Water dynamics in concentrated electrolytes: Local ion effect on hydrogen-bond jumps rather than collective coupling to ion clusters

0490901 - ÚOCHB 2019 RIV US eng J - Journal Article
Stirnemann, G. - Jungwirth, Pavel - Laage, D.
Water dynamics in concentrated electrolytes: Local ion effect on hydrogen-bond jumps rather than collective coupling to ion clusters.
Proceedings of the National Academy of Sciences of the United States of America. Roč. 115, č. 22 (2018), E4953-E4954. ISSN 0027-8424. E-ISSN 1091-6490
Institutional support: RVO:61388963
Keywords : molecular mechanism * reorientation
OECD category: Physical chemistry
Impact factor: 9.580, year: 2018

Zhang et al. (Proc Natl Acad Sci USA 114:10023-10028) speculate that ions and biomolecules slow down water dynamics in the same collective fashion. However, our prior studies had established the opposite. While in all cases the dominant effect is local (i.e., on the HB jumps) and not collective, ions and biomolecules affect water dynamics differently. This is confirmed by temperature-dependent studies showing that the slowdown effect of ions is mostly enthalpic due to the water–ion interaction, while that of proteins and DNA is mostly entropic due to an excluded-volume effect.
Permanent Link: http://hdl.handle.net/11104/0285018