POLAROGRAPHY OF URANIUM: III. URANIUM(VI) IN FLUORIDE MEDIA

1957 ◽  
Vol 35 (10) ◽  
pp. 1225-1236 ◽  
Author(s):  
David J. McEwen ◽  
Thomas De Vries
Keyword(s):  
Electron Transfer ◽  
Transfer Coefficient ◽  
Rate Constant ◽  
Transfer Process ◽  
Rate Constants ◽  
Electrode Reaction ◽  
Electron Transfer Process ◽  
Fold Excess

The uranium(VI) and (V) polarographic waves were studied in chloride and perchlorate supporting electrolytes of 0.1 M to almost neutral acidities and containing 0 to 100 fold excess of fluoride. The concentrations of the uranium(VI)–fluoride species (UO2Fn+2−n, n = 1 − 4) were calculated and it is shown that the first two species, UO2F+ and UO2F2, are either reduced reversibly at the D.M.E., or dissociate rapidly to the uncomplexed ion, UO2++, which is known to reduce reversibly. The UO2F4− species, and possibly also UO2F3− is reduced irreversibly, and the rate constant of the electron transfer process, kf°, and the transfer coefficient, α, were calculated by two methods. The electrode reaction is proposed as UO2Fn+2−n+e− = UO2++nF−. The rate of disproportionation of uranium(V) was found to depend upon the F/U ratio, and the rate constants for the reaction were calculated.

Chemistry of radical ions: the absolute rate constant of dimerization of radical anions of 1 ,1-diphenyl ethylene

1965 ◽  
Vol 288 (1413) ◽  
pp. 212-223 ◽  
Keyword(s):  
Electron Transfer ◽  
Rate Constant ◽  
Transfer Process ◽  
Aromatic Hydrocarbons ◽  
Radical Anions ◽  
Electron Affinities ◽  
Absolute Rate ◽  
Radical Ions ◽  
Electron Transfer Process ◽  
Absolute Rate Constant

The combination of the labile radical ions, (Ph 2 C:CH 2 )7~, Na+, into dimeric dianions Na + , C - (Ph) 2 .CH 2 .CH 2 .C(Ph) - 2, Na+ was investigated by a flow and a stopflow technique. The bimolecular rate constant of combination was found to be 2 to 3 x 106 1. mole-1 s-1. The reaction was initiated by an electron transfer naphthalene^ + (P/*,2C:CH2) naphthalene+ (P/*,2C:CH^) or terphenylener + (P7fc2C:CH2) ⇔ terphenylene + (Pfe2C:CH^). The equilibrium constant of the first electron transfer process was found to be 20 and of the second about 16. These results are consistent with recent determinations of electron affinities of aromatic hydrocarbons.

The Effect of p-Toluidine on the Two-Step Electroreduction of Zn(II) in Water-Methanol and Water-Dimethylformamide

1999 ◽  
Vol 64 (4) ◽  
pp. 585-594 ◽  
Author(s):  
Barbara Marczewska
Keyword(s):  
Electron Transfer ◽  
Binary Mixtures ◽  
Rate Constant ◽  
Rate Constants ◽  
Electrode Surface ◽  
Mercury Electrode ◽  
Forward Rate ◽  
Solvent Molecules ◽  
Activated Complex

The acceleration effect of p-toluidine on the electroreduction of Zn(II) on the mercury electrode surface in binary mixtures water-methanol and water-dimethylformamide is discussed. The obtained apparent and true forward rate constants of Zn(II) reduction indicate that the rate constant of the first electron transfer increases in the presence of p-toluidine. The acceleration effect may probably be accounted for by the concept of the formation on the mercury electrode an activated complex, presumably composed of p-toluidine and solvent molecules.

Thionine–graphene oxide covalent hybrid and its interaction with light

2017 ◽  
Vol 19 (22) ◽  
pp. 14412-14423 ◽  
Author(s):  
Ewelina Krzyszkowska ◽  
Justyna Walkowiak-Kulikowska ◽  
Sven Stienen ◽  
Aleksandra Wojcik
Keyword(s):  
Electron Transfer ◽  
Graphene Oxide ◽  
Excited State ◽  
Transfer Process ◽  
Singlet Excited State ◽  
Functionalized Graphene ◽  
Electron Transfer Process ◽  
Functionalized Graphene Oxide ◽  
Back Electron Transfer

Quenching of the thionine singlet excited state in covalently functionalized graphene oxide with an efficient back electron transfer process.

scholarly journals Electrokinetic and Impedimetric Dynamics of FeCo-Nanoparticles on Glassy Carbon Electrode

Nano Hybrids ◽  
2013 ◽  
Vol 3 ◽  
pp. 1-23 ◽  
Author(s):  
Chinwe O. Ikpo ◽  
Njagi Njomo ◽  
Kenneth I. Ozoemena ◽  
Tesfaye Waryo ◽  
Rasaq A. Olowu ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Glassy Carbon Electrode ◽  
Glassy Carbon ◽  
Transfer Process ◽  
Dimethyl Carbonate ◽  
Electrochemical Impedance ◽  
Ethylene Carbonate ◽  
Carbon Electrode ◽  
Electron Transfer Process ◽  
Feco Nanoparticles

The electrochemical dynamics of a film of FeCo nanoparticles were studied on a glassy carbon electrode (GCE). The film was found to be electroactive in 1 M LiClO4 containing 1:1 v/v ethylene carbonate dimethyl carbonate electrolyte system. Cyclic voltammetric experiments revealed a diffusion-controlled electron transfer process on the GCE/FeCo electrode surface. Further interrogation on the electrochemical properties of the FeCo nanoelectrode in an oxygen saturated 1 M LiClO4 containing 1:1 v/v ethylene-carbonate-dimethyl carbonate revealed that the nanoelectrode showed good response towards the electro-catalytic reduction of molecular oxygen with a Tafel slope of about 120 mV which is close to the theoretical 118 mV for a single electron transfer process in the rate limiting step; and a transfer coefficient (α) of 0.49. The heterogeneous rate constant of electron transfer (ket), exchange current density (io) and time constant (τ) were calculated from data obtained from electrochemical impedance spectroscopy and found to have values of 2.3 x 10-5 cm s-1, 1.6 x 10-4 A cm-2 and 2.4 x 10-4 s rad-1, respectively.

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