Voltammetric Studies and Electrode Kinetics of Some Arylhydrazone Derivatives of Pyrazolone in Aqueous Solutions at Mercury Electrode

M. T. Mohamed

Chemistry Department, Faculty of Science, Mansura University, Demiatta, Egypt.

The dc-polarography and cyclic voltammetry of some arylhydrazone derivatives of pyrazolone were measured in Britton-Robinson buffer series of pH 2-12. The results of dc-polarography indicated that all hydrazone compounds were reduced undergo an irreversible 4-electron reduction wave leading to the cleavage of the N-N bond and saturation of the C=N centre. The voltammograms recorded at different scan rates exhibited one cathodic peak. The E1/2 and Ep shifted to more negative potential with increasing the pH. A mechanism for the electrode reaction was suggested. The effect of substituents on the reduction mechanism and the kinetic parameters were calculated and discussed.

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