Projets par an
Résumé
Molecular aggregation plays an important role on optical phenomena, and optimizing the latter requires understanding the aggregation behavior as a function of the molecular structures. The formation of molecular aggregates composed of stilbazolium chromophores and small to medium-size anions is studied by carrying out classical molecular dynamics (MD) simulations, shedding light on the dynamics of spontaneous self-aggregation of anion-cation (AC) pairs and estimating their equilibrium aggregation constants. First, analyses based on atom-atom distances and on contact mapping (Voronoi tessellation) highlight that the interactions occur at the level of the methylpyridinium groups of the cations, which enabled monitoring the clustering dynamics. Then, simulations show that clusters containing up to 5 AC pairs dominate the populations. Among the AC pairs, two of them (where the stilbazolium bears a strong donor substituent and when the anion is SCN- or pTS-) aggregate into small clusters even at high concentration, corroborating related experimental results [ChemPhysChem. 11 (2010) 495–507]. Still, these MD simulations do not reveal strict relationships between the aggregate size and the nature of the anion. Nevertheless, AC pairs bearing iodide anions require longer MD simulation times to reach an asymptotic equilibrium tendency of the average number of clusters. Finally, the aggregates are shown to adopt a preferential Λ-shape with contributions from head-to-head and stacked forms. Complementarily, the analyses of the isoperimetric quotient reinforce the AC pairs are not forming spherical aggregates even for clusters including more than 10 AC pairs. So, when the stilbazolium bears a strong donor substituent and when the anion is pTS-, stacked aggregates are formed, at both low and high concentrations, resulting in excellent agreement with the measured aggregation equilibrium constant.
langue originale | Anglais |
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Numéro d'article | 117735 |
Nombre de pages | 10 |
journal | Journal of Molecular Liquids |
Volume | 344 |
Date de mise en ligne précoce | 5 oct. 2021 |
Les DOIs | |
Etat de la publication | Publié - 15 déc. 2021 |
Empreinte digitale
Examiner les sujets de recherche de « Self-aggregation of stilbazolium ion pairs in liquid chloroform. A molecular dynamics study ». Ensemble, ils forment une empreinte digitale unique.Projets
- 2 Terminé
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Dynamical Chromophore-Ion Interactions Probed by their Nonlinear Optical Properties – a Multi-Scale Theoretical Chemistry Investigation
Ramos, T. N. (Responsable du Projet) & CHAMPAGNE, B. (Responsable du Projet)
1/03/20 → 28/02/22
Projet: Recherche
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CÉCI – Consortium des Équipements de Calcul Intensif
CHAMPAGNE, B. (Responsable du Projet), Lazzaroni, R. (Responsable du Projet), Geuzaine , C. (Co-investigateur), Chatelain, P. (Co-investigateur) & Knaepen, B. (Co-investigateur)
1/01/18 → 31/12/22
Projet: Recherche
Équipement
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Plateforme Technologique Calcul Intensif
Champagne, B. (!!Manager)
Plateforme technologique Calcul intensifEquipement/installations: Plateforme technolgique
Activités
- 1 Présentation orale
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Second-order nonlinear optical responses of solutions of complex compounds – a multi-scale theoretical chemistry investigation
Ramos, T. N. (Orateur)
5 juil. 2022Activité: Discours ou présentation › Présentation orale