Polarographic behaviour of phenyl-2-picolylketone-2-pyridylhydrazone and its copper (II) complexes

The polarographic behaviour of phenyl-2-picolylketone-2-pyridylhydrazone, PPKPyH, has been studied in aqueous-ethanol mixtures of different pH's using DC and DP polarographic method. In the pH range 3.7–6.2, the observed single irreversible reduction wave is assigned to the splitting of the N—N bond and reduction of C=N centre. In alkaline medium, a second wave appears at more negative potential due to the reduction of the phenyl-2-picolylketone which is formed from the hydrolysis of PPKPyH. The optimum conditions for the analytical determination of PPKPyH was reported. Differential pulse polarography have been used to elucidate the complexation reaction between PPKPyH and copper(II) in unbuffered solutions. Two complexes are formed with log β1 = 4.42 and log β2 = 8.87.