Design, Synthesis, Spectroscopic Inspection, DFT and Molecular Docking Study of Metal Chelates Incorporating Azo Dye Ligand for Biological Evaluation

Abstract

A new heterocyclic azo dye ligand (L) was synthesized by the combination of 4-amino antipyrine with 4-aminophenol. The new Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) complexes were synthesized in excellent yields. The metal chelate structures were elucidated using elemental analyses, FT-IR, 1H-NMR, mass, magnetic moment, diffused reflectance spectral and thermal analysis (TG-DTG), and molar conductivity measurement. According to the FT-IR study, the azo dye ligand exhibited neutral tri-dentate behavior, binding to the metal ions with the azo N, carbonyl O, and protonated phenolic OH. The 1H-NMR spectral study of the Zn(II) complex supported the coordination of the zo dye ligand without proton displacement of the phenolic OH. Diffused reflectance and magnetic moment studies revealed the octahedral geometry of the complexes, as well as their good electrolytic nature, excepting the Zn(II) and Cd(II) complexes, which were nonelectrolytes, as deduced from the molar conductivity study. The theoretical calculations of optimized HOMO–LUMO energies, geometrical parameters, electronic spectra, natural atomic charges, 3D-plots of MEP, and vibrational wavenumbers were computed and elucidated using LANL2DZ and 6-311G (d, p) basis sets of density functional theory (DFT) with the approach of B3LYP DFT and TD-DFT methods. The ligand and complexes have been assayed for their antimicrobial activity and compared with the standard drugs. Most of the complexes have manifested excellent antimicrobial activity against various microbial strains. A molecular docking investigation was also performed, to acquire more information about the binding mode and energy of the ligand and its metal complexes to the Escherichia coli receptor using molecular docking. Altogether, the newly created ligand and complexes showed positive antibacterial effects and are worth future study.

Synthesis, Characterization, Antimicrobial, Density Functional Theory, and Molecular Docking Studies of Novel Mn(II), Fe(III), and Cr(III) Complexes Incorporating 4-(2-Hydroxyphenyl azo)-1-naphthol (Az)

“…In the infrared spectra of the unbound ligand, the phenolic–OH band could be seen anywhere between 3114 and 3218 cm –1 in wavelength. The vibration phenolic–OH was similarly eliminated in the metal complexes, which lends credence to the theory that the phenolic oxygen of the ligand plays a role in the formation of the C–O–M bond during deprotonation; , Table .…”

New mixed‐ligand thioether‐quinoline complexes of nickel(II), cobalt(II), and copper(II): Synthesis, structural elucidation, density functional theory, antimicrobial activity, and molecular docking exploration

“…These bands may be connected to the 2 B 1g → 2 E g and 2 B 1g → 2 B 2g transitions, respectively, which indicate octahedral geometry around the copper(II) core, 73 as shown in Table 1. The estimated value of the CuTeQ compound's μ eff , which suggests an octahedral geometry, 74 is 1.82 B.M. for its backbone‐to‐d 9 (t 2g 6 e g 3 ) electron configuration, Table 1.…”

“…2 B 2g transitions, respectively, which indicate octahedral geometry around the copper(II) core, 73 as shown in Table 1. The estimated value of the CuTeQ compound's μ eff , which suggests an octahedral geometry, 74…”

Efficiency and development of guanidine chelate catalysts for rapid and green synthesis of 7‐amino‐4,5‐dihydro‐tetrazolo[1,5‐a]pyrimidine‐6‐carbonitrile derivatives supported by density functional theory (DFT) studies

“…It is necessary to be familiar with the ΔE value that exists between LUMO and HOMO if one wants to ascertain the reactivity trend as an indicator of electron mobility. The following reactivity rankings, GUBZPd > GUBZCu > GUBZV > GUBZ, were found when it was determined that a lower value of ΔE implies that a molecule is more reactive 51,52 . Moreover, the level of chemical reactivity that a substance possesses is influenced by its hardness as well as its level of softness.…”