Solvent effect on the dimerization and hydration constant of benzoic acid

Abstract

The hydration and dimerization of benzoic acid have been studied at 25°C by partition and solubility measurement of water in organic phase containing benzoic acid. Organic solvents used include n-hexane, cyclohexane, toluene, benzene, chlorobenzene and 1,2-dichloroethane. The benzoic acid being denoted as HA, the following associated species have been found in the organic phase: HA · H2O, (HA)2, (HA)2· H2O and (HA)2·(H2O)2. The hydration constants of these hydrated species together with hydration-corrected dimerization and partition constants were evaluated. Possible structures of the hydrated species have been elucidated.