Synthesis, Corrosion Inhibition, In Silico ADME, DFT, and Antibacterial Activity of Pyridine-Based Schiff Base and Its Cu (II) Complex

Herein, we report the synthesis of an (E)-N-(pyridine-3-ylmethylene)pyridine-2-amine Schiff base (ENppa) and its Cu (II) complex (Cu-ENppa) using 2-aminopyridine (2APy) and pyridine-3-carbaldehyde (P3C). This study aimed to investigate the ADMET profiles, electronic features, antibacterial and anticorrosion activities of the synthesized ligand, and its Cu (II) complex. The compounds were characterized using various techniques, including CHN analysis, FT-IR, 1H and 13C NMR, MALDI-TOF MS, ICP-MS, SEM, TGA/DTA, UV-visible spectroscopy, and powder X-ray diffraction (PXRD). The Cu (II) ion exhibited tetrahedral geometry in the complex by coordinating with two nitrogen atoms, one from an imine group and the other from a pyridine ring. UV-visible spectroscopy and magnetic moment data also supported this geometry. TGA/DTA revealed three stages of decomposition at 141 degrees C degrees C-255 degrees C, 255 degrees C degrees C-367 degrees C, and 549 degrees C degrees C-659 degrees C, with CuO as the final residue. PXRD analysis identified ENppa and Cu-ENppa as nanocrystallites, with crystallinities of 82% and 49%, respectively. Both compounds were highly effective in inhibiting mild steel corrosion in acidic media, with inhibition efficiencies of 97% and 98%, respective for Cu-ENppa and ENppa. They also exhibited favorable ADME profiles, indicating potential as drug candidates for in silico ADME studies. The antibacterial activity results demonstrated promising efficacy, with Cu-ENppa showing higher activity than ENppa.