Non-Kasha fluorescence of pyrene emerges from a dynamic equilibrium between excited states - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Journal of Chemical Physics Année : 2022

Non-Kasha fluorescence of pyrene emerges from a dynamic equilibrium between excited states

Résumé

Pyrene fluorescence after a high-energy electronic excitation exhibits a prominent band shoulder not present after excitation at low energies. The standard assignment of this shoulder as a non-Kasha emission from the second-excited state (S2 ) has been recently questioned. To elucidate this issue, we simulated the fluorescence of pyrene using two different theoretical approaches based on the vertical convolution and nonadiabatic dynamics with nuclear ensemble approaches. To conduct the necessary nonadiabatic dynamics simulations with high-lying electronic states and deal with fluorescence timescales of about 100 ns of this large molecule, we developed new computational protocols. The results from both approaches confirm that the band shoulder is, in fact, due to S2 emission. We show that the non-Kasha behavior is a dynamic-equilibrium effect, not caused by a metastable S2 minimum. However, it requires considerable vibrational energy, which can only be achieved in collisionless regimes after transitions into highly excited states. This strict condition explains why the S2 emission was not observed in some experiments.
Fichier principal
Vignette du fichier
manuscript.pdf (1.06 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-03812836 , version 1 (13-10-2022)

Licence

Paternité

Identifiants

Citer

Gabriel Braun, Itamar Borges Jr., Adelia Aquino, Hans Lischka, Felix Plasser, et al.. Non-Kasha fluorescence of pyrene emerges from a dynamic equilibrium between excited states. Journal of Chemical Physics, 2022, ⟨10.1063/5.0113908⟩. ⟨hal-03812836⟩
47 Consultations
26 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More