DEPOLARIZATION DISPERSION OF TOTALLY SYMMETRICAL FUNDAMENTALS IN RESONANCE RAMAN-SPECTRA - ANALYSIS FOR AZOBENZENE DYES

The resonance Raman excitation profiles and depolarization dispersions for totally symmetric vibrations are studied under the energy region corresponding to an excitation of two low-energy states of 4-nitro-4'- diethylamino-azobenzene dye. In a contrast to the earlier analysis of this dye we assume that the low-energy states of the molecule studied have different polarizations. It results in the depolarization dispers ions of the Raman lines of totally symmetric vibrations. The effect is illustrated for two vibrations: nu(4) = 1342 cm(-1) and nu(7) 1448 cm (-1) for which excitation profiles show distinctive intensity distribu tion patterns due to interferences between the vibrational manifolds o f tile overlapping states. The nature of tile electronic (resonant) st ates and the magnitudes of Franck-Condon parameters determined from th e experiment are also briefly discussed.