Heterogeneous electron exchange of quinones in aprotic solvents

Rüssel, Christian; Janicke, W.

doi:10.1016/0022-0728(86)87047-4

Cited by 87 publications

(24 citation statements)

References 22 publications

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“…The 1 e – reduction potentials were measured under aprotic conditions [0.1 M (Bu 4 N)PF 6 in MeCN], while the 2 e – /2 H + potentials were determined in acidic aqueous solution (1 M p -TsOH). Reversible (or quasi-reversible) voltammograms were observed under both conditions for most derivatives, and in all cases it was possible to identify an appropriate mid-point potential. , Our measured reduction potentials correlate well with available values in the literature (cf. Tables S5 and S9) but, importantly, provide a self-consistent set of data for analysis.…”

Section: Resultssupporting

confidence: 83%

Quinone 1 e^– and 2 e^–/2 H⁺ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships

et al. 2016

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Quinones participate in diverse electron transfer and proton-coupled electron transfer processes in chemistry and biology. To understand the relationship between these redox processes, an experimental study was carried out to probe the 1 e– and 2 e–/2 H+ reduction potentials of a number of common quinones. The results reveal a non-linear correlation between the 1 e– and 2 e–/2 H+ reduction potentials. This unexpected observation prompted a computational study of 134 different quinones, probing their 1 e– reduction potentials, pKa values, and 2 e–/2 H+ reduction potentials. The density functional theory calculations reveal an approximately linear correlation between these three properties and an effective Hammett constant associated with the quinone substituent(s). However, deviations from this linear scaling relationship are evident for quinones that feature intramolecular hydrogen bonding in the hydroquinone, halogen substituents, charged substituents, and/or sterically bulky substituents. These results, particularly the different substituent effects on the 1 e– versus 2 e–/2 H+ reduction potentials, have important implications for designing quinones with tailored redox properties.

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Section: Resultssupporting

confidence: 83%

Quinone 1 e^– and 2 e^–/2 H⁺ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships

et al. 2016

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“…This value is comparable to DG comp of À33 kJ mol À1 reported for BQ in [C 2 mim][BF 4 ] [37]. Values of À45, À61 and À77 kJ mol À1 were reported for BQ in PC [16], MeCN [47] and DMSO [37], respectively, suggesting that the BQ 2À species is more stable in IL media, and is somewhat less likely, thermodynamically, to undergo comproportionation with BQ, than more conventional solvents. Recent papers [24,25] suggest that, in the limit of electrochemical reversibility, the presence of diffusion-controlled comproportionation can only be discerned from voltammetry when the scan rate is sufficiently fast or when the diffusion coefficients of the reaction species are significantly different, such that D BQ ÅÀ and D BQ > 1.5 or D BQ 2À and D BQ ÅÀ < 0:75.…”

Section: Simulation Of the Two Step Bq Reduction CVsupporting

confidence: 85%

The electrochemical reduction of 1,4-benzoquinone in 1-ethyl-3-methylimidazolium bis(trifluoromethane-sulfonyl)-imide, [C2mim][NTf2]: A voltammetric study of the comproportionation between benzoquinone and the benzoquinone dianion

Wang

Rogers

Belding

et al. 2010

Journal of Electroanalytical Chemistry

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“…When strong or moderately strong acids are present during the reduction of nitrobenzene in organic solvents, a complex sequence of electron and proton transfer reactions yield nitrosobenzene as intermediate and the corresponding hydroxylamine as product . Alternatively, the radical anion of nitrobenzene must be in principle more prone to exert ion‐pairing interactions with cations of small size, such as has been demonstrated in the case of the interaction between the reduced species of benzoquinone and nitrobenzene with tetraalkylammonium cations.…”

Section: Introductionmentioning

confidence: 99%

Effect of Electrolyte Ions on the Formation, Electroactivity, and Rectification Properties of Films Obtained by Electrografting

2019

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The oxidation of 4‐(4‐nitrophenyl)butyrate ions in acetonitrile was used to modify glassy carbon surfaces with films bearing 3‐(4‐nitrophenyl)propyl groups. The main features of the voltammetric reduction of the grafted nitrophenyl groups were studied in two different supporting electrolytes; n‐Bu4NPF6 and Me4NPF6. The best response was obtained with the less bulky electrolyte, which was explained by the major capability of these ions to diffuse inside the channels of the grafted film, as well as the better stabilization of the radical anions generated during the reduction process. It was also shown that the films electrografted in presence of the bulky n‐Bu4NPF6 are thicker but less compact than those prepared in Me4NPF6. The amount of nitrophenyl groups in the grafted film that can be reduced depends on the size of the electrolyte ions. The permeation of the electrolyte ions inside the film channels determines also the voltammetric behavior of ferrocene as redox probe. A current rectification phenomenon was observed in acetonitrile solutions of bulky and hydrophobic electrolytes like n‐Bu4NPF6 and n‐Hx4NPF6, whose marginal inclusion inside the film channels promotes both the entrance of ferrocene and the expelling of ferrocenium ions from these ones. This phenomenon was emulated through a CEC mechanism in solution, where the diffusion inside the channels was described as single chemical equilibria.

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Heterogeneous electron exchange of quinones in aprotic solvents

Cited by 87 publications

References 22 publications

Quinone 1 e^– and 2 e^–/2 H⁺ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships

Quinone 1 e^– and 2 e^–/2 H⁺ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships

The electrochemical reduction of 1,4-benzoquinone in 1-ethyl-3-methylimidazolium bis(trifluoromethane-sulfonyl)-imide, [C2mim][NTf2]: A voltammetric study of the comproportionation between benzoquinone and the benzoquinone dianion

Effect of Electrolyte Ions on the Formation, Electroactivity, and Rectification Properties of Films Obtained by Electrografting

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Heterogeneous electron exchange of quinones in aprotic solvents

Cited by 87 publications

References 22 publications

Quinone 1 e– and 2 e–/2 H+ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships

Quinone 1 e– and 2 e–/2 H+ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships

The electrochemical reduction of 1,4-benzoquinone in 1-ethyl-3-methylimidazolium bis(trifluoromethane-sulfonyl)-imide, [C2mim][NTf2]: A voltammetric study of the comproportionation between benzoquinone and the benzoquinone dianion

Effect of Electrolyte Ions on the Formation, Electroactivity, and Rectification Properties of Films Obtained by Electrografting

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Product

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Quinone 1 e^– and 2 e^–/2 H⁺ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships

Quinone 1 e^– and 2 e^–/2 H⁺ Reduction Potentials: Identification and Analysis of Deviations from Systematic Scaling Relationships