Rate constants and kinetic isotope effects in hydrogen abstractions by H from formic acid

2001 ◽  
Vol 27 (4-5) ◽  
pp. 475-483 ◽  
Author(s):  
A M Lossack ◽  
D M Bartels ◽  
E Roduner
Keyword(s):  
Formic Acid ◽  
Rate Constants ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope

α-DEUTERIUM KINETIC ISOTOPE EFFECTS IN SOLVOLYSES OF endo-NORBORNYL p-BROMOBENZENESULFONATE

1965 ◽  
Vol 43 (8) ◽  
pp. 2254-2258 ◽  
Author(s):  
C. C. Lee ◽  
Edward W. C. Wong
Keyword(s):  
Acetic Acid ◽  
Formic Acid ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Aqueous Dioxane ◽  
Kinetic Isotope ◽  
Different Temperatures

endo-Norbornyl-2-d p-bromobenzenesulfonate was synthesized and the isotope effects, as measured by kH/kD, were determined over a range of temperatures for solvolyses in 30% water – 70% dioxane, acetic acid, and formic acid. Values of kH/kD are of the order of 1.20. The data appear to indicate slightly higher isotope effects as the solvents are changed from aqueous dioxane to acetic acid to formic acid, as well as somewhat higher isotope effects at lower temperatures. Possible mechanistic implications of these results are presented. Relative titrimetric acetolysis rates, kexo/kendo, at different temperatures, and enthalpies and entropies of activation for these acetolyses are evaluated and discussed.

A Theoretical Analysis of Rate Constants and Kinetic Isotope Effects Corresponding to Different Reactant Valleys in Lactate Dehydrogenase

2006 ◽  
Vol 128 (51) ◽  
pp. 16851-16863 ◽  
Author(s):  
Silvia Ferrer ◽  
Iñaki Tuñón ◽  
Sergio Martí ◽  
Vicente Moliner ◽  
Mireia Garcia-Viloca ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Theoretical Analysis ◽  
Rate Constants ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope

Rate constants and kinetic isotope effects for Cl+CH4→ClH+CH3: a comparison between LSC-IVR and statistical theories

2002 ◽  
Vol 360 (1-2) ◽  
pp. 59-64 ◽  
Author(s):  
Emilio Martı́nez-Núñez ◽  
Antonio Fernández-Ramos ◽  
Saulo A Vázquez ◽  
Miguel A Rı́os
Keyword(s):  
Rate Constants ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope

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

Kinetic hydrogen isotope effects in the ionization of some carbon acids

1970 ◽  
Vol 318 (1535) ◽  
pp. 421-440 ◽  
Keyword(s):  
Aqueous Solutions ◽  
Rate Constants ◽  
Hydrogen Isotope ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Kinetic Isotope ◽  
Pyridine Bases ◽  
Carbon Acids ◽  
Ethyl Nitroacetate ◽  
Basic Strength

Rate constants in aqueous solutions are reported for proton and deuteron abstraction by a variety of bases from tricarbomethoxymethane, the propan-2-one-1-sulphonate ion, 2-acetylcyclohexanone and ethyl nitroacetate. The rates of ionization were measured by using bromine or iodine as scavengers to remove the anions, and, for ethyl nitroacetate by direct observation of the rate of appearance of the anion. The kinetic isotope effects vary from k H / k D = 2.5 to k H / k D = 10.3, and confirm the regularities previously found (Bell & Crooks 1965; Bell & Goodall 1966). In particular, the results for the reaction of ethyl nitro-acetate with nine bases show clearly that with increasing basic strength the isotope effect passes through a well-marked maximum. Sterically hindered pyridine bases give rise to abnormally high isotope effects, probably attributable to increased tunnel corrections.

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