Cryogenic Infrared Action Spectroscopy Fingerprints the Hydrogen Bonding Network in Gas-Phase Coumarin Cations
Cryogenic Infrared Action Spectroscopy Fingerprints the Hydrogen Bonding Network in Gas-Phase Coumarin Cations
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DOI：
10.1021/acs.jpca.0c06430
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发表时间：
2020-12-03
影响因子：
2.9
通讯作者：
Muyskens, Mark A.
中科院分区：
文献类型：
--
作者：
Carrascosa, Eduardo;Pellegrinelli, Robert P.;Muyskens, Mark A.
本文报道了两种常见的羟基香豆素东莨菪内酯和七叶苷及其糖苷衍生物东莨菪内酯和七叶苷气相阳离子的低温振动光谱。该研究允许直接观察这些分子的羟基之间的分子内相互作用。我们使用低温信使标记红外作用光谱检测3100-3800 cm（-1）光谱范围内的振动带，并讨论了相应的结构特征和氢键网络，他们暗示。实验数据的支持下，一个彻底的计算评估，包括调查的构象空间。通过计算构象与实验结果的比较，我们确定了OH振子的主要类型，并推断质子化和钠化如何影响这些分子的结构排列。这里提出的结果提供了直接的证据，轻微的结构差异如何敏感地影响香豆素衍生物中的氢键网络。
We report cryogenic vibrational spectra of gas-phase cations of two common hydroxycoumarins, scopoletin and esculetin, as well as their glycosidic derivatives, scopolin and esculin. The study allows direct observation of the intramolecular interactions between the hydroxyl groups of these molecules. We use cryogenic messenger-tagging IR action spectroscopy to detect vibrational bands in the 3100-3800 cm(-1 )spectral range and discuss the corresponding structural characteristics and hydrogen bonding networks that they imply. The experimental data are supported by a thorough computational evaluation, including investigation of the conformational space. Through comparison of the calculated conformers with the experimental results, we identify the main types of OH oscillators and infer how protonation and sodiation affect the structural arrangement of these molecules. The results presented here provide direct evidence of how slight structural differences sensitively affect the hydrogen bonding network in coumarin derivatives.