Bimolecular Rate Constant and Product Branching Ratio Measurements for the Reaction of C2H with Ethene and Propene at 79 K

2012 ◽  
Vol 116 (15) ◽  
pp. 3907-3917 ◽  
Author(s):  
Jordy Bouwman ◽  
Fabien Goulay ◽  
Stephen R. Leone ◽  
Kevin R. Wilson
Keyword(s):  
Rate Constant ◽  
Branching Ratio ◽  
Bimolecular Rate Constant ◽  
Product Branching

scholarly journals Direct measurements of the total rate constant of the reaction NCN + H and implications for the product branching ratio and the enthalpy of formation of NCN

2014 ◽  
Vol 16 (23) ◽  
pp. 11647-11657 ◽  
Author(s):  
Nancy Faßheber ◽  
Johannes Dammeier ◽  
Gernot Friedrichs
Keyword(s):  
High Temperature ◽  
Enthalpy Of Formation ◽  
Rate Constant ◽  
Branching Ratio ◽  
Total Rate ◽  
Direct Measurements ◽  
Temperature Rate ◽  
First Time ◽  
Product Branching ◽  
The Enthalpy Of Formation

The high-temperature rate constant of the reaction NCN + H, a key reaction for modelling NOx formation in flames, has been directly measured for the first time.

The reaction ND(a1 δ) + H2: laser spectroscopic measurement of room-temperature rate constant and H/D atom product branching ratio

2005 ◽  
Vol 31 (1-3) ◽  
pp. 193-203 ◽  
Author(s):  
R A Brownsword ◽  
T Laurent ◽  
D K Maity ◽  
R K Vatsa ◽  
H -R Volpp
Keyword(s):  
Rate Constant ◽  
Room Temperature ◽  
Branching Ratio ◽  
Spectroscopic Measurement ◽  
Temperature Rate ◽  
Product Branching ◽  
Laser Spectroscopic

Evaluation of the rate constant for the reaction OH+H2CO: Application of modeling and sensitivity analysis techniques for determination of the product branching ratio

1989 ◽  
Vol 91 (7) ◽  
pp. 4088-4097 ◽  
Author(s):  
Richard A. Yetter ◽  
Herschel Rabitz ◽  
Frederick L. Dryer ◽  
Robert G. Maki ◽  
R. Bruce Klemm
Keyword(s):  
Sensitivity Analysis ◽  
Rate Constant ◽  
Branching Ratio ◽  
Analysis Techniques ◽  
Product Branching

Effect of flow pattern in a supersonic nozzle reactor on product branching ratio for UV photolysis of UF6/CH4 mixtures

1996 ◽  
Vol 63 (3) ◽  
pp. 293-298
Author(s):  
Y. Kuga ◽  
S. Satooka ◽  
K. Takeuchi
Keyword(s):  
Flow Pattern ◽  
Supersonic Nozzle ◽  
Branching Ratio ◽  
Uv Photolysis ◽  
Product Branching

The NCO + NO Reaction Revisited:  Ab Initio MO/VRRKM Calculations for Total Rate Constant and Product Branching Ratios

2000 ◽  
Vol 104 (46) ◽  
pp. 10807-10811 ◽  
Author(s):  
Rongshun Zhu ◽  
M. C. Lin
Keyword(s):  
Ab Initio ◽  
Rate Constant ◽  
Branching Ratios ◽  
Total Rate ◽  
Ab Initio Mo ◽  
Product Branching

From Reduction to Oxidation: pH Controlled Reaction of 1 Hydroxyethyl Radical with Caffeic Acid Analogues.

2021 ◽  
Vol 11 ◽  
Author(s):  
Laboni Das ◽  
Shashi P Shukla ◽  
Suchandra Chatterjee ◽  
Ashis K Satpati ◽  
Soumyakanti Adhikari
Keyword(s):  
Caffeic Acid ◽  
Rate Constant ◽  
Reduction Process ◽  
Phenoxyl Radical ◽  
Alpha Tocopherol ◽  
Side Chain ◽  
Product Analysis ◽  
Bimolecular Rate Constant ◽  
Ethyl Radical ◽  
Computational Calculations

Aims: The aim is to search for newer and better antioxidants through kinetic spectroscopic studies in combination with product analysis and computation. Background: Antioxidant effect of caffeic acid, its derivative, and analogues have been well reported. The antioxidative efficiencies are related to their molecular structure, and two reaction pathways are well accepted, H-atom transfer (HAT) or single electron transfer. 1-hydroxy ethyl radical (1-HER) being an ethanol-derived free radical might be causing the onset of liver injury detected after alcohol administration. 1-HER has also been reported to react with fatty acids and endogenous antioxidants such as glutathione, ascorbic acid, and alpha-tocopherol Objective: The present study is an attempt to understand the reaction mechanism of 1-HER with caffeic acid, its derivative, and analogues in detail. Method: Pulse radiolysis with kinetic absorption spectroscopy has been employed to follow the reaction pathway and identify the intermediates produced in the reaction. The reaction products have been detected using LCMS/MS. Based on these studies, a consolidated mechanism has been proposed. Cyclic voltammetry measurements and computational calculations have been used in support of the proposed mechanism. Result: In the reaction of 1-hydroxy ethyl radical (1-HER) with caffeic acid and its oligomers, reduction takes place below the pKa1, while oxidation occurs with the deprotonated phenolic moiety. The reduction of caffeic acid generates a carbon-centered radical at the double bond of the side chain with a bimolecular rate constant of 1.5x1010 dm3 mol-1 s-1. Notably, a low concentration of oxygen was able to regenerate a part of the caffeic acid molecules in the reduction process. At pH 10 a phenoxyl radical is formed due to oxidation with a much lower bimolecular rate constant (4.2x108 dm3 mol-1 s-1). In the case of di-hydrocaffeic acid, only phenoxyl radical is formed at pH 10 and, no reaction could be observed below pH 8. Conclusion: Change in reactive pattern from reduction to oxidation with change in pH within the same set of reactants has been evidently established in the present study. The results point towards the importance of  unsaturation in the side chain of caffeic acid oligomers for their reaction with 1-HER at neutral pH. The effect of oxygen concentration on the antioxidative protection offered by this class of molecules might be intriguing for the quest of the effectiveness of antioxidants at low concentrations. Other: It may be inferred that the effect of pH on the reactivity pattern as observed is not 1-HER, but substrate-specific, in the present case, phenolic acids. This study generates further scope for in-depth studies on other polyphenols where unsaturation exists in the side chain.

Temperature dependence of the rate constant and the branching ratio for the reaction Cl+HO2

1982 ◽  
Vol 77 (2) ◽  
pp. 756-763 ◽  
Author(s):  
Yuan‐Pern Lee ◽  
Carleton J. Howard
Keyword(s):  
Temperature Dependence ◽  
Rate Constant ◽  
Branching Ratio

Photochemistry of acetylene. Bimolecular rate constant for the formation of butadiyne and reactions of ethynyl radicals

1979 ◽  
Vol 83 (3) ◽  
pp. 310-313 ◽  
Author(s):  
Allan H. Laufer ◽  
Arnold M. Bass
Keyword(s):  
Rate Constant ◽  
Bimolecular Rate Constant

scholarly journals THE RATE CONSTANT OF THE REACTION BETWEEN FERROUS IONS AND HYDROGEN PEROXIDE IN ACID SOLUTION

1957 ◽  
Vol 35 (5) ◽  
pp. 428-436 ◽  
Author(s):  
T. J. Hardwick
Keyword(s):  
Hydrogen Peroxide ◽  
Acid Solution ◽  
Sulphuric Acid ◽  
Acid Concentration ◽  
Rate Constant ◽  
Perchloric Acid ◽  
Ferrous Ion ◽  
Ferrous Ions ◽  
Bimolecular Rate Constant

Identical values of the bimolecular rate constant of the ferrous ion – hydrogen peroxide reaction were obtained from intercomparisons of the methods previously used in following this reaction. In perchloric acid the bimolecular rate constant is unaffected by acid concentration; in sulphuric acid it increases slightly in acid concentrations above 10−2N. The results agree with and explain the differences between those obtained by Baxendale and by Dainton, but are only in marginal agreement with those recently reported by Weiss.

Sign in / Sign up

Export Citation Format

Share Document