Quenching of by O(3P), O2(a1Δg), and other gases

1983 ◽  
Vol 61 (5) ◽  
pp. 921-926 ◽  
Author(s):  
Rex D. Kenner ◽  
Elmer A. Ogryzlo
Keyword(s):  
Gas Phase ◽  
Vibrational Level ◽  
Rate Constants ◽  
Atmospheric Modeling ◽  
Absolute Rate ◽  
Laboratory Observation ◽  
Qualitative Evidence ◽  
Modeling Studies ◽  
Vibrational Levels ◽  
The Absolute

Spectroscopic and kinetic results for the quenching of [Formula: see text] are presented, including the first reported laboratory observation of gas phase emission from vibrational levels greater than zero for this state. In addition, the absolute rate constants for quenching of the lowest vibrational level by O(3P), O2(a1Δg), [Formula: see text], CO2, SF6, HE, and Ar are given. These results are compared with the results of atmospheric modeling studies. Qualitative evidence is presented for the formation of O2(a1Δg) and [Formula: see text] in the quenching of this state.

The reactions of O(3P) with 2-propanone, 2-butanone, and 3-pentanone

1986 ◽  
Vol 64 (7) ◽  
pp. 1408-1414 ◽  
Author(s):  
John M. Roscoe
Keyword(s):  
Gas Phase ◽  
Rate Constants ◽  
Substrate Concentration ◽  
Activation Energies ◽  
Absolute Rate ◽  
The Absolute

The reactions of O(3P) with 2-propanone, 2-butanone, and 3-pentanone have been studied kinetically as a function of temperature and substrate concentration. The absolute rate constants for these reactions in the gas phase, in the units M−1 s−1, obey the following relations.[Formula: see text]The activation energies for these reactions are comparable to those for the reactions of O(3P) with alcohols, but the preexponential factors for the reactions of O(3P) with these ketones are significantly smaller than those for the analogous reactions with alcohols. The available data indicate that the reactivity of O(3P) toward ketones shows a variation with polar effects of substituents which is similar to that found for the reactions of OH with ketones.

The reactions of O(3P) with acetonitrile and propionitrile

1995 ◽  
Vol 73 (5) ◽  
pp. 666-674 ◽  
Author(s):  
Suzanne Budge ◽  
John M. Roscoe
Keyword(s):  
Hydrogen Atom ◽  
Gas Phase ◽  
Rate Constant ◽  
Rate Constants ◽  
Hydrogen Atom Abstraction ◽  
Absolute Rate ◽  
Analytical Results ◽  
Absolute Rate Constant ◽  
Secondary Reactions ◽  
The Absolute

The reactions of O(3P) with acetonitrile and propionitrile have been studied kinetically in the gas phase as a function of temperature and nitrile concentration. The rate constants obtained experimentally for the consumption of O(3P) in these reactions, in the units L mol−1 s−1, obey the following relations: O + acetonitrile: In k = 20.98 ± 0.23 − 2100 ± 200/T; and O + propionitrile: In k = 21.01 ± 0.19 − 1900 ± 200/T. Mechanisms are discussed in which the reaction is initiated by hydrogen atom abstraction and in which initiation is by addition of O(3P) to the nitrile, followed by decomposition of the addition complex. The kinetic and analytical results are best explained by the mechanism in which the reactions are initiated by RCN + O → R + OCN. In the case of the reaction with acetonitrile, the absolute rate constant is smaller than the experimental value by a factor of 7 ± 20%, independent of temperature, as a result of secondary reactions. Keywords: kinetics, reactions of O(3P) with nitriles.

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