Elucidation of hydrogen bonding formation by a computational, FT-IR spectroscopic and theoretical study between benzyl alcohol and isomeric cresols†
The densities (ρ) of binary mixtures of benzylalcohol with o-cresol, m-cresol and p-cresol have been measured at ambient atmospheric pressure over the entire composition range, and at a temperature range from 303.15 K to 323.15 K, with the help of a Rudolph Research Analytical digital densitometer (DDH-2911 model). Moreover, the speeds of sound (u) for these mixtures were also carried out at 303.15 K and 313.15 K. The measured data were used to calculate the excess volumes (VE) and excess isentropic compressibilities (κEs), and the results were computed in terms of Redlich–Kister & Hwang equations. The experimental speed of sound was compared in terms of Schaff's collision factor theory (CFT) and Jacobson's free length theory (FLT). The experimental excess molar volume (VE) was also used to test the validity of the Prigogine–Flory–Patterson (PFP) theory at 303.15 K and 313.15 K. The existence of hydrogen bonding in the binary mixtures of benzyl alcohol with cresols is further conformed by high level theoretical calculation, namely, density functional theory (DFT-B3LYP) with 6-311++G(d,p) basis sets was used to study the geometries, bond characteristics, interaction energies and natural bonding orbital (NBO) analysis of the hydrogen-bonded complexes in the gas phase, and the cross-associations in the mixture studied were investigated via quantum chemical calculations. The measured data were used to study intermolecular interactions between component molecules of binary mixtures with FT-IR spectroscopic studies.