P. Swiderek et B. Gootz, THE LOW-LYING SINGLET-TRIPLET TRANSITIONS OF PHENYLACETYLENE AND STYRENE - ANALYSIS OF THE VIBRONIC STRUCTURE, Berichte der Bunsengesellschaft fur Physikalische Chemie, 102(6), 1998, pp. 882-893
Citations number
49
Categorie Soggetti
Chemistry Physical
Journal title
Berichte der Bunsengesellschaft fur Physikalische Chemie
The ground state (S-0) and lowest tripler state (T-1) geometries and n
ormal coordinates of phenylacetylene and styrene have been calculated
using the MCSCF method with 4-31G basis set. Franck-Condon factors der
ived from these results reproduce the vibronic structure of S-0--> T-1
excitation spectra previously obtained by electron-energy-loss spectr
oscopy. The analysis of the spectra shows that the excitation in pheny
lacetylene takes place within the ring with only minor contributions f
rom the side group. The side group multiple C-C bond is not noticably
involved in the S-0--> T-1 excitation. In styrene the excitation is ma
inly localized in the exocyclic part of the molecule. The spectra are
therefore dominated by vibrations involving the stretching motion of t
he exocyclic C-C bonds.