Acta Phys. -Chim. Sin. ›› 2015, Vol. 31 ›› Issue (9): 1662-1666.doi: 10.3866/PKU.WHXB201507061


Ultrafast Dynamics of Benzene on the S2 State Investigated by Femtosecond Time-Resolved Photoelectron Spectroscopy

Huan. SHEN1,*(),Bing. ZHANG2   

  1. 1 College of Science, Huazhong Agricultural University, Wuhan 430070, P. R. China
    2 State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, P. R. China
  • Received:2015-04-10 Published:2015-09-06
  • Contact: Huan. SHEN
  • Supported by:
    the National Natural Science Foundation of China(21403080)


The ultrafast dynamics of benzene on the S2 state have been investigated by femtosecond time-resolved mass spectroscopy coupled with photoelectron imaging. The benzene molecule was excited to the S2 state by two 400 nm photons, and subsequently probed by one 267 nm photon. The timedependent ion yield of the parent ion consists of two components with different lifetimes. The first component at (90 ± 1) fs is because of internal conversion from the S2 state to the S1/S0 state. The second one, i.e., (5.0 ± 0.2) ps, is due to decay of the S1 state. The observed lifetime of the second component is shorter than previous results, indicating the existence of an additional decay process. With photoelectron spectra extracted from the time-resolved photoelectron imaging, this newly found deactivated process is assigned to intersystem crossing from the vibrational excited S1 state to the hot triplet state T3.

Key words: Time-resolved, Photoelectron spectroscopy, Benzene molecule, Internal conversion, Intersystem crossing