A new ternary Cu (II) complex with 4,7‐dimethyl‐1,10‐phenanthroline and NOO‐type tridentate Schiff base ligand: Synthesis, crystal structure, biomacromolecular interactions, and radical scavenging activities

Abstract

NOO‐type tridentate Schiff base, N‐salicylidene‐2‐aminobenzoic acid, (H2L), and its ternary Cu (II) complex containing H2L Schiff base and 4,7‐dimethyl‐1,10‐phenanthroline (4,7‐dmphen), [Cu(4,7‐dmphen)(H2L)]27H2O, have been synthesized and characterized by CHN analysis, ESI‐MS, FTIR, and single‐crystal X‐ray diffraction techniques. The interaction of alone H2L Schiff base ligand and ternary Cu (II) complex with biomacramolecules {calf thymus DNA (CT‐DNA) and bovine serum albumin (BSA)} has been investigated by electronic absorption and fluorescence spectroscopy. The experimental results indicate that H2L Schiff base ligand and ternary Cu (II) complex bind to CT‐DNA by means of a moderate intercalation mode. Furthermore, the fluorescence quenching mechanism between H2L Schiff base ligand and ternary Cu (II) complex with BSA possesses a static quenching process. Radical scavenging activity of H2L Schiff base ligand and ternary Cu (II) complex was measured in terms of EC50, using the DPPH and H2O2 methods. Biomacromolecule interactions and scavenging activity studies revealed that ternary Cu (II) complex yielded better results than H2L Schiff base ligand alone.