Ca 2+ -Cl − Association in Water Revisited: the Role of Cation Hydration

Abstract : We investigate the dissociation of a Ca2+-Cl− pair in water using classical molecular dynamics simulations with a polarizable interaction potential, parameterized from ab initio calculations. By computing the potential of mean force as a function not only of the interionic distance but also of the coordination numbers by water molecules, we show that it is necessary to use a collective variable describing the cation hydration in order to capture the dissociation mechanism. In the contact ion pair, the Ca2+ cation has a first coordination sphere containing 5 or 6 water molecules. The minimum free-energy path for dissociation involves a two-step process: First one or two additional water molecules enter the cation coordination shell, increasing the coordination number up to 7 with an almost fixed interionic distance. Then the dissociation of the ionic pair occurs at this fixed coordination number.
Type de document :
Article dans une revue
ChemPhysChem, Wiley-VCH Verlag, 2017, 18 (19), pp.2807 - 2811. 〈10.1002/cphc.201700286〉
Domaine :
Liste complète des métadonnées

Littérature citée [36 références]  Voir  Masquer  Télécharger

http://hal.upmc.fr/hal-01634885
Contributeur : Gestionnaire Hal-Upmc <>
Soumis le : mardi 14 novembre 2017 - 14:55:19
Dernière modification le : jeudi 11 janvier 2018 - 02:02:59

Fichier

Salanne_2017_Ca2+-Cl−.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

Collections

Citation

Mathieu Salanne, Sami Tazi, Rodolphe Vuilleumier, Benjamin Rotenberg. Ca 2+ -Cl − Association in Water Revisited: the Role of Cation Hydration. ChemPhysChem, Wiley-VCH Verlag, 2017, 18 (19), pp.2807 - 2811. 〈10.1002/cphc.201700286〉. 〈hal-01634885〉

Partager

Métriques

Consultations de la notice

42

Téléchargements de fichiers

2