Abstract Poly-parameter Linear Free Energy Relationships (PPLFERs) based on the Abraham solvation model are a useful tool for predicting and interpreting equilibrium partitioning of solutes in solvent systems. The focus of this work is neutral organic solutes partitioning in neutral organic liquid solvent-air systems. This is a follow-up to previous work (Brown, 2021) which developed predictive empirical correlations between solute descriptors and system parameters, allowing system parameters to be predicted from the solute descriptors of the solvent. A database of solute descriptors, and a database of system parameters supplemented by empirical predictions, form the basis for the development of new Quantitative Structure Property Relationships (QSPRs). A total of 11 QSPRs have been developed for the E , S , A , B and L solute descriptors, and the s , a , b , v , l , and c system parameters. The QSPRs were developed using a group-contribution method referred to as Iterative Fragment Selection. The method includes robust internal and external model validation and a well-defined Applicability Domain, including estimates of prediction uncertainty. System parameters can also be predicted by combining the solute descriptor QSPRs and the empirical correlations. The predictive power of PPLFERs applied using different combinations of experimental data, empirical correlations, and QSPRs are externally validated by predicting partition ratios between solvents and air. The uncertainty for predicting the log 10 K SA of diverse solutes in diverse solvents using only the new QSPRs and empirical correlations is estimated to be one log 10 unit or less. 

/pdf/qsprs-for-predicting-equilibrium-partitioning-in-solvent-air-6y8t443g.pdf

QSPRs for Predicting Equilibrium Partitioning in Solvent–Air Systems from the Chemical Structures of Solutes and Solvents

Development of Abraham model correlations for enthalpies of solvation of solutes dissolved in N-methylformamide, 2-pyrrolidone and N-methylpyrrolidone

Published solubility data for 4,5-dihydroxyanthraquinone-2-carboxylic acid dissolved in several organic solvents of varying polarity and hydrogen-bonding character are used to calculate the Abraham model solute descriptors. Calculated descriptor values suggest that 4,5-dihydroxyanthraquinone-2-carboxylic acid engages in intramolecular hydrogen formation between the two phenolic hydrogens and the proton acceptor sites (the lone electron pairs) on the neighboring quinone oxygen atom. Our study further shows that existing group contribution and machine learning methods provide rather poor estimates of the experimental-based solute descriptors of 4,5-dihydroxyanthraquinone-2-carboxylic acid, in part because the estimation methods to not account for the likely intramolecular hydrogen-bonds. The predictive aspect of the Abraham model is illustrated by predicting the solubility of 4,5-dihydroxyanthraquinone-2-carboxylic acid in 28 additional organic mono-solvents for which experimental data does not exist. 

/pdf/abraham-solvation-parameter-model-examination-of-possible-3v16tcwh.pdf

Abraham Solvation Parameter Model: Examination of Possible Intramolecular Hydrogen-Bonding Using Calculated Solute Descriptors

The solubility of organic molecules is crucial in organic synthesis and industrial chemistry; it is important in the design of many phase separation and purification units, and it controls the migration of many species into the environment. To decide which solvents and temperatures can be used in the design of new processes, trial and error is often used, as the choice is restricted by unknown solid solubility limits. Here, we present a fast and convenient computational method for estimating the solubility of solid neutral organic molecules in water and many organic solvents for a broad range of temperatures. The model is developed by combining fundamental thermodynamic equations with machine learning models for solvation free energy, solvation enthalpy, Abraham solute parameters, and aqueous solid solubility at 298 K. We provide free open-source and online tools for the prediction of solid solubility limits and a curated data collection (SolProp) that includes more than 5000 experimental solid solubility values for validation of the model. The model predictions are accurate for aqueous systems and for a huge range of organic solvents up to 550 K or higher. Methods to further improve solid solubility predictions by providing experimental data on the solute of interest in another solvent, or on the solute's sublimation enthalpy, are also presented.

https://lirias.kuleuven.be/bitstream/20.500.12942/713804/3/predicting-solubility-limits-of-organic-solutes-for-a-wide-range-of-solvents-and-temperatures.pdf

Predicting Solubility Limits of Organic Solutes for a Wide Range of Solvents and Temperatures.

A search of the published chemical and engineering literature found enthalpy of solution data for an additional 71, 39 and 46 organic compounds dissolved in heptane, cyclohexane and N,N-dimethylfor...

Updated Abraham model correlations to describe enthalpies of solvation of solutes dissolved in heptane, cyclohexane and N,N-dimethylformamide

Experimental solubility data are reported for anthracene, biphenyl, benzil, benzoin, 1-chloroanthraquinone, phenothiazine, pyrene, salicylamide, thioxanthen-9-one, xanthene, benzoic acid, 4-tert-bu...

Sara Strickland

Papers

Abraham model correlations for describing dissolution of organic solutes and inorganic gases in dimethyl carbonate