Ultralow-Temperature Kinetics of CH(X²Π) Reactions:  Rate Coefficients for Reactions with O₂ and NO (T = 13−708 K), and with NH₃ (T = 23−295 K)

Abstract

The pulsed laser photolysis (PLP), laser-induced fluorescence (LIF) technique for the study of the kinetics of free-radical reactions is applied to reactions of CH radicals both in the ultralow-temperature environment of a Cinétique de Réaction en Ecoulement Supersonique Uniforme (CRESU) apparatus, as well as in a conventional heated cell. The combined techniques provide kinetic data over an extremely wide temperature range. Rate coefficients are reported for the reactions of CH with O2 (T = 13−708 K), NO (T = 13−708 K), and NH3 (T = 23−295 K). All three reactions remain very rapid down to the lowest temperatures at which measurements were made and display differing temperature dependences. The results are discussed in the light of previous work on these systems and of the reaction mechanisms.

Measurement of the rate coefficient of the reaction CH+O2 ? products in the temperature range 2200 to 2600 K

“…The k 125 value determined in the present work is a factor of 3 -4 higher than the measurements of Berman et al [8] and Bocherel et al [9] in the temperature range of approximately A possible reason for this might 295 -700 K. be a change in the mechanism of the reaction of CH with O 2 at higher temperatures. Very little is known about the product distribution of this reaction.…”

The interstellar gas-phase chemistry of HCN and HNC

“…The CH 2 NH + C reaction may be a source of HCN and HNC but the production of CH 2 NH (through DR of CH 3 NH 3 + and CH 3 NH 2 + with a small contribution from the CH + NH 3 reaction (Bocherel et al 1996, Blitz et al 2012, Zabarnick et al 1989) is not efficient in molecular clouds leading to a low simulated abundance and only minor production of HCN and HNC.…”

The UMIST database for astrochemistry 2012

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