Cyclic voltamogram

In some cases the cyclic voltamogram itself recorded when ramping the electrode potential as described above shows a characteristic minimum around iipzc (e.g. with single crystal gold electrodes [86Kol, 96Ham2]) (Data obtained with this method are labelled CV). 

CS = coulostatic method, CV = cyclic voltamogram, FD = Faradaic distortion method, FR = Faradaic rectification, GD = galvanostatic double pulse method, IP = impedance method, PS = potential step method. See also list of... 

Figure 7.1 Cyclic voltamograms of Pt(l 11) electrodes modified by Bi, Sb, As, and Te deposition at intermediate coverages, as indicated, in 0.5 M H2SO4 solution. Sweep rate 50 mV/s.

Complexes with pyridine-2,6-diimine ligands, five-coordinate [NiX2(174)] (X = C1, Br) or six-coordinate [Ni(174)2]X2, were usually assumed to have innocent neutral ligands. The X-ray structure and spectroscopic characteristics of [Ni(174)2](PF6) confirm that the complex contains the neutral ligand ([174] ) and a divalent nickel ion.579 The cyclic voltamogram of this complex in CH2C12 shows three reversible one-electron-transfer processes at = 1.19 V, —1.30 V, and — 1.82V (vs. Fc+/Fc), of which the first is a one-electron oxidation, while the other two correspond to two successive one-electron reductions. The spectroscopic data allow one to assign these processes as follows ([174]1 is a one-electron reduced radical form of [174] ) [Nini(174)°2]3+ [NiII(174)02]21 - " [NiI(174)°2]+ = " [NiI(174)°(174)1 ]°. 

To further identify the electro-oxidation products of 1 , the C. V. of 1 and I3 were also recorded. There are similarities and dissimilarities in the cyclic voltamogram. While (Ep) = 0.690 V is same in both the C.V. s, there is another anodic peak at 1,054 mV (absent in the r - e 1 case) for the same concentration of 1-and two corresponding cathodic peaks at 787 and 406 mV as compared to that of 1. It was also noted that the anodic peak in the case of [1] = 0.5 mM was quite sharp manifesting a two-electron oxidation. It is not so in the case of I3. Thus recombination I.to form Ij, followed by the reaction of 1 with (excess) 1 in solution to form 1 and oxidation of 1 is not involved in the electro-oxidation of 1. 

A cyclic voltamogram of a saturated solution of 1 shows an anodic peak at 637 mV (scanning upto 1,000 mV) and two cathodic peaks at 615 and 316 mV. None of them at the position of the anodic/cathodic peak in C.V of oxidation of T. To further identify the electro-oxidation product of 1 Eq. 27.5, cyclic voltammogram of 1 at low concentration of I was rerecorded. For [T] <0.5 mM there is only one... 

The formal electrode potentials of diynyl complexes are greatly influenced by the nature of the other supporting ligands (Table V). For example, the cyclic voltamograms (CVs) of the iron complexes Fe(C=CC=CSiMe3)(CO)2(/ -C5R5)... 

Low temperature cyclic voltammetry is also able to demonstrate reduction of the individual rotamers of 2,3-dibromobutane [115]. At room temperature when there is fast bond rotation, reduction proceeds through the conformation with trans-periplanar arrangement of carbon-bromine bonds. At -120° C, a second peak at more negative potentials appears in the cyclic voltamogram, due to elimination from tlie staggered arrangement of carbon-bromine bonds. 

G. K. Rowe, M. T. Carter, J. Richardson, and R. W. Murray, Langmuir 11 1797 (1995). Obtaining electrode kinetic parameters from cyclic voltamograms involving proteins. 

Figure 9. Cyclic voltamograms for 1.0 x 10 M ascorbic acid (A), uric acid (B), dopamine...

Figure 32. (a) Cyclic voltamograms of a platinum electrode coated with a [Ni(4-TRPyP)] [PFg]4 film,... 

Figure 2 Cyclic voltamograms for (a) ferrocene [Fe(Cp)2] (Cp = cyclopentadienyl anion, measured in CH3CN with 0.1 M...

Os(IlI) solution at pH 3.1 contains an Os "OH species, whereas Os(lV) solutions at the same pH have an Os 0 species. From Pourbaix diagram we see that Os "OH complex remains protonated in the pH range 3.1 to 13. This means that at very high sweep rates electron transfer is going to be fast in comparison to proton transfer. As a consequence we should see one reversible peak in the cyclic voltamograms in this pH range. 

Because of zinc s high electronegativity, this element must have participated in some manner with the corrosion processes. About the only possible indications from the electrochemical and x-ray evaluations made, are the small reduction peaks observed at about — 1.15 V for protein solutions on the 5 V/min cyclic voltamograms. These cathodic peaks for use as evidence in showing zinc corrosion may just as well be reduction of copper products, since cathodic peaks are shifted negatively with respect to their redox potentials at faster sweep rates. 

Figure 2 Cyclic voltamograms for (a) ferrocene [Fe(Cp)2] (Cp = cyclopentadienyl anion, CsHs ) measured in CH3CN with O.iM BU4NPF6 dispiaying a reversible oxidation at 0.43 V versus SCE and (b) [Rh "(bpy)3] (bpy = 2,2 -bipyridine), an example of an irreversible reduction followed by two reversible reductions measured in CH3CN with 0.1 M Et4NC104 versus SCE. (Reprinted with permission from Kew, DeArmond, and Hanck 1974 American Chemical Society)...

Figure 11. Cyclic voltamograms of some of the anilines. Sweep rate 50 mV/s graphite paste electrode, Ag/AgCl reference electrode. The solvent was 50/50 acetonitrile/phosphate buffer, and the concentration was 0.1 mg/mL. Note that the oxidation potential of the aminochlorophenol is much lower than the anilines...

Figure 5.9 Cyclic voltamograms of Fc-peptides Fc-AspOMe 18 (i), Fc-AspOH 21 (ii), and Fc-CAspOBz] 24 (Hi), and Fc-[AspOH]2 27 (iv). 2.0M NaClO /MeOH glassy carbon working electrode, Pt counter electrode, and Ag/AgQ reference electrodes at a scan rate of lOOmVs" ...

Fig. 6.4 Cyclic voltamograms of TiCl4 solutions in BMMImN3 at 65 °C at different potential sweep rates concentration of TiCl4 0.025 mol (potential range 0 to —1.9 V)...

Fig. 6.12 Cyclic voltamograms of TiCl4 solutions in BMMImBF4 at concentrations 0.1-0.35 mol L in concentration steps 0.05 mol L . Scan rate 0.1 V s ...

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