In:
Journal of Theoretical and Computational Chemistry, World Scientific Pub Co Pte Ltd, Vol. 10, No. 02 ( 2011-04), p. 231-244
Abstract:
The mechanism and kinetics of the reaction of CH 3 OCF 2 CF 2 OCH 3 with OH radicals have been studied theoretically by a direct density functional theory dynamics method. All possible H -abstraction channels and displacement processes taking place on two different conformers of CH 3 OCF 2 CF 2 OCH 3 have been taken into consideration. The potential energy surface information including the optimized geometries and harmonic vibrational frequencies of all the stationary points and barrier heights involved in these channels were obtained at the BB1K/6-31+G(d,p) level of theory. The rate constants were calculated using improved canonical variational transition state theory (ICVT) with the small-curvature tunneling correction (SCT) over the temperature range of 200–2000 K. The overall rate constant for the title reaction, which was obtained by considering the weight factor of each conformer from the Boltzman distribution function, is in reasonable agreement with the available experimental value. Three-term Arrhenius expression is fitted to be k T = 1.56 × 10 -20 T 2.47 exp (-124.64/ T ) cm 3 molecule -1 s -1 (200–2000 K). Also, the enthalpies of formation of the reactant CH 3 OCF 2 CF 2 OCH 3 and product radicals CH 3 OCF 2 CF 2 OCH 2 and CH 3 OCF 2 CF 2 O , which lack experimental or theoretical data, were evaluated via applying isodesmic reactions.
Type of Medium:
Online Resource
ISSN:
0219-6336
,
1793-6888
DOI:
10.1142/S0219633611006402
Language:
English
Publisher:
World Scientific Pub Co Pte Ltd
Publication Date:
2011
detail.hit.zdb_id:
2096537-0
detail.hit.zdb_id:
2092261-9
