ISSN:
0538-8066
Keywords:
Chemistry
;
Physical Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The kinetics of C2H5O2 and C2H5O2 radicals with NO have been studied at 298 K using the discharge flow technique coupled to laser induced fluorescence (LIF) and mass spectrometry analysis. The temporal profiles of C2H5O were monitored by LIF. The rate constant for C2H5O + NO → Products (2), measured in the presence of helium, has been found to be pressure dependent: k2 = (1.25±0.04) × 10-11, (1.66±0.06) × 10-11, (1.81±0.06) × 10-11 at P (He) = 0.55, 1 and 2 torr, respectively (units are cm3 molecule-1 s-1). The Lindemann-Hinshelwood analysis of these rate constant data and previous high pressure measurements indicates competition between association and disproportionation channels: C2H5O + NO + M → C2H5ONO + M (2a), C2H5O + NO → CH3CHO + HNO (2b). The following calculated average values were obtained for the low and high pressure limits of k2a and for k2b : k2a0 = (2.6±1.0) × 10-28 cm6 molecule-2 s-1, k2ax = (3.1±0.8) × 10-11 cm3 molecule-1 s-1 and k2b ca. 8 × 10-12 cm3 molecule-1 s-1. The present value of k2a0, obtained with He as the third body, is significantly lower than the value (2.0±1.0) × 10-27 cm6 molecule-2 s-1 recommended in air. The rate constant for the reaction C2H5O2 + NO → C2H5O + NO2 (3) has been measured at 1 torr of He from the simulation of experimental C2H5O profiles. The value obtained for k3 = (8.2±1.6) × 10-12 cm3 molecule-1 s-1 is in good agreement with previous studies using complementary methods. © 1995 John Wiley & Sons, Inc.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/kin.550271109
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