Solvent dynamical effects in electron transfer: Predicted consequences of non‐Debye relaxation processes and some comparisons with experimental kinetics

1989 ◽  
Vol 90 (2) ◽  
pp. 912-922 ◽  
Author(s):  
George E. McManis ◽  
Michael J. Weaver
2015 ◽  
Vol 17 (8) ◽  
pp. 5538-5542 ◽  
Author(s):  
James K. Utterback ◽  
Molly B. Wilker ◽  
Katherine A. Brown ◽  
Paul W. King ◽  
Joel D. Eaves ◽  
...  

Kinetic modeling of transient absorption measurements provides rate constants for the excited state relaxation processes relevant for photochemical H2 generation.


Author(s):  
Р.А. Кастро ◽  
Н.И. Анисимова ◽  
А.А. Кононов

AbstractThe results of studying dielectric relaxation processes in the Ge_28.5Pb_15S_56.5 glassy system are presented. The existence of the non-Debye relaxation process caused by the distribution of relaxors over the relaxation time according to the Cole–Cole model is revealed. The energy and structural parameters are calculated: the activation energy E _ p = 0.40 eV and the molecular dipole moment μ = 1.08 D. The detected features are explained within the model according to which the chalcogenide-glass structure is a set of dipoles formed by charged defects such as D ^+ and D ^–.


1976 ◽  
Vol 157 (3) ◽  
pp. 591-598 ◽  
Author(s):  
C Greenwood ◽  
T Brittain

The kinetics of the electron-transfer process which occurs between ferrocytochrome c and partially reduced mammalian cytochrome oxidase were studied by the rapid spectrophotometric techniques of stopped flow and temperature jump. Stopped-flow experiments showed initial very fast extinction changes at 605 nm and at 563 nm, indicating the simultaneous reduction of cytochrome a and oxidation of ferrocytochrome c. During this ‘burst’ phase, say the first 50 ms after mixing, it was invariably found that more cytochrome c had been oxidized than cytochrome a had been reduced. This discrepancy in electron equivalents may be accounted for by the rapid reduction of another redox site in the enzyme, possibly that associated with the extinction changes observed at 830 nm. During the incubation period in which the partially reduced oxidase was prepared, the rate of reduction of cytochrome a by ferrocytochrome c, at constant reactant concentrations, decreased with time. Temperature-jump experiments showed the presence of two relaxation processes. The faster of the two phases was assigned to the electron-transfer reaction between cytochrome c and cytochrome a. A study of the concentration-dependence of the reciprocal relaxation time for this phase yielded a rate constant of 9 X 10(6)M-1-s-1 for the electron transfer from cytochrome c to cytochrome a, and a value of 8.5 X 10(6)M-1-s-1 for the reverse reaction. The equilibrium constant for the electron-transfer reaction is therefore close to unity. The slower phase has been interpreted as signalling the transfer of electrons between cytochrome a and another redox site within the oxidase molecule.


2001 ◽  
Vol 13 (19) ◽  
pp. 4359-4366
Author(s):  
Z C Xia ◽  
C Q Tang ◽  
D X Zhou

Molecules ◽  
2019 ◽  
Vol 24 (14) ◽  
pp. 2605 ◽  
Author(s):  
Yin ◽  
Zhang ◽  
Wang ◽  
Feng ◽  
Zhao ◽  
...  

MnFe2O4 NPs are successfully decorated on the surface of SiO2 sheets to form the SiO2-MnFe2O4 composite via one-pot hydrothermal synthesis method. The phase identification, morphology, crystal structure, distribution of elements, and microwave absorbing properties in S-band (1.55~3.4 GHz) of the as-prepared composite were investigated by XRD, SEM, TEM, and Vector Network Analyzer (VNA) respectively. Compared with the pure MnFe2O4 NPs, the as-prepared SiO2-MnFe2O4 composite exhibits enhanced microwave absorption performance in this frequency band due to the strong eddy current loss, better impedance matching, excellent attenuation characteristic, and multiple Debye relaxation processes. The maximum reflection loss of −14.87 dB at 2.25 GHz with a broader −10 dB bandwidth over the frequency range of 1.67~2.9 GHz (1.23 GHz) can be obtained at the thickness of 4 mm. Most importantly, the preparation method used here is relatively simple, hence such composite can be served as a potential candidate for effective microwave absorption in S-band.


2000 ◽  
Vol 62 (3) ◽  
pp. 3293-3298 ◽  
Author(s):  
Alexander Leyderman ◽  
Shi-Xian Qu

1974 ◽  
Vol 137 (1) ◽  
pp. 113-116 ◽  
Author(s):  
Maurizio Brunori ◽  
Colin Greenwood ◽  
Michael T. Wilson

Temperature-jump studies on the electron-transfer reaction between azurin and cytochrome c-551 clearly reveal two chemical relaxations. The amplitudes of these relaxation processes have identical spectral distributions, but the relaxation times show different dependences on the reactant concentrations. These findings are discussed in terms of possible models.


1993 ◽  
Vol 71 (3-4) ◽  
pp. 741-757 ◽  
Author(s):  
Walter G. Gl�ckle ◽  
Theo F. Nonnenmacher

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