Conformationally resolved spectra of acetaminophen by UV-UV hole burning and IR dip spectroscopy in the gas phase
Conformationally resolved spectra of acetaminophen by UV-UV hole burning and IR dip spectroscopy in the gas phase
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通过气相 UV-UV 烧孔和红外浸入光谱法对乙酰氨基酚进行构象分辨光谱
DOI：
10.1039/c2cp43552g
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
et al.
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文献类型：
--
作者：
W. Y. Sohn;et al.
通过使用 UV-UV 烧孔 (HB) 和红外浸入光谱测量对乙酰氨基酚的电子和振动光谱。 HB 光谱显示 4 个不同物种共存，其中包括两个新物种。光谱中的低频跃迁由具有甲基自由转子基组的一维周期性电势再现。通过分析，我们得出结论，对乙酰氨基酚有两个构象异构体，每个构象异构体从最稳定的 0a1 和最热的 1e 内旋转能级开始产生两个独立的转变。还发现之前报道中的反式构象异构体的HB谱是来自1e激发能级的，而顺式构象异构体的HB谱则受到反式构象异构体跃迁的污染。甲基旋转运动的电位曲线在 S0 和 S1 中均确定。
Electronic and vibrational spectra of acetaminophen were measured by using UV-UV hole burning (HB) and IR dip spectroscopy. HB spectra show the coexistence of 4 different species, which include two new ones. Low-frequency transitions in the spectra are reproduced by a one-dimensional periodic potential with a free-rotor basis set for the methyl group. From the analysis, we concluded that acetaminophen has two conformers and each conformer gives two independent transitions starting from the most stable 0a1 and the hot 1e internal rotational levels. It is also found that the HB spectrum of the trans-conformer in the previous report is that from the 1e excited level, while the HB spectrum of the cis-conformer is contaminated by the transitions of the trans-conformer. Potential curves of the methyl rotational motion are determined both in S0 and S1.