Thermophysical and spectroscopic properties of binary liquid systems: acetophenone/cyclopentanone/cyclohexanone with N-methylformamide

The intermolecular interactions in the binary liquid systems of N-methylformamide with acetophenone and cyclic ketones (cyclopentanone and cyclohexanone) were studied with combined experimental and computational methodology. The speed of sound (u), density (rho) and viscosity (eta) values are measured for binary mixtures of N-methylformamide with ketones over the entire range of mole fraction at temperatures (T) of 303.15-318.15K, at atmospheric pressure. From the experimental results, the values of excess molar volume (V-E), excess isentropic compressibility (kappa(E)(s)), deviation in viscosity (Delta eta) and excess Gibbs free energy of activation of viscous flow (Delta G*(E)) are evaluated. The experimental results indicate an intermolecular association between the binary liquid mixtures. Furthermore, the nature of the hydrogen bond of the associated complexes is further confirmed by high-level theoretical calculations. The structures, interactional energies and natural bonding orbital analysis of the hydrogen-bonded complex have been calculated in the gas phase using the density functional theory method at the B3LYP/6-311++G (d, p) level.