scholarly journals Quantum Suppression of Intramolecular Deuterium Kinetic Isotope Effects in a Pericyclic Hydrogen Transfer Reaction

2019 ◽  
Vol 123 (17) ◽  
pp. 3647-3654
Author(s):  
Xiao Li ◽  
Darrin M. York ◽  
Matthew P. Meyer
Keyword(s):  
Hydrogen Transfer ◽  
Transfer Reaction ◽  
Isotope Effects ◽  
Kinetic Isotope Effects ◽  
Hydrogen Transfer Reaction ◽  
Kinetic Isotope

Kinetic study of the proton transfer reaction between 1-nitro-1-(4-nitrophenyl)alkanes and TBD and MTBD bases in acetonitrile solvent

2001 ◽  
Vol 79 (7) ◽  
pp. 1128-1134 ◽  
Author(s):  
Iwona Grzeskowiak ◽  
Wtodzimierz Galezowski ◽  
Arnold Jarczewski
Keyword(s):  
Proton Transfer ◽  
Kinetic Study ◽  
Transfer Reaction ◽  
Isotope Effects ◽  
Ion Pairs ◽  
Kinetic Isotope Effects ◽  
Proton Transfer Reaction ◽  
Comparable Amount ◽  
Kinetic Isotope ◽  
Proton Transfer Reactions

The rates of proton transfer reactions between C-acids of the series of nitroalkanes with increasing bulk of R = H, Me, Et, i-Pr substituent as: 4-nitrophenylnitromethane (0), 1-(4-nitrophenyl)-1-nitroethane (1), 1-(4-nitrophenyl)-1-nitropropane (2), 2-methyl-1-(4-nitrophenyl)-1-nitropropane (3) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (MTBD) have been measured in acetonitrile at pseudo-first-order conditions. The product of the proton transfer reaction with MTBD in acetonitrile is dissociated into free ions while that of the TBD reaction is composed of a comparable amount of ions and ion pairs. The second-order rate constants (k2H) for these bases of almost equal strength in acetonitrile (pKa = 24.70, 24.97 for MTBD and TBD) and C-acids 1, 2, and 3 are: 317, 86, 7.6 dm3 mol–1 s–1; and 15 200, 5300, 1100 dm3 mol–1 s–1, respectively. The appropriate primary deuterium kinetic isotope effects (kH/kD) are 12.5, 10.8, 6.9; and 9.9, 11.2, 12.6. The influence of steric hindrance brought by reacting C-acids and bases is discussed. The different structure of the transition states and the products as mono- and double-hydrogen bonded complexes for these series of C-acids and MTBD and TBD bases is manifested by a distinct reaction mechanism which we attempt to explain.Key words: proton transfer, kinetic study, C-acids, organic bases, acetonitrile, kinetic isotope effects.

scholarly journals Computational Replication of the Abnormal Secondary Kinetic Isotope Effects in a Hydride Transfer Reaction in Solution with a Motion Assisted H-Tunneling Model

2014 ◽  
Vol 79 (5) ◽  
pp. 1989-1994 ◽  
Author(s):  
Sadra Kashefolgheta ◽  
Mortezaali Razzaghi ◽  
Blake Hammann ◽  
James Eilers ◽  
Daniel Roston ◽  
...  
Keyword(s):  
Transfer Reaction ◽  
Isotope Effects ◽  
Hydride Transfer ◽  
Kinetic Isotope Effects ◽  
Tunneling Model ◽  
Kinetic Isotope ◽  
Hydride Transfer Reaction ◽  
Reaction In Solution
Sign in / Sign up

Export Citation Format

Share Document