Azo-Hydrazo Tautomerism: Further Evidence Based On Polarographic Reduction And Acidity Function Of Some Heterocyclic Compounds Containing Oximino-Group

Abstract

Potentiometric pKa and polarographic behaviour of l,3-indandione-monoxime-2-phenyl azo and four of its substituted derivatives were investigated in buffer solution of pH -2-12. The results showed that the compounds are in the azo-form, where its reduction wave precedes that of the oxime. A mechanism for the electrodic processes was proposed. Half-wave potentials showed fair correlation with Hammett's s constants while pKa is practically independent.