Ultrafast imaging of electronic relaxation in n-propylbenzene: Direct observation of intermediate state.
The ultrafast dynamics of the second singlet electronically excited state (S2) in n-propylbenzene has been investigated by femtosecond time-resolved photoelectron imaging coupled with photofragmentation spectroscopy. The intermediate state for the deactivation of the S2 state is observed by transient photoelectron kinetic energy distributions and photoelectron angular distributions. An ultrafast electronic relaxation process on timescale of the fitted ∼50 fs was observed in the S2 state by time-resolved photoelectron imaging and it is attributed to the S1←S2 internal conversion (IC). The time constant of 1.23 (±0.2) ps is determined for the further deactivation of the intermediate S1 state.
School of Physics and Optoelectronic Engineering, Nanjing University of Information Science & Technology, 210044 Nanjing, China. Electronic address: yuzhu.liu@gmail.com.
Yuzhu
Y
Liu
Paul Scherrer Institute, 5232 Villigen, Switzerland.
Thomas
T
Gerber
Paul Scherrer Institute, 5232 Villigen, Switzerland.
Peter
P
Radi
Paul Scherrer Institute, 5232 Villigen, Switzerland.
Gregor
G
Knopp
Internal conversion; Photochemical; Photoelectron imaging spectroscopy; Pump–probe; Ultrafast