Pulse radiolysis studies XI. Protonation reactions of aromatic anions in some aliphatic alcohols

1967 ◽  
Vol 45 (10) ◽  
pp. 1119-1123 ◽  
Author(s):  
Shigeyoshi Arai ◽  
E. L. Tremba ◽  
J. R. Brandon ◽  
Leon M. Dorfman
Keyword(s):  
Rate Constants ◽  
Pulse Radiolysis ◽  
Activation Energies ◽  
Aliphatic Alcohols ◽  
Absolute Rate ◽  
Protonation Reaction ◽  
Exponential Factors ◽  
Aromatic Anions ◽  
Anion Radicals

The protonation reaction of aromatic anion radicals in the aliphatic alcohols, [Formula: see text]has been investigated by the pulse radiolysis method. Activation energies for this reaction have been determined for the anthracenide anion and diphenylide anion in methanol, ethanol, and isopropanol, and for the naphthalenide anion in isopropanol. Absolute rate constants have been determined as well for the phenanthrenide, o-terphenylide, and m-terphenylide anions in isopropanol at 25 °C. The values for the rate constants, activation energies, and the pre-exponential factors are given. Those properties of the system which determine the kinetics are briefly discussed.

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 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 pulse radiolysis of aqueous solutions of some inorganic compounds

1965 ◽  
Vol 286 (1406) ◽  
pp. 320-336 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Metal Ions ◽  
Absorption Spectra ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Inorganic Compounds ◽  
Absolute Rate ◽  
Transient Species ◽  
Temperature Coefficients ◽  
Complex Metal

The reactions of the hydrated electron, e — aq. with a variety of inorganic metal ions, complex metal ions and anions have been investigated with pulses of 4 MeV electrons. Absolute rate constants have been measured in each case and some temperature coefficients have also been determined. Absorption spectra of transient species produced by the pulse have been obtained. Some of these species are unstable valency states produced by reduction withe — aq. , e.g. Ni + , Cr v ; others are the result of oxidation by OH, e.g. Cu 3+ . We have obtained rate constants for the reactions OH+Cu 2+ and H+MnO - 4 . The significance of the rate constants and spectra is discussed.

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.

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