Synthesis, Spectral characterizations, Antioxidant, and Antibacterial studies of novel Schiff base and its metal complexes

Abstract

A new Schiff base ligand was produced by refluxing 8-hydroxyjulolidine-9-carboxaldehyde with H-imidazo[1,2-a]pyridin-6-amine in methanol using an acetic acid catalyst. The ligand was studied by elemental analysis, IR, ¹H and ¹³C NMR, and ESI-MS, resulting in an 86% yield. Metal complexes of Fe(II), Co(II), Ni(II), Cu(II), and Zn(II) were then formed by reacting them with metal acetate salts. The coordination of azomethine nitrogen and phenolic oxygen was established through characterization. The antioxidant capability was tested using a DPPH radical scavenging experiment, which revealed that metal complexes outperformed free ligands. The disc diffusion method was used to assess antibacterial activity against Gram-positive and Gram-negative bacteria, and metal complexes demonstrated superior inhibition zones.