Coriolis interaction of small and large aromatic hydrocarbons

• Published in: Journal of molecular spectroscopy Vol. 360; pp. 49 - 54
• Main Authors: Baba, Masaaki, Kanaoka, Ayumi, Tohyama, Hiromi, Katori, Toshiharu, Kunishige, Sachi, Nishiyama, Akiko, Misono, Masatoshi
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.06.2019
• Subjects: Benzene; Coriolis interaction; Coronene; Degenerate levels; Intramolecular vibrational energy redistribution; Coriolis interaction; Degenerate levels; Coronene; Intramolecular vibrational energy redistribution; Benzene
• ISSN: 0022-2852; 1096-083X
• DOI: 10.1016/j.jms.2019.04.012

[Display omitted] •Theoretical treatments of Coriolis interaction for the vibrational and rotational levels of a symmetric-top molecule.•Shifts of rotational lines in the high-resolution spectrum of benzene by Coriolis interactions.•Rotational contours of vibronic bands of Coronene which are considerably different with vibrational modes.•Intramolecular vibrational energy redistribution (IVR) enhanced by Coriolis interaction. Energy shifts by Coriolis interaction between the degenerate levels are discussed for aromatic hydrocarbons with D6h symmetry, benzene and coronene. The degenerate vibrations of e symmetry (the second-order irreducible representation) necessarily exist in a molecule with the n-fold symmetry axis (n⩾3), of which the rotational levels are expressed by the oblate symmetric-top model. The high-resolution spectrum was accurately analyzed by applying the theoretical model of Coriolis interaction, which significantly shifts the vibrational and rotational levels. The Coriolis interaction enhances intramolecular vibrational energy redistribution (IVR) at high vibrational levels in the electronic excited state. A rapid decrease in the fluorescence quantum yield at the vibrational levels above 3000 cm−1 in the S1 state of benzene (Channel 3) is shown to be mainly due to level mixing by Coriolis interaction.