FEMTOSECOND REAL-TIME PROBING OF REACTIONS .20. DYNAMICS OF TWISTING,ALIGNMENT, AND IVR IN THE TRANS-STILBENE ISOMERIZATION REACTION

Citation
Js. Baskin et al., FEMTOSECOND REAL-TIME PROBING OF REACTIONS .20. DYNAMICS OF TWISTING,ALIGNMENT, AND IVR IN THE TRANS-STILBENE ISOMERIZATION REACTION, Journal of physical chemistry, 100(29), 1996, pp. 11920-11933
Citations number
40
Categorie Soggetti
Chemistry Physical
ISSN journal
00223654
Volume
100
Issue
29
Year of publication
1996
Pages
11920 - 11933
Database
ISI
SICI code
0022-3654(1996)100:29<11920:FRPOR.>2.0.ZU;2-8
Abstract
The femtosecond real-time dynamics of the isomerization reaction of tr ans-stilbene under collisionless conditions are studied using (2+1) re sonance-enhanced multiphoton ionization (REMPI) and femtosecond deplet ion spectroscopy (FDS) in a pump-probe scheme. The observed transients reflect the macroscopic sample anisotropy decay (rotational coherence ) and intramolecular vibrational energy redistribution (IVR) as well a s the ethylenic twisting isomerization reaction. Polarization-resolved measurements are performed to isolate the influence of rotational dyn amics, and the measured anisotropy decay is compared with theoretical calculations of rotational coherence at room temperature. The IVR and nonradiative (isomerization) processes of trans-stilbene are studied a s a function of S-1 excess vibrational energy up to similar to 6500 cm (-1). These results are compared with previous measurements of trans-s tilbene under collisionless conditions and with predictions of RRK and RRKM theories.