Infrared spectra of protonated coronene and its neutral counterpart in solid parahydrogen: implications for unidentified interstellar infrared emission bands.
Infrared spectra of protonated coronene and its neutral counterpart in solid parahydrogen: implications for unidentified interstellar infrared emission bands.
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质子化晕苯及其在固体仲氢中的中性对应物的红外光谱：对未识别的星际红外发射带的影响。
DOI：
10.1002/anie.201308971
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发表时间：
2014
影响因子：
--
通讯作者：
Yuan‐Pern Lee
中科院分区：
文献类型：
--
作者：
M. Bahou;Yu;Yuan‐Pern Lee
大的质子化多环芳烃(H(+)PAHs)可能是来自星际物体的不明红外(UIR)发射带的载体，但在实验室中表征大的H(+)PAHs的红外(IR)光谱是具有挑战性的。记录了含少量冠烯的仲氢(C24H12)在基质沉积过程中产生的质子化冠烯(1-C24H13(+))和单氢化冠烯(1-C24H13(.))的红外吸收光谱。这些光谱的分辨率远高于由Depfer和其同事通过红外多光子解离获得的光谱。质子化的芘和冠烯的红外光谱似乎具有UIR谱带特征所需的生色团，随着苯环数量的增加，光谱位移指向正确的方向，指向UIR谱带的位置。因此，较大的质子化聚合态多环芳烃可能是UIR波段载体中的关键物种。
Large protonated polycyclic aromatic hydrocarbons (H(+) PAHs) are possible carriers of unidentified infrared (UIR) emission bands from interstellar objects, but the characterization of infrared (IR) spectra of large H(+) PAHs in the laboratory is challenging. IR absorption spectra of protonated coronene (1-C24 H13 (+) ) and mono-hydrogenated coronene (1-C24 H13 (.) ), which were produced upon electron bombardment of parahydrogen containing a small proportion of coronene (C24 H12 ) during matrix deposition, were recorded. The spectra are of a much higher resolution than those obtained by IR multiphoton dissociation by Dopfer and co-workers. The IR spectra of protonated pyrene and coronene collectively appear to have the required chromophores for features of the UIR bands, and the spectral shifts on an increase in the number of benzenoid rings point in the correct direction towards the positions of the UIR bands. Larger protonated peri-condensed PAHs might thus be key species among the carriers of UIR bands.