Caveats in the interpretation of time-resolved photoionization measurements: A photoelectron imaging study of pyrrole.
Caveats in the interpretation of time-resolved photoionization measurements: A photoelectron imaging study of pyrrole.
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DOI：
10.1063/1.4972096
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发表时间：
2016-12
期刊：
影响因子：
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通讯作者：
Stuart W Crane;Magdalena M Zawadzki;James O. F. Thompson;N. Kotsina;O. Ghafur;D. Townsend
中科院分区：
文献类型：
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作者：
Stuart W Crane;Magdalena M Zawadzki;James O. F. Thompson;N. Kotsina;O. Ghafur;D. Townsend
我们报告的时间分辨光电子成像研究气相吡咯在267-240 nm的激发区域，记录结合300 nm的探针。特别令人感兴趣的是最低的（3s/πσ*）态，它表现出非常弱的振子强度，但被认为是在≤254 nm的波长下直接激发的。然而，我们的结论是，我们的光电子数据在所有的波长调查的唯一显着贡献是从非共振电离。我们的研究结果并不排除（3s/πσ*）状态激发（似乎是通过支持时间分辨离子产率测量证实），但潜在地突出了重要的警告，关于使用和解释的光反应物电离测量询问系统中的动力学过程，表现出显着的拓扑结构之间的差异的势能表面的中性和阳离子状态。
We report time-resolved photoelectron imaging studies of gas-phase pyrrole over the 267-240 nm excitation region, recorded in conjunction with a 300 nm probe. Of specific interest is the lowest-lying (3s/πσ*) state, which exhibits very weak oscillator strength but is thought to be excited directly at wavelengths ≤254 nm. We conclude, however, that the only significant contribution to our photoelectron data at all wavelengths investigated is from non-resonant ionization. Our findings do not rule out (3s/πσ*) state excitation (as appears to be confirmed by supporting time-resolved ion-yield measurements) but do potentially highlight important caveats regarding the use and interpretation of photoreactant ionization measurements to interrogate dynamical processes in systems exhibiting significant topological differences between the potential energy surfaces of the neutral and cation states.