THE RESONANCE RAMAN EXCITATION-SPECTRA OBTAINED FROM THE OPTICALLY FORBIDDEN S-O-S-I TRANSITION OF A MODEL CAROTENOID

The fluorescence excitation spectrum and resonance Raman excitation sp ectra of four stretching vibrations were recorded from the optically f orbidden S-0-S-1 transition in a model carotenoid in order to achieve vibrational frequencies of the excited S-1-state. Moreover, the resona nce Raman excitation spectra indicate the existence of a further elect ronic state below the state defined as S-1 up to now.