- P-ISSN 1225-0163
- E-ISSN 2288-8985
Algal(II) Multidentate N, O-Schiff base ligands, such as bis(salicylaldehyde) ethylenediimine(SED), bis(salicylaldehyde) propylenediimine(SPD), bis(salicylaldehyde) diethylenetriimine(SDT), bis (salicylaldehyde) triethylenetetraimine(STT) and bis(salicyl-aldehyde)tetraethylenepentaimine(STP) were prepared. Stepwise proton dissociation constants of the Schiff base were measured potentiometrically in ethanol and a mixture of 70% dioxane and 30% <TEX>$H_2O$</TEX>. The stability constants of copper(II)-Schiff base complexes were in the order of Cu(II)-SPD<Cu(II)-SED<Cu(II)-SDT<Cu(II)-STT<Cu(II)-STP and were increased with the number of donor atoms. Reduction potentials obtained by cyclovoltagram were shifted to the negative potential in the order of Cu(II)-SPD<Cu(II)-SDT<TEX>${\leq}$</TEX>Cu(II)-SED~STT<TEX>${\leq}$</TEX>Cu(II)-STP. Oxidation-reduction process of the Cu(II)-Schiff base complexes was involved with one-electron reaction.