Subpicosecond anisotropic CARS studies of vibrational mode-selective photoexcitation and relaxation of trans-stilbene. First few picoseconds
Résumé
Sub-picosecond coherent anti-Stokes Raman scattering (CARS) spectra of singlet trans-stilbene (tSB) in heptane have been obtained using UV excitation and CARS probe for the 0–5 ps time range. The excited state CARS spectra of tSB in heptane exhibits mode-selective dynamics. Different temporal behaviors of the three investigated S1 Raman bands (1181, 1242 and 1565 cm−1) are observed. These results are discussed with respect to possible role of vibrational energy redistribution and associated conformational changes.