Synthesis, spectral characterisation, and biological studies of N,N’-Bis(4-isopropylbenzylidene)-2,3-diaminopyridene and their metal complexes

The present study involves the synthesis of N,N’-bis(4-Isopropylbenzylidene)-2,3-diaminopyridene and its cobalt(II), nickel(II), and copper(II) complexes and investigating their biological activity against a selected cancer cell. The presence of the imine group in the Schiff base ligands have been the cause of various biological activities, which upon coordination with transition metals may further enhance the activity. In this regard, we have synthesized few transition metal complexes containing Schiff base ligand to investigate their biological activity. All the synthesized compounds were characterized by various spectral and analytical techniques. The complexes were characterized on the basis of metal estimation studies, conductance behaviour, magnetic property, IR, UV-Vis, EPR (liquid nitrogen temperature) spectral studies, and thermal analysis. The metal ions and ligands are maintained at 1:2 ratio in the synthesized complexes. Various studies have indicated that the Co(II) complex likely adopts an octahedral geometry, while a square planar geometry is proposed for both the Cu(II) (distorted) and Ni(II) complexes. The electrochemical properties of the complexes were studied by cyclic voltammetry. The Schiff base and its complexes were scrutinized against bacterial and fungal pathogens. The cobalt and copper complexes show the maximum activity towards the bacterial pathogen S. aureus; therefore, they were further scrutinized for minimum inhibitory concentration studies. The copper complex is found to have moderate cytotoxicity against the breast cancer cell line (MCF-7).