Benzene solubility in water: A reassessment

It is shown that the results of molecular dynamics simulations on the hydration thermodynamics of benzene at room temperature [Schravendijk and van der Vegt, J. Chem. Theory Comput. 1 (2005) 643] are in line with a former theoretical analysis [Graziano and Lee, J. Phys. Chem. B 105 (2001) 10367]. In fact: (a) the benzene–water van der Waals interaction energy proves to be larger in magnitude than the work of cavity creation and is able to account for the experimental finding that the hydration of benzene is a spontaneous process under the Ben-Naim standard conditions around room temperature; (b) the weak benzene–water H-bonds do not provide a significant contribution to benzene solubility in water because the favorable enthalpic component is almost entirely compensated for by an unfavorable entropic component. This enthalpy–entropy compensation occurs because the H-bonding potential of benzene is not strong.