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Titolo:
Theoretical study of the solvent effect on the hydrogen abstraction reaction of the methyl radical with hydrogen peroxide
Autore:
Delabie, A; Creve, S; Coussens, B; Nguyen, MT;
Indirizzi:
Univ Louvain, Dept Chem, B-3001 Heverlee, Belgium Univ Louvain Heverlee Belgium B-3001 Dept Chem, B-3001 Heverlee, Belgium DSM Res, NL-6160 MD Geleen, Netherlands DSM Res Geleen Netherlands NL-6160 MD es, NL-6160 MD Geleen, Netherlands
Titolo Testata:
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
, volume: 5, anno: 2000,
pagine: 977 - 981
SICI:
0300-9580(200005)5:<977:TSOTSE>2.0.ZU;2-5
Fonte:
ISI
Lingua:
ENG
Soggetto:
DENSITY-FUNCTIONAL THEORY; BECKMANN REARRANGEMENT; ENERGIES; MODEL; ATOM; CONTINUUM; MECHANISM;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
33
Recensione:
Indirizzi per estratti:
Indirizzo: Nguyen, MT Univ Louvain, Dept Chem, Celestijnenlaan 200F, B-3001 Heverlee,Belgium Univ Louvain Celestijnenlaan 200F Heverlee Belgium B-3001 gium
Citazione:
A. Delabie et al., "Theoretical study of the solvent effect on the hydrogen abstraction reaction of the methyl radical with hydrogen peroxide", J CHEM S P2, 5, 2000, pp. 977-981

Abstract

The hydrogen abstraction reaction of the methyl radical with hydrogen peroxide (CH3. + HOOH --> CH4 + HOO.) in both the gas phase and aqueous solution was studied by means of quantum chemical calculations. The gas phase reaction was described at the MP2, QCISD(T) and CCSD(T) levels of theory. To evaluate the effect of the solvent? different continuum solvation models wereused. First, as a necessary calibration, the performance of the polarizable continuum model (PCM), the conductor like screening model (CPCM) and the conductor like screening model for real solvents (COSMO-RS) was tested in the calculation of the free energies of hydration for a set of 16 neutral organic molecules. The PCM and CPCM solvation models reproduce the experimental hydration free energies best, with an rms value of about 0.2 kcal mol(-1). The solvent effect on both the activation and reaction energies of the reaction of the methyl radical with hydrogen peroxide was subsequently calculated. All solvation models confirm the experimentally observed decrease inreaction rate in going from gas phase to aqueous solution. The PCM and CPCM suggest an increase in activation energy by about 4 kcal mol(-1), corresponding thus to a 1000-fold decrease in reaction rate, in good agreement with experiment. The reason for such a strong solvent effect is a larger stabilization of hydrogen peroxide by water.

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Documento generato il 18/11/17 alle ore 05:50:33