Ultrasonic, Refractometry, FT-IR and DFT Studies on Hydrogen Bonding Interactions of Ethylene Glycol/Hexanol Binary Mixtures

The density (ρ), ultrasonic velocity (U), viscosity (η) and refractometry (nD) measurements are performed on the ethylene glycol/hexanol binary liquid mixtures in the range of temperatures 298.15-323.15 K. Various parameters such as adiabatic compressibility (β), acoustic impedance (Z), intermolecular free length (Lf), internal pressure (π) and relaxation time (τ) were calculated based on the experimentally determined values. The excess parameters were calculated to interpret the hydrogen bond networks and environment associated with the liquid solution. The interaction energy between the mixture components is analyzed using the DFT-B3LYP calculations using 6-311+G(d,p), 6-311++G(d,p) basis sets. The FT-IR spectra support the hydrogen bond in the system. The optimization energy, dipole moment of the components were also represented to correlate the measured parameters. The various theories of ultrasonic velocities and mixing rules for refractive index values were also attempted to estimate the ultrasonic speed, refractive index values of the ethylene glycol/hexanol binary system.