Topological analysis of thermodynamic properties of binary mixtures containing 1-butyl-3-methylimidazolium tetrafluoroborate and cycloalkanones

This work presents densities, rho, speeds of sound, u, and molar heat capacities, C (p), of 1-butyl-3-methylimidazolium tetrafluoroborate (1) + cyclopentanone or cyclohexanone (2) mixtures as a function of composition at 293.15, 298.15, 303.15, 308.15 K and excess molar enthalpies, H (E) of same mixtures at 298.15 K. The measured rho, u and C (p) values were used to calculate excess molar volumes, V (E), excess isentropic compressibilities, and excess heat capacities, . The V (E), , H (E) and have been tested in terms of Graph theory. The analysis of V (E) data and IR spectroscopic data has suggested that (1 + 2) mixtures are characterized by interactions between hydrogen and oxygen atom of cyclopentanone or cyclohexanone with fluorine atom of [BF4](-) anion and proton of -CH3 group attached to imidazolium ring of [Bmim](+) cation. The quantum mechanical calculations also support the proposed molecular entities in pure as well as mixed states along with observations inferred from IR data of the studied mixtures. The V (E), , H (E) and values estimated by Graph theory are in agreement with experimental values.