TIME-RESOLVED RESONANCE RAMAN-SPECTRA OF TRANS-STILBENE AND CIS-STILBENE IN THE LOWEST EXCITED TRIPLET-STATE

Time-resolved resonance Raman spectra are obtained of the lowest excited triplet state T1 produced from each of the trans and cis isomers of stilbene in methanol at room temperature, and from trans-stilbene in glycerol at 203 K. The room-temperature spectra are found to be identical for the two isomers. The spectra are compared with preliminary results of a quantum chemical force field calculation of frequencies of ag modes a planar T1 trans-stilbene. The T1 spectra are tentatively ascribed to a planar or near-planar trans geometry. Implications for the stilbene T1 potential energy surface are discussed. © 1990.