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Title: Theoretical and experimental investigation of the dynamics of theproduction of CO from the CH3 + O and CD3 + O reactions

Combined experimental and theoretical investigations of the title reactions are presented. Time-resolved Fourier transform infrared (FTIR) emission studies of CO (v = 1) produced from the CH{sub 3} + O and CD{sub 3} + O reactions show that there is approximately a one-third reduction in the branching to the CO channel upon deuteration of the methyl radical. Direct dynamics, classical trajectory calculations using a B3LYP potential surface, confirm the existence of the CO producing channel. The calculations show that the CO comes from the decomposition of HCO produced by the elimination of H{sub 2} from highly vibrationally excited methoxy radicals. Scans of the potential surface reveal no saddle point for the direct elimination of H{sub 2} from methoxy. The minimum-energy path for this elimination is a stepwise process involving first a CH bond cleavage, forming H + H{sub 2}CO, followed by an abstraction, forming H{sub 2} + HCO. However, at the high internal energies produced in the initial O + CH{sub 3} addition, trajectories for the direct elimination of H{sub 2} from methoxy are observed. The predicted branching ratio between the CO and H{sub 2}CO channels is in good agreement with previous room-temperature measurements, and there is predicted to bemore » little temperature dependence to it. The observed reduction in the branching to the CO channel upon deuteration is also well reproduced in the calculations.« less
Authors:
; ; ; ; ;
Publication Date:
OSTI Identifier:
928319
Report Number(s):
LBNL--52072
R&D Project: 401001; BnR: KC0301020; TRN: US200815%%837
DOE Contract Number:
DE-AC02-05CH11231
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry A; Journal Volume: 105; Journal Issue: 36; Related Information: Journal Publication Date: 2001
Research Org:
COLLABORATION - U.Colorado
Country of Publication:
United States
Language:
English
Subject:
37; BRANCHING RATIO; CLEAVAGE; DEUTERATION; METHOXY RADICALS; METHYL RADICALS; PRODUCTION; TEMPERATURE DEPENDENCE; TRAJECTORIES