Showing papers on "Cyclic voltammetry published in 1968"

Anodic oxidation of amines. Part I. Cyclic voltammetry of aliphatic amines at a stationary glassy-carbon electrode

Abstract: The anodic oxidations of seventeen aliphatic amines have been examined by cyclic voltammetry at a glassy-carbon electrode in aqueous alkaline solution. All are irreversibly oxidized. Primary amines show no wave. Secondary amines show one wave. Most tertiary amines show two waves and the peak potentials of the first waves are less positive than those of secondary amines. The peak potentials of the first wave of substituted tertiary amines shift to more positive values with increasing electronegativity of the substituent, and some amines with a strongly electron withdrawing group give one wave or no wave. A linear relationship is obtained between the pKa values and peak potentials of the first waves for tertiary amines. The postulated reaction mechanism for tertiary amines involves loss of two electrons, followed by reaction with water to form a secondary amine and an aldehyde.

The Cu / CuF2 Couple in Anhydrous Hydrogen Fluoride

Abstract: The electrochemical behavior of a Cu electrode was investigated in basic, anhydrous . Anodization of Cu established the couple. Micropolarization and bias tests indicated that this couple was reversible, and its potential vs. an H2 electrode in the same solution agreed well with that predicted from thermodynamic data. Thus the couple is suitable for use as a reference electrode in basic . The formation of a relatively thick, insoluble anodic film at a copper electrode was demonstrated by cyclic voltammetry and chronopotentiometry. Anodic‐cathodic cycling of an electrode gave rise to significant roughening of the electrode surface as shown by i‐E curves, E‐t curves, and differential capacitance measurements on cycled electrodes. X‐ray analysis of the anodic film confirmed the presence of crystalline copper fluoride. The formation of appears to proceed via dissolution of Cu to form Cu2+ ions, followed by precipitation of the on the electrode surface. The polarization behavior of Cu electrodes in anhydrous solution containing added showed that anodic film formation can be approximated by Tafel lines with an apparent exchange current density of about . Properties of the anodic film of are quite similar to those observed for noncontinuous anodic films formed in aqueous solutions.

Cyclic voltammetry of diphenylpicrylhydrazyl in tetrahydrofuran

Abstract: Cyclic voltammetry has revealed four reversible single electron transfer processes in the oxidation and reduction of diphenylpicrylhydrazyl (DPPH) in tetrahydrofuran (THF). These are associated wit...