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 the butanols

1983 ◽  
Vol 61 (12) ◽  
pp. 2716-2720 ◽  
Author(s):  
John M. Roscoe
Keyword(s):  
Free Energy ◽  
Gas Phase ◽  
Rate Constants ◽  
Substrate Concentration ◽  
Kinetic Data ◽  
Absolute Rate ◽  
Gas Phase Reactions ◽  
Linear Free Energy ◽  
Different Types ◽  
Energy Relations

The reactions of O(3P) with the butanols were studied kinetically as a function of temperature and substrate concentration. The absolute rate constants for the gas phase reactions, in the units M−1 s−1, obey the following relations.[Formula: see text]The results suggest that although the α-CH bond in these alcohols is the most reactive one, reaction of O(3P) with other CH bonds in the alcohols is also appreciable. The kinetic data for these and other alcohols are separated into contributions from the different types of CH bonds and the results are discussed in terms of linear free energy relations.

The reactions of atomic oxygen with 1-propanol and 2-propanol

1979 ◽  
Vol 57 (11) ◽  
pp. 1269-1273 ◽  
Author(s):  
A. L. Ayub ◽  
John M. Roscoe
Keyword(s):  
Rate Constants ◽  
Atomic Oxygen ◽  
Activation Energies ◽  
Steric Effects ◽  
Absolute Rate ◽  
Exponential Factors ◽  
The Absolute

The reactions of O(3P) with n-propanol and isopropanol were studied as a function of temperature. The absolute rate constants for these reactions, in the units M−1 s−1, obey the following relations.[Formula: see text]The activation energies of these reactions are similar to those of the corresponding reactions of methanol and ethanol, although some dependence on the strength of the α-C—H bond is discernible. The nearly constant pre-exponential factors for the reactions of methanol, ethanol, n-propanol, and isopropanol suggest that no special steric effects are present in the reactions of these compounds with O(3P). Mechanisms are discussed for the reactions of n-propanol and isopropanol with O(3P).

The reactions of atomic oxygen with methanol and ethanol

1976 ◽  
Vol 54 (6) ◽  
pp. 984-989 ◽  
Author(s):  
Cynthia M. Owens ◽  
John M. Roscoe
Keyword(s):  
Carboxylic Acid ◽  
Rate Constants ◽  
Atomic Oxygen ◽  
Activation Energies ◽  
Absolute Rate ◽  
Data Support ◽  
The Absolute

The reactions of O(3P) with CH3OH and C2H5OH were studied as a function of temperature. The absolute rate constants for these reactions fit the following expressions:[Formula: see text](Activation energies are in kJ/mol. Rate constants are in 1 mol−1 s−1.) The data support abstraction of the α-H atom as the primary step. The α-C—H bond in ethanol is apparently weaker than that in methanol, and this alters the nature of subsequent steps in the mechanisms for these reactions. The presence of oxygen alters the stoichiometric coefficients for these reactions and produces the corresponding carboxylic acid.

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 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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