Redox Catalysis Of Electrochemical Reactions Research Articles

Cyclic voltammetric response of homogeneous catalysis of electrochemical reaction. Part 3: A theoretical and numerical approach for one-electron two-step reaction scheme

• Homogeneous molecular catalysis of electrochemical reactions for the one-electron two-step reaction scheme is discussed. • The exact expression of species concentrations, current-voltage and turnover frequency is derived. • The effect of the intrinsic and operational parameters on current and turnover frequency is analysed. A theoretical model for homogeneous redox catalysis of electrochemical reactions for the one-electron two-step reaction scheme is discussed. This model is described by the system of nonlinear time dependent partial differential equations for which the nonlinear term is related to a homogeneous reaction. The species concentration, current-voltage and turnover frequency curves for the transient condition have been calculated by solving the equations using a new analytical method. The current response and turnover frequency predicted under steady-state conditions when t → ∞ are in good agreement with earlier results, proving the validity of the mathematical analysis. The effect of two rate constants and initial concentration of substrate on current and turn over frequency is discussed. Our analytical results for concentration are compared with numerical (MATLAB) results, and good agreement is noted.

Cyclic voltammetric response of homogeneous catalysis of electrochemical reactions: Part 1. A theoretical and numerical approach for EE’C scheme

This paper reports the mathematical modelling of homogeneous redox catalysis of electrochemical reactions for the EE’C scheme. This model is described by the system of nonlinear differential equations for which the nonlinear term is related to homogeneous reaction. The concentration of species and current–voltage curves at a planar electrode has been calculated by solving the nonlinear equations using a simple and new innovative approach which is named as Rajendran-Joy method(RJM). In particular, the limiting current and plateau current is highly sensitive to the solution flow rate and the concentrations of the mediator and substrate employed. The effect of two dimensionless parameters that group the experimental intrinsic and operational parameters on current is discussed. Our analytical results for cyclic voltammetry current are compared with simulation results, and satisfactory agreement is noted. The characteristic of concentration and the current–potential response for the extreme values of parameters are also provided.

In Memoriam of Jean‐Michel Savéant (1933–2020)

In Memoriam of Jean‐Michel Savéant (1933–2020)

ChemInform Abstract: Chemical vs. Redox Catalysis of Electrochemical Reactions. Reduction of trans‐1,2‐Dibromocyclohexane (I) by Electrogenerated Aromatic Anion Radicals and Low Oxidation State Metalloporphyrins

ChemInformVolume 19, Issue 6 Article ChemInform Abstract: Chemical vs. Redox Catalysis of Electrochemical Reactions. Reduction of trans-1,2-Dibromocyclohexane (I) by Electrogenerated Aromatic Anion Radicals and Low Oxidation State Metalloporphyrins D. LEXA, D. LEXA Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this authorJ.-M. SAVEANT, J.-M. SAVEANT Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this authorK. B. SU, K. B. SU Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this authorD. L. WANG, D. L. WANG Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this author D. LEXA, D. LEXA Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this authorJ.-M. SAVEANT, J.-M. SAVEANT Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this authorK. B. SU, K. B. SU Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this authorD. L. WANG, D. L. WANG Lab. Electrochim. Mol., CNRS, Univ. Denis Diderot, F-75251 Paris, Fr.Search for more papers by this author First published: February 9, 1988 https://doi.org/10.1002/chin.198806083Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume19, Issue6February 9, 1988 RelatedInformation

Chemical vs. redox catalysis of electrochemical reactions. Reduction of trans-1,2-dibromocyclohexane by electrogenerated aromatic anion radicals and low oxidation state metalloporphyrins

Chemical vs. redox catalysis of electrochemical reactions. Reduction of trans-1,2-dibromocyclohexane by electrogenerated aromatic anion radicals and low oxidation state metalloporphyrins

How to Design Organometallic “Electron-Reservoirs”

Abstract Two essential facets of transition metal organometallic compounds are (i) their ability to undergo transformations of organic and inorganic species at the metal and (ii) the ease of redox changes induced by the metal. This Comment indicates the potential of this second aspect and how organometallics may be designed and used to promote electron transfer (ET). Inexpensive, easily available organometallic electron-reservoirs can conveniently effect a variety of stoichiometric and catalytic ET processes. The salt effect and the activation of dioxygen are especially under our scrutiny in stoichiometric reactions. Catalytic ET involves redox catalysis of electrochemical reactions (the catalyst lowers the overpotential) and electro-catalysis of organometallic reactions (ligand substitution, decomplexation, isomerization, chelation, insertion). These processes can be effected using (instead of an electrode) iron sandwich compounds: the electron-deficient ferricinium Cp2Fe+ (17 valence electrons) for oxidations and the electron-reservoir compound CpFeIC6Me6(19 valence electrons) for reductions.

Investigation of two radical intermediates in the anodic oxidation of 1,4-dihydropyridines by electrochemiluminescence

The chemiluminescence generated in the anodic oxidation of 1,4-dihydropyridines (PyRH) in the presence of 9,10-diphenylanthracene (DPA) or of bis-[1,2,3-trimethyl-1,2-dihydrobenzimidazolyl-(2)]/luminophore systems (B 2/L) was investigated at a rotating platinum disk electrode and by cyclic voltammetry connected with luminescence intensity measurements in a 1:1 acetonitrile + toluene mixture. From the luminescence-potential curves, some new findings on the ECL of dihydropyridines (PyRH) are reported and the cation radicals PyRH π+ are proved to be primary intermediates. The shape and the intensity of the luminescence-potential curves are discussed in terms of structure. If E ox 1 2 (DPA), the system PyRH/DPA appears to be a practical example of the homogeneous redox catalysis of electrochemical reactions.

Homogeneous redox catalysis of electrochemical reactions electron transfers followed by a very fast chemical step

Homogeneous redox catalysis of electrochemical reactions can be used as a means for characterizing very short-lived intermediates formed upon electron transfer with the electron-transfers reagent. What happens when the reaction following the electron-transfer step is so fast that it takes place within the molecular diffusion layer (solvent cage) is discussed and illustrated with previously reported experimental data. The problem of the transition between a sequential electron transfer -chemical reaction mechanism and a concerted mechanism is also addressed.

Homogeneous redox catalysis of electrochemical reactions: Catalytic reduction of diphenylsulphide

Homogeneous redox catalysis of electrochemical reactions: Catalytic reduction of diphenylsulphide

Homogeneous redox catalysis of electrochemical reactions: Part IV. Kinetic controls in the homogeneous process as characterized by stationary and quasi-stationary electrochemical techniques

The analysis of homogeneous redox catalysis of an EC electrochemical reaction: Electrode process Catalytic process A + 1 e ⇌ B ( I el ) P + 1 e ⇌ Q ( 0 ) Q + A ⇌ k 2 k 1 B + P ( I sol ) B → k C ( II ) is greatly simplified if the stationary-state assumption can be made for species B. Two limiting situations are then obtained for extreme values of k/k 2 involving kinetic control of the overall reaction either by the forward reaction (I sol) or by reaction (II) with (I sol) as a preequilibrium. The polarization problem has been numerically solved for these two limiting cases as well as for the transition between them in the context of stationary or quasi-stationary electrochemical methods such as rotating disc voltammetry or classical polarography. The scope and limitations are discussed showing that it can be safety applied in the application of homogeneous redox catalysis to the determination of equilibrium and rate parameters of irreversible systems that are inaccessible through the standard use, of electrochemical kinetic techniques. The treatment has been extended to more complex processes, i.e. those involving the overall exchange of two electrons along an ECE or a solution electron-transfer mechanism. Procedures for the practical determination of the equilibrium and rate parameters of an irreversible system from homogeneous redox catalysis data are discussed.

Homogeneous redox catalysis of electrochemical reactions: Part V. Cyclic voltammetry

Cyclic voltammetry appears as a more convenient tool for studying homogeneous redox catalysis than polarography, due to the recording of the current potential being much faster and the control of the diffusion process more accurate and involving a much more extended range of rates. The theory of homogeneous redox catalysis in the context of cyclic voltammetry is presented for the EC reaction scheme, i.e. the simplest of the mechanisms in which the initial electron-transfer process is followed by chemical reaction. The treatment involves a stationary-state assumption regarding the initial product of the electron transfer The dimensionless voltammograms then depend upon two kinetic parameters and of the ratio of the substrate and catalyst concentrations. Two limiting situations are found for the kinetic control of the catalytic process according to the relative magnitude of the, follow-up chemical reaction and the backward electron-transfer rates. In one of these the kinetic control is by the forward homogeneous electron transfer, while in the other it is by the follow-up chemical reactions. In these two cases the system depends upon only two parameters, allowing a detailed discussion of the shape and characteristics of the voltammograms to be presented, as well a set of working curves giving the relative catalytic increase of the peak current as a function of the pertinent kinetic parameter and of the substrate—catalyst concentration ratio. A numerical procedure is presented for the resolution of the general case involving a mixed kinetic control by the two reactions. Diagnostic criteria for the recognition of the two limiting cases and the transition to mixed kinetic control are given, as well as procedures for determining the characteristic rate constants. The theory is then extended to the more frequently encountered two-electron processes which involves only a slight modification of the results pertaining to the EC scheme. Experimental illustrations of the main theoretical results are given in the context of the reduction of aromatic halides in aprotic media. The results obtained in this study have as their main application the determination, through the redox catalytic method, of the rate and equilibrium parameters for irreversible systems that would be far beyond the possibilities offered by the standard use of electrochemical techniques.

Determination of the lifetimes of unstable ion radicals by homogeneous redox catalysis of electrochemical reactions. Application to the reduction of aromatic halides

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDetermination of the lifetimes of unstable ion radicals by homogeneous redox catalysis of electrochemical reactions. Application to the reduction of aromatic halidesC. P. Andrieux, C. Blocman, J. M. Dumas-Bouchiat, F. M'Halla, and J. M. SaveantCite this: J. Am. Chem. Soc. 1980, 102, 11, 3806–3813Publication Date (Print):May 1, 1980Publication History Published online1 May 2002Published inissue 1 May 1980https://doi.org/10.1021/ja00531a023RIGHTS & PERMISSIONSArticle Views609Altmetric-Citations154LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts

Homogeneous redox catalysis of electrochemical reactions: Part III. Rate determining electron transfer. Kinetic characterization of follow-up chemical reactions

Electrochemical systems involving moderately fast charge transfers and very fast irreversible follow-up chemical reactions usually escape from kinetic and mechanistic characterization through the standard use of electrochemical techniques. It is shown that these difficulties can be overcome using an indirect approach which involves the homogeneous redox catalysis of the considered electrochemical reaction. A procedure for determining the rate constant of such fast follow-up reaction is presented. It is illustrated by the determination of the cleavage rate constant of the chlorobenzene anion radical in DMF which reaches a value on the order of 10 7 s −1.