Fluorescence quenching of benzaldehyde in water by hydrogen atom abstraction

• Verfasst von: Fletcher, Katharyn M. [VerfasserIn]
• Verfasst von: Bunz, Uwe H. F. [VerfasserIn]
• Verfasst von: Dreuw, Andreas [VerfasserIn]
• Titel: Fluorescence quenching of benzaldehyde in water by hydrogen atom abstraction
• Verf.angabe: Katharyn Fletcher, Uwe H. F. Bunz, and Andreas Dreuw
• Umfang: 4 S.
• Fussnoten: Gesehen am 07.12.2017
• Titel Quelle: Enthalten in: ChemPhysChem
• Jahr Quelle: 2016
• Band/Heft Quelle: 17(2016), 17, S. 2650-2653
• ISSN Quelle: 1439-7641
• DOI: doi:10.1002/cphc.201501059
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1566136296

Abstract

We computed the mechanism of fluorescence quenching of benzaldehyde in water through relaxed potential energy surface scans. Time-dependent density functional theory calculations along the protonation coordinate from water to benzaldehyde reveal that photoexcitation to the bright ππ* (S3) state is immediately followed by ultrafast decay to the nπ* (S1) state. Evolving along this state, benzaldehyde (BA) abstracts a hydrogen atom, resulting in a BAH. and OH. radical pair. Benzaldehyde does not act as photobase in water, but abstracts a hydrogen atom from a nearby solvent molecule. The system finally decays back to the ground state by non-radiative decay and an electron transfers back to the OH. radical. Proton transfer from BAH+ to OH− restores the initial situation, BA in water.