The reaction between cyano radicals (which are ubiquitous in interstellar clouds) and methylamine (a molecule detected in various interstellar sources) has been investigated in a synergistic experimental and theoretical study. The reaction has been found to be very fast in the entire range of temperatures investigated (23–297 K) by using a CRESU apparatus coupled to pulsed laser photolysis – laser induced fluorescence. The global experimental rate coefficient is given by In addition, dedicated electronic structure calculations of the underlying potential energy surface have been performed, together with capture theory and RRKM calculations. The experimental data have been interpreted in the light of the theoretical calculations and the product branching ratio has been established. According to the present study, in the range of temperatures investigated the title reaction is an efficient interstellar route of formation of cyanamide, NH₂CN, another interstellar species. The second most important channel is the one leading to methyl cyanamide, CH₃NHCN (an isomer of aminoacetonitrile), via a CN/H exchange mechanism with a yield of 12% of the global reaction in the entire range of temperatures explored. For a possible inclusion in future astrochemical models we suggest, by referring to the usual expression the following values: α = 3.68 × 10⁻¹² cm³ molec⁻¹ s⁻¹, β = −1.80, γ = 7.79 K for the channel leading to NH₂CN + CH₃; α = 5.05 × 10⁻¹³ cm³ molec⁻¹ s⁻¹, β = −1.82, γ = 7.93 K for the channel leading to CH₃NHCN + H.

The gas phase reaction between the CN radical and acetonitrile CH ₃ CN was investigated experimentally with a CRESU apparatus and a slow flow reactor as well as theoretically to explore the temperature and pressure dependence of its rate coefficient from 354 K down to 23 K.