Synthesis, characterization, structure determination from powder X-ray diffraction data, and biological activity of azo dye of 3-aminopyridine and its complexes of Ni(II) and Cu(II)

In the present work azo dye ligand of 3-aminopyridine (L) and its complexes of NiII and CuII were synthesized, characterized and evaluated for antibacterial and antifungal activities in vitro. The L ligand was synthesized by reacting diazonium ion of 3-aminopyridine with 1-naphthole in presence of sodium acetate. The ligand (L) and its complexes were characterized by elemental analysis (CHN), magnetic susceptibility, molar conductivity, UV-Vis spectra, and infrared technique. The (L) azo dye exhibited high sensing for the pH changes. The color of L dye changed from red in basic medium to yellow color in acidic medium. The data of CHN, UV-Vis and magnetic susceptibility indicate that the complexes [Ni(L)2Cl2] and [Cu(L)2Cl2] are tetrahedral. The complexes of Ni(II) and Cu(II) exhibited potent activity against growth of Staphylococcus aureus and Escherichia Coli as well as against Penicillium Sp. And Aspergillus niger. Under visible irradiation (395 nm), the (L) azo dye of pyridine exhibited a significant change in the spectra under irradiation.                     KEY WORDS: Pyridine, Photoisomerization, Pyridylazo, Biological activity, pH sensor   Bull. Chem. Soc. Ethiop. 2020, 34(3), 523-532. DOI: https://dx.doi.org/10.4314/bcse.v34i3.