Schiff base ligands derived from 2-pyridinecarboxaldehyde and its complexes: characterization, thermal, electrochemical, and catalytic activity results

Two novel Schiff base ligands (E)-N,N'-bis(pyridin-2-ylmethylene)cyclohexane-1,4-diamine and (E)-N,N'-bis(pyridin-2-ylmethylene)benzene-1,4-diamine and their binuclear Cu(II), Ni(II), and Co(II) complexes have been synthesized from 2-pyridinecarboxaldehyde, 1,4-diaminobenzene, and trans-1,4-diaminocyclohexane. Characterizations of the synthesized compounds were carried out by thermal analysis, analytical and spectroscopic methods. Catalytic activity of the complex compounds showed some low and some high performances towards the oxidation reactions of cyclohexene and styrene, especially higher performances were obtained for the oxidation of styrene. Thermal examination of the title compounds revealed that complex compounds, apart from Cu(II) complex, were more resistant to temperature, which increases their chance to be used as catalysts towards chemical reactions carried out in high temperatures. Electrochemical features of both ligands and complexes have also been explained.