Structural, Electrochemical, DNA Binding and Cleavage Properties of Nickel(II) Complex [Ni(H₂biim)₂(H₂O)₂]²⁺of 2,2'-Biimidazole

Abstract

A nickel(II) complex [Ni(H 2 biim) 2 (H 2 O) 2 ](ClO 4 ) 2 ·H 2 O (1) of biimidazole ligand has been synthesized and characterized (Where H 2 biim = 2,2'-biimidazole). The single crystal X-ray diffraction of the complex shows a dimeric structure with six coordinated psudo-octahedral geometry. The cyclic voltammograms of complex exhibited one quasireversible reduction wave (E pc = −0.61 V) and an irreversible oxidation wave (E pa = 1.28 V) in DMF solution. The interaction of the complex with Calf-Thymus DNA (CT-DNA) has been investigated by absorption and fluorescence spectroscopy. The complex is an avid DNA binder with a binding constant value of 1.03 × 10 5 M −1. The results suggest that the nickel(II) complex bind to CT-DNA via intercalative mode and can quench the fluorescence intensity of EB bind to CT-DNA with K app value of 3.2 × 10 5 M −1. The complex also shown efficient oxidative cleavage of supercoiled pBR322 DNA in the presence of hydrogen peroxide as oxidizing agent. The DNA cleavage by complex in presence of quenchers; viz. DMSO, KI, NaN 3 and EDTA reveals that hydroxyl radical or singlet oxygen mechanism is involved. The complex showed invitro antimicrobial activity against four bacteria and two fungi. The antimicrobial activity was nearer to that of standard drugs and greater than that of the free ligand.

A trinuclear copper (II) complex of naproxen‐appended salicylhydrazide: Synthesis, crystal structure, DNA binding and molecular docking study

“…A 1,10‐phenanthroline is a good candidate for binding with DNA base pairs due to the in‐plane distortion of phenanthroline moiety on complexation. [ 79 ] Thus, complex 1 adopts intercalative binding mode via π‐π stacking between cytosine 15 and phenanthroline, which is in agreement with the UV–visible spectrometric DNA‐complex 1 interaction study.…”

“…A 1,10-phenanthroline is a good candidate for binding with DNA base pairs due to the in-plane distortion of phenanthroline moiety on complexation. [79] Thus, complex 1 adopts intercalative binding mode via π-π F I G U R E 1 0 Minimum energy docking pose of ct-DNA with complex 1 showing intermolecular interactions (left). Intercalation interaction of phenanthroline moiety in complex 1, and cytosine (top right).…”

Synthesis, Characterization, DNA/HSA Interaction, and Cytotoxic Activity of a Copper(II) Thiolate Schiff Base Complex and Its Corresponding Water-Soluble Stable Sulfinato–O Complex Containing Imidazole as a Co-ligand

“…In electrophoresis, the fastest migration is observed for supercoiled form (form I). When one strand of DNA is cleaved, the DNA supercoils are relaxed to generate a slower moving NC form (form II), while cleavage of both DNA strands results in a linear form (form III), which migrates − in between SC and NC forms. Metal complexes can cleave nucleic acids via both oxidative and hydrolytic pathways .…”