Peuravaara, P., Karjalainen, J., Zhu, J., Mareš, J., Lantto, P., Vaara, J. (2018) Chemical shift extremum of 129Xe(aq) reveals details of hydrophobic solvation. Scientific Reports, 8, 7023. https://doi.org/10.1038/s41598-018-25418-4
Chemical shift extremum of ¹²⁹Xe(aq) reveals details of hydrophobic solvation
|Author:||Peuravaara, Petri1; Karjalainen, Jouni1,2; Zhu, Jianfeng1,3;|
1NMR Research Unit, P.O. Box 3000, FI-90014 University of Oulu, Oulu, Finland
2Research Unit of Medical Imaging, Physics, and Technology, P.O. Box 5000, FI-90014 University of Oulu, Oulu, Finland
3Saskatchewan Structural Sciences Center, 110 Science Place, Saskatoon, SK S7N 5C9, Canada
|Online Access:||PDF Full Text (PDF, 2.7 MB)|
|Persistent link:|| http://urn.fi/urn:nbn:fi-fe2018060725517
|Publish Date:|| 2018-06-07
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 an increasing term corresponding to the energetics of the Xe-H₂O collisions. The latter moves the chemical shift maximum up in temperature, as compared to the density maximum. In water, the computed temperature of the shift maximum is found to be sensitive to both the details of the binary chemical shift function and the coordination number. This work suggests that, material parameters allowing, the maximum should be exhibited by other liquids, too.
|Type of Publication:||
A1 Journal article – refereed
|Field of Science:||
114 Physical sciences
116 Chemical sciences
J.M. and J.V. have obtained support from the Academy of Finland (Project No. 296292). P.L. is supported by the Academy of Finland, Project No. 285666. Additional financial support has been obtained from the University of Oulu (Kvantum Institute).
|Academy of Finland Grant Number:||
296292 (Academy of Finland Funding decision)
285666 (Academy of Finland Funding decision)
Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-018-25418-4.
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