Reaction of OH radicals with CH₃NH₂ in the gas phase: experimental (11.7–177.5 K) and computed rate coefficients (10–1000 K)

Abstract

Nitrogen-bearing molecules, like methylamine (CH3NH2), can be the building blocks of amino acids in the interstellar medium (ISM). At the ultralow temperatures of the ISM, it is important to know...

Gas-phase formation of glycolonitrile in the interstellar medium

“…However, the addition reaction between OH and CH 3 CN leading to CH 3 C(OH)N, competes with reaction (13) under low-pressure conditions at 10 K, with a computed rate coefficient of approximately 5 × 10 −14 cm 3 molecule −1 s −1 . As the temperature exceeds 200 K, the addition reaction becomes pressure-independent, and our calculated values align well with experimental data within the temperature range of 256 to 388 K. 51…”

“…In the low-pressure regime, the canonical unified statistical (CUS) 25,26 model can be utilized. This model allows us to approximate the rate coefficient for the formation of the C + D products as:…”

“…The measured rate coefficient for this reaction within the temperature range of 256-388 K is of the order of 10 À14 cm 3 molecule À1 s À1 . 50 We have determined the rate coefficient for reaction (13) at 10 K using the canonical unified statistical theory 25,26 under the low-pressure limit. Within these pressure conditions, the tunneling effect was taken into account using the Pilgrim program 28 with the small-curvature approximation, considering tunneling energies above the energy of the reactants.…”

“…A free energy bottleneck (TS1) to the barrierless formation of a vibrationally excited species (S * ),A + B → S*ii. The second bottleneck (TS2) occurs in the vicinity of a saddle point, where S * undergoes an elimination reaction:S* → C + DIn the low-pressure regime, the canonical unified statistical (CUS) 25,26 model can be utilized. This model allows us to approximate the rate coefficient for the formation of the C + D products as:In eqn (6), the association rate coefficient, denoted as k 1 , corresponds to eqn (4).…”

Theoretical kinetics analysis of the OH + CH3OH hydrogen abstraction reaction using a full‐dimensional potential energy surface

“…In the range 50–2000 K the rate constants are very fast, in the order of 10 −10 cm 3 molecule −1 s −1 . Note that this data is of a similar order to that obtained with the other two approaches 12,37 …”