Nano-synthesis, solid-state structural characterization, and antimicrobial and anticancer assessment of new sulfafurazole azo dye-based metal complexes for further pharmacological applications

A new azo dye ligand (abbreviated as H3L) derived from coupling of sulfafurazole diazonium salt with 2,4-dihydroxybenzaldehyde was prepared and characterized applying different spectroscopic and analytical techniques. The novel nanosized trivalent Cr and Fe alongside with divalent Mn, Co, Ni, and Cd complexes with H3L have been synthesized for further promising pharmaceutical uses. All complexes were totally characterized by investigating various analytical and spectral tools such as microanalysis, FT-IR, H-1 NMR, UV-Vis, powder XRD, and TEM spectra as well as magnetic moment and molar conductance measurements. Microanalysis, TGA, and conductance studies confirmed the formation of all metal complexes in 1:1 (L: M) molar ratio with covalent mode. The FT-IR and H-1 NMR investigation asserted the chelation of H3L to different metal ions through azo nitrogen and phenolic deprotonated hydroxy oxygen in the o-position. UV-Vis, ESR, and magnetic moment studies revealed octahedral geometry around Cr and Fe ions, whereas Mn, Co, Ni, and Cd complexes displayed tetrahedral configurations. XRD patterns and TEM images proved homogeneous distribution over the chelates surfaces and nanometric size of complexes particles. Molecular modeling was used to optimize the complexes' geometric structure showing good harmonity with the experimental results. The antifungal and antibacterial efficiencies were strongly enhanced upon complex formation. Cr(III) and Ni(II) complexes showed the strongest and promising anticancer activities (IC50 = 7.64 and 6.99 mu g/ml) among the tested compounds, whereas Cd(II) complex showed moderate anticancer efficiency (IC50 = 12.10 mu g/ml), compared with the 5-fluorouracil (applied standard drug) with IC50 = 6.44 mu g/ ml.