scholarly journals Extremely Elevated Room-Temperature Kinetic Isotope Effects Quantify the Critical Role of Barrier Width in Enzymatic C–H Activation

2014 ◽  
Vol 136 (23) ◽  
pp. 8157-8160 ◽  
Author(s):  
Shenshen Hu ◽  
Sudhir C. Sharma ◽  
Alexander D. Scouras ◽  
Alexander V. Soudackov ◽  
Cody A. Marcus Carr ◽  
...  
Keyword(s):  
Room Temperature ◽  
Isotope Effects ◽  
Critical Role ◽  
Kinetic Isotope Effects ◽  
Barrier Width ◽  
Kinetic Isotope

Secondary Kinetic Isotope Effects in Bimolecular Nucleophilic Substitutions. V. The Role of the Solvent in the Reaction Between Methyl Iodide and Pyridine

1972 ◽  
Vol 50 (7) ◽  
pp. 982-985 ◽  
Author(s):  
K. T. Leffek ◽  
A. F. Matheson
Keyword(s):  
Transition State ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
State Structure ◽  
Transition State Structure ◽  
Initial State ◽  
Nucleophilic Substitutions ◽  
Kinetic Isotope ◽  
Deuterium Isotope Effects

Secondary kinetic deuterium isotope effects are presented for the reaction of methyl-d3 iodide and pyridine in four different solvents. Calculations on mass and moment of inertia change with deuteration in the initial state and an assumed tetrahedral transition state, together with internal rotational effects, are used to rationalize the inverse isotope effects. It is concluded from the variation of the isotopic rate ratio, that the transition state structure varies with solvent.

scholarly journals Kinetic Isotope Effects for Alkaline Phosphatase Reactions:  Implications for the Role of Active-Site Metal Ions in Catalysis

2007 ◽  
Vol 129 (31) ◽  
pp. 9789-9798 ◽  
Author(s):  
Jesse G. Zalatan ◽  
Irina Catrina ◽  
Rebecca Mitchell ◽  
Piotr K. Grzyska ◽  
Patrick J. O'Brien ◽  
...  
Keyword(s):  
Alkaline Phosphatase ◽  
Metal Ions ◽  
Active Site ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope

Use of Kinetic Isotope Effects to Delineate the Role of Phenylalanine 87 in P450BM-3

2002 ◽  
Vol 30 (2) ◽  
pp. 107-118 ◽  
Author(s):  
Dan A Rock ◽  
Anthony E Boitano ◽  
Jan L Wahlstrom ◽  
Denise A Rock ◽  
Jeffrey P Jones
Keyword(s):  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope

Role of Solvent on Nonenzymatic Peptide Bond Formation Mechanisms and Kinetic Isotope Effects

2013 ◽  
Vol 135 (23) ◽  
pp. 8708-8719 ◽  
Author(s):  
Katarzyna Świderek ◽  
Iñaki Tuñón ◽  
Sergio Martí ◽  
Vicent Moliner ◽  
Juan Bertrán
Keyword(s):  
Isotope Effects ◽  
Bond Formation ◽  
Peptide Bond ◽  
Kinetic Isotope Effects ◽  
Formation Mechanisms ◽  
Peptide Bond Formation ◽  
Kinetic Isotope ◽  
Role Of Solvent

Secondary Kinetic Isotope Effects in Bimolecular Nucleophilic Substitutions. IV. The Temperature Dependence of the Deuterium Effect for the Reaction of N,N-Dimethyl-d6-aniline and Methyl p-toluenesulfonate. Correlation of Isotope Effects on Activation Parameters

1971 ◽  
Vol 49 (3) ◽  
pp. 439-446 ◽  
Author(s):  
K. T. Leffek ◽  
A. F. Matheson
Keyword(s):  
Temperature Dependence ◽  
Isotope Effect ◽  
Isotope Effects ◽  
Activation Parameters ◽  
Kinetic Isotope Effects ◽  
Nucleophilic Substitutions ◽  
Kinetic Isotope ◽  
Similar Correlation ◽  
Straight Lines

The temperature dependence of the isotope effect for the reaction of dimethylaniline and dimethyl-d6-aniline with methyl p-toluenesulfonate in nitrobenzene solvent has been measured, yielding the result, (ΔHD* − ΔHH*) = −134 ± 30 cal mole−1, (ΔSD* − ΔSH*) = −0.15 ± 0.09 cal mol–1 degree−1.This result has been compared with 15 other temperature dependence studies by plotting ΔΔH* per D atom vs. TΔΔS* per D atom. The points fall on two clearly separated straight lines. A similar correlation is found for a plot of ΔΔG* per D atom vs. ΔΔH* per D atom.The significance of the correlation is discussed and a possible rationalization, in terms of mechanism and particularly the role of the solvent is given.

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