scholarly journals Kinetic Isotope Effects in Multipath VTST: Application to a Hydrogen Abstraction Reaction

2015 ◽  
Vol 120 (8) ◽  
pp. 1911-1918 ◽  
Author(s):  
Luis Simón-Carballido ◽  
Tiago Vinicius Alves ◽  
Agnieszka Dybala-Defratyka ◽  
Antonio Fernández-Ramos
Keyword(s):  
Isotope Effects ◽  
Hydrogen Abstraction ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope ◽  
Abstraction Reaction ◽  
Hydrogen Abstraction Reaction

Arrhenius-Parameter und kinetischer Isotopeneffekt für die Reaktion von Wasserstoffatomen mit Silan

1974 ◽  
Vol 29 (3) ◽  
pp. 493-496 ◽  
Author(s):  
Peter Potzinger ◽  
Louis C. Glasgow ◽  
Bruno Reimann
Keyword(s):  
Kinetic Isotope Effect ◽  
Relative Rate ◽  
Isotope Effects ◽  
Preexponential Factor ◽  
Kinetic Isotope Effects ◽  
Hydrogen Atoms ◽  
Kinetic Isotope ◽  
Abstraction Reaction ◽  
Upper Limits ◽  
Relative Rate Constants

The Reaction of Hydrogen Atoms with Silane; Arrhenius Parameters and Kinetic Isotope Effect Relative rate constants were measured for the systems H + C2H4/SiD4 and D + C2D4/SiH4 over a wide temperature range. From the known arrheniusparameter for the reaction H + C2H4 the activation energy EA and the preexponential factor A of the abstraction reactionH + SiD4 → HD + SiD3may be calculated. Values of EA = 3.2 kcal/Mol and A = 4.92 • 1013 cm3 Mol-1 sec-1 were obtained. Upper limits for the kinetic isotope effects are given in the paper

Dynamics calculations for the Cl+C2H6 abstraction reaction: Thermal rate constants and kinetic isotope effects

2003 ◽  
Vol 118 (14) ◽  
pp. 6280-6288 ◽  
Author(s):  
A. Fernández-Ramos ◽  
E. Martı́nez-Núñez ◽  
J. M. C. Marques ◽  
S. A. Vázquez
Keyword(s):  
Rate Constants ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope ◽  
Thermal Rate Constants ◽  
Abstraction Reaction

Hydrogen abstraction from (2H3)methyl acetate by methyl and trifluoromethyl radicals

1981 ◽  
Vol 34 (4) ◽  
pp. 727 ◽  
Author(s):  
NL Arthur ◽  
PJ Newitt
Keyword(s):  
Rate Constants ◽  
Methoxy Group ◽  
Methyl Acetate ◽  
Isotope Effects ◽  
Hydrogen Abstraction ◽  
Kinetic Isotope Effects ◽  
Temperature Range ◽  
Kinetic Isotope ◽  
Acetyl Group

A study of hydrogen abstraction from CH3COOCD3 by CH3 radicals in the temperature range 113-232�, and by CF3 radicals in the range 83-212�, has yielded data on the reactions: CH3+CH3COOCD3 → CH4+CH2COOCD3 (1)CH3+CH3COOCD3 → CH3D+CH3COOCD2 (2) CF3+CH3COOCD3 → CF3H+CH2COOCD2 (3) CF3+CH3COOCD3 → CF3D+CH3COOCD2 (4) The corresponding rate constants, based on the values 1013.34 and 1013.36 cm3 mol-1 s-1 for the recombination of CH3 and CF3 radicals, respectively, are given by (k in cm3 mol-1 s-1 and E in J mol-1): logk1 = (11.31�0.12)-(43500�1030)/19.145T (1) logk1 = (11.31�0.12)-(53460�640)/19.145t (2) logk3 = (11.12�0.06)=(34260�450)/19.145T � (3) logk4 =(10.93�0.12)-(38650�900)/19.145T (4)These results lead to kinetic isotope effects at 400 K for attack on the acetyl group of 11, for the CH3 reaction, and 24, for the CF3 reaction, thus confirming the values we obtained previously. For attack on the methoxy group, the kinetic isotope effects are 8 and 4, for the CH3 and CF3 reactions, respectively.

Micelle-induced change of mechanism in the reaction of muonium with acetone

1996 ◽  
Vol 74 (11) ◽  
pp. 1945-1951 ◽  
Author(s):  
John M. Stadlbauer ◽  
Krishnan Venkateswaran ◽  
Hugh A. Gillis ◽  
Gerald B. Porter ◽  
David C. Walker
Keyword(s):  
Dielectric Constant ◽  
Free Radical ◽  
Key Words ◽  
Resonance Spectrum ◽  
Addition Reaction ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Level Crossing ◽  
Kinetic Isotope ◽  
Abstraction Reaction

Muonium atoms add to the O atom of the carbonyl group of acetone to give the muonated free radical (CH3)2Ċ-O-Mu when the reaction takes place in water or hydrocarbons, but not when the acetone is localized in micelles. Micelles have no effect on the formation of muonated cyclohexadienyl radicals when muonium reacts with benzene under similar conditions. The addition reaction with acetone appears to have been subsumed by a faster alternative reaction in the micellar environment. Evidence is presented for this interpretation rather than for an inhibition of the radical or for a shift in the muon level-crossing resonance spectrum with hydrogen (muonium) bonding, though major shifts are seen for the spectrum of this radical in pure solvents of widely different dielectric constant. It is suggested that muonium's "abstraction" reaction takes over in micelles because significant micelle-induced enhancement effects were previously observed in that type of reaction. The data are consistent with a rate constant for the abstraction reaction of muonium with acetone in micelles of >6 × 108 M−1 s−1. Key words: muonium, kinetic isotope effects, micelle enhancement, H/Mu-addition, H/Mu abstraction.

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