Solvent and substituent effects on the electron-transfer rate constants of tetraphenylporphyrins and their iron complexes

1978 ◽  
Vol 17 (2) ◽  
pp. 228-231 ◽  
Author(s):  
Sebrina Ni ◽  
L. Dickens ◽  
J. Tappan ◽  
L. Constant ◽  
D. G. Davis
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Transfer Rate ◽  
Substituent Effects ◽  
Iron Complexes ◽  
Electron Transfer Rate

A Comparison between Interfacial Electron-Transfer Rate Constants at Metallic and Graphite Electrodes

2006 ◽  
Vol 110 (39) ◽  
pp. 19433-19442 ◽  
Author(s):  
William J. Royea ◽  
Thomas W. Hamann ◽  
Bruce S. Brunschwig ◽  
Nathan S. Lewis
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Transfer Rate ◽  
Interfacial Electron Transfer ◽  
Electron Transfer Rate ◽  
Graphite Electrodes

scholarly journals The effects of the chemical environment of menaquinones in lipid monolayers on mercury electrodes on the thermodynamics and kinetics of their electrochemistry

2021 ◽  
Author(s):  
Karuppasamy Dharmaraj ◽  
Dirk Dattler ◽  
Heike Kahlert ◽  
Uwe Lendeckel ◽  
Felix Nagel ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Transfer Rate ◽  
Chemical Environment ◽  
Lipid Monolayers ◽  
Redox Potentials ◽  
Electron Transfer Rate ◽  
Thermodynamics And Kinetics ◽  
Mercury Electrodes ◽  
Kinetics Of

AbstractThe effects of the chemical environment of menaquinones (all-trans MK-4 and all-trans MK-7) incorporated in lipid monolayers on mercury electrodes have been studied with respect to the thermodynamics and kinetics of their electrochemistry. The chemical environment relates to the composition of lipid films as well as the adjacent aqueous phase. It could be shown that the addition of all-trans MK-4 to TMCL does not change the phase transition temperatures of TMCL. In case of DMPC monolayers, the presence of cholesterol has no effect on the thermodynamics (formal redox potentials) of all-trans MK-7, but the kinetics are affected. Addition of an inert electrolyte (sodium perchlorate; change of ionic strength) to the aqueous phase shifts the redox potentials of all-trans MK-7 only slightly. The formal redox potentials of all-trans MK-4 were determined in TMCL and nCL monolayers and found to be higher in nCL monolayers than in TMCL monolayers. The apparent electron transfer rate constants, transfer coefficients and activation energies of all-trans MK-4 in cardiolipins have been also determined. Most surprisingly, the apparent electron transfer rate constants of all-trans MK-4 exhibit an opposite pH dependence for TMCL and nCL films: the rate constants increase in TMCL films with increasing pH, but in nCL films they increase with decreasing pH. This study is a contribution to understand environmental effects on the redox properties of membrane bond redox systems. Graphical abstract

Calculation of Electron Transfer Rate Constants from Spectra in Re(I) Chromophore−Quencher Complexes

1996 ◽  
Vol 118 (40) ◽  
pp. 9782-9783 ◽  
Author(s):  
Juan Pablo Claude ◽  
Darryl S. Williams ◽  
Thomas J. Meyer
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Transfer Rate ◽  
Electron Transfer Rate

Efficient photoinduced electron transfer between C60/C70 and zinc octaethylporphyrin studied by nanosecond laser photolysis method

2000 ◽  
Vol 04 (06) ◽  
pp. 591-598 ◽  
Author(s):  
MOHAMED E. EL-KHOULY ◽  
MAMORU FUJITSUKA ◽  
OSAMU ITO
Keyword(s):  
Electron Transfer ◽  
Rate Constants ◽  
Photoinduced Electron Transfer ◽  
Transfer Rate ◽  
Transient Absorption ◽  
Laser Light ◽  
Solvent Polarity ◽  
Nanosecond Laser ◽  
Electron Transfer Rate ◽  
Absorption Bands

Photoinduced electron-transfer processes between C 60 or C 70 and zinc octaethylporphyrin ( ZnOEP ) have been studied in polar solvents with the nanosecond laser flash photolysis method, observing the transient absorption spectra in the visible and near-IR regions. By the predominant excitation of ZnOEP with 532 nm laser light the transient absorption bands of 3 ZnOEP * decayed, accompanied by the appearance of the transient absorption bands of [Formula: see text] and [Formula: see text]. By the predominant excitation of C 60 and C 70 with 610 nm laser light the decays of [Formula: see text] and [Formula: see text] were observed, accompanied by the appearance of [Formula: see text] and [Formula: see text]. The electron transfer rate constants (k et ) and the quantum yields (Φ et ) of [Formula: see text] and [Formula: see text] formation via 3 ZnOEP * and [Formula: see text] or [Formula: see text] have been evaluated. These values increase with the solvent polarity; in polar benzonitrile these values are higher than for other porphyrins such as zinc tetraphenylporphyrin. The back electron transfer rate constants were evaluated from the decays of [Formula: see text] and [Formula: see text], which also show a solvent polarity dependence.

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