Synthesis, characterization, and antimicrobial activity of hexa-coordinated cobalt (II) complexes with Salicylaldehyde-derived schiff base ligands

Schiff base metal complexes have a wide range of applications in various fields, especially in the biological field. In this work, Hexa-coordinated (Co2+) complexes, bis(N-Salicylaldehyde ethanolamine) Co complex (CoSBC1) and bis(N-Salicylaldehyde-2-aminopyridine) Co complex (CoSBC2), have been synthesized by the reactions between transition metal (Co) with Schiff base that derived from Salicylaldehyde with ethanol-amine or 2-aminopyridine. The Characterization of the purified complexes was achieved via FT-IR, Elemental analysis, SEM, UV-Vis, and TGA analyses. The conductivity of the Schiff bases and their complexes was studied to prove that they behave as non-electrolytes. Furthermore, the antimicrobial, antibacterial, antifungal, and antialgal activities of the two Schiff bases hexa-coordinated complexes were studied to estimate the broad-spectrum applicability. Both CoSBC1 and CoSBC2 displayed more anti-Gram-positive bacterial activity (32–40 mm) than anti-Gram-negative bacterial activity (32 mm). All the results indicate that the prepared Schiff bases hexacoordinated Co(II) complexes exhibit good antimicrobial efficiency against bacteria, fungi, and algae.