title: Water-Mediated Hydrophobic Interactions.
abstract: Hydrophobic interactions are driven by the combined influence of the direct attraction between oily solutes and an additional water-mediated interaction whose magnitude (and sign) depends sensitively on both solute size and attraction. The resulting delicate balance can lead to a slightly repulsive water-mediated interaction that drives oily molecules apart rather than pushing them together and thus opposes their direct (van der Waals) attraction for each other. As a consequence, competing solute size-dependent crossovers weaken hydrophobic interactions sufficiently that they are only expected to significantly exceed random thermal energy fluctuations for processes that bury more than ∼1 nm(2) of water-exposed area.
authors.affiliation: Department of Chemistry, Purdue University, West Lafayette, Indiana 47907; email: bendor@purdue.edu.
authors.forename: Dor
authors.initials: D
authors.lastname: Ben-Amotz
keywords: compensation; crossover; enthalpy; entropy; free energy; hydrophobic; potential of mean force; water-mediated