Issue 8, 2018

Ion hydration: linking self-diffusion and reorientational motion to water structure

Abstract

Ions affect the self-diffusion and relaxation of water. Such ion-induced changes of water dynamics have long been rationalized in terms of the change of the water structure around the ions. The aim of this paper is to establish a link between dynamics and the “water structure” on the basis of the extended jump (EJ) model for the reorientational motion of water, Eyring's transition state theory of the self-diffusion of water, and the statistical thermodynamic preferential solvation theory developed from the Kirkwood–Buff (KB) theory. Through the synthesis of the above three, we formulate a scheme to correlate the ion-induced water dynamics changes to the water structure. With this new formulation, it is shown that chaotropic or negatively hydrated ions preferentially bind the transition state of water motion thereby stabilizing the transition state, whereas the exclusion of kosmotropes or positively hydrated ions suppresses the formation of the transition state. The ion effects on water dynamics are thus analyzed in a unified manner in terms of KB integrals, which represent the (averaged) “structures” of water.

Graphical abstract: Ion hydration: linking self-diffusion and reorientational motion to water structure

Article information

Article type
Paper
Submitted
28 Oct 2017
Accepted
18 Jan 2018
First published
08 Feb 2018

Phys. Chem. Chem. Phys., 2018,20, 5909-5917

Ion hydration: linking self-diffusion and reorientational motion to water structure

S. Shimizu and N. Matubayasi, Phys. Chem. Chem. Phys., 2018, 20, 5909 DOI: 10.1039/C7CP07309G

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements