Probing the Sub-microsecond Photodissociation Dynamics in Gas-Phase Retinal Chromophores
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- 作者：Lutz Lammich ; Iben Bloch Nielsen ; Hella Sand ; Annette Svendsen ; Lars H. Andersen
- 刊名：Journal of Physical Chemistry A
- 出版年：2007
- 出版时间：May 31, 2007
- 年：2007
- 卷：111
- 期：21
- 页码：4567 - 4572
- 全文大小：142K
- 年卷期：v.111,no.21(May 31, 2007)
- ISSN：1520-5215
文摘
The photoinduced fragmentation of a retinal model chromophore (all-trans-n-butyl protonated Schiff-baseretinal) was studied in vacuo using a new experimental technique. The apparatus is able to record thephotodissociation yield of gas-phase biomolecular ions in the first microseconds after absorption. Togetherwith the existing ion storage ring ELISA, which operates on the millisecond to second time scale, the completedecay dynamics of such molecules can now be followed. In the case of retinal, the time-dependent fragmentationyield observed after irradiation with a 410 nm laser pulse exhibits contributions from one- and two-photonabsorption, which decay non-exponentially with lifetimes on the order of 1 ms and 1 
s, respectively. Thedecay can be simulated using a statistical model, yielding good agreement with the experimental findings onboth the millisecond and the microsecond time scales. No indication for nonstatistical processes is found forthis molecule, the upper limit for a possible direct rate being a factor of 104 below the observed statisticaldissociation rate.
s, respectively. Thedecay can be simulated using a statistical model, yielding good agreement with the experimental findings onboth the millisecond and the microsecond time scales. No indication for nonstatistical processes is found forthis molecule, the upper limit for a possible direct rate being a factor of 104 below the observed statisticaldissociation rate.