Cyclic voltammetry, conjugated

It is known that the reduction potentials of quinones are related to the aromatic stabilization of the parent conjugated systems. In an attempt to relate the annulenediones 171,177, and 178 to the tetradehydro[18]annuIene system Breslow and coworkers63 have studied their electrochemical reduction by cyclic voltammetry. These diones can easily be reduced to the corresponding dianions, e.g. 171 - 179. These... 

Phenothiazine derivatives and compounds with two or three thiazine rings conjugated to each other, such as 98 and 99 <2004JA1388>, 159, 160, and 161 <2003EJO3534>, have interesting electronic properties (see also Section 12.2) and their cyclic voltammetry has been studied. These compounds are oxidized stepwise until each phenothiazine moiety has lost an electron. 

Nitrenium ions can be viewed as products from two-electron oxidation of amines (Fig. 13.13) followed by loss of a proton. Thus they need to be considered as intermediates in the oxidation of amines. In two early studies, diarylnitrenium ions were shown to have formed in the oxidation of diarylamines. Svanholm and Parker carried out cyclic voltammetry on A,A-di-(2,4-methoxyphenyl)amine (25) in acetonitrile with alumina added to suppress any adventitious nucleophiles. The voltam-mogram revealed two sequential oxidation processes (1) formation of the cation radical 26, and (2) either the nitrenium ion 27 or its conjugate acid. In strongly acidic solution the latter was sufficiently stable that its absorption spectrum could be recorded. 

Olah generated similar dicationic species upon treatment of 4-hydroxy- or 4-methoxy- nitrosobenzenes with 1 1 HSO F-SbFs in SO2 (Scheme 6) These species were stable in the superacid media and were characterized by NMR spectroscopy. No nitrenium ion species were detected. Although Olah was unable to detect simple monoarylnitrenium ions, a few stabilized diarylnitrenium ions were detected during cyclic voltammetry experiments on the corresponding diarylamine in CHsCN, For example, the di-para-anisylnitrenium ion and its conjugate acid (Scheme 7) were both observed. This ion had a lifetime of about 1 s in CH CN. ... 

Electric arcs, in metal vapor synthesis, 1, 224 Electric-field-induced second harmonic generation Group 8 metallocenes, 12, 109 for hyperpolarizability measurement, 12, 107 Electrochemical cell assembly, in cyclic voltammetry, 1, 283 Electrochemical irreversibility, in cyclic voltammetry, 1, 282 Electrochemical oxidation, arene chromium carbonyls, 5, 258 Electrochemical properties, polyferrocenylsilanes, 12, 332 Electrochemical reduction, bis-Cp Zr(III) and (IV) compounds, 4, 745 Electrochemical sensors biomolecule—ferrocene conjugates... 

A series of SAMs formed on Au from mono- and dithiol conjugated aromatic molecules was characterized by cyclic voltammetry, grazing incidence Fourier transform infrared spectroscopy, contact angle measurement, and ellipsometry.43 The analyses indicated that the molecular orientation of conjugated phenylene- and thophene-based dithiols became less tilted with respect to the surface normal as the chain length of the organic molecules increased. 

Electrochemical studies confirmed the presence of redox-active nanoparticles. Differential pulse and cyclic voltammetry studies were conducted. Cyclic voltammetry showed that the complex displays an electrochemically reversible ferrocene/ ferrocenium couple (Figure 9.6). The oxidation potential for the hybrid CPMV-Fc conjugate and free ferrocenecarboxylic acid in solution was determined E1/2 of CPMV-Fc was 0.23 V, and Elj2 of free ferrocenecarboxylic acid was 0.32 V versus the Ag/AgCl electrode, respectively. This shift is expected for the conversion of the carboxyl group of ferrocenecarboxylic acid to an amide on coupling to the virus capsid, since the amide is less electron-withdrawing. 

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