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Updated: May 9, 2026
08:22
Measurement of Ultrafast Vibrational Coherences in Polyatomic Radical Cations with Strong-Field Adiabatic Ionization
Published on: August 6, 2018
Mapping multidimensional excited state dynamics using pump-impulsive-vibrational-spectroscopy and
Jan Philip Kraack1, Amir Wand, Tiago Buckup
1Physikalisch-Chemisches Institut, Ruprecht-Karls Universität Heidelberg, D-69210 Heidelberg, Germany.
Physical Chemistry Chemical Physics : PCCP
|July 30, 2013
Summary
Pump-impulsive vibrational spectroscopy (pump-IVS) reveals excited state dynamics in carotenoids. This method tracks internal conversion, vibrational relaxation, and ground state decay with high temporal resolution.
Area of Science:
- Chemical Physics
- Spectroscopy
- Photochemistry
Background:
- Carotenoids like β-carotene and lycopene are vital pigments with complex photoexcitation dynamics.
- Understanding excited-state processes is crucial for fields ranging from photosynthesis to photoprotection.
Purpose of the Study:
- To investigate the excited state vibrational dynamics of β-carotene and lycopene after photoexcitation.
- To compare the capabilities of time-domain spectroscopic techniques with frequency-domain methods for studying photochemical dynamics.
Main Methods:
- Utilized pump-impulsive vibrational spectroscopy (pump-IVS) with <30 fs temporal resolution.
- Employed pump-degenerate-four-wave-mixing (pump-DFWM) for corroboration.
- Compared findings with Femtosecond Stimulated Raman Scattering (FSRS).
Main Results:
- Resolved the S2-S1 internal conversion process in carotenoids.
- Tracked subsequent vibrational relaxation and decay to the electronic ground state.
- Identified fingerprint frequencies indicative of bonding and structural changes.
Conclusions:
- Pump-IVS and pump-DFWM effectively resolve photochemical dynamics, including structural changes.
- FSRS offers complementary insights, highlighting the benefits of combining these techniques.
- A multi-technique approach provides a comprehensive understanding of vibrational dynamics in reactive species.
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