Anion-cation contrast of small molecule solvation in salt solutions
Hervø-Hansen, Stefan LU ; Heyda, Jan ; Lund, Mikael LU
and Matubayasi, Nobuyuki
(2022)
In Physical Chemistry Chemical Physics
24(5).
p.3238-3249
- Abstract
The contributions from anions and cations from salt are inseparable in their perturbation of molecular systems by experimental and computational methods, rendering it difficult to dissect the effects exerted by the anions and cations individually. Here we investigate the solvation of a small molecule, caffeine, and its perturbation by monovalent salts from various parts of the Hofmeister series. Using molecular dynamics and the energy-representation theory of solvation, we estimate the solvation free energy of caffeine and decompose it into the contributions from anions, cations, and water. We also decompose the contributions arising from the solute-solvent and solute-ions interactions and that from excluded volume, enabling us to... (More)
The contributions from anions and cations from salt are inseparable in their perturbation of molecular systems by experimental and computational methods, rendering it difficult to dissect the effects exerted by the anions and cations individually. Here we investigate the solvation of a small molecule, caffeine, and its perturbation by monovalent salts from various parts of the Hofmeister series. Using molecular dynamics and the energy-representation theory of solvation, we estimate the solvation free energy of caffeine and decompose it into the contributions from anions, cations, and water. We also decompose the contributions arising from the solute-solvent and solute-ions interactions and that from excluded volume, enabling us to pin-point the mechanism of salt. Anions and cations revealed high contrast in their perturbation of caffeine solvation, with the cations salting-in caffeine via binding to the polar ketone groups, while the anions were found to be salting-out via perturbations of water. In agreement with previous findings, the perturbation by salt is mostly anion dependent, with the magnitude of the excluded-volume effect found to be the governing mechanism. The free-energy decomposition as conducted in the present work can be useful to understand ion-specific effects and the associated Hofmeister series.
(Less)
- author
- Hervø-Hansen, Stefan
LU
; Heyda, Jan
; Lund, Mikael
LU
and Matubayasi, Nobuyuki
- organization
- publishing date
- 2022-02-07
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Chemistry Chemical Physics
- volume
- 24
- issue
- 5
- pages
- 12 pages
- publisher
- Royal Society of Chemistry
- external identifiers
-
- scopus:85124056388
- pmid:35044392
- ISSN
- 1463-9076
- DOI
- 10.1039/d1cp04129k
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © the Owner Societies.
- id
- 1144fa06-9826-4910-8393-ec7d53dcdc8a
- date added to LUP
- 2022-02-28 17:50:17
- date last changed
- 2024-07-06 18:58:08
@article{1144fa06-9826-4910-8393-ec7d53dcdc8a,
abstract = {{<p>The contributions from anions and cations from salt are inseparable in their perturbation of molecular systems by experimental and computational methods, rendering it difficult to dissect the effects exerted by the anions and cations individually. Here we investigate the solvation of a small molecule, caffeine, and its perturbation by monovalent salts from various parts of the Hofmeister series. Using molecular dynamics and the energy-representation theory of solvation, we estimate the solvation free energy of caffeine and decompose it into the contributions from anions, cations, and water. We also decompose the contributions arising from the solute-solvent and solute-ions interactions and that from excluded volume, enabling us to pin-point the mechanism of salt. Anions and cations revealed high contrast in their perturbation of caffeine solvation, with the cations <i>salting-in</i> caffeine <i>via </i>binding to the polar ketone groups, while the anions were found to be <i>salting-out</i> via perturbations of water. In agreement with previous findings, the perturbation by salt is mostly anion dependent, with the magnitude of the excluded-volume effect found to be the governing mechanism. The free-energy decomposition as conducted in the present work can be useful to understand ion-specific effects and the associated Hofmeister series.<br/></p>}},
author = {{Hervø-Hansen, Stefan and Heyda, Jan and Lund, Mikael and Matubayasi, Nobuyuki}},
issn = {{1463-9076}},
language = {{eng}},
month = {{02}},
number = {{5}},
pages = {{3238--3249}},
publisher = {{Royal Society of Chemistry}},
series = {{Physical Chemistry Chemical Physics}},
title = {{Anion-cation contrast of small molecule solvation in salt solutions}},
url = {{http://dx.doi.org/10.1039/d1cp04129k}},
doi = {{10.1039/d1cp04129k}},
volume = {{24}},
year = {{2022}},
}