Synthesis, Electrochemical and Antioxidant Properties of New Thiazolylazo‐based Mixed Ligand Metal Complexes

Abstract

The complexes of 4‐(2‐thiazolylazo)resorcinol (TAR) and 2,2′‐bipyridine (bpy), [M(bpy)(TAR)(H2O)]AcO [(M=CoII, CuII, ZnII] and [Mn(bpy)(TAR)AcO] were synthesized and their structure was determined by elemental analysis, thermal analysis (DTA/TGA), IR spectroscopy, molar conductivity, and magnetic measurements. The ligand 4‐(2‐thiazolylazo)resorcinol coordinated to metalII ions via azo and thiazolyl group nitrogens and one oxygen atom of resorcinol, while 2,2′‐bipyridine also contributed two coordination bonds via its nitrogen atoms. The electrochemical profile of the compounds was investigated by cyclic voltammetry (CV) which confirmed their electrochemical activity. The results obtained by CV method pointed out that the electrode reactions were diffusion controlled. The total antioxidant capacities of the ligands and complexes were evaluated by using cupric reducing antioxidant capacity (CUPRAC) method. The complexes displayed more antioxidant activity than their ligands. The Trolox equivalent antioxidant activity (TEAC) values of all complexes exhibited more higher and approximate values to Trolox but bpy ligand did not show any activity.