Reassignment of ground and first excited state vibrations in phenol Original Research Article

The phenol molecule has been chosen to demonstrate how dispersed fluorescence spectroscopy can be used to assign hot bands, i.e. vibronic transitions starting from the vibrationally excited electronic ground state. The procedure outlined in this paper provides important information on fundamental out-of-plane vibrations in the electronic excited S1 state that are not observed in jet-cooled spectra. The results obtained lead to a new interpretation of the most intense hot bands in the UV absorption spectrum of phenol. We derive vibrational frequencies for the modes 10b1, 10b1 and 41 (Varsanyiʹs nomenclature) which are different from those given in the literature.