Multidimensional spectroscopy of beta-carotene: vibrational cooling in the excited state.
Pump-degenerate four wave mixing (Pump-DFWM) is used for investigating the vibrational dynamics in the excited state of beta-carotene in solution. In this 2D technique, an initial pump pulse promotes the system to the excited state, which is then probed by the succeeding DFWM sequence. We focus particularly on the internal conversion between the S(2) and S(1) state with high temporal and spectral resolution. The frequency shift of the excited state vibrations is measured and is explained as mode-specific vibrational cooling. Our results suggest an internal conversion in a time range between 260 and 500 fs without any intermediate states.
Buckup
Tiago
T
Fachbereich Physikalische Chemie, Hans-Meerwein Str., Philipps-Universität Marburg, D-35043 Marburg, Germany.
Hauer
Jürgen
J
Möhring
Jens
J
Motzkus
Marcus
M
D013057:Spectrum Analysis / Q000379:methods*; D014732:Vibration; D019207:beta Carotene / Q000737:chemistry*
D019207:beta Carotene