Synthesis, characterization, X-ray Crystallography, Photoluminescence property and DNA binding activity of Co(II) and Ni(II) complexes of a pyrazole-containing Schiff-base ligand

Abstract

Two new complexes, [Co(MPAFA)₃](ClO₄)₂ (1) and [Ni(MPAFA)₃](NO₃)₂·2H₂O (2), of an ‘NN’ bidentate Schiff-base ligand, N-(furan-2-ylmethyl)-1-(5-methyl-1H-pyrazol-3-yl)methanimine (MPAFA), have been synthesized and characterized by physicochemical and spectral methods such as elemental analyses, conductance, IR, UV-Vis, and emission spectra. In both complexes, three ligands coordinate with a metal ion to form 1:3 complexes. Both 1 and 2 are distorted octahedral and cationic, behaving as 1:2 electrolytes. IR spectra showed that each of the ligands coordinates via the pyrazolyl tertiary nitrogen and the azomethine nitrogen atoms. Single crystal X-ray studies confirmed CoN₆ and NiN₆ coordination for 1 and 2, respectively, and showed that both complexes exhibit π…π stacking and various hydrogen bonding interactions. Both 1 and 2 are fluorescent and participate in DNA binding with calf thymus DNA (CT-DNA) via groove binding.

Keywords:

• Pyrazole
• Co(II) and Ni(II) complexes
• photoluminescence property
• X-ray crystallography
• DNA binding activity

Acknowledgment

Suman Mandal is thankful to the University of Kalyani for providing financial support in the form of a University Research Fellowship. The financial assistance received from the University of Kalyani in the form of a Personal Research Grant is thankfully acknowledged by N.C. Saha. The authors are thankful to the DST-FIST (Level-2; SR/FST/CS-II/2019/96) program for providing instrumental facilities in the Department of Chemistry, University of Kalyani.

Disclosure statement

No potential conflict of interest was reported by the authors.