We report the identification of methoxymethanol (CH3OCH2OH) as a photochemistry product of condensed methanol (CH3OH) based on temperature-programmed desorption studies conducted following photon irradiation at energies below the ionization threshold (9.8 eV) of condensed methanol. The first detection of methoxymethanol in the interstellar medium was reported in 2017 based on data from Bands 6 and 7 from the Atacama Large Millimeter/submillimeter Array (ALMA). The cosmic synthesis of “complex” organic molecules such as methyl formate (HCOOCH3), dimethyl ether (CH3OCH3), acetic acid (CH3COOH), ethylene glycol (HOCH2CH2OH), and glycolaldehyde (HOCH2CHO) has been attributed to UV photolysis of condensed methanol found in interstellar ices. Experiments conducted in 1995 demonstrated that electron-induced radiolysis of methanol cosmic ice analogues yields methoxymethanol. In three recent publications (2016, 2017, and 2018), methoxymethanol was considered as a potential tracer for reactions induced by secondary electrons resulting from the interaction of cosmic rays with interstellar ices. However, the results presented in this study suggest that methoxymethanol can be formed from both radiation chemistry and photochemistry of condensed methanol.
Hope Schneider, Anna Caldwell-Overdier, Sophie Coppieters ‘t Wallant, Lan Dau, Jean Huang, Ifunanya Nwolah, Muhammad Kasule, Christina Buffo, Ella Mullikin, Lily Widdup, Aury Hay, Si Tong Bao, Jeniffer Perea, Mayla Thompson, Rhoda Tano-Menka, Mileva Van Tuyl, Amy Wang, Sophia Bussey, Nina Sachdev, Christine Zhang, Michael C. Boyer, and Christopher R. Arumainayagam, "Detection of Methoxymethanol as a Photochemistry Product of Condensed Methanol," Monthly Notices of the Royal Astronomical Society: Letters 2019, 485 (1), L19.