Tran T.T.D., Bui T.T.T., Lo T.N., 2026, Determination of the Acid Dissociation Constant of Succinic Acid in Aqueous Solvent using Density Functional Theory and a Continuum Solvation Model, Chemical Engineering Transactions, 126, 433-438.
Succinic acid is a pivotal bio-based building block whose industrial application and reaction kinetics are fundamentally driven by its acid dissociation constant pKa. Consequently, a precise determination of pKa is essential for chemical engineers to accurately model molecular speciation and design efficient, sustainable production systems. In this study,the acid dissociation constants of succinic acid in aqueous solution were investigated using density functional theory (DFT) combined with the SMD continuum solvation model. Geometry optimizations and thermodynamic calculations were performed using various functionals with the 6-311+G(d,p) basis set. The pK1 and pK2 values were derived from the calculated Gibbs free energies of deprotonation. The results showed that the M06 functional gave the closest agreement with experimental data, with absolute deviations of 0.14 and 0.71 pK units, respectively. This benchmarking study suggests that the M06 functional provides a reasonable description of the succinic acid ionization in aqueous solution and serves as a useful reference for related dicarboxylic acid systems.
