Effect of temperature and position of OH group in isomeric butanediols in intermolecular interactions with 2-chloroaniline: A thermodynamic, DFT and molecular dynamics approach

Abstract

The pronounced effect of the position of the hydroxyl groups in isomeric butanediols (1, 2-butanediol (12BDL), 1, 3-butanediol (13BDL) and 1, 4-butanediol (14BDL)) in the formation of hydrogen bonds with 2-chloroaniline (2CA) was investigated by using experimental and computational methods. The density (ρ) and speed of sound (u) in binary mixture was determined at T = (303.15–318.15) K and at atmospheric pressure p = 0.1 MPa. Values of excess molar volume (VmE), and excess isentropic compressibility (ksE) were determined by using experimental data. It was observed that these excess properties (VmEksE) departs negatively from the ideal mixture which indicates the formation of intermolecular hydrogen bonds. The volumetric properties like excess partial molar volume (V‾m,1EV‾m,2E), partial molar volume (V‾m,10,V‾m,20) and excess partial molar volume (V‾m,10EV‾m,20E) are derived at infinite dilutions. Quantum mechanical approach was used to study the intermolecular hydrogen bond interactions in self and cross-associated complexes of 2-chloroaniline and isomeric butanediols with the aid of DFT in the gas phase, while classical molecular dynamic simulations were carried out in the liquid phase. Experimental, quantum mechanical and classical molecular dynamic methods are used to investigate the formation of a hydrogen-bonded network between 2-chloroaniline and isomeric butanediols mixtures. The investigated results were further confirmed by the existence of hydrogen bonding evolution between 2-chloroaniline and isomeric butanediols through FT-IR Spectral studies. The Fourier transform Infrared spectroscopic data strongly confirms and support the existence of intermolecular hydrogen bonding and molecular associations between component molecules.