The Reactions of Active Nitrogen with Simple Alcohols

1973 ◽  
Vol 51 (22) ◽  
pp. 3671-3679 ◽  
Author(s):  
John M. Roscoe ◽  
Sharon G. Roscoe
Keyword(s):  
Isotope Effect ◽  
Rate Constants ◽  
Initial Step ◽  
Activation Energies ◽  
Active Nitrogen ◽  
Activated State ◽  
Small Primary

The reactions of active nitrogen with CH3OH, C2H5OH, n-C3H7OH and iso-C3H7OH have been studied as a function of temperature. The 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.)Experiments with CH3OH, CH3OD, and CD3OD indicate a small primary isotope effect for OH and a secondary isotope effect for CH. This, with other data, implies that abstraction of a H atom from the alcohol is not an important initial step.Consumption of N atoms ranged from 4.7 to 7.1 times the alcohol consumed. With the exception of the reaction of active nitrogen with iso-C3H7OH, the only detectable stable reaction product was HCN. Intervention of O atoms as intermediates appears to be important in all the reactions. In the reaction of active nitrogen with iso-C3H7OH, acetone, and acetonitrile were also found as products in amounts of about 26% and 14% respectively of the HCN yield. These products appear to arise through O atom intervention.Mechanisms for the reactions and the nature of the activated state in the initial step are discussed.

Reactions of trifluoromethyl radicals. V. Hydrogen abstraction from methyl acetate and methyl (2H3)Acetate

1980 ◽  
Vol 33 (7) ◽  
pp. 1437
Author(s):  
NL Arthur ◽  
PJ Newitt
Keyword(s):  
Isotope Effect ◽  
Rate Constants ◽  
Methoxy Group ◽  
Methyl Acetate ◽  
Kinetic Isotope Effect ◽  
Hydrogen Abstraction ◽  
Activation Energies ◽  
Temperature Range ◽  
Kinetic Isotope ◽  
Acetyl Group

Hydrogen abstraction by CF3 radicals from CH3COOCH3 and CD3COOCH3 has been studied in the temperature range 78-242°, and data have been obtained for the reactions: CF3 + CH3COOCH3 → CF3H+[C3H5O2] �������������(3) CF3 + CH3COOCH3 → CF3H+CH2COOCH3������������ (4) CF3 + CD3COOCH3 → CF3D+CD2COOCH3������������ (6) CF3 + CD3COOCH3 → CF3H+CD3COOCH2������������ (7) The corresponding rate constants, based on the value of 1013.36 cm3 mol-1 S-1 for the recombination of CF3 radicals, are given by (k in cm3 mol-1 s-1 and E in J mol-1): logk3 = (11.52�0.05)-(35430�380)/19.145T ���� (3)logk4 = (11.19�0.07)-(34680�550)/19.145T ���� (4)logk6 = (11.34�0.06)-(46490�490)/19.145T ���� (6)logk7 = (11.26�0.05)-(36440�400)/19.145T ���� (7)At 400 K, 59% of abstraction occurs from the acetyl group, and 41 % from the methoxy group. The kinetic isotope effect at 400 K for attack on the acetyl group is 25, due mainly to a difference in activation energies.

THE REACTIONS OF ACTIVE NITROGEN WITH THE BUTANES

1954 ◽  
Vol 32 (7) ◽  
pp. 718-724 ◽  
Author(s):  
R. A. Back ◽  
C. A. Winkler
Keyword(s):  
Nitrogen Atom ◽  
Rate Constants ◽  
Hydrogen Cyanide ◽  
Main Product ◽  
Activation Energies ◽  
Reactive Species ◽  
Atomic Nitrogen ◽  
Initial Attack ◽  
Active Nitrogen ◽  
Rate Controlling Step

The main product of the reactions of active nitrogen with n- and iso-butanes at 75 °C. and 250 °C. was hydrogen cyanide. Small amounts of C2 hydrocarbons, mainly ethylene and acetylene, were produced in both reactions. Second order rate constants were calculated on the assumption that the reactive species in active nitrogen is atomic nitrogen, and that the initial attack of a nitrogen atom is the rate-controlling step. The activation energies were then estimated to be 3.6 kcal. and 3.1 kcal. and the probability factors 4.5 × 10−4 and 4.4 × 10−4, for the n-butane and isobutane reactions respectively.

THE INHIBITED AUTOXIDATION OF STYRENE: PART I.THE DEUTERIUM ISOTOPE EFFECT FOR INHIBITION BY 2,6-DI-tert-BUTYL-4-METHYLPHENOL

1962 ◽  
Vol 40 (9) ◽  
pp. 1851-1864 ◽  
Author(s):  
J. A. Howard ◽  
K. U. Ingold
Keyword(s):  
Isotope Effect ◽  
Rate Constants ◽  
Activation Energies ◽  
Deuterium Isotope Effect ◽  
Apparent Absence ◽  
Elementary Reactions ◽  
Tert Butyl ◽  
Rapid Exchange ◽  
Phenolic Inhibitor

Most previous work on the inhibition of autoxidation by phenols has indicated that the reaction involves abstraction of the phenolic hydrogen. However, the apparent absence of any appreciable deuterium isotope effect made it difficult to believe that abstraction could be rate controlling. The present work using styrene as the substrate, 2,6-di-tert-butyl-4-methyl-phenol as the inhibitor, and azo-bis-isobutyronitrile as the initiator has shown that this reaction has an unexpectedly large isotope effect, e.g. ~10.6 at 65 °C. Previous failures to detect an isotope effect are attributed to the rapid exchange of deuterium which takes place between deuterated phenols and traces of moisture or other hydroxyl-containing compounds present in the substrate. Rate constants and activation energies for some of the elementary reactions in the inhibited and uninhibited oxidation of styrene have been measured. It is suggested that a compound which functions in the same way as a weak phenolic inhibitor is formed in the apparently uninhibited oxidation.

Kinetics of esterification of monoisopropylphenols with phosphoryl trichloride

1989 ◽  
Vol 54 (5) ◽  
pp. 1311-1317
Author(s):  
Miroslav Magura ◽  
Ján Vojtko ◽  
Ján Ilavský
Keyword(s):  
Liquid Phase ◽  
Rate Constants ◽  
Reaction Rates ◽  
Activation Energies ◽  
The Individual ◽  
Kinetics Of

The kinetics of liquid-phase isothermal esterification of POCl3 with 2-isopropylphenol and 4-isopropylphenol have been studied within the temperature intervals of 110 to 130 and 90 to 110 °C, respectively. The rate constants and activation energies of the individual steps of this three-step reaction have been calculated from the values measured. The reaction rates of the two isomers markedly differ: at 110 °C 4-isopropylphenol reacts faster by the factors of about 7 and 20 for k1 and k3, respectively. This finding can be utilized in preparation of mixed triaryl phosphates, since the alkylation mixture after reaction of phenol with propene contains an excess of 2-isopropylphenol over 4-isopropylphenol.

Ordering kinetics in synthetic Mg(Al,Fe3+)2O4 spinels: Quantitative elucidation of the whole Al-Mg-Fe partitioning, rate constants, activation energies

2014 ◽  
Vol 99 (11-12) ◽  
pp. 2203-2210 ◽  
Author(s):  
F. Parisi ◽  
D. Lenaz ◽  
F. Princivalle ◽  
L. Sciascia
Keyword(s):  
Rate Constants ◽  
Activation Energies ◽  
Ordering Kinetics

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.

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