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

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 (-CHO) for UV-CPL in the Lyman-α region. Our calculations show that -CHO was produced by CH and CHCH(OH)CH or CH and O (triplet). The computed electronic circular dichroism spectra show that -CHO and the intermediate (CHCH(OH)CH) could absorb the UV-CPL originating from the Lyman-α emitter spectrum, suggesting that the photolysis of -CHO or CHCH(OH)CH upon irradiation could induce chiral symmetry breakage.