Solution and Solid State Study of Nickel(II) Ternary ComplexesContaining 5-Aminolevulinic Acid Drug and Amino Acids

Solution equilibria of the systems Ni(II)-5-aminolevulinic acid as ligand (A) and the amino acids[alanine (Ala), valine (Val), methylamine (Met), imidazole (Imi), Histidine (His), serine (Ser), cysteine(Cys) and penicillamine (Pen)] as ligands (L) have been studied pH-metrically. The stability constantsof mixed ligand complexes were calculated with I = 0.10 mol L-1 KNO3 using HYPERQUAD programat 25 ± 0.1 ºC. The log10 X values showed a higher stabilities for the mixed ligand complexes comparedto the binary analogues. The synthesis and characterization of the new amino acid mononuclear Ni(II)binary complex [NiA] (1) and ternary complex [NiAL] (2) were achieved via molar conductance,elemental analysis UV-vis, IR, 1H NMR, thermal analysis and magnetic moment. The thermogravimetricanalysis of complexes were investigated by TG-DTA suggests that the complexes possess high thermalstability formation and their respective nickel oxide for 1 and nickel sulfide for 2 as final chemicalentities, which are thermally stable. The nickel(II) chelates were found to be non-electrolytes,diamagnetic moments and the geometry around Ni(II) ion in complexes 1 and 2 is square planar