ChemInform Abstract: ELECTRON TRANSFER REACTIONS OF HALOGENATED ALIPHATIC PEROXYL RADICALS: MEASUREMENT OF ABSOLUTE RATE CONSTANTS BY PULSE RADIOLYSIS

1980 ◽  
Vol 11 (19) ◽  
Author(s):  
J. E. PACKER ◽  
R. L. WILLSON ◽  
D. BAHNEMANN ◽  
K.-D. ASMUS
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Pulse Radiolysis ◽  
Peroxyl Radicals ◽  
Transfer Reactions ◽  
Absolute Rate ◽  
Electron Transfer Reactions

scholarly journals Thiyl free radicals and the oxidation of ferrocytochrome c Direct observation of coupled hydrogen-atom- and electron-transfer reactions

1986 ◽  
Vol 240 (3) ◽  
pp. 905-907 ◽  
Author(s):  
L G Forni ◽  
R L Willson
Keyword(s):  
Electron Transfer ◽  
Free Radicals ◽  
Hydrogen Atom ◽  
Pulse Radiolysis ◽  
Transfer Reactions ◽  
Absolute Rate ◽  
Electron Transfer Process ◽  
Electron Transfer Reactions ◽  
Thiyl Radicals ◽  
Ferrocytochrome C

Absolute rate constants for the reaction of ferrocytochrome c with the thiyl radicals derived from cysteine, GSH, penicillamine and N-(2-mercaptopropionyl)glycine were measured by using the technique of pulse radiolysis. The reaction is believed to occur through a one-electron-transfer process, in agreement with the hypothesis that thiols may act as catalysts linking hydrogen-atom- and electron-transfer reactions.

scholarly journals Thiyl and phenoxyl free radicals and NADH Direct observation of one-electron oxidation

1986 ◽  
Vol 240 (3) ◽  
pp. 897-903 ◽  
Author(s):  
L G Forni ◽  
R L Willson
Keyword(s):  
Electron Transfer ◽  
Free Radicals ◽  
Hydrogen Atom ◽  
Pulse Radiolysis ◽  
Biological Significance ◽  
Transfer Reactions ◽  
Absolute Rate ◽  
Transfer Processes ◽  
Biochemical Systems ◽  
Electron Transfer Processes

Absolute rate constants for the reaction of NADH with thiyl free radicals derived from various sulphur-containing compounds of biological significance were measured by using the technique of pulse radiolysis. These and related reactions with phenoxyl free radicals are believed to occur through one-electron-transfer processes. Further evidence comes from studies with deuterated NADH. The results support the possibility that, in biochemical systems, thiols may act as catalysts linking hydrogen-atom and electron-transfer reactions.

scholarly journals Concerted proton-electron transfer reactions in the Marcus inverted region

Science ◽  
2019 ◽  
Vol 364 (6439) ◽  
pp. 471-475 ◽  
Author(s):  
Giovanny A. Parada ◽  
Zachary K. Goldsmith ◽  
Scott Kolmar ◽  
Belinda Pettersson Rimgard ◽  
Brandon Q. Mercado ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Charge Recombination ◽  
Transfer Reactions ◽  
Inverted Region ◽  
Electron Transfer Reactions ◽  
Proton Coupled Electron Transfer ◽  
Marcus Inverted Region ◽  
A Charge ◽  
Theory Yield

Electron transfer reactions slow down when they become very thermodynamically favorable, a counterintuitive interplay of kinetics and thermodynamics termed the inverted region in Marcus theory. Here we report inverted region behavior for proton-coupled electron transfer (PCET). Photochemical studies of anthracene-phenol-pyridine triads give rate constants for PCET charge recombination that are slower for the more thermodynamically favorable reactions. Photoexcitation forms an anthracene excited state that undergoes PCET to create a charge-separated state. The rate constants for return charge recombination show an inverted dependence on the driving force upon changing pyridine substituents and the solvent. Calculations using vibronically nonadiabatic PCET theory yield rate constants for simultaneous tunneling of the electron and proton that account for the results.

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