Numerical Modeling of ECE‐ECE and Parallel EE‐EE Mechanisms in Cyclic Voltammetry. Reduction of 1,4‐Benzenedisulfonyl Difluoride and 1,4‐Naphthalenedisulfonyl Difluoride

Abstract

A numerical model of the process where the ECE-ECE sequence competes with the parallel EE-EE mechanisms of reduction has been developed. The ECE-ECE/EE-EE model was applied to complex, experimentally observed processes, in which the parallel path of anion-radical reduction could be expected. The applicability of the proposed model was examined experimentally for two chemical systems: (i) 1,4-benzenedisulfonyl difluoride (1,4-BDF) and (ii) 1,4-naphthalenedisulfonyl difluoride (1,4-NDF). For both model compounds the reduction processes on Hg and glassy carbon electrodes were investigated by means of cyclic voltammetry performed in DMF solutions containing 0.3 M of TBAP. In contrast to other reductive cleavage reactions such as the fragmentation of the C-Hal -type bond, the electro-reduction of anion-radicals ArSO 2 F À. was evident. The elementary kinetic parameters of the process are determined and discussed.

Surface ECE mechanism in protein film voltammetry—a theoretical study under conditions of square-wave voltammetry

“…This situation is commonly observed for electroactive molecules that can exist as more than one isomer; for example, cis and trans isomers of transition metal complexes, but it is also frequently met by some proteins and other important biomolecules [7,[13][14][15][16][17][18][19]. The features of the SW voltammetric responses in such scenario will significantly depend on the value of the chemical kinetic parameter l, but they will be also affected by the values of the electron transfer kinetic parameters K 1 and K 2 of the two reduction steps.…”

“…If we consider a surface electron transferchemical reaction (EC) mechanism for example, and if the product of the first electron step can be converted chemically to another electroactive specie, then we assign these reactions to follow the surface electron transfer-chemical reactionelectron transfer (ECE) mechanistic pathway. Although this reaction mechanism is quite complex, it is a widespread pathway of many proteins [7] and other important compounds in organic electrochemistry [1,7,[13][14][15][16][17][18][19]. For example, the product of the first electron transfer step can undergo protonation, elimination, substitution, or reorganization reaction to give second electroactive specie [1,[13][14][15][16][17][18][19].…”

“…Although this reaction mechanism is quite complex, it is a widespread pathway of many proteins [7] and other important compounds in organic electrochemistry [1,7,[13][14][15][16][17][18][19]. For example, the product of the first electron transfer step can undergo protonation, elimination, substitution, or reorganization reaction to give second electroactive specie [1,[13][14][15][16][17][18][19]. As the most familiar among the voltammetric techniques, the cyclic voltammetry is commonly used for characterization of electrochemically active systems following the ECE pathway [7, 13-16, 18, 19].…”

Quantitative Separation of an Adsorption Effect in Form of Defined Current Probabilistic Responses for Catalyzed / Inhibited Electrode Processes

“…The remaining experimental details concerning DMF solutions were identical with those described in previous paper [17].…”

Iso Points in Electrochemistry. Classification and Verification by Experiment and Theory

“…All sets of equations were solved with the use of ESTYM_PDE electrochemical software by K. Kaczmarski, described in and tested in reference. One can indicate several examples of electrochemical problems solved by experiment/model comparison with the use of cyclic voltammetry , square‐wave voltammetry , electrochemical impedance spectroscopy and linear sweep voltammetry/rotating disk electrode . Theoretical background of electrochemical simulations one can find in .…”