Molecular dynamics study of nitrobenzene and 2-nitrophenyloctyl ether saturated with water

Abstract

In this paper, results obtained from molecular dynamics (MD) simulations on the water-saturated organic liquids nitrobenzene (NB) and 2-nitrophenyloctyl ether (NPOE) are presented. Both solvents are extremely important in many areas of chemistry, and they are seen as the most promising successors of n-octanol for ion transfer studies at the liquid-liquid interface. Thermodynamic (mass density, enthalpy of vaporization), structural (radial distribution functions) and dynamic (diffusion coefficients) properties of both liquids have been calculated and compared with those obtained from MD simulations of the corresponding pure (water-free) organic liquids. The relatively polar nature of NB allows for an efficient incorporation of water into the organic liquid, minimizing the impact on the solvent structure and dynamics. NPOE exhibits added hydrophobicity due to the presence of along aliphatic chain, and this has an effect on its water solvation properties. Steric effects caused by these chains, together with the much slower dynamic response of the solvent, substantially hinder the motion of water and prevent interactions with other water molecules. The different behaviour of these solvents towards water provides a good means for studying the properties of these liquids at the interface with water.