Laser catalysis and transition state spectra of the H+H2 exchange reaction

1988 ◽  
Vol 88 (9) ◽  
pp. 5525-5535 ◽  
Author(s):  
Tamar Seideman ◽  
Moshe Shapiro
Keyword(s):  
Transition State ◽  
Exchange Reaction

Allowed and Forbidden Reaction Paths for the H2 + D2 Exchange Reaction

1975 ◽  
Vol 53 (4) ◽  
pp. 549-555 ◽  
Author(s):  
James S. Wright
Keyword(s):  
Transition Metal ◽  
Transition State ◽  
Exchange Reaction ◽  
Barrier Height ◽  
Dissociation Energy ◽  
Basis Set ◽  
Reaction Paths ◽  
Double Zeta ◽  
Double Zeta Basis

Symmetry arguments and abinitio s.c.f. calculations (double-zeta basis set) are used to show that the exchange reaction H2+ D2 → 2HD could proceed in a concerted fashion through a six-center transition state. The computed barrier height of 90 kcal/mol for this process lies below the experimental dissociation energy of H2 (but above the computed dissociation energy) and also below the energy required for exchange through a four-center transition state. Either the termolecular(2 + 2 + 2 ) or bimolecular(4 + 2 ) cycloadditions are thermally allowed. The presence of a transition metal would allow the reaction to proceed through a four-center geometry, leading to the formation of a possibly stable metal-H4 complex.

Unequal primary kinetic isotope effects in the base-catalysed H–D exchange of diastereotopic protons

1980 ◽  
Vol 58 (1) ◽  
pp. 72-78 ◽  
Author(s):  
Robert R. Fraser ◽  
Philippe J. Champagne
Keyword(s):  
Transition State ◽  
Exchange Reaction ◽  
Isotope Effect ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Deuterium Isotope Effect ◽  
Kinetic Isotope

Primary kinetic isotope effects have been measured for the base-catalyzed exchange reaction of 4′,1″-dimethyl-1,2,3,4-dibenzcyclohepta-1,3-diene-6-one, 1. It was found that the isotope effects kH/kT and kD/kT for the faster exchanging protons (13.6 and 3.8 respectively) are significantly larger than the corresponding values for the slower exchanging protons (4.6 and 1.6 respectively). These differences could result from truly unequal isotope effects due to transition state differences or intrusion of a second pathway for exchange of the less reactive proton in the dedeuteration reaction. The data appear to support the latter interpretation. The secondary deuterium isotope effect was found to be 1.18.

scholarly journals Isotope exchange reaction in tritium-contaminated vacuum pump oil: mechanism and HTO effect

RSC Advances ◽  
2017 ◽  
Vol 7 (2) ◽  
pp. 890-896 ◽  
Author(s):  
Liang Dong ◽  
Na Yang ◽  
Yong Yang ◽  
Weiyi Li ◽  
Yi Quan ◽  
...  
Keyword(s):  
Transition State ◽  
Exchange Reaction ◽  
Isotope Exchange ◽  
Vacuum Pump ◽  
Isotope Exchange Reaction

HTO is not only a reactant, but also acts as the proton shuttle in the transition state.

Transition state dynamics of the OH+H2O hydrogen exchange reaction studied by dissociative photodetachment of H3O2-

2000 ◽  
Vol 115 ◽  
pp. 147-160 ◽  
Author(s):  
Hans-Jürgen Deyerl ◽  
A. Khai Luong ◽  
Todd G. Clements ◽  
Robert E. Continetti
Keyword(s):  
Transition State ◽  
Exchange Reaction ◽  
Hydrogen Exchange ◽  
Dissociative Photodetachment
Sign in / Sign up

Export Citation Format

Share Document