Berlin 2015 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 55: Inorganic/Organic Interfaces: Electronic Properties II
O 55.4: Vortrag
Mittwoch, 18. März 2015, 16:00–16:15, HE 101
Inverse electron transfer in nitro-substituted monomolecular films — Prashant Waske1,2, •Tobias Wächter1, Andreas Terfort2, and Michael Zharnikov1 — 1Applied Physical Chemistry, Heidelberg University, 69120 Heidelberg, Germany — 2Institut für Anorganische und Analytische Chemie, Universität Frankfurt, 60438 Frankfurt, Germany
Self-assembled monolayers of nitro-substituted aromatic thiols were prepared on Au(111) substrates and characterized by several complementary spectroscopic techniques. The introduction of the nitro tail group had a positive effect on the quality of the monolayers, which were either superior or comparable to their non-substituted analogues. All molecules in the films were found to be bound to the substrate via the thiolate anchor and to have an upright orientation. The [N 1s]π* and [O 1s]π* decay spectra of the monolayers did not exhibit any trace of charge (electron) transfer (CT) through the molecular framework to the substrate, following the resonant excitation of the tail group. This was explained by the energy considerations hindering CT to the substrate but enabling a reverse process (ICT), i.e. the neutralization of the core ionized state by electron transfer from the substrate/molecular backbone. Traces of this process could be tentatively identified as an admixture of resonant contributions to the non-resonant decay spectra at the O K-edge. The experimental data suggest that only the ring adjacent to the nitro group was involved in the ICT process.