Metal complexes of azo mesalamine drug: Synthesis, characterization, and their application as an inhibitor of pathogenic fungi

Abstract

A novel azo dye ligand, formed by the coupling of 5‐aminosalycalic acid (mesalamine drug) with 2‐amino pyrimidine (H2L) and its Co2+, Ni2+, and Cu2+ complexes, was synthesized. The structures of ligand and its complexes have been described by elemental analysis, inductively coupled plasma (ICP), thermogravimetric analysis (TGA), magnetic moment measurements, molar conductance, ultraviolet–visible (UV–Vis), X‐ray powder diffraction, infrared (IR), 1H‐nuclear magnetic resonance (NMR), 13C NMR, and electron impact (EI) mass spectral studies. The obtained data detected that the H2L ligand acts as monobasic tridentate via C=N, azo nitrogen, and deprotonated OH groups. The data supported the formation of 1:2 (M:L) for Co2+ complex, while Ni2+ and Cu2+ gave 1:1 (M:L) complexes mononuclear formulation. The Co2+ and Ni2+ complexes have octahedral structures, while Cu2+ complex has tetrahedral geometry. The ligand and its Co2+, Ni2+, and Cu2+ complexes were applied as an antifungal against a set of root rot‐associated soil‐born phytopathogenic fungi and compared with the effect of Hatric (recommended fungicide). Our findings revealed that the metal complexes exhibited greater antifungal activity than the parent ligand. The Cu2+ complex was found to be the most effective compound. The effect of Hatric and Cu2+ complex on structural alterations of Fusarium semitectum was studied by scanning electron microscopy (SEM).