Thermodynamic and computational study of paracetamol in aqueous solutions of some sustainable amino acid-based ionic liquids

Experimental and computational study of the interactions between paracetamol and amino acid based ionic liquids ILs; [Ch][Gly], [Ch][L-Ala], and [Ch][L-Val] have been carried out in aqueous media at temperature range (298.150-313.150) K. In the experimental section, the density and speed of sound for ternary solutions containing (ILs + H2O + Paracetamol) have measured, and the standard partial molar volume and partial molar isentropic compressibility have evaluated trough Redlich-Mayer equation. Also, the standard apparent molar expansibility has been obtained for paracetamol in the studied solutions to find out parameters influences the volume, and clearly the temperature and size of anion are dominant factors. So that, the volume of the paracetamol increases with increasing anion size by rising temperature. The Hepler constant has evaluated from temperature derivation of the standard apparent molar expansibility, and is used to describe the structure making or breaking tendency of the paracetamol in the studied solutions. The decrease in the negative values of Delta V-tr(phi)0, and increase in Delta K-tr(phi)0 values with an increase in the AA-ILs concentration indicates that the nonpolar - nonpolar and polar - nonpolar interactions between the API-IL and amino acid are dominant. The SPT theory was used to compare the standard partial molar volume contribution, which results show that the obtained values are in good agreement with the experimental data. Finally, Gaussian analysis was used to calculate the interaction energies of the systems in the specified structure. (C) 2020 Elsevier Ltd.

Automated summary

Experimental and computational study was conducted on the interactions between paracetamol and amino acid based ionic liquids. Results showed that temperature and anion size are key factors influencing the volume of paracetamol, with nonpolar-nonpolar and polar-nonpolar interactions being dominant. Experimental data and SPT theory calculations were in good agreement.