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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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
30 Aug 2012
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| In: |
Physical chemistry, chemical physics
Year: 2012, Volume: 14, Issue: 40, Pages: 13979-13988 |
| ISSN: | 1463-9084 |
| DOI: | 10.1039/C2CP42248D |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.1039/C2CP42248D Verlag, Volltext: https://pubs.rsc.org/en/content/articlelanding/2012/cp/c2cp42248d 
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| Author Notes: | Jan Philip Kraack, Tiago Buckup and Marcus Motzkus |
| Summary: | 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. |
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| Item Description: | Gesehen am 06.11.2018 |
| Physical Description: | Online Resource |
| ISSN: | 1463-9084 |
| DOI: | 10.1039/C2CP42248D |