Intermolecular interaction in the binary mixtures of ketones with nonpolar molecules

Abstract

Excess free energy of mixing and excess molar polarization in the binary mixtures of ketones (acetone, MIBK, DIBK and acetyl acetone) in nonpolar solvents (carbon tetrachloride, Benzene, cyclohexane and n-heptane) is evaluated by Winkelmann–Quitzsch (WQ) and Ray et al. theory by using the experimental findings of relative permittivity and refractive index. The trend of variation of excess free energy of mixing and excess correlation factor depicts a clear picture of molecular association and liquid structure in the binary mixtures. The induction effect is less due to the steric hindrance of isobutyl group of DIBK and the short range interactions between the molecules are least for which WQ and Ray et al. modified equations hold good for the binary mixture of DIBK and nonpolar solvents at the same molar concentration of polar solvents. However, the induction effect is more in acetyl acetone in comparison to acetone and MIBK for which the peak value of ∆Fab/∆Pab lies in the region of 0.2mol fraction of polar liquids whereas the peak value of ∆FWQ/∆PWQ lies in the equimolar concentration of polar and nonpolar solvents. The observation clearly indicates that the polar-induced nonpolar interaction and induced nonpolar-induced nonpolar interaction in binary liquid mixtures contributes a lot to decrease the excess molar polarization in acetone, MIBK and acetyl acetone.