Projects per year
Abstract
A sequential approach combining molecular dynamics and density functional theory calculations has been worked out to unravel the second harmonic generation responses of anion–cation (AC) pairs when they form dimeric aggregates, where the cation is a stilbazolium derivative and the anions range from small inorganic iodide to medium-size organic p-toluenesulfonate. These complexes showed a strong self-aggregation behavior in molecular dynamics simulations within high-concentration conditions and formed stable dimeric aggregates, (AC)2, which can adopt different structural shapes from stacked, Λ, to head-to-head configurations. These various structures are associated with different symmetries, which are shown to modulate the second- and third-order nonlinear optical (NLO) responses. By consolidating the NLO results of this work with those previously obtained for single AC pairs [ J. Chem. Inf. Model. 2020, 60, 4817−4826], we have been able to explain the experimentally observed variations of the electrical-field-induced second harmonic generation (EFISHG) responses of these complexes as a function of concentration [ ChemPhysChem 2010, 11, 495−507]. Moreover, results have highlighted that (i) the second-order contribution, μβ//, dominates the global EFISHG response; (ii) the μβ// responses of dimers are about half of those computed for the parent AC pairs, while the third-order contributions, γ//, are reduced by only 10%; (iii) these distinct trends are ascribed to the formation of dimers adopting mainly Λ and head-to-head shapes, increasing the centrosymmetric character, in comparison to the monomers, a situation in which the second-order response cancels out as well as influences the dipole moment on μβ//; (iv) the presence of a strong amino donor group in the cation enhances the μβ// response by 1 order of magnitude and γ// by about a factor of 2; and finally, (v) dimeric aggregation has similar effects on the hyper-Rayleigh scattering response, βHRS, as on μβ//, while it reduces the one-dimensional character of βHRS. This work constitutes a step forward for the modeling of the NLO responses of AC aggregates in solution.
Original language | English |
---|---|
Pages (from-to) | 3386-3397 |
Number of pages | 12 |
Journal | The Journal of Physical Chemistry. B, Condensed matter, materials, surfaces, interfaces & biophysical |
Volume | 125 |
Issue number | 13 |
Early online date | 26 Mar 2021 |
DOIs | |
Publication status | Published - 8 Apr 2021 |
Fingerprint
Dive into the research topics of 'Second harmonic generation responses of ion pairs forming dimeric aggregates'. Together they form a unique fingerprint.Projects
- 2 Finished
-
Dynamical Chromophore-Ion Interactions Probed by their Nonlinear Optical Properties – a Multi-Scale Theoretical Chemistry Investigation
Ramos, T. N. (PI) & CHAMPAGNE, B. (PI)
1/03/20 → 28/02/22
Project: Research
-
CÉCI – Consortium of high performance computing centers
CHAMPAGNE, B. (PI), Lazzaroni, R. (PI), Geuzaine , C. (CoI), Chatelain, P. (CoI) & Knaepen, B. (CoI)
1/01/18 → 31/12/22
Project: Research
Equipment
-
High Performance Computing Technology Platform
Champagne, B. (Manager)
Technological Platform High Performance ComputingFacility/equipment: Technological Platform
Activities
- 1 Oral presentation
-
Second-order nonlinear optical responses of solutions of complex compounds – a multi-scale theoretical chemistry investigation
Ramos, T. N. (Speaker)
5 Jul 2022Activity: Talk or presentation types › Oral presentation