The electrochemical behaviour of the nickel(II) ion at the dropping mercury electrode in the presence of some complexing agents—III

Crow, D. R.

doi:10.1016/0013-4686(83)87017-0

Cited by 7 publications

(2 citation statements)

References 9 publications

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“…Nevertheless, there are situations of interest where this does not hold true due to significant changes in diffusivity as a result of the chemical reactions, such as in the formation of supramolecular adducts [4] or the complexation of metal ions in natural media [5]. Thus, Crow developed a methodology for the determination of complexation equilibrium constants based on diffusivity measurements [6,7], which was extended to supramolecular systems [8,9]. Also, very different diffusivities can be found when studying ion transfer processes between two liquid phases of very different properties, such as between conventional solvents and liquid membranes [10].…”

Section: Introductionmentioning

confidence: 98%

Voltammetric speciation studies of systems where the species diffusivities differ significantly

Laborda

Olmos

Martı́nez-Ortiz

et al. 2014

J Solid State Electrochem

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A rigorous and simple analytical solution is reported for the square scheme in single pulse techniques at (hemi)spherical electrodes when the electron transfers are reversible and the coupled chemical reactions are at equilibrium. The solution presented imposes no restriction to the values of the diffusion coefficients of the different species, and then it fully describes the cases where the coupled chemical processes involve significant changes of diffusivity. Simple criteria are discussed to understand and predict the effects of electrode radius, experiment time-scale and chemical thermodynamics on the results obtained in normal pulse voltammetry and derivative voltammetry. Unlike at macroelectrodes and ultramicroelectrodes, the position of the voltammograms (in these and other voltammetric techniques) is time dependent at spherical electrodes of intermediate size when the diffusion coefficients of the species are unequal. An analytical expression for the half-wave potential is given to describe this behaviour and also to assist the quantitative determination of the diffusion coefficients, formal potentials and equilibrium constants with the electrochemical techniques abovementioned.

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Section: Introductionmentioning

confidence: 98%

Voltammetric speciation studies of systems where the species diffusivities differ significantly

Laborda

Olmos

Martı́nez-Ortiz

et al. 2014

J Solid State Electrochem

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“…Usually, the diffusion coefficients of A, B, and C are comparable, especially if the three species are structurally similar. − Recent research has voltammetrically identified three distinct areas in which significant inequality of diffusion coefficients occurs. The first is when room temperature ionic liquids (RTILs) are used as solvents ,− in which different levels of charge in A, B, and C lead to major differences in the three diffusion coefficients.…”

Section: Introductionmentioning

confidence: 99%

Modeling Diffusion Effects for a Stepwise Two-Electron Reduction Process at a Microelectrode: Study of the Reduction of para-Quaterphenyl in Tetrahydrofuran and Inference of Fast Comproportionation of the Dianion with the Neutral Parent Molecule

et al. 2009

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This paper presents a study of voltammetry at microdisc electrodes for a stepwise two electron reduction (A + 2e− ⇌ B + e− ⇌ C) where the relevant formal potentials of the A/B and B/C couples are such that two distinct voltammetric waves are seen. Simulations are used to explore quantitatively the effect of comproportionation (A + C → 2B) on the observed cyclic voltammetry and potential-step chronoamperometry. It is found that, in the limit of electrochemical reversibility, the presence of comproportionation can be discerned using cyclic voltammetry only at high scan-rates and when the diffusion coefficients of the species (D A, D B, and D C) are significantly different, such that D B/D A > 1.5 and D C/D A > 1.5 or D B/D A < 0.75 and D C/D A < 0.75. The theory is used to provide clear evidence for diffusionally controlled comproportionation in the stepwise two electron reduction of para-quaterphenyl in the solvent THF.

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Electrochemical Reduction of Vanadium(V)‐Cupferron Complex, VO(cupf)₂OH

Kaplun

Ivanov

2019

Electroanalysis

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Electrochemical reduction of vanadium(V) complex with cupferron (N‐nitroso‐N‐phenylhydroxylamine), VVO(cupf)2OH, has been studied by polarography in wide potential range to verify the catalytic mechanism of electroreduction of coordinated cupferron ligand. Reduction of the complex was studied in the concentration range from 2 ⋅ 10−5 M to 10−3 M. Depending on the process conditions kinetics of catalytic reduction of coordinated cupferron is either controlled by adsorption step or governed by mixed control of diffusion and chemical reaction. Kinetic parameters of the reduction process are reported. Reduction of VVO(cupf)2OH complex is accompanied by adsorption and autoinhibition phenomena. V(II) ion in the surface bound complex of vanadium with cupferron catalyzes reduction of coordinated cupferronate ligands. In 1 mM solutions, the catalytic reduction of coordinated cupferron ligand shifts to more cathodic potentials due to formation of a monolayer of adsorbed vanadium(III)‐cupferron complexes. Reduction kinetics in the presence of tetraalkylammonium salt is consistent with multilayer cooperative adsorption of anionic vanadium(II)‐cupferron complex and tetraalkylammonium cations.

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The electrochemical behaviour of the nickel(II) ion at the dropping mercury electrode in the presence of some complexing agents—III

Cited by 7 publications

References 9 publications

Voltammetric speciation studies of systems where the species diffusivities differ significantly

Voltammetric speciation studies of systems where the species diffusivities differ significantly

Modeling Diffusion Effects for a Stepwise Two-Electron Reduction Process at a Microelectrode: Study of the Reduction of para-Quaterphenyl in Tetrahydrofuran and Inference of Fast Comproportionation of the Dianion with the Neutral Parent Molecule

Electrochemical Reduction of Vanadium(V)‐Cupferron Complex, VO(cupf)₂OH

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The electrochemical behaviour of the nickel(II) ion at the dropping mercury electrode in the presence of some complexing agents—III

Cited by 7 publications

References 9 publications

Voltammetric speciation studies of systems where the species diffusivities differ significantly

Voltammetric speciation studies of systems where the species diffusivities differ significantly

Modeling Diffusion Effects for a Stepwise Two-Electron Reduction Process at a Microelectrode: Study of the Reduction of para-Quaterphenyl in Tetrahydrofuran and Inference of Fast Comproportionation of the Dianion with the Neutral Parent Molecule

Electrochemical Reduction of Vanadium(V)‐Cupferron Complex, VO(cupf)2OH

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Product

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Electrochemical Reduction of Vanadium(V)‐Cupferron Complex, VO(cupf)₂OH