Laser Photoelectron Spectroscopy and Dynamics of S 1 p -Fluorotoluene

Laser photoelectron spectra have been obtained following the preparation of 10 vibrational states in S 1 p -fluorotoluene. For eight of the vibrational states (up to ∼850 cm -1 excess energy), excitation and ionization with nanosecond laser pulses gives rise to photoelectron spectra with well-resolved vibrational peaks. For the other two states (>1100 cm -1 excess energy), the photoelectron spectra show a loss of structure when nanosecond pulses are used, as a result of intramolecular dynamics, but this structure is recovered when overlapped picosecond pulses are used. In all cases the vibrational peaks in the photoelectron spectra are assigned, and the spectra are used to deduce the frequencies of 12 vibrational modes in the ion.