How a usual carbamate can become an unusual intermediate: a new chemical pathway to form glycinate in the interstellar medium

Experiments on the thermal reactivity of carbon dioxide (CO2) and methylamine (CH3NH2) are reported and show methylammonium methylcarbamate (CH3NHCOO− CH3NH ) and methylcarbamic acid (CH3NHCOOH) are formed at low temperature in solid environment. The VUV (λ > 120 nm) irradiation of carbamate induces the formation of methylammonium glycinate (MAG). Calculations have been performed to give an insight on the pathway for the formation of the methylcarbamic acid (MCA). These calculations show that the methylamine environment play an important role in the barrier and a cooperative effect of the methylamine molecules has to be taken into account. The implication on the interstellar reactivity is also discussed because this pathway to form glycinate can occur in interstellar ices.