Synthesis, characterization, and cytotoxic activity of some transition metal complexes with didentate (N,N) donor azo dye ligand derived from p-Anisidine

Abstract

In an alkaline ethanolic solution, 2-[1-(4-Methoxyphenyl)azo]-4,5-dichloro imidazole (4-MPADI) was prepared by reacting a diazonium chloride salt solution of p-Anisidine with 4,5-Dichloroimidazole. Various metal ions, such as Cu(II), Pt(IV) and Au(III), were complexed with the synthesized ligand 4-MPADI. A variety of spectral techniques have been used to study the structures of the azo dye ligand (4-MPADI) and its chelate complexes, including elemental analysis (C.H.N), mass spectrum, 1H NMR, 13C NMR, FT-IR, UV–Vis, XRD, thermal analysis (TGA/DTA), and magnetic measurements. The molar conductivity indicates the complexes are electrolytes and contain conductive species except for the Cu(II)-Complex. Based on the results, the ligand (N, N) behaves as a didentate and coordinates to the metal ion via the nitrogen atom of the azomethine group (C = N) of heterocyclic imidazole molecule, as well as the nitrogen atom of the azo group (N = N). Additionally, DPPH radical scavenging assays were used to investigate the antioxidant activity of the ligand, Pt(IV), and Au(III). A DPPH radical scavenging assay measured the antioxidant activity of produced compounds in comparison with ascorbic acid, a known antioxidant. However, in vitro anticancer and toxicity test results were obtained against human oesophagal cancer (SK-GT4) cells using the ligand (4-MPADI), Pt(IV) and Au(III).