Analyzing the structure of the metal complexes of biologically active azo dye ligand

Abstract

A novel azo dye ligand was created by diazotizing 4‐aminoantipyrine and then coupling it with 2‐aminophenol as part of a methodical investigation of physiologically active compounds, 4‐aminoantipyrine. The novel complexes containing Cr(III), Fe(III), Mn(II), Co(II), Ni(II), Zn(II), Cu(II), and Cd(II) were created from the target ligand (L). The structures of the ligand and metal complexes were verified by elemental analyses, thermogravimetric analysis–difference thermogravimetry (TGA‐DTG), conductivity measurements, infrared (IR), UV–Vis, 1H‐nuclear magnetic resonance (NMR), X‐ray diffraction (XRD), and mass spectrometry. Using the Gaussian 09 tool, the density functional theory (DFT)/B3LYP method was utilized to compute the energy gaps and other important theoretical features. Also, the newly synthesized azo dye ligand, in comparison with metal complexes, was screened for its antimicrobial activity. The crystal structures of Staphylococcus aureus and Bacillus subtilis as gram‐positive bacteria, Salmonella sp. and Escherichia coli as gram‐negative bacteria, and fungal (Aspergillus fumigatus and Candida albicans) species were compared with the produced azo dye and its metal complexes via molecular docking. Most of the complexes exhibited greater antimicrobial activities against these organisms than did the original azo dye ligand.