Hydrogen Bonding

The article "Benzene forms hydrogen bonds with water" by S. Suzuki, et al. (14 August., p. 942) represents a major advance in our understanding of their interactions between water and aromatic structures. The authors show that benzene forms hydrogen bonds with water through the π electron system of benzene. Although they did not mention it, their work should also be useful for rationalizing the solubilities or aromatic compounds in water. For example, from literature tabulations it is known that the solubility of benzene in water is 35 times greater than that of cyclohexane. The results of Suzuki et al. are consistent with and can be used to help understand this independent solubility information because cyclohexane, unlike benzene, does not have a π electron system and will therefore not form solubility-enhancing π system hydrogen bonds with solvent water molecules.