Title :

Photoinduced electron transfers after t-stilbene incorporation in zeolite. Effect of the presence of an electron acceptor on the reactivity

Author(s) :

Moissette, Alain [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Hureau, Matthieu [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516
Col, Perrine [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516 [LASIRE]
Vezin, Herve [Auteur]
Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516

Journal title :

Microporous and Mesoporous Materials

Pages :

128-135

Publisher :

Elsevier BV

Publication date :

2017-12

ISSN :

1387-1811

English keyword(s) :

ZSM-5 zeolite
t-stilbene
Dicyanobenzene
Electron transfers
Long-lived charge separated states

HAL domain(s) :

Chimie/Chimie théorique et/ou physique

English abstract : [en]

Diffuse reflectance UV–vis absorption and EPR spectroscopies are used to study photoinduced electron transfers in supramolecular assemblies composed of donor (t-stilbene, t-St) and acceptor (dicyanobenzene, DCB) guest ...
Show more >Diffuse reflectance UV–vis absorption and EPR spectroscopies are used to study photoinduced electron transfers in supramolecular assemblies composed of donor (t-stilbene, t-St) and acceptor (dicyanobenzene, DCB) guest molecules incorporated in MFI zeolites. By using Al-free silicalite-1, it clearly appears that the presence of the acceptor has no effect on the reactivity and that no electron transfer occurs to DCB after t-St photoionization and radical cation (t-St●+) formation. On the contrary, we show evidence for the striking slowing down of the recombination reaction in the presence of the acceptor molecule in the channels of MZSM-5 (M = Na+, Cs+). In these Al-rich zeolites, electron transfers are mediated by the framework which does not remain passive after photoexcitation. Indeed, zeolite acts both as an electron acceptor and as an electron donor and strongly influences the reaction mechanisms. The donor character is put forward to explain the indirect recombination of the radical cation to form an electron/hole pair. Concerning the acceptor ability of zeolite, we show that the attracting and stabilizing character of NaZSM-5 competes with the acceptor property of dicyanobenzene and then, does not allow total electron transfer to the guest. Even if the DCB●− radical anion formation does not occur, HYSCORE experiments show strong electron density in the surrounding of DCB indicating partial electron transfer and explaining the trapping of electron and the slowing down of the charge recombination.Show less >

Language :

Anglais

Peer reviewed article :

Oui

Audience :

Internationale

Popular science :

Non

Administrative institution(s) :

Université de Lille
CNRS

Collections :

• Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement (LASIRE) - UMR 8516

Research team(s) :

Propriétés magnéto structurales des matériaux (PMSM)

Submission date :

2021-06-17T13:28:13Z
2021-09-09T14:28:22Z
2021-09-10T10:39:39Z