论文标题
DFT研究脂肪族侧组的星际PAH分子
DFT study on interstellar PAH molecules with aliphatic side groups
论文作者
论文摘要
多环芳族烃（PAH）分子已长期裁定，有助于在3.3、6.2、6.2、6.2、7.7、8.6、11.2和12.7μm处进行经常检测到的不同的发射特征，其较弱和混合特征分布在3-20μm区域。相对较弱的3.4μm发射特征已归因于脂肪族起源作为载体。与IT上的脂肪族功能组的PAH是3.4μm发射带的拟议潜在候选载体之一，但是，载体的分配仍然是神秘的。在这项工作中，我们在对称和紧凑的PAH分子上采用密度功能理论（DFT）计算。冠状动脉（C24H12）具有脂肪族侧组，以研究在3-4μm处观察到的特征的任何光谱相似性。这项研究中考虑的侧组为-H（氢化），-CH3（甲基），-CH2 -CH3（乙基）和-CH = CH2（乙烯基）官能团。考虑到PAH中可能存在氘（D），我们还将D包括在脂肪族侧组中以研究光谱行为。我们对这些分子的IR光谱进行了详细的分析，并讨论了可能的天体物理含义。
Polycyclic Aromatic Hydrocarbon (PAH) molecules have been long adjudged to contribute to the frequently detected distinct emission features at 3.3, 6.2, 7.7, 8.6, 11.2 and 12.7 μm with weaker and blended features distributed in the 3-20 μm region. The comparatively weaker 3.4 μm emission feature has been attributed to have an aliphatic origin as carrier. PAH with aliphatic functional group attached to it is one of the proposed potential candidate carriers for the 3.4 μm emission band, however, the assignment of carrier is still enigmatic. In this work, we employ Density Functional Theory (DFT) calculation on a symmetric and compact PAH molecule; coronene (C24H12) with aliphatic side group to investigate any spectral similarities with observed features at 3-4 μm. The side groups considered in this study are -H (hydrogenated), -CH3 (methyl), -CH2-CH3 (ethyl) and -CH=CH2 (vinyl) functional groups. Considering the possible presence of deuterium (D) in PAHs, we also include D in the aliphatic side group to study the spectral behavior. We present a detailed analysis of the IR spectra of these molecules and discuss possible astrophysical implications.
