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 ( c -C 3 H 6 O) for UV-CPL in the Lyman-α region. Our calculations show that c -C 3 H 6 O was produced by CH 3 + and CH 3 CH(OH)CH 3 or C 3 H 7 • and O (triplet). The computed electronic circular dichroism spectra show that c -C 3 H 6 O and the intermediate (CH 3 CH(OH)CH 2 + ) could absorb the UV-CPL originating from the Lyman-α emitter spectrum, suggesting that the photolysis of c -C 3 H 6 O or CH 3 CH(OH)CH 2 + upon irradiation could induce chiral symmetry breakage.