Results 251 to 260 of about 107,082 (295)

Isotope Effects in Chemical Kinetics

Annual Review of Physical Chemistry, 1975
Recent studies on hydrogen isotope transfer reactions in the gas phase chemistry of thermal and excited species, ionic systems, and reactive scattering and theoretical attempts made to rationalize experimental observations are critically reviewed. Topics discussed are bimolecular reactions, termolecular reactions, unimolecular decomposition reactions ...
openaire   +1 more source

Relative 14C–13C Kinetic Isotope Effects

The Journal of Chemical Physics, 1971
Model-reaction calculations are used to show that relative 14C–13C kinetic isotope effects, defined as r=ln(k12/k14)/ln(k12/k13), should, within the framework of the presently accepted statistical-thermodynamic theory of such effects in the harmonic approximation, generally be restricted to the range 1.8≤r≤2.0.
Marvin J. Stern, P. Christian Vogel
openaire   +1 more source

Equilibrium and kinetic isotope effects

Berichte der Bunsengesellschaft für physikalische Chemie, 1972
AbstractThe equilibrium distribution effects of deuterium and of tritium between liquid water, hydrogen gas and palladium hydride differ from one another in a characteristic manner. They are discussed in terms of zero point energies.Direct measurements of the deuterium distribution between liquid water and palladium hydride yielded an uncommonly high ...
openaire   +1 more source

Glutathione reductase: solvent equilibrium and kinetic isotope effects

Biochemistry, 1988
Glutathione reductase catalyzes the NADPH-dependent reduction of oxidized glutathione (GSSG). The kinetic mechanism is ping-pong, and we have investigated the rate-limiting nature of proton-transfer steps in the reactions catalyzed by the spinach, yeast, and human erythrocyte glutathione reductases using a combination of alternate substrate and solvent
K K, Wong, M A, Vanoni, J S, Blanchard
openaire   +2 more sources

Chlorine Kinetic Isotope Effects on Enzymatic Dehalogenations

Accounts of Chemical Research, 2002
Enzymatic dehalogenation reactions are important for the bioremediation of the environment because of the increasing anthropogenic pollution with halogen-containing organic compounds. Chlorine kinetic isotope effects have been measured for four hydrolytic dehalogenases.
openaire   +2 more sources

Kinetic Isotope Effects on Chemical Reactions

2009
This chapter describes a number of examples of kinetic isotope effects on chemical reactions of different types (simple gas phase reactions, SN2 and E reactions in solution and in the gas phase, α and β secondary isotope effects, etc.). These examples are used to illustrate many aspects of the measurement, interpretation, and theoretical calculation of
Max Wolfsberg, W. Alexander Van Hook, Piotr Paneth   +2 more
openaire   +1 more source

Kinetic isotope effects calculated with the instanton method

Journal of Computational Chemistry, 2011
AbstractThe ring‐opening reaction of the cyclopropylcarbinyl radical proceeds via heavy‐atom tunneling at low temperature. We used instanton theory to calculate tunneling rates and kinetic isotope effects with on‐the‐fly calculation of energies by density functional theory (B3LYP).
Jan, Meisner, Judith B, Rommel, Johannes, Kästner   +2 more
openaire   +2 more sources

Studies elucidate solvent kinetic isotope effects

Chemical & Engineering News Archive, 1994
Results from recent theoretical and experimental studies on reactions of solvated gas-phase clusters could help researchers discriminate between two alternative models of the effects of different solvents on reaction kinetics. The studies, described at the American Chemical Society meeting in San Diego, focus on solvent kinetic isotope effects ...
openaire   +1 more source

Kinetic Deuterium Isotope Effects in Glucocorticoid Receptor Activation

Journal of Receptor Research, 1984
Activation and deactivation of the chick thymus glucocorticoid receptor protein was studied in ordinary and heavy water by DNA-cellulose binding of the tritiated triamcinolone acetonide-receptor complex. Activation was significantly slower in heavy water if it was promoted by incubation at elevated temperature in buffers of low ionic strength.
openaire   +2 more sources

Fluorine kinetic isotope effects

Journal of the American Chemical Society, 1993
Olle Matsson, Jonas Persson, B. Svante Axelsson, Bengt Laangstroem   +3 more
openaire   +1 more source