تحضير وتشخيص ليكاندات عضوية ثنائية الأزوميثين والعديد من معقداتها المخلبية مع الدراسة البكتيرية لها

Synthesis and Characterization of Organic Bis-Azomethine Ligands and Several of Their Chelate Complexes with a Study of Their Antibacterial Activity

In this research, new organic ligands of the bis-azomethine Schiff base type were synthesized using triethylenetetramine (TETA) as the amine source with different aromatic aldehydes such as terephthalaldehyde the ligand (2E,12E)-3,6,9,12-tetraaza-1(1,4)-benzenacyclotridecaphane-2,12-diene. Chemical formula (C14H20N4 and cinnamaldehyde the ligand, N1,N2-bis(2-(((1Z,2E)-3- phenylallylidene)amino)ethyl)ethane-1,2-diaminethe . Chemical formula (C24H30N4). The prepared ligands were then reacted with some transition metal ions such as Ni(II), Cu(II), Zn(II), Pd(II), and Pt(IV) to obtain stable coordination complexes.The synthesized compounds were characterized using various spectroscopic techniques including FT-IR, UV-Vis, NMR, and elemental analysis, in addition to studying their magnetic susceptibility and molar conductivity to determine the geometric structure of the complexes. Nickel and palladium complexes adopted a square planar geometry, while copper complexes showed variations in geometric shape depending on the type of ligand. The copper complex with the first ligand adopted an octahedral shape, whereas with the second ligand it took a square planar shape. Zinc and platinum complexes, on the other hand, adopted an octahedral geometry. The biological activity of both the ligands and their metal complexes was tested against a group of Gram-positive and Gram-negative bacteria, as well as the fungus Candida albicans, using the disk diffusion method. The results showed that the metal complexes possess higher biological activity than the free ligands, especially the complexes of copper, zinc, and platinum. This is attributed to the increased permeability into microbial cells due to coordination and the reduced polarity of the ligands after binding with the metal ions. This study suggests the potential of using these complexes as antimicrobial agents and may open new avenues for the development of novel therapeutic compounds based on chelating Schiff base ligands.