Chemical shift extremum of 129Xe(aq) reveals details of hydrophobic solvation.

ABSTRACT: The 129Xe chemical shift in an aqueous solution exhibits a non-monotonic temperature dependence, featuring a maximum at 311 K. This is in contrast to most liquids, where the monotonic decrease of the shift follows that of liquid density. In particular, the shift maximum in water occurs at a higher temperature than that of the maximum density. We replicate this behaviour qualitatively via a molecular dynamics simulation and computing the 129Xe chemical shift for snapshots of the simulation trajectory. We also construct a semianalytical model, in which the Xe atom occupies a cavity constituted by a spherical water shell, consisting of an even distribution of solvent molecules. The temperature dependence of the shift is seen to result from a product of the decreasing local water density and a

SUBMITTER: Peuravaara P 

PROVIDER: S-EPMC5935698 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature