PICOSECOND TIME-RESOLVED FOURIER-TRANSFORM RAMAN-SPECTROSCOPY OF 9,10-DIPHENYLANTHRACENE IN THE EXCITED SINGLET-STATE

Time-resolved Fourier transform Raman spectroscopy of the highly fluorescent chromophore 9,10-diphenylanthracene (DPA) in cyclohexane and ethanol is described. Raman spectra of the first excited singlet state of DPA were obtained with 100-ps resolution at several time delays between pump pulses at 355 nm and probe pulses at 1064 nm. The near-infrared excited-state Raman scattering is enhanced by resonance with an excited-state transition of DPA. The excited-state Raman bands decay in about 5-6 ns. Evidence for interaction of the solvent with the DPA excited state is observed in the cyclohexane C-H stretching bands.