Density, viscosity, ultrasonic and thermoacoustic studies of aqueous nicotinamide (Vitamin B3) binary mixtures: Temperature dependence

• Published in: The Journal of chemical thermodynamics 2025-03, Vol.202, p.107424, Article 107424
• Main Authors: Subbarao, R., Vishwam, T.
• Format: Article
• Language: English
• Subjects: DFT; Hydrogen bond; Nicotinamide; Ultrasonic velocity; Volumetric properties
• ISSN: 0021-9614
• DOI: 10.1016/j.jct.2024.107424

[Display omitted] •Study of molecular interactions of Nicotinamide in aqueous medium.•Volumetric and thermoacoustic studies of mixtures at various temperatures.•Relative association values indicating a structure-forming interaction in the mixtures.•Positive Gibbs free energy and enthalpy suggest a non-spontaneous, endothermic reaction within the mixtures.•Nicotinamide interacts with water molecules, fostering a highly cohesive environment via H-bonding. The density (ρ) and ultrasonic velocity (u) measurements were performed for nicotinamide (Vitamin B3) in a water medium with various concentrations (0.101 to 1.111) mol·kg−1 in the temperatures range of 298.15 K to 323.15 K. Experimental data is used to estimate volumetric parameters such as apparent molar volume (VΦ), partial molar volume (V∅o), thermoacoustic parameters like adiabatic compressibility (β), acoustic impedance (Z), intermolecular free length (Lf), ultrasonic attenuation (αf2), relative association (RA), relaxation time (τ), and internal pressure (πi). In addition, thermodynamic parameters such as Gibbs free energy (ΔG), Enthalpy (ΔH), and Entropy (ΔS) are also evaluated to interpret the molecular interaction in the medium. The single-point energy calculation is also determined in a gaseous state and an aqueous medium using the IEFPCM model at HF, DFT/B3LYP, and MP2 methods using 6-311G ++(d,p) basis set to estimate the strength of the hydrogen bond. The results are interpreted in terms of structure-making or structure-breaking effects of drug molecules in the mixtures.