Molecular interaction studies of Gamma-aminobutyric acid (GABA) in an aqueous medium at various temperatures: A comprehensive analysis using volumetric, thermoacoustic and DFT methods

• Published in: The Journal of chemical thermodynamics 2025-02, Vol.201, p.107404, Article 107404
• Main Authors: Gandikota, Ramesh, Vishwam, T.
• Format: Article
• Language: English
• Subjects: Acoustic studies; DFT; GABA molecule; Molecular interaction; Single point energy
• ISSN: 0021-9614
• DOI: 10.1016/j.jct.2024.107404

[Display omitted] •Investigation into the molecular interactions of GABA in an aqueous medium.•Volumetric and thermoacoustic studies of GABA solutions across different temperatures.•Viscous forces from H-bond interactions cause a non-linear variation in relaxation time.•Relative association values indicate structure-forming interactions in the mixtures.•GABA interacts with water molecules, creating a highly cohesive environment through hydrogen bonding. The interaction of Gamma-aminobutyric acid (GABA) in an aqueous medium at various concentrations (0.101–1.086) mol·kg−1 as a function of temperature is being studied using volumetric, viscosity and acoustic analysis. The calculation of apparent molar volume (VΦ), partial molar volume (V∅o), apparent molar isentropic compression (Kϕ) and partial molar isentropic compression (Kϕ0) of GABA in an aqueous medium has been done by measuring the densities and speed of the sound in the temperature range of 298.15–323.15 K. The thermo-acoustic parameters like adiabatic compressibility (βs), acoustic impedance (Z), intermolecular free length (Lf), relative association (RA), relaxation time (τ), internal pressure (πi), enthalpy (ΔH), Gibbs free energy (ΔG), and change in entropy (ΔS) are also computed. The strength of the hydrogen bond interaction of GABA in an aqueous medium and its dipole moment are calculated using single-point energy calculations. These calculations employ IEFPCM and PCM solvation models using DFT/B3LYP and MP2 methods with the 6-311G++ (d, p) basis set. The outcomes are interpreted in terms of hydrogen bond interactions that exist in the mixture.