Molecular interaction between thiamine hydrochloride-DMSO binary mixture: a TDR spectroscopic approach

The dielectric measurements of thiamine hydrochloride (vitamin B1 hydrochloride) and dimethyl sulphoxide (DMSO) binary mixtures have been carried out in the frequency range of 10 MHz to 50 GHz at 25°C, 20°C and 15°C using the TDR technique. The dielectric parameters such as complex dielectric permittivity ɛ*(ω), static dielectric permittivity (ɛs), relaxation time (τ), and asymmetric distribution parameter (β) are obtained by using Cole-Davidson model. These parameters are used to compute thermodynamic properties, Kirkwood correlation factor (geff), and excess molar volume (VE). The heteromolecular H-bonding existing in the binary mixture is explained.