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Title: Ab initio/density functional theory and multichannel RRKM calculations for the Ch{sub 3}O + CO reaction

The potential energy surface for the reaction of methoxy radical with carbon monoxide has been studied using the G2(B2LYP/MP2/CC) method. Two reaction mechanisms were revealed. The hydrogen abstraction of CH{sub 3}O by CO produces CH{sub 2}O + HCO via a barrier of 24.19 kcal/mol. The addition of CH{sub 3}O to CO proceeds to an intermediate CH{sub 3}OCO via a barrier of 6.39 kcal/mol. The products, CH{sub 3} and CO{sub 2}, can be formed in two ways. One is the C-O bond cleavage of the CH{sub 3}OCO radical. The other involves the isomerization of CH{sub 3}OCO to the CH{sub 3}CO{sub 2} radical and the subsequent C-C bond fission. CH{sub 2}O and HCI can be formed via the path CH{sub 3}OCO {r{underscore}arrow} TS6 {r{underscore}arrow} IM4 {r{underscore}arrow} TS7 {r{underscore}arrow} CH{sub 2}O + HCO. A radical product, CH{sub 2}COOH, is formed through the hydrogen rearrangement of the CH{sub 3}CO{sub 2} radical. Multichannel RRKM calculations have been carried out for the total and individual rate constants for various channels over a wide range of temperatures and pressures using the ab initio data. At lower temperatures, the title reaction is dominated by the stabilization of the CH{sub 3}OCO radical. At higher temperatures, the CH{sub 3} +more » CO product channel and the direct hydrogen abstraction channels become dominant and competitive. The title reaction shows the typical fall-off behavior. The calculations were compared with the available experimental data.« less
Authors:
; ;
Publication Date:
OSTI Identifier:
20001100
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry A: Molecules, Spectroscopy, Kinetics, Environment, amp General Theory; Journal Volume: 103; Journal Issue: 40; Other Information: PBD: 7 Oct 1999
Research Org:
Shandong Univ., Jinan (CN)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; MATHEMATICAL MODELS; METHOXY RADICALS; CARBON MONOXIDE; CHEMICAL REACTION KINETICS