Theoretical Investigation into a Possibility of Formation of Propylene Oxide Homochirality in Space

Yuta Hori; Honami Nakamura; Takahide Sakawa; Natsuki Watanabe; Megumi Kayanuma; Mitsuo Shoji; Masayuki Umemura; Yasuteru Shigeta

doi:10.1089/ast.2022.0005

Theoretical Investigation into a Possibility of Formation of Propylene Oxide Homochirality in Space

Astrobiology. 2022 Nov;22(11):1330-1336. doi: 10.1089/ast.2022.0005. Epub 2022 Sep 6.

Authors

Yuta Hori¹, Honami Nakamura¹, Takahide Sakawa¹, Natsuki Watanabe¹, Megumi Kayanuma², Mitsuo Shoji¹, Masayuki Umemura¹, Yasuteru Shigeta¹

Affiliations

¹ Center for Computational Sciences, University of Tsukuba, Ibaraki, Japan.
² Research Center for Computational Design of Advanced Functional Materials, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan.

Abstract

The preferential synthesis or destruction of a single enantiomer by ultraviolet circularly polarized light (UV-CPL) has been proposed as a possible triggering mechanism for the extraterrestrial origin of homochirality. Herein, we investigate the photoabsorption property of propylene oxide (c-C₃H₆O) for UV-CPL in the Lyman-α region. Our calculations show that c-C₃H₆O was produced by CH₃⁺ and CH₃CH(OH)CH₃ or C₃H₇^• and O (triplet). The computed electronic circular dichroism spectra show that c-C₃H₆O and the intermediate (CH₃CH(OH)CH₂⁺) could absorb the UV-CPL originating from the Lyman-α emitter spectrum, suggesting that the photolysis of c-C₃H₆O or CH₃CH(OH)CH₂⁺ upon irradiation could induce chiral symmetry breakage.

Keywords: Circularly polarized light; Density functional theory; Homochirality; Lyman-αregion; Propylene oxide.