Ab initio quantum chemical studies of reaction mechanism for CH2CO with NCO

Zhang, Weichao; Du, Benni

doi:10.1016/j.theochem.2005.12.004

Cited by 14 publications

(9 citation statements)

References 47 publications

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“…In previous experiment, CH 2 NCO and CO have been detected as primary reaction products, while P 3 (HCCO＋HNCO) was only considered as a minor contribution to the products. Therefore, the theoretical prevision is in good agreement with the previous experimental 21 and theoretical 25,26 results. Furthermore, as can be noted in this work we have only considered the reaction channels on the doublet potential energy surface.…”

Section: Reaction Mechanism Of Ch 2 Co＋ncosupporting

confidence: 89%

“…Furthermore, a hydrogen abstraction reaction to produce HNCO＋HCCO can be viewed as a minor or negligible product channel. The results were confirmed in two theoretical investigations by Zhang 25 and Sun, 26 in which they gave several key reaction channels and corresponding theoretical reaction rates.…”

Section: Introductionsupporting

confidence: 72%

“…For more accurately describing the reaction mechanism of CH 2 CO＋NCO and confirming the conclusion deduced from the experiments by Edwards et al 21 and the previous simple theoretical descriptions, 25,26 a detailed theoretical study on the CH 2 CO＋NCO reaction is desirable, especially for the isomerization processes of the corresponding intermediates. By comparing theoretical results with experimental ones, we can validate the experimental results and bring forward the experimental product distribution and pathways, while it can also provide theoretical data for the further experiment.…”

Section: Introductionmentioning

confidence: 69%

“…[15][16][17][18][19][20][21] But relative to the experimental studies, the knowledge on the theoretical studies for CH 2 CO is rare limited. Up to now, only the reaction mechanisms and product distribution of CH 2 CO with Cl, 22,23 F, 24 and NCO 25,26 have been investigated theoretically. In 1998, Edwards et al 21 determined primary products of the reaction CH 2 CO＋NCO by experimental methods.…”

Section: Introductionmentioning

confidence: 99%

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Theoretical Study on the Reaction Mechanism of Ketene CH₂CO with Isocyanate NCO Radical

Zhao

Kan

Yu³

et al. 2007

Chin. J. Chem.

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The bimolecular single collision reaction potential energy surface of an isocyanate NCO radical with a ketene CH 2 CO molecule was investigated by means of B3LYP and QCISD(T) methods. The computed results indicate that two possible reaction channels exist on the surface. One is an addition-elimination reaction process, in which the CH 2 CO molecule is attacked by the nitrogen atom at its methylene carbon atom to lead to the formation of the intermediate OCNCH 2 CO followed by a C-C rupture channel to the products CH 2 NCO＋CO. The other is a direct hydrogen abstraction channel from CH 2 CO by the NCO radical to afford the products HCCO＋HNCO. Because of a higher barrier in the hydrogen abstraction reaction than in the addition-elimination reaction, the direct hydrogen abstraction pathway can only be considered as a secondary reaction channel in the reaction kinetics of NCO＋ CH 2 CO. The predicted results are in good agreement with previous experimental and theoretical investigations.

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Section: Reaction Mechanism Of Ch 2 Co＋ncosupporting

confidence: 89%

Section: Introductionsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 69%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Theoretical Study on the Reaction Mechanism of Ketene CH₂CO with Isocyanate NCO Radical

Zhao

Kan

Yu³

et al. 2007

Chin. J. Chem.

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“…For the triplet reaction channel, we have carried out a kinetic study using conventional transition-state theory [33,34], which was used in the gas phase reaction of formaldehyde with hydroperoxyl radical by Anglada et al [33]. Our reaction, which is similar to the reaction of formaldehyde with hydroperoxyl radical, begins with a formation of a postreactant complex (CR) via a barrierless process before the transition state and the release of the products.…”

Section: Methodsmentioning

confidence: 99%

Direct dynamics study on mechanism and kinetics of the biradical self‐reaction of HOO

Zhang

Wang

2010

Int J of Quantum Chemistry

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A theoretical study of the mechanism and the kinetics for the hydrogen abstraction reaction of the biradical hydroperoxy radical has been presented at the CCSD(T)/6-311þþG(3d,2p)//CCSD/6-31þG(d,p) level of theory. Our theoretical calculations suppose a stepwise mechanism involving the formation of a postreactant complex in the triplet and singlet entrance channels. Four transition states of the sixmembered chain complexes ( 3 TS1 and 1 TS1) and six-membered ring complexes ( 3 TS2 and 1 TS2) are located at the high dual level CCSD(T)/6-311þþG(3d,2p)//CCSD/6-31þG(d,p) method. The rate constants of Path 1 $ Path 4 at the CCSD(T)/6-311þþG(3d,2p)//CCSD/6-31þG (d,p) level are calculated by means of the conventional transition state theory (TST) and canonical variational TST without and with smallcurvature tunneling (SCT) correction within the temperature range of 200-2,500 K. The calculated results show that the triplet channel is the dominating reaction channel and Path 2 is found to be the most favorable pathway. The rate constants of Path 2 are in good agreement with the experimental values at the experimentally measured temperatures. Moreover, the variational effect is not obvious in the low temperature range but is not neglectable in the high temperature range. The SCT plays an important role particularly in the low temperature range.

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Theoretical study on reaction mechanism of isocyanate radical NCO with ethene

Pang

Xie

Zhang

et al. 2008

Int J of Quantum Chemistry

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The NCO ϩ C 2 H 4 reaction is simple and prototype for reaction of the NCO radical with unsaturated hydrocarbons, and it is considered to be important in fuel-rich combustion. In this article, we for the first time perform detailed theoretical investigations for its reaction mechanism based on Gaussian-3//B3LYP scheme covering various entrance and decomposition channels. The most favorable channel is firstly the NCO and C 2 H 4 approach each other, forming a weakly-bound complex L1 OCN⅐⅐⅐C 2 H 4 , followed by the formation of isomer L2 OCNCH 2 CH 2 via a small barrier of 1.3 kcal/mol. Transition states of any decomposable or isomeric channels for L2 in energy are much higher than reactants, which indicate that adduct L2 has stabilization effect in this NCO ϩ C 2 H 4 reaction. The direct H-abstraction channel leading to P1 HNCO ϩ C 2 H 3 , might have an important contribution to the eventual products in high temperature. These results can well explain available kinetic experiment. Moreover, reaction mechanism for the title reaction is significantly different from the NCO ϩ C 2 H 2 reaction which proceeds on most favorably to generate the products HCN ϩ HCCO and OCCHCN ϩ H via a four-membered ring intermediate.

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Ab initio quantum chemical studies of reaction mechanism for CH2CO with NCO

Cited by 14 publications

References 47 publications

Theoretical Study on the Reaction Mechanism of Ketene CH₂CO with Isocyanate NCO Radical

Theoretical Study on the Reaction Mechanism of Ketene CH₂CO with Isocyanate NCO Radical

Direct dynamics study on mechanism and kinetics of the biradical self‐reaction of HOO

Theoretical study on reaction mechanism of isocyanate radical NCO with ethene

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Ab initio quantum chemical studies of reaction mechanism for CH2CO with NCO

Cited by 14 publications

References 47 publications

Theoretical Study on the Reaction Mechanism of Ketene CH2CO with Isocyanate NCO Radical

Theoretical Study on the Reaction Mechanism of Ketene CH2CO with Isocyanate NCO Radical

Direct dynamics study on mechanism and kinetics of the biradical self‐reaction of HOO

Theoretical study on reaction mechanism of isocyanate radical NCO with ethene

Contact Info

Product

Resources

About

Theoretical Study on the Reaction Mechanism of Ketene CH₂CO with Isocyanate NCO Radical

Theoretical Study on the Reaction Mechanism of Ketene CH₂CO with Isocyanate NCO Radical