Synthesis and Characterization of Innovative Tetraazamacrocyclic Complexes of La(III) and their Antibacterial, Antifungal, Antioxidant and Antidiabetic Activity.

A new series of macrocyclic complexes of lanthanum (III) derived from the template condensation reaction of bis(benzyl)-4-nitro-1,2-phenylene diamine with different diamines such as 4-nitro-1,2-phenylene diamine, 4-bromo-1,2-phenylene diamine, ethylene diamine, 1,2-diamino propane and 4-chloro-1,2-phenylene diamine in the presence of lanthanum chloride salt. The ligand was synthesized by the condensation of benzyl and 4-nitro-1,2 phenylene diamine. The synthesized complexes have been analyzed by elemental analysis, conductance measurement and characterized by spectral analysis, i.e. UV-visible, IR, ¹H-NMR, Mass, XRD and TGA techniques. The presence of sharp narrow peaks in the X-ray diffractogram confirmed the crystalline nature of the synthesized complexes. Antioxidant and Antidiabetic studies were performed for ligand and all complexes. The strongest antioxidant activity was recorded as 80% at 1000 mg/L for [La(C₄₀H₂₆N₅O₂Cl₂Br)]Cl.5H₂O complex with IC₅₀ value of 203.9247 mg/L. In addition to these, compounds were successfully also screened for their biological efficacies against a few pathogenic strains of bacteria and fungi.It was found that ligand and compexes show good antimicrobial results.