Molecular Dynamics Study on Microheterogeneity and Preferential Solvation in Methanol/Chloroform Mixtures

Molecular dynamics simulations have been used to study the structure and properties of methanol/chloroform mixtures with varying molecular fractions. The results of the simulations of the neat liquids have been validated by comparing the calculated radial distribution functions with those previously published. Experimental and calculated densities of the mixture at various molar ratios were in very good agreement. The analysis of radial distribution functions of the mixtures at different concentrations revealed clustering effects in the solvent mixture. To provide a more detailed insight into this phenomenon, local molecular fractions at varying distances are presented that clearly show these clustering effects. It was also demonstrated, that in such a mixture hydrophilic and hydrophobic parts of amphiphilic solutes are preferentially solvated by methanol or chloroform, respectively.