Influence of supporting electrolyte activity on formal potentials measured for dissolved internal standards in acetonitrile

Measurement of the diffusion coefficients of [Ru(NH3)6]3+ and [Ru(NH3)6]2+ in aqueous solution using microelectrode double potential step chronoamperometry

“…Also, Baticle et al found that the ratio for the Fe 2+ jFe 3+ couple was 1.24 in a H 2 SO 4 solution [23]. One possible reason was that charged species may form ion-pairs with supporting electrolyte, which was widely cited in related researches [19,[25][26][27][28]. Counter ions of electrolyte may associate with charged redox species, and the total size of these species becomes larger.…”

The measurement of the diffusion coefficients of ferrocene and ferrocenium and their temperature dependence in acetonitrile using double potential step microdisk electrode chronoamperometry

“…Literature concerning the effect of temperature on the behaviour of ferrocene in organic media is somewhat scarce. When the FcjFc + couple is used as an internal reference standard the formal potential, E o f , of the couple corresponds to the potential mid-way between the anodic and cathodic peaks in cyclic voltammetry corrected by the term RT F ln D Fc D Fc þ [15][16][17]. Accordingly, the knowledge of the diffusion coefficients of both Fc and Fc + important in the area of voltammetry [18].…”

“…Many of the literature papers report the diffusion coefficients of ferrocene, although very few measure and report the corresponding values for the ferrocenium species, and those that do report diffusion coefficients for both the parent and product species are in wide disagreement. Most commonly, the ratio of the charged and neutral diffusion coefficients is measured and values ranging between 0.80 [15,[19][20][21] and 0.95 [18] have been reported, and in some cases, equal diffusion coefficients are assumed [14,22,23]. Rogers et al investigated the redox behaviour of the FcjFc + couple in room temperature ionic liquids (RTILs) using the technique of double potential step chronoamperometry at microdisk electrodes [24].…”

“…Numerous articles report the ion-pairing effect of perchlorate in acetonitrile and the formation of the [Fc + ClO 4 À ] ion-pair, following the process shown below (Eq. (2)) in acetonitrile [15,[28][29][30].…”

Direct Electrochemical Determination of Thermodynamic Factors in Aprotic Binary Electrolytes

“…23 In the same publication, the effect of ion pairing is also mentioned as an explanation for the non-ideal behavior of a cyclic voltammogram. A similar concept is discussed in Redepenning et al 24 In addition, the ratio of ferrocene to supporting electrolyte may introduce a diffusion overpotential, which would affect oxidation and reduction peak potentials asymmetrically (compare Eq. 27).…”