Synthesis, spectral characterization, DNA-binding and antimicrobial profile of biological active mixed ligand Schiff base metal(II) complexes incorporating 1,8-diaminonaphthalene

Abstract

Mixed-ligand complexes of bivalent metal ions, viz, Co(II), Ni(II), Cu(II), and Zn(II) of the composition [ML(dan)]Cl (where L = Schiff base ligand, dan = 1,8-diaminonaphthalene and M = Co(II), Ni(II), Cu(II), Zn(II)) have been synthesized and characterized. The stoichiometric ratio of the prepared complexes has been estimated using complementary techniques such as elemental analyses, FT-IR, UV-vis and EPR spectra, magnetic and molar conductivity measurements. The study shows that all the complexes have square planar geometry. The synthesized compounds have been tested in vitro against various types of pathogenic bacteria to weigh up their antimicrobial properties. They have lofty activity against the tested bacteria. The complexes have higher activity than the free ligands. The interaction of synthesized complexes with calf thymus DNA (CT-DNA) has been studied by absorption spectroscopic technique and viscosity measurements. The complexes show a successful interaction with CT-DNA via intercalation mode. In addition, molecular docking approach has been performed for predicting the binding free energy of the synthesized compounds with 1BNA receptor.

Graphical abstract

Keywords:

• Mixed-ligand complexes
• DNA-binding
• 1,8-diaminonaphthalene
• antimicrobial activity
• molecular docking

Acknowledgments

The authors express their sincere and heartfelt thanks to the VHNSN College Managing Board, Principal and Head of the Department of Chemistry, for providing the research facility and constant encouragement. TC thanks the Managing Board and Principal of KVS Matriculation School for their moral support.

Disclosure statement

No potential conflict of interest was reported by the authors.