A kinetic study of ferrocenium cation decomposition utilizing an integrated electrochemical methodology composed of cyclic voltammetry and amperometry

Abstract

A novel, easy, quick, and inexpensive integrated electrochemical methodology composed of cyclic voltammetry and amperometry has been developed for the determination of the kinetic stability of higher oxidation states for inorganic complexes. In this study, ferrocene and its derivatives have been used as model systems and the corresponding ferrocenium cations were generated in situ during the electrochemical experiments to determine their kinetic stabilities. The study found that the ferrocenium cations decompose following the first-order kinetics at 27 ± 3 °C in the presence of ambient oxygen and water. The half-lives of the ferrocenium, carboxylate ferrocenium, and decamethyl ferrocenium cations were found to be 1.27 × 10(3), 1.52 × 10(3), and ≫11.0 × 10(3) s, respectively, in acetonitrile solvent having a 0.5 M tetrabutylammonium hexafluorophosphate electrolyte. These results are in agreement with the previous reports, i.e. the ferrocenium cation is unstable whereas the decamethyl ferrocenium cation has superior stability. The new methodology has been established by performing various experiments using different concentrations of ferrocene, variable scan rates in cyclic voltammetry, different time periods for amperometry, and in situ spectroelectrochemical experiments.

Characterization of a BODIPY Dye as an Active Species for Redox Flow Batteries

“…No additional peaks appear, indicating that ferrocenium is stable far beyond the timescale of a typical CV experiment. UV/Vis spectroscopy data (Figure ) showed no change over the course of 1 month, which further shows that ferrocenium is stable when stored under inert conditions . Accordingly, RFBs using ferrocene as an active species will maintain charge provided that oxygen is excluded from the electrolyte solution.…”

“…UV/Vis spectroscopy data ( Figure 3) showedn oc hange over the course of 1month, whichf urther showst hat ferrocenium is stable when stored under inert conditions. [29] Accordingly, RFBs using ferrocene as an active speciesw ill maintain charge provided that oxygen is excluded from the electrolyte solution. Similar experimentsw ere carried out with cobaltocene.…”

Survey of Redox-Active Moieties for Application in Multiplexed Electrochemical Biosensors

“…Some of the degradation is, no doubt, due to the poor stability of some of the potential reporters. The ferrocenium ion, for example, is known to be unstable in aqueous solution in the presence of oxygen 24 and the increasing current seen with gallocyanine presumably occurs due to redox-driven modification of the reporter. In addition, some of the degradation we see is likely due to the instability of the SAM when repeatedly scanned at high or low potentials.…”

Construction and Characterization of a Chitosan-Immobilized-Enzyme and β-Cyclodextrin-Included-Ferrocene-Based Electrochemical Biosensor for H2O2 Detection

“…The electron mediator with low oxidation potential distributed in the chitosan membrane can react with the reducing enzyme rapidly. The oxidation and reduction states are relatively stable, but are reversible [ 30 , 31 ]. Therefore, an electron channel between the enzyme activity center and the electrode can be established.…”