Electronic Quenching of N(2D) by N2: Theoretical Predictions, Comparison with Experimental Rate Constants, and Impact on Atmospheric Modeling

2013 ◽  
Vol 4 (14) ◽  
pp. 2292-2297 ◽  
Author(s):  
B. R. L. Galvão ◽  
A. J. C. Varandas ◽  
J. P. Braga ◽  
J. C. Belchior
Keyword(s):  
Rate Constants ◽  
Atmospheric Modeling ◽  
Experimental Rate ◽  
Theoretical Predictions

Kinetics of cyclohexene hydrogenation and of thiophene hydrogenolysis over cobalt-molybdenum catalysts of different composition

1979 ◽  
Vol 44 (12) ◽  
pp. 3676-3687 ◽  
Author(s):  
Vlastimil Vyskočil ◽  
Miloš Kraus
Keyword(s):  
Low Temperature ◽  
Rate Constants ◽  
Atmospheric Pressure ◽  
Kinetic Data ◽  
Oxygen Adsorption ◽  
Experimental Rate ◽  
Cyclohexene Hydrogenation ◽  
Molybdenum Catalysts ◽  
Kinetics Of

The kinetics of the title reactions has been measured at 350°C and atmospheric pressure on six Co-Mo-AL2O3 catalysts prepared by successive impregnation of the support with solutions of molybdenum and cobalt salts and containing these components in different ratios as well as on a commercial Cherox 36-00 catalyst. The activity of these catalysts depend strongly on their composition and showed similar trends for both reactions. Kinetic data were correlated by equations of Langmuir-Hishelwood type. Their adsorption coefficients have a similar value for different catalysts and all differences in the activity reflected in rate constants. Surface concentrations of molybdenum were determined by low temperature oxygen adsorption and were correlated with experimental rate constants.

Formation of Carbon Dioxide in the Belousov-Zhabotinsky-Reaction

1984 ◽  
Vol 39 (10) ◽  
pp. 993-997 ◽  
Author(s):  
H. D. Försterling ◽  
H. Idstein ◽  
R. Pachl ◽  
H. Schreiber
Keyword(s):  
Carbon Dioxide ◽  
Rate Constants ◽  
Organic Reactions ◽  
Experimental Rate ◽  
Belousov Zhabotinsky Reaction

Abstract The rate of formation of CO2 in the BZ system is measured and compared to the predictions of the Field-Körös-Noyes (FKN)-theory. The experimental rate is found to be larger than the theoretical rate by a factor of about 100. This discrepancy cannot be easily explained without severe changes in the FKN model. Moreover, improved rate constants of the most important organic reactions in the BZ system are given.

A THEORETICAL STUDY FOR H2 + CN ↔ HCN + H REACTION AND ITS KINETIC ISOTOPE EFFECTS WITH VARIATIONAL TRANSITION STATE THEORY

2006 ◽  
Vol 05 (04) ◽  
pp. 769-777 ◽  
Author(s):  
LI-PING JU ◽  
KE-LI HAN ◽  
JOHN Z. H. ZHANG
Keyword(s):  
Transition State ◽  
Rate Constants ◽  
Transition State Theory ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
State Theory ◽  
Variational Transition State Theory ◽  
Kinetic Isotope ◽  
Theoretical Predictions ◽  
Variational Transition State

We present variational transition state theory (VTST) calculations for the H 2 + CN → HCN + H (R1) and D 2 + CN → DCN + D (R2) reactions and their reverses based on a global many-body expansion potential energy surface (PES) for ground-state H 2 CN (ter Horst MA, Schatz GC, Harding LB, J Chem Phys105:558, 1996). It is found that the tunneling effects are negligible over the 200–2000 K temperature range and non-negligible over 100–200 K for R1 and R2 reactions. The C–N bond acts almost as a spectator for both reactions. The present VTST rate constants are in good agreement with the available experimental results and the previous theoretical predictions for R1 and R2 reactions except for the overestimation of rate constants by VTST at lower temperatures that may be caused by recrossing effect. Additionally, the kinetic isotope effects are important for the forward R1 and R2 reactions, but not for the reverses of R1 and R2.

Catalytic effect of cetyltrimethylammonium bromide on the radical destruction oxidation of pyrocatechol violet

1980 ◽  
Vol 45 (11) ◽  
pp. 2883-2889 ◽  
Author(s):  
Jan Lasovský ◽  
František Březina ◽  
Ladislav Nekl
Keyword(s):  
Hydrogen Peroxide ◽  
Rate Constants ◽  
Cetyltrimethylammonium Bromide ◽  
Optimum Conditions ◽  
Pyrocatechol Violet ◽  
Radical Oxidation ◽  
Experimental Rate ◽  
Cobalt Compounds ◽  
Cobalt Dichloride ◽  
Usual Formalism

The effect of cetyltrimethylammonium bromide (I) on the radical oxidation of pyrocatechol violet by hydrogen peroxide was studied in the presence of N,N'-ethylenediamine-bis(o-aminobenzaldimine)cobalt(II) bromide and cobalt dichloride. After a short, faster period the reaction obeys the 1st order formalism. In the presence of I the experimental rate constants are as much as 42 times higher than in "pure" solutions. In optimum conditions (dye concentration 1.75 . 10-4 mol l-1) the reaction can be described in terms of the usual formalism of micellar catalysis. In solutions containing I the effect of cobalt compounds can be traced down to cobalt concentration levels of 10-8 mol l-1. The dependences of the experimental rate constants on the concentrations of hydrogen peroxide and cobalt compounds and on the temperature and pH are discussed.

Theoretical and Experimental Rate Constants for Two Isotopic Modifications of the Reaction H + H2

Science ◽  
1990 ◽  
Vol 249 (4966) ◽  
pp. 269-271 ◽  
Author(s):  
J. V. Michael ◽  
J. R. Fisher ◽  
J. M. Bowman ◽  
Q. Sun
Keyword(s):  
Rate Constants ◽  
Experimental Rate

Significance of Experimental Rate Constants

Nature ◽  
1962 ◽  
Vol 194 (4827) ◽  
pp. 471-472 ◽  
Author(s):  
J. H. TAPLIN
Keyword(s):  
Rate Constants ◽  
Experimental Rate

Étude cinétique de l'ouverture thermique de la liaison C—C d'aziridines et d'époxydes dipôles-1,3 potentiels: I. Méthode d'étude expérimentale

1985 ◽  
Vol 63 (8) ◽  
pp. 2245-2252 ◽  
Author(s):  
Aïcha Derdour ◽  
Fernand Texier
Keyword(s):  
Rate Constants ◽  
Heterocyclic Compounds ◽  
The Other ◽  
Azomethine Ylide ◽  
Carbon Bond ◽  
Experimental Rate ◽  
Carbon Carbon Bond ◽  
Kinetic Treatment

The thermolysis of the 2-cyanoaziridines (1), 2-alkoxycarbonylaziridines (2), 2-arylaziridines (3), and 2,2-dicyano-3-aryloxiranes (4) leads to a rupture of the carbon –carbon bond yielding an azomethine ylide and the ylide of a carbonyl. The reaction of these ylides of azomethine with methyl acetylene dicarboxylate (MADC) leads to the formation of a 3-pyroline, which is transformed, according to the substituants, to a 2-pyrroline or to pyrrole. The addition of the ylides of carbonyl leads to the formation of dihydrofurans. Through the kinetic treatment of the addition of these heterocyclic compounds (1 to 4) to MADC, it is possible to determine the rate constants for the opening of the C—C bond (k1). In the case of the aziridines 1, the rates have been determined by ir while hplc has been used in the other cases. Relative to the heterocyclic compounds, the order of the experimental rate constants (kex) is always equal to one. In the cases of theN-cyclohexyl-2-cyano-3-alkylaziridines and of the N-cyclohexyl-2-carbomethoxy-3-phenylaziridine, kex varies with the concentration of MADC and this implies that the rate constants for the cycloaddition of the ylide of azomethine and its reclosing to give aziridine are similar. In the other cases, kex is independent of the concentration of MADC and this implies that the heterocyclic compounds are slowly transformed into 1,3-dipoles, followed by a rapid cycloaddition, [Formula: see text]. [Journal translation]

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