Synthesis and characterization of 2-(2-quinolylmethyleneamino)phenol complexes with Co and Mn

Abstract

Synthesis of the azomethine 2-(2-quinolylmethyleneamino)phenol and its Co and Mn complexes is described. Ligand was prepared by mixing of 2-quinolynecarboxaldehyde and o-aminophenol, while metal complexes were prepared by addition of the ligand to corresponding Co(II) and Mn(II) acetate solutions. After precipitation the complexes were recrystallized and isolated. The structure of the ligand was investigated by elemental analysis, IR and mass spectrometry, while the preparation of metal complexes was confirmed by IR spectrometry. The possibility of using this ligand as a spectrophotometric reagent for Co and Mn determination has also been investigated. The composition and stability constants of the complexes in water/methanol solution, ϑ(methanol) = 10% at constant temperature, t = (25 ± 1) °C and ionic strength I = 0.5 M (KNO 3), have been determined. It was found that the metal complexes formed in the solution are of the ML 2 type. Linear calibration diagrams at different pH values have been obtained and the lowest detection limit was found to be 0.1 and 0.08 μg/ml at investigated experimental conditions for Co and Mn determination, respectively.