The correlation and prediction of infinite dilution activity coefficients of compounds in water at 298.15 K

Application of a General Computer Algorithm Based on the Group-Additivity Method for the Calculation of Two Molecular Descriptors at Both Ends of Dilution: Liquid Viscosity and Activity Coefficient in Water at Infinite Dilution

“…Comparison of the present result with those published in earlier articles [8,9] reveals that it lies in the same range of prediction accuracy: Abraham’s method, described in [8], being based on the five descriptors: excess molar refractivity, dipolarity/polarizability, overall or summation hydrogen bond acidity and basicity, and the McGowan volume, yielded a correlation coefficient R 2 of 0.977 and a leave-one-out cross-validation correlation coefficient Q 2 of 0.976 and corresponding standard errors of 0.284 and 0.29, respectively, for 655 structurally diverse compounds; the ant-colony optimization method, outlined in [9], limited to 105 hydrocarbons and founded on four topological descriptors and the refractivity, resulted in a correlation coefficient R 2 of 0.9893 and a standard error of 0.3996 for the calibration set, and a Q 2 of 0.9891 and a standard error of 0.3865 for the prediction set. The main advantage of the present method lies in its ease of use in that—just like in the previous subsection—a simple 2D drawing is needed to help to find all the compound’s atom groups and then sum up their contributions according to Table 3.…”

“…In addition, only values have been considered which have been measured at or reduced to 298.15 K. Primary sources of experimental data have been the collective reports mentioned earlier [8,9]. Additional data have been found for 1-propoxypropan-2-ol [73], several alkyl and alkenyl alcohols and alkylbenzenes [74], valeric and crotonic aldehyde [75], variously substituted benzoic acids [76,77], naphthoic acids [78,79], isatin [80], 2-cyanoguanidine [81], florfenicol [82], thiamphenicol [83] and various sulfonamides [84,85].…”

“…Several methods for the γ ∞ calculation have been published, based on QSPR or group contribution methods (e.g., ASOG or UNIFAC), summed up in [8]. An interesting approach founded on the ant-colony optimization (ACO) method, which allowed to select five relevant descriptors out of 1160 quantum-chemical and topological descriptors [9].…”

Calculation of Abraham model L-descriptor and standard molar enthalpies of vaporization and sublimation for C9 - C26 mono-alkyl alkanes and polymethyl alkanes

“…The published QSAR and group contribution methods are applicable to a much smaller number of chemical and biological processes. Moreover, the Abraham model solute descriptors for a given molecule can be used to predict many other properties such as vapor pressure, water-to-organic solvent partition coefficients, gas-to-water partition coefficients, solubility ratios, enthalpies of solvation, molar heat capacities of hydration 101 , and the infinite dilution activity coefficients of the compound in water 102,103 . There is no need to calculate a different set of descriptor values for each property that one wishes to predict.…”

Combining Molecular Dynamics and Machine Learning to Predict Self-Solvation Free Energies and Limiting Activity Coefficients

“…Experimental values for the self-solvation free energy, ΔG solv self , were obtained from the CompSol database. 66 Experimental values for the infinite dilution activity coefficient (IDAC), γ ∞ , in water were taken from the work of Abraham et al 67 To also have experimental hydration free energies available only those subsets of the data sets were considered that are also present in the FreeSolv database. 68 Also only substances that are liquid at standard ambient temperature and pressure were considered.…”