Rate of H-D substitution reaction in interstellar methanol

Abstract

Extreme deuterium fractionation of interstellar methanol has been observed in molecular clouds. Since methanol (CH3OH) is formed efficiently by grain-surface reactions: CO->H2CO->CH3OH, it is reasonable to consider that deuterated methanol is also produced by surface reactions involving deuterium atom. Indeed, we showed experimentally that d-methanol is produced efficiently by H-D substitution reaction in methanol: CH3OH->CH2DOH->CHD2OH->CD3OH. In our poster, we report the reaction rate and detail process of the H-D substitution reactions.