POTENTIOMETRIC INVESTIGATION OF Fe(IlI),Ni(II) AND Cu(II) COMPLEXES OF SOME ISATIN AND THIOPHENE ISOTHIOSEMICARBAZONES

Abstract

The coordination compounds of isatin-thiosemicarbazone (L 1 ) and its Sbenzyl-ester (L 2 ), and of thiophene-2-aldehyde-thiosemicarbazone (L 3 ) and its S-benzylester (L 4 .HCI) with Cu(II), Ni(II) and Fe(III) were investigated via Potentiometrie method.According to the study done by using the Irving-Rossotti technique, the protonization constants of the ligands and the stability constants of the relevant complexes in 50% dmso/water medium were found. The behavior of the isothiosemicarbazone ligands in the solvent medium was evaluated by considering the likely Z-E isomerizations. The preliminary data, which can be and Cu(ll) Complexes useful in tracing the formations of metal compounds according to the Ζ and Ε isomers of isothiosemicarbazones, were obtained by the Potentiometrie method.