Kinetic studies of dioxygen and superoxide ion in acetonitrile at gold electrodes using ultrafast cyclic voltammetry

Guo, Zhiyong; Lin, Xucong

doi:10.1016/j.jelechem.2004.10.011

Cited by 10 publications

(6 citation statements)

References 41 publications

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“…The third shallow wave with its maximum at ca. −0.9 V (peak c ) appears in a region that is characteristic of the O 2 /O 2 •- couple in acetonitrile or DMF; , the absence of a reversible wave suggests that O 2 •- (similarly to other radicals) contributes to the overall chemical process of dioxirane decomposition and it is quickly consumed . In fact, we previously reported evidence concerning a rapid electron-transfer chain reaction mediated by the superoxide ion for TFDO decomposition .…”

Section: Resultsmentioning

confidence: 92%

Concerning the Reactivity of Dioxiranes. Observations from Experiments and Theory

et al. 2008

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The challenging hypothesis of a "biphilic" (i.e., electrophilic vs nucleophilic) character for dioxirane reactivity, which envisages that electron-poor alkenes are attacked by dioxiranes in a nucleophilic fashion, could not be sustained experimentally. Rate data, which estimate Hammett "rho" values for the epoxidation of 3- or 4-substituted cinnamonitriles X x Ph-CH=CH-CN, unequivocally allow one to establish that dioxiranes epoxidize electrophilically even alkenes carrying electron-withdrawing groups. The greater propensity of methyl(trifluoromethyl)dioxirane TFDO (1b) to act as an electrophilic oxidant with respect to dimethyldioxirane DDO (1a) parallels the cathode reduction potentials for the two dioxiranes, as measured by cyclic voltammetry. A simple FMO approach for alkene epoxidation is helpful to conceive a likely rationale for the greater oxidizing power of TFDO as compared to DDO.

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Section: Resultsmentioning

confidence: 92%

Concerning the Reactivity of Dioxiranes. Observations from Experiments and Theory

et al. 2008

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“…By contrast, O 2 •– is highly reactive and spontaneously disproportionates in protic solvents. In addition, some supporting electrolytes have been used with aprotic solvents, such as tetra- n -butylammonium perchlorate, tetramethylammonium perchlorate, tetraethylammonium perchlorate (TEAP), tetra- n -butylammonium iodide, ,− and tetraethylammonium tetrafluoroborate …”

Section: Generation Of the Superoxide Ionmentioning

confidence: 99%

“…The use of ultramicroelectrodes showed extraordinary advantages in previous studies involving the electrochemical behavior of O 2 and O 2 •– in nonaqueous solvents, which is a fundamental study in biological systems. ,,,,, Katayama et al determined the concentration and diffusion coefficient of O 2 by using CA with both macrodisk and ultramicrodisk electrodes. This method is advantageous for ILs because all measurements can be conducted with only a small amount of solution and without information on the physical properties of the solution, that is, viscosity and density.…”

Section: Effect Of Electrodes On O2 •– Generationmentioning

confidence: 99%

Superoxide Ion: Generation and Chemical Implications

Hayyan¹,

Hashim²,

AlNashef³

2016

Chem. Rev.

1,721

1,058

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Superoxide ion (O2(•-)) is of great significance as a radical species implicated in diverse chemical and biological systems. However, the chemistry knowledge of O2(•-) is rather scarce. In addition, numerous studies on O2(•-) were conducted within the latter half of the 20th century. Therefore, the current advancement in technology and instrumentation will certainly provide better insights into mechanisms and products of O2(•-) reactions and thus will result in new findings. This review emphasizes the state-of-the-art research on O2(•-) so as to enable researchers to venture into future research. It comprises the main characteristics of O2(•-) followed by generation methods. The reaction types of O2(•-) are reviewed, and its potential applications including the destruction of hazardous chemicals, synthesis of organic compounds, and many other applications are highlighted. The O2(•-) environmental chemistry is also discussed. The detection methods of O2(•-) are categorized and elaborated. Special attention is given to the feasibility of using ionic liquids as media for O2(•-), addressing the latest progress of generation and applications. The effect of electrodes on the O2(•-) electrochemical generation is reviewed. Finally, some remarks and future perspectives are concluded.

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“…These authors assumed that the process is the reduction of superoxide to O 2 2- followed by rapid protonation to give HO 2 - , the latter reaction causing the overall reaction to be irreversible. Recently Guo and Lin studied the reduction of dioxygen in anhydrous ACN using ultrafast cyclic voltammetry and were able to detect an apparently reversible reduction feature near −2.8 V versus ferrocene/ferrocenium that might be due to the O 2 -• /O 2 2- couple.…”

Section: Introductionmentioning

confidence: 99%

Study of the Electrochemical Reduction of Dioxygen in Acetonitrile in the Presence of Weak Acids

2005

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The electrochemical reduction of dioxygen has been studied in acetonitrile at glassy-carbon electrodes. The initial step is the reversible one-electron reduction to form superoxide. In the presence of hydrogen-bond donors (water, methanol, 2-propanol), the superoxide forms a complex with the donor resulting in a positive shift in the potential that can be analyzed to obtain formation constants for these complexes. Stronger acids result in protonation of the superoxide followed by reduction to produce HO2-. In the absence of hydrogen-bond donors, the reduction of superoxide occurs at very negative potentials, and this second reduction peak is very much drawn-out along the potential axis, indicating a small value of the transfer coefficient, alpha. The addition of hydrogen-bond donors, HA, brings about a positive shift in this peak, without a noticeable change in shape. The reaction occurring at the second peak is a concerted proton and electron transfer (CPET) in which the electron is transferred to superoxide and a proton is transferred from HA to the superoxide, forming HO2- and A- in a concerted process. An estimation of the standard potential for this reaction shows that the second reduction always occurs at a high driving force, which explains the small value of alpha that is observed. Consistent with a CPET, a kinetic isotope effect, HA versus DA, was detected for the three hydrogen-bond donors. The increasing positive shift of the second peak with increasing water concentration has been interpreted as being a consequence of the change in the formal potential, as water is both a reactant in the process and a participant through the hydrogen-bond stabilization of the anions.

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Kinetic studies of dioxygen and superoxide ion in acetonitrile at gold electrodes using ultrafast cyclic voltammetry

Cited by 10 publications

References 41 publications

Concerning the Reactivity of Dioxiranes. Observations from Experiments and Theory

Concerning the Reactivity of Dioxiranes. Observations from Experiments and Theory

Superoxide Ion: Generation and Chemical Implications

Study of the Electrochemical Reduction of Dioxygen in Acetonitrile in the Presence of Weak Acids

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