Thermodynamic framework for the predicting the properties of amino-benzoic acids

Extensive experimental and theoretical thermochemical studies of 2-, 3-, and 4-amino-benzoic acids have been carried out, including combustion calorimetry, vapor pressure measurements, and high-level quantum-chemical calculations. We have collected available primary experimental results on vapour pressures, phase transitions (solid-solid, solid-liquid, crystal-gas, and liquid-gas), and enthalpies of formation. These data were evaluated using empirical, semi-empirical and quantum chemical methods. The consistent sets of evaluated thermodynamic data were used to develop the "centerpiece" based group-additivity method for predicting enthalpies of formation and enthalpies of vaporization of di- and tri-substituted benzenes. It was found that the agglomeration of three substituents on the benzene ring has no consequences for the energetics of the molecule in terms of additional group-additivity parameters This observation is important to reliably assess the energetics of the bio-relevant molecules. (C) 2021 Elsevier Ltd.