Evidence for the two-state-two-mode model in retinal protonated Schiff-bases from pump degenerate four-wave-mixing experiments

We apply spectrally-resolved pump degenerate four-wave-mixing for the characterization of excited state low-frequency vibrational coherences during the initial events in excited state double-bond isomerization of retinal protonated Schiff-bases. A set of low-frequency coherences in the energetic ran...

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Hauptverfasser: Kraack, Jan Philip (VerfasserIn) , Buckup, Tiago (VerfasserIn) , Motzkus, Marcus (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: 30 Aug 2012
In: Physical chemistry, chemical physics
Year: 2012, Jahrgang: 14, Heft: 40, Pages: 13979-13988
ISSN:1463-9084
DOI:10.1039/C2CP42248D
Online-Zugang:Verlag, Volltext: http://dx.doi.org/10.1039/C2CP42248D
Verlag, Volltext: https://pubs.rsc.org/en/content/articlelanding/2012/cp/c2cp42248d
Volltext
Verfasserangaben:Jan Philip Kraack, Tiago Buckup and Marcus Motzkus
Beschreibung
Zusammenfassung:We apply spectrally-resolved pump degenerate four-wave-mixing for the characterization of excited state low-frequency vibrational coherences during the initial events in excited state double-bond isomerization of retinal protonated Schiff-bases. A set of low-frequency coherences in the energetic range of 100-350 cm−1 appears in the dynamics already for very early delays after initial excitation (<100 fs). The modulations are rapidly damped (<800 fs) and detectable only in a certain time window after initial excitation (<0.6 ps). Following the initial relaxation process, which leads the molecule to a stationary point in the S1 state, it is not possible to re-excite the coherences in the excited state. Based on our observations, we conclude that the activation of the coherences is only possible to occur in a well-defined region of the excited state potential near the Franck-Condon region. Our results give direct experimental indication for the validity of the “Two-State-Two-Mode model”, frequently applied for the interpretation of retinal isomerization dynamics.
Beschreibung:Gesehen am 06.11.2018
Beschreibung:Online Resource
ISSN:1463-9084
DOI:10.1039/C2CP42248D