Photoelectron spectroscopy of isolated luciferin and infraluciferin anions in vacuo: competing photodetachment, photofragmentation and internal conversion.
Photoelectron spectroscopy of isolated luciferin and infraluciferin anions in vacuo: competing photodetachment, photofragmentation and internal conversion.
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DOI：
10.1039/c7cp04815g
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发表时间：
2017-08
期刊：
影响因子：
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通讯作者：
J. Woodhouse;Mariana Assmann;M. Parkes;H. Grounds;Steven J Pacman;James C. Anderson;G. Worth;H. Fielding
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文献类型：
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作者：
J. Woodhouse;Mariana Assmann;M. Parkes;H. Grounds;Steven J Pacman;James C. Anderson;G. Worth;H. Fielding
利用光电子能谱和量子化学计算，对普遍存在的生物发光探针荧光素及其红移程度最大的类似物红外荧光素的电子结构和激发态动力学进行了研究。在我们的电喷雾电离源中，去质子化阴离子主要以酚盐形式形成，这与将荧光素和红外荧光素作为不稳定的氧化荧光素和氧化红外荧光素发光体模型的研究直接相关。在357 - 230纳米范围内进行光激发后，我们发现从高能激发态到S1(1ππ*)态的内转换与电子脱除过程存在有效竞争。在红外荧光素中，我们发现脱羧反应也与直接电子脱除和内转换过程存在竞争。这项详尽的光谱学与计算研究明确了荧光素和红外荧光素的电子结构及电子弛豫过程，将为新型生物发光系统的设计及应用提供参考。
The electronic structure and excited-state dynamics of the ubiquitous bioluminescent probe luciferin and its furthest red-shifted analogue infraluciferin have been investigated using photoelectron spectroscopy and quantum chemistry calculations. In our electrospray ionization source, the deprotonated anions are formed predominantly in their phenolate forms and are directly relevant to studies of luciferin and infraluciferin as models for their unstable oxyluciferin and oxyinfraluciferin emitters. Following photoexcitation in the range 357-230 nm, we find that internal conversion from high-lying excited states to the S1(1ππ*) state competes efficiently with electron detachment. In infraluciferin, we find that decarboxylation also competes with direct electron detachment and internal conversion. This detailed spectroscopic and computational study defines the electronic structure and electronic relaxation processes of luciferin and infraluciferin and will inform the design of new bioluminescent systems and applications.