Isotope effects in solution: contrasts between muonium and hydrogen in reactions with acetone

1990 ◽  
Vol 68 (10) ◽  
pp. 1719-1724 ◽  
Author(s):  
David C. Walker
Keyword(s):  
Free Radicals ◽  
Physical Properties ◽  
Rate Constants ◽  
Nuclear Physics ◽  
Reaction Rate ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Reaction Rate Constants ◽  
Thiyl Radicals ◽  
Kinetic Isotope

Munonium atoms are hydrogen isotopes with positive muons rather than protons, deuterons, or tritons as nuclei. Thus, they have one ninth the mass of 1H, and microsecond lifetimes. By using nuclear physics counting techniques, muonium can be studied in a wide variety of media and its chemical and physical properties used to appraise hydrogen. Results are described for the interaction of muonium with acetone, showing two types of kinetic isotope effects, formation of free radicals, evidence for intermolecular "muonium bonding", and micelle-induced enhancements of reaction rate constants. Keywords: isotope effects, muonium atoms, muonium bonding, thiyl radicals, micelles.

Direct dynamics calculations of reaction rate and kinetic isotope effects in enzyme catalysed reactions

2002 ◽  
Vol 122 ◽  
pp. 223-242 ◽  
Author(s):  
Gary Tresadern ◽  
Sara Nunez ◽  
Paul F. Faulder ◽  
Hong Wang ◽  
Ian H. Hillier ◽  
...  
Keyword(s):  
Reaction Rate ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Direct Dynamics ◽  
Kinetic Isotope

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

Ab initio predictions and experimental confirmation of large tunneling contributions to rate constants and kinetic isotope effects for hydrogen atom transfer reactions

1986 ◽  
Vol 108 (12) ◽  
pp. 3515-3516 ◽  
Author(s):  
Bruce C. Garrett ◽  
Donald G. Truhlar ◽  
Joel M. Bowman ◽  
Albert F. Wagner ◽  
Daniel. Robie ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Ab Initio ◽  
Rate Constants ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Hydrogen Atom Transfer ◽  
Experimental Confirmation ◽  
Transfer Reactions ◽  
Atom Transfer ◽  
Kinetic Isotope

Variational transition state theory rate constants and H/D kinetic isotope effects for CH 3 + CH 3 OCOH reactions

2019 ◽  
Vol 41 (3) ◽  
pp. 231-239 ◽  
Author(s):  
Edson F. V. Carvalho ◽  
Guilherme D. Vicentini ◽  
Tiago Vinicius Alves ◽  
Orlando Roberto‐Neto
Keyword(s):  
Transition State ◽  
Rate Constants ◽  
Transition State Theory ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
State Theory ◽  
Variational Transition State Theory ◽  
Kinetic Isotope ◽  
Variational Transition State

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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