Fourier Transform Microwave Spectra Of Cis-3-hexenal, Trans-3-hexenal, Cis-2-hexenal And Trans-2-hexenal: Structural Isomers And Isomerization

Ozawa, Ryoto

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https://hdl.handle.net/2142/116715 Copy

Description

Title

Fourier Transform Microwave Spectra Of Cis-3-hexenal, Trans-3-hexenal, Cis-2-hexenal And Trans-2-hexenal: Structural Isomers And Isomerization

Author(s)

Ozawa, Ryoto

Contributor(s)

• Kawashima, Yoshiyuki
• Kuze, Nobuhiko

Issue Date

2022-06-21

Keyword(s)

Rotational structure/frequencies

Abstract

{\it cis}-3-Hexenal ({\it c}3-HA; O=CH-CH$_2$-CH=CH-CH$_2$-CH$_3$) is known as an odor molecule of grass and the {\it c}3-HA easily isomerizes to {\it trans}-2-hexenal ({\it t}2-HA). Rotational spectra of the {\it c}3-HA and its structural isomers were observed by Fourier transform microwave (FTMW) spectroscopy in the frequency region 4.8-23 GHz. We reported that two conformers of the {\it c}3-HA, {\it SG’cS} and {\it CScS}, were assigned\footnote{S. Yoshizawa, N. Kuze and Y. Kawashima, ISMS2019, P3866 (2019).}: in {\it SG’cS}, {\it S}, {\it G’}, {\it c}, and {\it S} in order denote the {\it skew}, {\it gauche’}, {\it cis} and {\it skew} around the dihedral angles OC(1)C(2)C(3), C(1)C(2)C(3)=C(4), C(2)C(3)=C(4)C(5) and C(3)=C(4)C(5)C(6), respectively. We found other four conformers which were assigned to the {\it SStS} and {\it S’S’tS} conformers of {\it trans}-3-hexenal ({\it t}3-HA), and the {\it TcSG’} and {\it TcST} conformers of {\it cis}-2-hexenal ({\it c}2-HA) by comparing from the results of ab initio calculation. We also observed the rotational spectra of the {\it t}2-HA which had been reported in 2015\footnote{R. Yokoyama, Y. Kawashima, and E Hirota, 9th Annual Meeting on Molecular Science, Tokyo, 4P008 (2015).}. The spectra of the {\it c}3-HA and {\it t}3-HA were observed in room temperature. When the nozzle temperature increased, the maximum of spectral intensities of the {\it c}3-HA and {\it t}3-HA reach at around 350 K while the intensities of the {\it t}2-HA and {\it c}2-HA are stronger. This evidence shows that the {\it c}3-HA and {\it t}3-HA isomerized into the {\it t}2-HA and {\it c}2-HA.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Handle URL

https://hdl.handle.net/2142/116715

DOI

https://doi.org/10.15278/isms.2022.TD08

Copyright and License Information

Copyright 2022 held by the authors

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