2021/10/14 by Atsuki Ishibashi, A. Ishibashi, H. Hidaka +6
Chemistry · Earth and Planetary Sciences · Physics and Astronomy · #Acetic acid #Aldehyde #Astrochemistry #Astrophysics #Astrophysics and Star Formation Studies #Atmospheric Ozone and Climate #Catalysis #Chemistry #Formate #Interstellar medium #Methanol #Methyl formate #Molecular Spectroscopy and Structure #Molecule #Organic chemistry #Photochemistry #Photodissociation #Physics #Radical #Ultraviolet #astro-ph.GA
paper · pdf · doi:10.3847/2041-8213/ac3005
published in The Astrophysical Journal Letters 921(1), L13 (IOP Publishing) · Accepted in ApJL; 10 figures including 5 figures in Appendix
arxiv created 2021/10/14 · openalex publication_date 2021/10/29 · arxiv updated 2021/11/17 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Abstract Three structural isomers of the C 2 H 4 O 2 molecule, namely, methyl formate (MF; HCOOCH 3 ), acetic acid (CH 3 COOH), and glycolaldehyde (HOCH 2 CHO), have attracted considerable attention as targets for understanding pathways toward molecular complexity in the interstellar medium (ISM). Among these isomers, MF is decisively abundant in various astronomical objects. For various formation pathways of MF, surface reactions on cosmic dust would play an important role. However, when compared to observations, the formation of MF has been found to be relatively inefficient in laboratory experiments in which methanol (CH 3 OH)-dominant ices were processed by ultraviolet photons and cosmic-ray analogs. Here, we show experimental results on the effective formation of MF by the photolysis of CH 3 OH on water ice at 10 K. We found that the key parameter leading to the efficient formation of MF is the supply of OH radicals by the photolysis of H 2 O, which significantly differs from CH 3 OH-rich experimental conditions. Moreover, using an ultrahigh-sensitivity surface analysis method, we succeeded in constraining the decisive formation pathway of MF via the photolysis of methoxymethanol (MM; CH 3 OCH 2 OH), which would improve our current understanding of chemical evolution in the ISM.