Coulomb potentials electron transfer

Controlled-potential coulometry involves nearly complete reduction or oxidation of an analyte ion at a working electrode maintained at a constant potential and integration of the current during the elapsed time of the electrolysis. The integrated current in coulombs is related to the quantity of analyte ion by Faraday s law, where the amps per unit time (coulomb) is directly related to the number of electrons transferred, and thus to the amount of analyte electrolyzed. 

An electron transferring across the metal surface first sustains the electrostatic coulomb potential due to the sinface potential, x, and then enters into the exchange and correlation potential field,, caused by the ion-electron and electron-electron... 

The investigation of electron ionization is clearly in the early stages in comparison with the electron transfer studies, and additional work on the influence of orientation on Augmentation will be required before a coherent pattern emerges and a model for fragmentation can be attempted. However, a simple model that considers ionization in terms of the Coulomb potential developed between the electron and the polar molecule, taking the electron transition probability into account, reproduces the main experimental features. This model accounts qualitatively for the steric effect measured and leads to simple, generally applicable, expressions for the maximum (70 eV) ionization cross section. 

Upon electronic excitation the redox properties of either the electron donor (D) or the acceptor (A) are enhanced. The feasibility of an electron transfer can be estimated from a simple free reaction energy consideration as customary in the frame of the Rehm-Weller approach (Eq. (1)) [11], where Efy2 (P) and 4) represent the oxidation and reduction potential of the donor or the acceptor, respectively. AEexcit stands for the electronic excitation energy, whereas Aiscoui indicates the coulombic interaction energy of the products formed (most commonly radical ions). This simplified approach allows a first approximation on the feasibility of a PET process without considering the more complex kinetics as controlled by the Marcus theory [6c]. For exergonic processes (AG<0) a PET process becomes thermodynamically favorable. 

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