Rate constants of the combination of methyl radicals with nitric oxide and oxygen

1975 ◽  
Vol 7 (5) ◽  
pp. 639-648 ◽  
Author(s):  
Allan H. Laufer ◽  
Arnold M. Bass

The Rice-Herzfeld free-radical mechanism for the thermal decomposition of saturated hydrocarbons, including both the uninhibited reaction and that partially inhibited by nitric oxide, involves the rate constants of various individual steps. If standard values are assumed for the rate constants of H -abstraction from n -pentane by methyl radicals, alkyl radical recombination, and addition of methyl to nitric oxide, then those of all the steps for a series of paraffins can be found. The method depends on measurements of the rate constant in the region where the chain reaction is of the first order, the inhibitory action of nitric oxide as a function of paraffin pressure, and the acceleration of paraffin decomposition rate produced by high pressures of nitric oxide. Values are derived for propane, three pentanes ( neo -, iso - and normal pentane) and three octanes ( normal octane, 2:3:4-trimethyl pentane and 2:2:4-trimethyl pentane), and the variations of the several rate constants with structure are discussed.


1964 ◽  
Vol 86 (10) ◽  
pp. 1929-1934 ◽  
Author(s):  
A. Maschke ◽  
B. S. Shapiro ◽  
F. W. Lampe
Keyword(s):  

1956 ◽  
Vol 34 (2) ◽  
pp. 103-107 ◽  
Author(s):  
P. B. Ayscough ◽  
E. W. R. Steacie

A study of the reactions of trifluoromethyl radicals, produced by the photolysis of hexafluoroacetone, with propane, n-butane, and isobutane has been made. The rate constants of the hydrogen-abstraction reactions have been determined at temperatures between 27 °C and 119 °C and the activation energies found to be 6.5 ± 0.5, 5.1 ± 0.3, and 4.7 ± 0.3 kcal./mole respectively. These values are compared with those obtained for the reactions with methane and ethane, and with the corresponding reactions of methyl radicals.


1995 ◽  
Vol 99 (35) ◽  
pp. 13126-13131 ◽  
Author(s):  
Akira Masaki ◽  
Shigeru Tsunashima ◽  
Nobuaki Washida

1978 ◽  
Vol 56 (23) ◽  
pp. 2934-2939 ◽  
Author(s):  
D. L. Singleton ◽  
R. J. Cvetanović

Rate constants for the reactions O(3P) + HX → OH + X (X = Br, I) have been determined by a phase shift technique. Oxygen atoms were generated by modulated mercury photosensitized decomposition of nitrous oxide, and were monitored by the chemiluminescence from the reaction with nitric oxide. Over the temperature interval 298–554 K, the rate constants are satisfactorily represented by the Arrhenius expressions kO+HBr = (8.09 ± 0.86) × 109 exp (−3.59 ± 0.08)/RT and kO+HI = (2.82 ± 0.27) × 1010 exp (−1.99 ± 0.07)/RT, where the units are ℓ mol−1 s−1 and kcal mol−1. The indicated uncertainties are one standard deviation. The results of bond energy–bond order calculations, incorporating recently proposed modifications, are discussed.


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