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Theoretical analysis of the rate constants for the interstellar reaction N+OH→NO+H
Author(s) -
Cobos C. J.
Publication year - 1995
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.550270303
Subject(s) - chemistry , reaction rate constant , ab initio , adiabatic process , atmospheric temperature range , potential energy surface , thermodynamics , quantum , interstellar cloud , computational chemistry , molecular cloud , physics , kinetics , quantum mechanics , astrophysics , organic chemistry , stars
The title reaction, a key elementary process involved in the chemistry of molecular clouds, has been theoretically studied over the 5–600 K temperature range. Rate constants calculations have been carried out using the full version of the statistical adiabatic channel model in conjunction with a potential energy surface that has been derived from recent ab initio quantum chemical data. By using various switching functions, the influence of the attenuation of the bound‐complex bending frequency upon NOH bond elongation on the temperature dependence of the reaction was investigated. The rate constants exhibit a slightly positive temperature dependence with a calculated rate constant value at 300 K in very good agreement with the measured value. A comparison with the available experimental data between 250 and 515 K suggests that recrossing trajectories might occur with increasing importance as the temperature increases. However, the nonstatistical recrossing effects are expected to be of minor importance at interstellar temperatures such that the rate constants over the 5–200 K temperature range are given by k = 8.41 × 10 −12 T +0.30 cm 3 molecule −1 s −1 . The rate constant calculated at 10 K is consistent with that derived in the astrochemical modeling of the L134N dark cloud. Rate constants for individual quantum states are also presented. © 1995 John Wiley & Sons, Inc.