature on the enthalpies of solvation for 68 compounds dissolved in dibutyl ether and for 79 compounds dissolved in ethyl acetate. It is shown that an Abraham solvation equation with five descriptors can be used to correlate the experimental enthalpies of solvation in dibutyl ether and ethyl acetate to within standard deviations of 1.88 and 2.16kJ/mol, respectively. The derived correlations provide very accurate mathematical descriptions of the measured enthalpy of solvation data at 298K, which in the case of ethyl acetate span a range of about 71kJ/mol. Mathematical correlations have also been derived for predicting the enthalpies of solvation in dibutyl ether, ethyl acetate, water and 15 additional organic solvents based on the Goss modified version of the Abraham model. Expressions based on this latter model were found to correlate the experimental enthalpies of solvation to within an overall average standard deviation of 2.29kJ/mol for the 18 solvents studied.

Data have been assembled from the published literature on the enthalpies of solvation for 159 compounds dissolved in N,N-dimethylformamide and for 84 compounds dissolved in tert-butanol. It is shown that an Abraham solvation equation can be used to correlate the experimental enthalpies of solvation in N,N-dimethylformamide and tert-butanol to within standard deviations of 3.08 kJ/mol and 2.48 kJ/mol, respectively. The derived correlations provide very accurate mathematical descriptions of the measured enthalpy of solvation data at 298 K, which in the case of N,N-dimethylformamide span a range of about 108 kJ/mol. Mathematical correlations have also been derived for predicting the enthalpies of solvation in both solvents based on the Goss modified version of the Abraham model. Expressions based on this latter model were found to correlate the experimental enthalpies of solvation to within an overall average standard deviation of 2.82 kJ/mol for the two solvents studied. (C) 2008 Elsevier B.V. All rights reserved.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Gas-to-RTIL (room-temperature ionic liquid) partition coefficients have been compiled for 592 different solute-RTIL combinations. These partition coefficients were converted into water-to-RTIL partition coefficients using the corresponding gas-to-water partition coefficients. Both sets of partition coefficients were analyzed using the Abraham solvation parameter model with cation-specific and anion-specific equation coefficients. The derived equations correlated the experimental gas-to-RTIL and water-to-RTIL partition coefficient data to within 0.10 and 0.14 log units, respectively. The 8 sets of calculated cation-specific equation coefficients and 4 sets of calculated anion-specific equation coefficients can be combined to yield expressions capable of predicting the partition coefficients of solutes in 32 different RTILs.

Data have been assembled from the published literature on the enthalpies of solvation for more than 100 compounds in heptane, hexadecane, cyclohexane, and benzene. It is shown that an Abraham solvation equation with five descriptors can be used to correlate the experimental solvation enthalpies to within standard deviations of 1.85 kJ/mol (heptane), 1.84 kJ/mol (hexadecane), 1.66 kJ/mol (cyclohexane), and 2.08 kJ/mol (benzene). The derived correlations provide very accurate mathematical descriptions of the measured enthalpy of solvation data, which in the case of benzene span a range of 111 kJ/mol. Division of the experimental values into a training set and a test set shows that there is no bias in predictions, and that the predictive capability of the correlations is better than 2.63 kJ/mol.

Data have been assembled from the published literature on the enthalpies of solvation for more than 100 compounds in toluene and carbon tetrachloride. It is shown that an Abraham solvation equation with five descriptors can be used to correlate the experimental solvation enthalpies to within standard deviations of 2.19 and 2.070 kJ⋅mol−1 for toluene and carbon tetrachloride, respectively. The derived correlations provide very accurate mathematical descriptions of the measured enthalpy of solvation data at 298 K that in the case of carbon tetrachloride span a range of 105 kJ⋅mol−1. Division of the experimental values into a training set and a test set shows that there is no bias in the predictions, and that the predictive capability of the correlations is better than 2.5 kJ⋅mol−1.

Data have been assembled on the enthalpies of solvation of 373 compounds in water and 138 compounds in 1-octanol. It is shown that an Abraham solvation equation with five descriptors can be used to correlate the experimental solvation enthalpies to within standard deviations of 3.68 kJ/mol (water) and 2.66 kJ/mol (1-octanol). The derived correlations provide very accurate mathematical descriptions of the observed enthalpies of solvation, which in the case of water span a range of 150 kJ/mol. Division of the experimental values into a training set and a test set shows that there is no bias in predictions and that the predictive capability of the correlations is better than 4 kJ/mol.

This document includes supplemental material to an article titled Enthalpy of solvation correlations for gaseous solutes dissolved in benzene and in alkane solvents based on the Abraham model, published in QSAR & Combinatorial Science.