Hydrogen—Deuterium Kinetic Isotope Effect, an Experimental and Theoretical Study over a Wide Range of Temperature

1962 ◽  
Vol 37 (7) ◽  
pp. 1541-1553 ◽  
Author(s):  
Terry E. Sharp ◽  
Harold S. Johnston
Keyword(s):  
Isotope Effect ◽  
Kinetic Isotope Effect ◽  
Theoretical Study ◽  
Kinetic Isotope ◽  
Wide Range ◽  
Hydrogen Deuterium

Primary kinetic isotope effect in the gas phase photochlorination of ethyl chloride-1-d1

1984 ◽  
Vol 62 (5) ◽  
pp. 899-906 ◽  
Author(s):  
Jan Niedzielski ◽  
T. Yano ◽  
E. Tschuikow-Roux
Keyword(s):  
Activation Energy ◽  
Gas Phase ◽  
Isotope Effect ◽  
Ground State ◽  
Rate Constants ◽  
Kinetic Isotope Effect ◽  
Kinetic Isotope ◽  
Primary Reference ◽  
Hydrogen Deuterium ◽  
Increasing Temperature

The abstraction of hydrogen/deuterium from CH3CHDCl by ground state chlorine atoms produced photolytically from Cl2 has been investigated at temperatures betwen 280 and 368 K. The relative rates for the internal competition[Formula: see text]are found to conform to an Arrhenius rate law:[Formula: see text]These data, taken together with the external competition results for the C2H5Cl/CH3CHDCl system, in conjunction with the competitive results using CH4 as a primary reference, have yielded the rate constants (cm3 s−1):[Formula: see text]The relatively weak primary kinetic isotope effect, kH/kD, decreases with increasing temperature from 1,855 at 280 K to 1.66 at 365 K. The results are compared with those obtained based on the BEBO method. While both the trend and the magnitude of the kinetic isotope effect are satisfactorily predicted, the activation energy is not.

scholarly journals An experimental and theoretical study on the kinetic isotope effect of C2H6 and C2D6 reaction with OH

2015 ◽  
Vol 641 ◽  
pp. 158-162 ◽  
Author(s):  
Fethi Khaled ◽  
Binod Raj Giri ◽  
Milán Szőri ◽  
Béla Viskolcz ◽  
Aamir Farooq
Keyword(s):  
Isotope Effect ◽  
Kinetic Isotope Effect ◽  
Theoretical Study ◽  
Kinetic Isotope

scholarly journals Path Integral Calculation of the Hydrogen/Deuterium Kinetic Isotope Effect in Monoamine Oxidase A-Catalyzed Decomposition of Benzylamine

Molecules ◽  
2019 ◽  
Vol 24 (23) ◽  
pp. 4359 ◽  
Author(s):  
Mateusz Z. Brela ◽  
Alja Prah ◽  
Marek Boczar ◽  
Jernej Stare ◽  
Janez Mavri
Keyword(s):  
Monoamine Oxidase ◽  
Isotope Effect ◽  
Path Integral ◽  
Kinetic Isotope Effect ◽  
Monoamine Oxidase A ◽  
Kinetic Isotope ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Hydrogen Deuterium ◽  
Rate Limiting

Monoamine oxidase A (MAO A) is a well-known enzyme responsible for the oxidative deamination of several important monoaminergic neurotransmitters. The rate-limiting step of amine decomposition is hydride anion transfer from the substrate α–CH2 group to the N5 atom of the flavin cofactor moiety. In this work, we focus on MAO A-catalyzed benzylamine decomposition in order to elucidate nuclear quantum effects through the calculation of the hydrogen/deuterium (H/D) kinetic isotope effect. The rate-limiting step of the reaction was simulated using a multiscale approach at the empirical valence bond (EVB) level. We applied path integral quantization using the quantum classical path method (QCP) for the substrate benzylamine as well as the MAO cofactor flavin adenine dinucleotide. The calculated H/D kinetic isotope effect of 6.5 ± 1.4 is in reasonable agreement with the available experimental values.

Solvent effects on the structure of SN2 transition states

1978 ◽  
Vol 56 (20) ◽  
pp. 2691-2699 ◽  
Author(s):  
Kenneth Charles Westaway
Keyword(s):  
Transition State ◽  
Isotope Effect ◽  
Solvent Effects ◽  
Kinetic Isotope Effect ◽  
Transition States ◽  
State Structure ◽  
Transition State Structure ◽  
Kinetic Isotope ◽  
Wide Range ◽  
Leaving Group

Two research groups have used heavy atom leaving group kinetic isotope effects to determine how the structure of an SN2 transition state is affected by a change in solvent. Two completely different types of behaviour were observed in these studies. In one case, the leaving group kinetic isotope effect, and thus the transition state structure, changed markedly when the solvent was varied over a reasonably narrow range. In the other study, the leaving group kinetic isotope effect (transition state structure) remained constant over a wide range of solvents. A model describing the interaction between solvent molecules and SN2 transition states is developed and a SolvationruleforSN2reactions which rationalizes the different experimental results is explained and justified. Finally, predictions based on the solvation rule are shown to be in agreement with the results of theoretical calculations of solvent effects on SN2 transition states and secondary α deuterium kinetic isotope effect measurements.

Reversed Kinetic Isotope Effect during Penetration of Cathodic Hydrogen/Deuterium into NiCu30 Alloy

1977 ◽  
Vol 32 (3-4) ◽  
pp. 343-344 ◽  
Author(s):  
H. J. Bauer ◽  
J. Grosselfinger ◽  
M. Zwick
Keyword(s):  
Isotope Effect ◽  
Kinetic Isotope Effect ◽  
Magnetic Measurements ◽  
Kinetic Isotope ◽  
Hydrogen Deuterium ◽  
Cathodic Charging

Abstract The cathodic charging with H/D of a NiCu alloy containing 30 At.-% Cu followed by magnetic measurements indicates that D penetrates faster into the alloy than H.

The mechanism of the thermal decarbonylation of 2,2-dimethyl-3-butenal

1977 ◽  
Vol 55 (22) ◽  
pp. 3951-3954 ◽  
Author(s):  
Robert J. Crawford ◽  
Stuart Lutener ◽  
Hirokazu Tokunaga
Keyword(s):  
Carbon Monoxide ◽  
Isotope Effect ◽  
Kinetic Isotope Effect ◽  
First Order ◽  
First Order Kinetics ◽  
Kinetic Isotope ◽  
Hydrogen Deuterium ◽  
Thermal Decarbonylation

The thermal decarbonylation of 2,2-dimethyl-3-butenal is shown to be an intramolecular extrusion of carbon monoxide concerted with the transfer of hydrogen (deuterium) to the γ-position. The reaction displays a kinetic isotope effect of 2.8 (at 296.9 °C) and follows first order kinetics (Ea = 44.2 ± 0.2 kcal mol−1, log A = 13.4 ± 0.3).

Sign in / Sign up

Export Citation Format

Share Document