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.