Synthesis and characterization of potential antioxidant agent of novel pyridylazo ligand and its palladium complex

A new azo dye ligand namely ((E)-1-(4-hydroxy-3-(pyridin-3-yldiazenyl)phenyl)ethan-1-one) (HPPE) was synthesized by the coupling reaction of diazoinium salt of 3-aminopyridine and 4-hydroxyacetophenone. The palladium complex was prepared by reacting palladium chloride with the HPPE ligand. These compounds were characterized by different techniques such as mass, 1H-NMR, infrared, UV-Vis spectroscopies. The infrared data reveal that azo ligand reacting as bidentate via oxygen and nitrogen atom of azo group and it reveals the important functions as carbonyl group, methyl group, and azo group in the ligand and the complex such. The palladium complex is square planer. The ligand showed a visible colorimetric pH sensitive chemosensor, fast response time and is fully reversible and exhibited a large wavelength shift more than170 nm accompanied by excellent sensitivity of pH in the range of 3-9. The HPPE ligand and palladium complex showed potential antioxidant activity especially the ligand showed activity so close to the ascorbic acid. KEY WORDS: Antioxidant, Palladium complex, Pyridyl, Azo dye, Acidity Bull. Chem. Soc. Ethiop. 2024, 38(5), 1301-1310.                                             DOI: https://dx.doi.org/10.4314/bcse.v38i5.9