Our automated reaction discovery program, AutoMeKin, has been utilized to
investigate the formation of glycolonitrile (HOCH2βCN) in the gas phase
under the low temperatures of the interstellar medium (ISM). The feasibility of
a proposed pathway depends on the absence of barriers above the energy of
reactants and the availability of the suggested precursors in the ISM. Based on
these criteria, several radical-radical reactions and a radical-molecule
reaction have been identified as viable formation routes in the ISM. Among the
radical-radical reactions, OH+CH2βCN appears to be the most relevant,
considering the energy of the radicals and its ability to produce
glycolonitrile in a single step. However, our analysis reveals that this
reaction produces hydrogen isocyanide (HNC) and formaldehyde (CH2βO), with
rate coefficients ranging from (7.3-11.5)Γ10β10 cm3
moleculeβ1 sβ1 across the temperature range of 10-150 K. This finding
is particularly interesing given the persistently unexplained overabundance of
hydrogen isocyanide in the ISM. Among the radical-molecule reactions
investigated, the most promising one is OH+CH2βCNH, which forms
glycolonitrile and atomic hydrogen with rate coefficients in the range
(0.3-6.6)Γ10β10 cm3 moleculeβ1 sβ1 within the 10-150 K
temperature range. Our calculations indicate that the formation of both
hydrogen isocyanide and glycolonitrile is efficient under the harsh conditions
of the ISM