Femtosecond time-resolved analysis of the photophysics of the indole molecule

Applying femtosecond pump–probe spectroscopy at different wavelengths we demonstrate that for the indole molecule an efficient coupling does not exist between the initially excited ππ* state and the adjacent higher lying πσ* state. This result which is in contrast to corresponding theoretical studies is represented by a stable population of the ππ* state. The analysis of the time-dependent photoelectron spectra reveals further information about the energetics of the pump and probe processes.