Hydrogen Bonding Interactions of m-Chlorotoluene with 1-Alkanol Analyzed by Thermodynamic, Fourier Transform Infrared Spectroscopy, Density Functional Theory, and Natural Bond Orbital

Fourier transform infrared spectroscopy (FT-IR) has been employed to obtain information about the nature of interactions in the liquid solutions of pure solvents and their mixtures of m- chlorotoluene (MCT) with 1-alkanol systems at different mole fractions. Furthermore, densities (ρ) and speeds of sound ( u ) of binary mixtures of MCT with a set of five 1-alkanols, namely, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol, were measured as a function of composition at 298.15 K. From the experimental quantities, the excess volumes ( V E ), isentropic compressibility ( k s ), and excess isentropic compressibility ( k s E ) were calculated for the binary mixtures over the entire composition range and under the atmospheric pressure. These excess properties ( V E ) and ( k s E ) were correlated with the Redlich-Kister polynomial equation. Additionally, theoretical density functional theory calculations and natural bond orbital analyses were carried out to further discern the nature and strength of interactions between MCT and 1-alkanols. Moreover, the recorded FT-IR spectra-derived excess properties and quantum chemically derived data revealed the presence of interactions between component molecules in binary liquid solutions.