THE ANTI-STOKES RESONANCE RAMAN-SPECTRUM OF PHOTOEXCITED S-1 TRANS-STILBENE

Anti-Stokes resonance Raman spectra of S-1 trans-stilbene have been me asured for vibrational wavenumbers up to 1570 cm(-1). Trans-stilbene i n n-hexane was excited at 290-310 nm and probed at 580-620 nm, respect ively, with 8 ps resolution. All the dominant bands seen in the Stokes spectrum of the S-1, state are also seen in the anti-Stokes spectrum. Some anti-Stokes bands, notably those at 1570, 1240, 1180, 980, 720 a nd 285 cm(-1), decrease markedly in relative intensity on a approximat e to 10 ps timescale, displaying dynamics similar to those observed fo r the changes in the band position and bandwidth of several features i n the Stokes spectrum.