Copper(II) complexes with NNN and NNO Schiff base ligands as efficient photodegradation agents for methylene blue, preferential BSA binder and biomaterial transplants

Abstract

Herein, a monomeric copper(II) complex of the general formula [Cu(L)Cl2] (1) and a polymeric copper(II) complex bearing the formula [Cu2L/2(µ-N3)(N3)]n, (2) have been synthesized using NNN and NNO tridentate Schiff base ligands, L and L/ where L = N-((6-methoxypyridin-2-yl)methylene)(piperidin-2-yl)methane amine and L/ = 1-((3-(methylamino)propylimino)methyl)naphthalene-2-ol. Both the complexes have been characterized by single crystal X-ray diffraction and UV–Vis, FTIR, ESI-MS spectroscopic studies. The crystal structure of the complex (1) reveals a square pyramidal geometry whereas the structure of the complex (2) exhibits elongated square pyramidal geometry and the asymmetric unit of the complex contains two Cu(II) ions connected by the single µ-azido bridge. The electronic structures of the complexes are optimized by Density Functional Theory (DFT) calculations to explore their coordination stabilities and chemically reactive parameters. Besides, the Hirshfeld surfaces and two-dimensional fingerprint plot are also carried out to visualize the intermolecular interactions in the crystal of complex 1 and complex 2. Photodegradation against Methylene Blue (MB) proves the greater efficiency of complex 2 as a photodegradation agent for MB organic pollutant dye. Preferential binding studies of both the complexes towards the protein, Bovine Serum Albumin (BSA), by a series of spectroscopic techniques reveal that complex 1 strongly interacts with BSA. The spectroscopic data are well correlated by molecular docking studies. These interaction studies prompted us for cell viability studies against SiHa cancer cell to check whether the complexes may be used as biomaterial transplants or not. It is observed that the cell viability increases with time demonstrating the biocompatible nature of the complexes as well as their uses as biomaterial transplants. © 2021 Elsevier B.V.