J. Xu et al., ULTRAFAST INTRAMOLECULAR AND CAGING DYNAMICS OF I-2 IN CCL4 FROM RESONANCE RAMAN-SPECTROSCOPY, Journal of Raman spectroscopy, 28(6), 1997, pp. 433-443
The resonance Raman overtone progressions of I-2 in CCl4 following exc
itation in the bound and continuum parts of the B state are presented.
It is shown that the Raman contribution from the bound part is damped
by predissociation as that of an outgoing wavepacket crossing over to
the purely repulsive B '' (1) Pi(1u), (3) Pi(2g), a (3) Pi(1g) and a'
(3) Sigma(g)(-)(0) states. The Raman data deliver information about l
ocation and time of curve crossing events which is consistent with the
previous results in liquid Xe and the femtosecond pump-probe studies
in liquids. For excitation in the continuum part, the Raman overtone i
ntensities show structures which are assigned to a coherent recoil of
fragments in the cage. In addition, a broad structureless emission bac
kground appears for all excitation wavelengths shorter than 570 nm, wh
ich is assigned to incoherent recoils caused by vibrational relaxation
and return of the I atoms in the Franck-Condon window of the B state
to the ground state. (C) 1997 by John Whey & Sons, Ltd.