Real-time observation of ultrafast internal conversion in ethylbenzene by femtosecond time-resolved photoelectron imaging.
The ultrafast dynamics of the second singlet electronically excited state (S2) in ethylbenzene has been studied by femtosecond time-resolved photoelectron imaging. The time evolution of the photoelectron signal can be well described by a biexponential decay: a rapid relaxation pathway with a time constant of 60 ( ± 9) fs and a longer-lived channel on a timescale of 2.58 ( ± 0.22) ps. The rapid relaxation is ascribed to the ultrafast internal conversion from the S2state to the vibrationally hot S1state. This internal conversion process has been observed in real time. The slow photoelectron signal reflects the depopulation of secondarily populated high vibronic S1state.
Paul Scherrer Institute, 5232 Villigen, Switzerland. yuzhu.liu@psi.ch
Yuzhu
Y
Liu
Thomas
T
Gerber
Yaroslav
Y
Sych
Peter
P
Radi
Gregor
G
Knopp
D001555:Benzene Derivatives / Q000737:chemistry* / Q000528:radiation effects*; D003199:Computer Systems; D004583:Electrons; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007700:Kinetics; D007834:Lasers; D008422:Materials Testing / Q000295:instrumentation / Q000379:methods; D010783:Photometry / Q000295:instrumentation* / Q000379:methods; D017785:Photons; D013057:Spectrum Analysis / Q000295:instrumentation* / Q000379:methods
D001555:Benzene Derivatives; C004912:ethylbenzene