Solid-liquid equilibrium of 2,3-dimethoxybenzoic acid in fifteen mono-solvents: Determination, Correlation, Hansen solubility parameter, molecular dynamic simulation and thermodynamic analysis

This current research work was devoted to investigating solid-liquid equilibrium solubility, Hansen solubility parameters (HSPs), intermolecular interaction and thermodynamic analysis of 2,3dimethoxybenzoic acid (o-veratric acid) in fifteen mono-solvent systems namely water, methanol (MtOH), ethanol (EtOH), n-propanol (NPOH), isopropanol (IPOH), n-butanol (NBOH), methyl acetate (MtAC), ethyl acetate (EtAC), n-propyl acetate (NPAC), isopropyl acetate (IPAC), n-butyl acetate (NBAC), ethylene glycol monomethyl ether (EGME), ethylene glycol monoethyl ether (EGEE), 1,4-dioxane (Diox) and acetonitrile (MeCN) by experimentation, mathematical relationships and molecular simulations. The measurement of solubility of o-veratric acid was conducted by laser monitoring method under 0.1 MPa, and corresponding measuring temperature range was 278.15 K to 323.15 K in most mono-solvents except Diox (288.15 K 323.15 K). The maximum of o-veratric acid solubility expressed in mole faction was found in Diox at 323.15 K (0.1717), while the minimum of solubility value was observed as 4.791e-3 in water at 278.15 K. At 298.15 K, o-veratric acid solubility in selected solvents had a general order of: Diox approximate to EGME > EGEE > MtOH > MtAC > EtOH > EtAC > MeCN > NPOH > NPAC > IPOH > NBOH > IPAC approximate to NBAC > water. Molecular similarities between o-veratric acid and fifteen selected mono-solvents were deeply considered with the help of HSPs concept. Moreover, solubility values were computationally expressed by Margules, Wilson, NRTL, NRTL-SAC and UNIQUAC model with the average relative deviation (ARD) of no higher than 5.365%. For explaining solubility behavior of o-veratric acid, molecular electrostatic potential surface, Hirschfeld surface as well as solvation free energy of overatric acid were analyzed by molecular simulation. Furthermore, the dissolution thermodynamic properties (Delta(dis)G, Delta H-dis and Delta S-dis) of o-veratric acid dissolving in selected solvents and mixing thermodynamic properties (Delta(mix)G, Delta H-mix and Delta S-mix) of o-veratric acid with fifteen solvents were estimated by UNIQUAC model, the results of which indicated the dissolution processes were spontaneous, endothermic as well as entropy increasing and mixing processes were spontaneous as well as entropy-increasing. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

This research focused on the solubility, intermolecular interaction, and thermodynamic analysis of 2,3-dimethoxybenzoic acid in fifteen different solvent systems. The study utilized experimentation, mathematical relationships, and molecular simulations to investigate the properties of the compound. The results provided insights into the solubility behavior and thermodynamic properties of 2,3-dimethoxybenzoic acid in various solvents.