Vibrational coherence in the solution phase photoisomerization reaction of cis-stilbene

Coherent low frequency (100–125 cm−1) nuclear motion was detected in the cis → trans condensed phase isomerization of stilbene. A mode, associated with phenyl torsional motion, has a vibrational dephasing time of 100 fs and exhibits solvent-dependent wavepacket dynamics. Selective probe wavelengths (600, 650 and 690 nm) exhibit phase shifts for the wavepacket dynamics that are also solvent sensitive.