Synthesis, characterization, and antibacterial activities of some metal complexes with tripodal Schiff base ligand derived from pyrrole-2-carboxaldehyde

Abstract

The tripodalheptadentate Schiff base ligand, C21H27N7, was derived from pyrrole-2-carboxaldehyde with tris(2-aminoethyl)amine (tren) and its complexes with Cd(II), Co(II), Mn(II) and Ni(II) metal ions have been synthesized. The Schiff base and its metal complexes have been identified by IR, UV-Vis, 1H-NMR, 13C-NMR spectroscopy, elemental analysis and thermo gravimetric analysis (TGA). According to the spectroscopic and elemental analyses data, it was found that the Schiff base was coordinated to the metal ions as a potentially heptadentate ligand. All compounds showed antibacterial properties against the gram-positive bacteria; Bacillus cereus, Staphylococcus aureus, and gram-negative bacteria; Pseudomonas aeruginosa, Escherichia coli by using disc diffusion and micro-broth dilution methods. Also, the metal complexes showed a greater inhibitory effect than their individual ligand. Bacillus cereus was the most susceptible bacterial species to Co(II) complex while Escherichia coli required a relatively higher minimum inhibition concentration of Mn(II) complex.