A polarographic method for elucidating the position of complexing metal ion in azo-dyestuff complexes

The location of chosen metal ions in their chelates of azo-dyestuffs like a rsenate I, arsenate III, chlorophosphonazo III, and nitrosulphonazo III has been studied by direct current polarography, differential pulse polarograp hy, and adsorptive stripping voltammetry. It has been noticed that the cath odic wave (peak) of a complex has appeared when the ate-group was involved in forming the complex. On the basis of the received results and a survey o f the literature, it has been stated that the polarographic method can be u sed as a criterion which solves the location of a metal ion in its chelate of an electrochemically active, multifunctional ligand.