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

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. A newly synthesized azo dye ligand and its Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) complexes require a range of techniques, including elemental analyses and spectroscopic studies. Nitrogen of the azo group and one oxygen of the carbonyl group coordinate the azo ligand to the metal ions, acting as a neutral bidentate ligand, according to the inferred IR spectra. The molar conductance data indicated that all the complexes were electrolytes. Octahedral geometry was suggested for the complexes being studied. The proposed structural equations for the complexes were, in general, expressed as [M(L)Cl2(H2O)2]center dot Cr(III), x = 1, n = 0; Cd(II), x = n = 0; Zn(II), x = 0, n = 1, and [M(L)(Cl)(H2O)3] Clx center dot nH2O Mn(II), Co(II), Ni(II), and Cu(II), x = 1; Clx [M = Fe(III), x = 2]. image