S2→S1 internal conversion in β-carotene: Strong vibronic coupling from amplitude oscillations of transient absorption bands

Abstract

(Figure Presented) What happens next? Oscillatory dynamics during internal conversion of β-carotene from the "bright" S2 to the "dark" S1 electronic state is observed by femtosecond broadband transient absorption and fluorescence. The spectral evolution was described quantitatively by modeling the quantum dynamics in a three-level system, and the vibronic coupling element was determined (V ≈ 95 cm -1). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.