INTERMOLECULAR VIBRATIONS OF THE PHENOL DIMER REVEALED BY SPECTRAL HOLE-BURNING AND DISPERSED FLUORESCENCE SPECTROSCOPY

Inter- and intramolecular vibrations of the Phenol dimer have been exa mined using spectral hole burning and dispersed fluorescence spectrosc opy. The dispersed fluorescence spectra have been recorded via excitat ion of the electronic donor origin and all intermolecular vibrational transitions. The Franck-Condon intensity pattern allowed a straightfor ward assignment of the ground state vibrational frequencies to the exc ited state frequencies, which were examined by hole-burning spectrosco py. The existence of another conformer that possibly absorbs in the re gion of interest was ruled out by hole-burning spectroscopy. For obtai ning the hole-burning spectra, the electronic origin of the donor chro mophore was analyzed, while the hole-burning laser was scanned over th e region of interest. As both acceptor and donor part belong to one mo lecule the hole-burning signal could be analyzed via fluorescence from one of the chromophores. (C) 1995 American Institute of Physics.