fr
Article scientifique
Accès libre
Anglais

Change of Quadrupole Moment upon Excitation and Symmetry Breaking in Multibranched Donor‐Acceptor Dyes

Publié dansChemPhysChem, vol. 21, no. 15, p. 1718-1730
Date de publication2020
Résumé

Upon photoexcitation, a majority of quadrupolar dyes, developed for large two-photon absorption, undergo excited-state symmetry breaking (ES-SB) and behave as dipolar molecules. We investigate how the change of quadrupole moment upon S 1  <- S 0  excitation, ? Q , influences the propensity of a dye to undergo ES-SB using a series of molecules with a A -π- D -π- A motif where D is the exceptionally electron-rich pyrrolo[3,2-b]pyrrole and A are accepting groups. Tuning of ? Q is achieved by appending a secondary acceptor group, A? , on both sides of the D core and ES-SB is monitored using a combination of time-resolved IR and broadband fluorescence spectroscopy. The results reveal a clear correlation between ? Q and the tendency to undergo ES-SB. When A is a stronger acceptor than A? , ES-SB occurs already in non-dipolar but quadrupolar solvents. When A and A? are identical, ES-SB is only partial even in highly dipolar solvents. When A is a weaker acceptor than A? , the orientation of ? Q changes, ES-SB is observed in dipolar solvents only and involves major redistribution of the excitation over the D -π- A  and D - A? branches of the dye.

Groupe de recherche
Financement
  • Swiss National Science Foundation - 200020‐184607
Citation (format ISO)
SZAKACS, Zoltan et al. Change of Quadrupole Moment upon Excitation and Symmetry Breaking in Multibranched Donor‐Acceptor Dyes. In: ChemPhysChem, 2020, vol. 21, n° 15, p. 1718–1730. doi: 10.1002/cphc.202000253
Fichiers principaux (1)
Article (Accepted version)
accessLevelPublic
Identifiants
ISSN du journal1439-4235
422vues
350téléchargements

Informations techniques

Création13/08/2020 09:12:00
Première validation13/08/2020 09:12:00
Heure de mise à jour15/03/2023 22:25:09
Changement de statut15/03/2023 22:25:08
Dernière indexation05/05/2024 17:06:10
All rights reserved by Archive ouverte UNIGE and the University of GenevaunigeBlack