Barrier permeabilities for a symmetric Eckart potential as studied by the kinetic isotope effects for hydrogen/deuterium abstraction from neopentane by hydrogen atoms in the gas phase

1987 ◽  
Vol 83 (11) ◽  
pp. 2053-2065 ◽  
Author(s):  
Noboru Fujisaki ◽  
Amanz Ruf ◽  
Tino Gäumann
Keyword(s):  
Gas Phase ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Hydrogen Atoms ◽  
Eckart Potential ◽  
Kinetic Isotope ◽  
Hydrogen Deuterium

Isotope effects in nucleophilic substitution reactions. V. The mechanism of the decomposition of 1-phenylethyldimethylphenylammonium halides in chloroform

1986 ◽  
Vol 64 (6) ◽  
pp. 1206-1214 ◽  
Author(s):  
Helen Alma Joly ◽  
Kenneth Charles Westaway
Keyword(s):  
Ground State ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Steric Effects ◽  
Halide Ions ◽  
Substitution Reactions ◽  
Kinetic Isotope ◽  
Hydrogen Deuterium ◽  
Primary Substrate ◽  
Triple Ion

Secondary α and β hydrogen–deuterium kinetic isotope effects have been used together to show that the SN reaction between 1-phenylethyldimethylphenylammonium ion and bromide or iodide ion in chloroform occurs by way of an SN2 mechanism within a triple ion in spite of the fact that it reacts faster than the primary substrate, benzyldimethylphenylammonium bromide. The very loose transition state and steric effects in the ground state appear to be responsible for the unusually fast SN2 reactions between 1-phenylethyldimethylphenylammonium ion and halide ions in chloroform.

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

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