Photochemically activated reactions, despite being a powerful tool to covalently stabilize self-organized molecular structures on metallic surfaces, have struggled to take off due to several not yet well understood light-driven processes that can affect the final result. A thorough understanding of the photoinduced charge transfer mechanisms at the organic/metal interface would pave the way to controlling these processes and to developing on-surface photochemistry. Here, by time-resolved two-photon photoemission measurements, we track the relaxation processes of the first two excited molecular states at the interface between porphyrin, the essential chromophore in chlorophyll, and two different orientations of the silver surface. Due to the energy alignment of the porphyrin first excited state with the unoccupied sp-bands, an indirect charge transfer path, from the substrate to the molecule, opens in porphyrin/Ag(100) 250 fs after the laser pump excitation. The same time-resolved measurements carried out on porphyrin/Ag(111) show that in the latter case such an indirect path is not viable.

Tognolini, S., Ponzoni, S., Sedona, F., Sambi, M., Pagliara, S., Role of the Substrate Orientation in the Photoinduced Electron Dynamics at the Porphyrin/Ag Interface, <<THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS>>, 2015; 18 (Agosto): 3632-3638. [doi:10.1021/acs.jpclett.5b01528] [http://hdl.handle.net/10807/68534]

Role of the Substrate Orientation in the Photoinduced Electron Dynamics at the Porphyrin/Ag Interface

Tognolini;Silvia; Ponzoni;Stefano; Sedona;Francesco; Sambi;Mauro; Pagliara
2015

Abstract

Photochemically activated reactions, despite being a powerful tool to covalently stabilize self-organized molecular structures on metallic surfaces, have struggled to take off due to several not yet well understood light-driven processes that can affect the final result. A thorough understanding of the photoinduced charge transfer mechanisms at the organic/metal interface would pave the way to controlling these processes and to developing on-surface photochemistry. Here, by time-resolved two-photon photoemission measurements, we track the relaxation processes of the first two excited molecular states at the interface between porphyrin, the essential chromophore in chlorophyll, and two different orientations of the silver surface. Due to the energy alignment of the porphyrin first excited state with the unoccupied sp-bands, an indirect charge transfer path, from the substrate to the molecule, opens in porphyrin/Ag(100) 250 fs after the laser pump excitation. The same time-resolved measurements carried out on porphyrin/Ag(111) show that in the latter case such an indirect path is not viable.
Inglese
Tognolini, S., Ponzoni, S., Sedona, F., Sambi, M., Pagliara, S., Role of the Substrate Orientation in the Photoinduced Electron Dynamics at the Porphyrin/Ag Interface, <<THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS>>, 2015; 18 (Agosto): 3632-3638. [doi:10.1021/acs.jpclett.5b01528] [http://hdl.handle.net/10807/68534]
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10807/68534
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 8
social impact