Thermodynamic functions of proton ionization of para-substituted benzenethiols
Abstract
ΔG025, ΔH025, and ΔS025 values for ionization of four para-substituted benzenethiols have been calculated from thermodynamic pKa values determined in water over a range of temperatures. These, together with earlier results for meta-substituted benzenethiols, show that effects on the free energy of ionization for benzenethiols are primarily related to changes in entropy and that these compounds cannot be considered as forming an isoenthalpic series.