Nano-synthesis, characterization, modeling and molecular docking analysis of Mn (II), Co (II), Cr (III) and Cu (II) complexes with azo pyrazolone ligand as new favorable antimicrobial and antitumor agents

Novel nanosized Mn (II), Co (II), Cr (III) and Cu (II) complexes were synthesized with 2‐((5‐oxo‐1,3‐diphenyl‐4,5‐dihydro‐1H‐pyrazol‐4‐yl)diazenyl) benzoic acid, HL applying precipitation method. Their structures were characterized based on the elemental and thermal analyses, spectra (FT‐IR, UV–Vis, MS, ESR and XRD), conductivity and magnetic moment measurements. IR spectra offered that HL behaves as monobasic tri‐dentate ligand towards Mn (II), Cr (III) and Cu (II) and monobasic bi‐dentate towards Co (II). The XRD results unambiguously confirmed the crystalline nature and nano‐sized particles of Cu (II) complex while HL and other complexes exhibited amorphous phases. The magnetic moment data, UV–Vis and ESR spectra supported the formation of octahedral geometries for Mn (II), and Cr (III) complexes, whereas Co (II), and Cu (II) complexes showed tetrahedral arrangement. The activation parameters for the thermal degradation stages were theoretically calculated using TGA curves. The obtained data showed the inspected complexes as favorable antimicrobial drug candidates. The studied compounds were screened out for their antitumor and antimicrobial activities. The inspected compounds exhibited a reasonable antibacterial activity and weak antitumor efficacy. The in vitro results were confirmed using the in silico molecular docking analysis (docking server) applying x‐ray crystallographic structures of the proteins (4 m01, 3 t88, 1zap & 4ynt) from PDB (Protein Data Bank). HL and probably its complexes displayed adequate binding with the receptors of 4 m01, 3 t88, 1zap, and 4ynt microorganisms. The obtained data show the inspected complexes as favorable antimicrobial drug candidates.