Cyclic voltammetry influence

Lemos MANDA, Pombeiro AJL (1992) Digital simulation of cyclic voltammetry - influence of the space discretization technique. Port Electrochim Acta 10 89-99... 

Successful electrodeposition of Sb2To3 has been reported for the first time by Leimkiihler et al. [229] who prepared polycrystalline thin films of the material on different transparent conductive oxides, as well as CdTe and Mo, from uncomplexed solutions made by mixing stock solutions of SbCb, Te02, and phthalate buffer (pH 4). The electrochemical process was discussed in detail based on results obtained by cyclic voltammetry on ITO/glass. The bath temperature was found to influence... 

Bouchard, G., Carrupt, P. A., Testa, B., Gobry, V., Girault, H. H. The apparent lipophilicity of quaternary ammonium ions is influenced by Galvani potential difference, not ion-pairing a cyclic voltammetry study. Pharm. Res. 2001, 18, 702-708. 

Figure 6.9 Cyclic voltammetry of a Pt(llO) rotating disk electrode in a CO-saturated 0.1 M HCIO4 solution, (a) Influence of the voltage scan rate, (b) Influence of the disk rotation rate.

As a general criterion one must bear in mind that, in cyclic voltammetry, the presence of a following chemical reaction has little influence on the forward peak, whereas it has a considerable effect on the reverse peak. 

For further contributions on the dia-stereoselectivity in electropinacolizations, see Ref. [286-295]. Reduction in DMF at a Fig cathode can lead to improved yield and selectivity upon addition of catalytic amounts of tetraalkylammonium salts to the electrolyte. On the basis of preparative scale electrolyses and cyclic voltammetry for that behavior, a mechanism is proposed that involves an initial reduction of the tetraalkylammonium cation with the participation of the electrode material to form a catalyst that favors le reduction routes [296, 297]. Stoichiometric amounts of ytterbium(II), generated by reduction of Yb(III), support the stereospecific coupling of 1,3-dibenzoylpropane to cis-cyclopentane-l,2-diol. However, Yb(III) remains bounded to the pinacol and cannot be released to act as a catalyst. This leads to a loss of stereoselectivity in the course of the reaction [298]. Also, with the addition of a Ce( IV)-complex the stereochemical course of the reduction can be altered [299]. In a weakly acidic solution, the meso/rac ratio in the EHD (electrohy-drodimerization) of acetophenone could be influenced by ultrasonication [300]. Besides phenyl ketone compounds, examples with other aromatic groups have also been published [294, 295, 301, 302]. 

Makhotkina, O. and Kilmartin, P. A. (2009). Uncovering the influence of antioxidants on polyphenol oxidation in wines using an electrochemical method Cyclic voltammetry. J. Electroanal. Ghem. 633,165-174. 

The quasi-reversihle electroreduction processes of Zn(II) in the absence and in the presence of Ai,Ai -dimethylthiourea (DMTU) were quantitatively compared by Sanecld [91], It has been shown that in the presence of DMTU enhanced response of cyclic voltammetry and normal pulse polarography was complex and could be resolved into its regular reduction part and a part caused by the catalytic influence of adsorption of organic substance. 

Chen and Abruna [104] have studied, using ac and dc cyclic voltammetry, interfacial interaction between the adsorbed porcine pancreatic phospholipase Ai and mercury. The authors have proposed reaction mechanism based on the interaction of cystine residues (disulfide) with mercury. They have found that surface reactions are complex and that several factors influence their mechanism. Their results and observations agree with the reaction pathway postulated for the... 

It should also be recalled that a full electrochemical, as well as spectroscopic and photophysical, characterization of complex systems such as rotaxanes and catenanes requires the comparison with the behavior of the separated molecular components (ring and thread for rotaxanes and constituting rings in the case of catenanes), or suitable model compounds. As it will appear clearly from the examples reported in the following, this comparison is of fundamental importance to evidence how and to which extent the molecular and supramolecular architecture influences the electronic properties of the component units. An appropriate experimental and theoretical approach comprises the use of several techniques that, as far as electrochemistry is concerned, include cyclic voltammetry, steady-state voltammetry, chronoampero-metry, coulometry, impedance spectroscopy, and spectra- and photoelectrochemistry. 

It is certain that, in the first reduction step in aprotic solvents, an electron is accepted by the LUMO of the organic compound. However, it was fortunate that this conclusion was deduced from studies that either ignored the influence of solvation energies or used the results in different solvents. Recently, Shalev and Evans [55] estimated the values of AG V(Q/Q ) for 22 substituted nitrobenzenes and nine quinones from the half-wave potentials measured by cyclic voltammetry. For quinones and some substituted nitrobenzenes, the values of AG V(Q/Q ) in a given solvent were almost independent of the EA values. Similar results had been observed for other aromatic hydrocarbons in AN (Section 8.3.2) [56]. If AG V(Q/ Q ) does not vary with EA, there should be a linear relation of unit slope between El/2 and EA. Shalev and Evans [55], moreover, obtained a near-linear relation between AG V(Q/Q ) and EA for some other substituted nitrobenzenes. Here again, the Ey2-EA relation should be linear, although the slope deviates from unity.8)... 

The best way to gauge the influence of convective stirring on prospective elec-troanalytical experiments such as chronoamperometry or cyclic voltammetry is to conduct preliminary experiments with a well-behaved, reversible electrode reaction employing the same experimental setup to be used for examination of the system of interest. Increases in the expected constant values of it1/2 with increasing t or ip/v1/2 with decreasing v, respectively, signal the point at which convective transport becomes important. 

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