Radial distribution and hydrogen bonded network graphs of alcohol-aniline binary mixture

Hydrogen bonds play a vital role in the stability and functioning of biomolecules. Suitable binary liquids are often used as prototypes for the study of biologically significant hydrogen bond studies and their intricate networks. Often, such systems show deviations in their physico-chemical properties from ideal conditions. As a continuation of our research interest in biologically important hydrogen-bonded systems, this paper reports the classical molecular dynamic studies on mixtures of aniline with 8 primary alcohols (C_RH_2R+1-OH, R = 1 to 8) for the complete concentration range. The energetics results indicate the predominance of OH--O interactions over other hydrogen bonds. Structures in the network are analyzed using radial distribution function (RDF), hydrogen bond statistics, and graph theoretical analysis (GTA). Coordination numbers, hydrogen bond statistics, and GTA show a bunching of alcohol-alcohol hydrogen bonds for lower aniline concentrations, while the aniline-aniline interactions are not affected by changes in the concentration.

Interaction energies are calculated using B3LYP/6-311G++(d, p) density functional theory using Gaussian-09. The molecular dynamics simulations are carried out using GROMACS (V 2020.6) with the OPLS/AA force field and the simulation box is visualized using VMD. The NetworkX Python package is used for GTA calculation.