Synthesis, Characterization Biological Activity and Molecular Docking of Some Trivalant Transition Metal Complexes with Schiff Bases Derived from o-Vanillin

Abstract

This study highlights the synthesis and characterization of tetradentate ONNO Schiff base ligands H₂L¹ (N, N-Bis(vanillinidene)-4-chloro-1,2-phenylenediamine), and H₂L² (N,N-Bis(vanillinidene)-4-nitro-1,2-phenylenediamine) and  Fe(III), Co(III), Cr(III) complexes of H₂L¹ and H₂L². The Schiff base ligands H₂L¹ and H₂L² have been synthesized from o-vanillin and 4-chloro-o-phenylenediamine and 4-nitro-o-phenylenediamine by condensing them in 2:1 molar ratio, respectively. Ligands and complexes have been characterized by microanalytical technique, FTIR, UV, NMR spectroscopy and magnetic susceptibility. On coordination to the metal centers, the ν(C=N) and ν (C-O) peaks shifted to lower frequencies and new peaks for (M-N) and (M-O) appears in the range 535-560 and 421-460 cm^-1, respectively. The Schiff base ligand and complexes have been screened for antimicrobial property against bacteria and fungi.  Molecular docking has also been carried out against CPE(Clostridium perfringens enterotoxin) (PDB ID:2XH6). It has been observed that affinity of complex is greater than ligand.