Direct measurement of the reaction methyl + hydroxyl at ambient temperature in the pressure range 0.3-6.2 mbar

Abstract

The falloff behavior of the CH3 + OH recombination reaction CH3 + OH -CH30H (la) has been quantitatively investigated for the first time. Methyl decay profiles were measured in a flow reactor at 300 K and in a pressure range between 0.3 and 6.2 mbar. The experimental conditions were such that a possible channel to 'CH, + H 2 0 did not contribute strongly to the CH3 profiles. Rate coefficients were extracted from the data by comparison of the experimental profiles with computer simulations. The results are in accord with the limiting rate coefficient suggested by Hochanadel et al., km1,(298 K) = 9.3 X 10-" cm3 molecule-' s-I.l The experimental falloff curve is described by use of this value for k", together with an interpolation formula given by Tree: from which an approximate value for the low-pressure limit kola = (2.5 1.0) X cm6 molecule-z s-l has been derived (bath gas helium). For a quantitative assessment of the possible channel to 'CHI + HzO, reaction Id, measurements of H20 were carried out, yielding an estimated upper limit for the rate coefficient of kId(300 K) 5 5 X cm3 molecule-' s-l.

Elementary Reactions in the Methanol Oxidation System. Part I: Establishment of the Mechanism and Modelling of Laminar Burning Velocities

“…Data on the low temperature side consist essentially of the recent measurements in our laboratory on the 'CH2 channel [84]. From this study and the results of Hack et al [85] on the reverse, we conclude that this channel is endothermic, contrary to the current literature data and this is the reason for attributing a heat of formation (300 K) of 434.7 kJ/mol to 'CH2 in this study.…”

Kinetics and mechanisms of the reactions of O(1D)‐Atoms with CF3Br and CF2BrCF2Br in the gas phase and in solid argon matrices

“…We assumed that k,, is comparable to the rate coefficient k(CH3+OH) = 3 . 5~1 0 -~' c r n~s -' [33]. Concerning kgb, experimental results provided a rather wide range between 2 .…”

Implementation of a variational code for the calculation of rate constants and application to barrierless dissociation and radical recombination reactions: CH3OH = CH3 + OH

“…Figure 6 shows a comparison of our calculated rate constants (obtained from MRPT(6,4)/ACCD//CAS(6,4)/ACCD data and related dissociation rate constants and equilibrium constants) and literature data. [57][58][59][60][61][62][63] These recombination rate constants (in cm 3 molecule À1 s À1 ) are best fitted to:…”