Hydration of Fluorobenzenes: A Molecular Dynamics Simulation Investigation

Molecular dynamics simulations of benzene and 12 fluorobenzenes with various degrees of fluorine substitution in water reveal that the accumulation of water in the first solvent shell decreases with increase in number of fluorine atoms relative to benzene, with an exception of hexafluorobenzene. Further, the solute-solute radial density function indicates that partially substituted fluorobenzenes sample pi\documentclass-stacked and T-shaped geometries. In contrast benzene and hexafluorobenzene sample only the T-shaped geometries. Comparison of solute-solute and solute-solvent radial density functions suggests that solute-solute interactions is preferred over solute-solvent interaction, which suggests the hydrophobic nature of fluorobenzenes, which increases with increase in number of fluorine atoms on the phenyl ring. The spatial distribution of water around the fluorobenzenes suggests that water avoids the C-F bond group, which indicates increase in hydrophobicity of fluorobenzenes with number of fluorine atoms.