Spectrophotometric studies prior to construction of ISE is very necessary step, and Selective and simple determination of elements via Ion Selective Electrodes (ISE) are very attractive in chemical analysis. In order to obtaining the new ISE for determination of La3+ ions, the interaction of N, N'-adipylbis (5-phenylazo salicylaldehyde hydrazone (L) with different trivalent and divalent metal ions, investigated, the complexation of L with Cr3+, Al3+, Ce3+, Gd3+, Yb3+ and La3+ ions and also Ni2+, Cu2+, ions in acetonitrile solution are studied spectrophotometrically, and confirmed by conductometric, NMR and IR studies.
It was found that in the studied trivalent metal ions, 1:1 complexes were formed in solution. In the case of divalent metal ions both ML and M2L complexes were formed. The Kf Values of the resulting complexes between ligand and different metal ions were evaluated by computer processing of the corresponding mole ratio data to an equation that derived former using a non-linear curve-fitting program, KINFIT. The resulting Kf values for all metal ion complexes studied showed that the stability of the complexes studied varies in the order of: La3+ > Yb3+ > Ce3+ > Gd3+ > Al3+ > Cr3+. The results revealed that this ligand is candidate for construction of new ISE for simple and selective determination of La3+ ions.