Mooney Ciarán R S, Parkes Michael A, Zhang Lijuan, Hailes Helen C, Simperler Alexandra, Bearpark Michael J, Fielding Helen H
Department of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdom.
Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, United Kingdom.
J Chem Phys. 2014 May 28;140(20):205103. doi: 10.1063/1.4874643.
Using a combination of photoelectron spectroscopy measurements and quantum chemistry calculations, we have identified competing electron emission processes that contribute to the 350-315 nm photoelectron spectra of the deprotonated green fluorescent protein chromophore anion, p-hydroxybenzylidene-2,3-dimethylimidazolinone. As well as direct electron detachment from S0, we observe resonant excitation of the 2(1)ππ* state of the anion followed by autodetachment. The experimental photoelectron spectra are found to be significantly broader than photoelectron spectrum calculated using the Franck-Condon method and we attribute this to rapid (∼10 fs) vibrational decoherence, or intramolecular vibrational energy redistribution, within the neutral radical.
通过结合光电子能谱测量和量子化学计算，我们确定了导致去质子化绿色荧光蛋白发色团阴离子对羟基苄叉-2,3-二甲基咪唑啉酮350 - 315纳米光电子能谱的竞争电子发射过程。除了从S0直接电子脱离外，我们还观察到阴离子的2(1)ππ*态的共振激发，随后是自脱离。实验光电子能谱比使用弗兰克-康登方法计算的光电子谱明显更宽，我们将此归因于中性自由基内快速（约10飞秒）的振动退相干或分子内振动能量重新分布。
