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arXiv · 2105.10248

Deciphering the Rotational Spectrum of the First Excited Torsional State of Propylene Oxide

Pascal Stahl·Benjamin E. Arenas·Oliver Zingsheim·Melanie Schnell·Laurent Margulès·Roman A. Motiyenko·Guido W. Fuchs·Thomas F. Giesen
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Abstract

The first excited torsional state of the chiral molecule propylene oxide, $\mathrm{CH_{3}C_{2}H_{3}O}$, is investigated from millimeter up to sub-millimeter wavelengths (75-950 GHz). The first excited vibrational mode of propylene oxide, $\upsilon_{24}$, is analysed using the programs ERHAM and XIAM. Rotational constants and tunneling parameters are provided, and a description of the A-E splittings due to internal rotation is given. Furthermore, the potential barrier height to internal rotation $V_{3}$ is determined to be $V_{3} = 894.5079(259) \mathrm{cm^{-1}}$ . Our results are compared with quantum chemical calculations and literature values. We present a line list of the dense spectrum of the first excited torsional state of propylene oxide in the (sub-)millimeter range. Our results will be useful for further studies of chiral molecules in vibrationally excited states, and will enable astronomers to search for rotational transitions originating from $\upsilon_{24}$ of propylene oxide in interstellar space.

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Pascal Stahl, Benjamin E. Arenas, Oliver Zingsheim, Melanie Schnell, Laurent Margulès, Roman A. Motiyenko, Guido W. Fuchs, Thomas F. Giesen. 2021-05-21. Deciphering the Rotational Spectrum of the First Excited Torsional State of Propylene Oxide. https://doi.org/10.1016/j.jms.2021.111445

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