Blanchet, V., Raffael, K., Turri, G., Chatel, B., Girard, B., Garcia, I.A., Wilkinson, I. and Whitaker, B.J. (2008) Time-dependent photoionization of azulene: Competition between ionization and relaxation in highly excited states. Journal of Chemical Physics, 128 (16). p. 164318.
Pump-probe photoionization has been used to map the relaxation processes taking place from highly vibrationally excited levels of the S2 state of azulene, populated directly or via internal conversion from the S4 state. Photoelectron spectra obtained by 1+2’ two-color time-resolved photoelectron imaging are invariant (apart from in intensity) to the pump-probe time delay and to pump wavelength. This reveals a photoionization process which is driven by an unstable electronic state (e.g. doubly excited state) lying below the ionization potential. This state is postulated to be populated by a probe transition from S2 and to rapidly relax via an Auger like process onto highly vibrationally excited Rydberg states. This accounts for the time invariance of the photoelectron spectrum. The intensity of the photoelectron spectrum is proportional to the population in S2. An exponential energy gap law is used to describe the internal conversion rate from S2 to S0. The vibronic coupling strength is found to be larger than 60±5 μeV.
|Copyright, Publisher and Additional Information:||© 2008 American Institute of Physics. This is an author produced version of a paper published in The Journal of Chemical Physics. Uploaded in accordance with the publisher's self-archiving policy.|
|Institution:||The University of Leeds|
|Academic Units:||The University of Leeds > Faculty of Maths and Physical Sciences (Leeds) > School of Chemistry (Leeds)|
|Depositing User:||Sherpa Assistant|
|Date Deposited:||30 May 2008 08:56|
|Last Modified:||16 Sep 2016 13:36|
|Publisher:||American Institute of Physics|