Investigation of DNA binding and bioactivities of furan cored Schiff base Cu (II), Ni (II), and Co (III) complexes: Synthesis, characterization and spectroscopic properties

Novel binary metal complexes,1[Cu(FMIMBMOP)2],2[Ni(FMIMBMOP)2] and3[Co(FMIMBMOP)3], where FMIMBMOP (2‐((E)‐((furan‐2‐yl)methylimino)methyl)‐4‐bromo‐6‐methoxyphenol), were synthesized and characterized using different analytical techniques. Result of spectral studies reveals that square planar geometry is assigned for Cu (II) and Ni (II) complexes, whereas octahedral geometry is assigned for Co (III) complex. The thermodynamic and kinetic parameters for the degradation of the complexes were ascertained by Coats–Redfern method for thermogravimetric data attained from thermogravimetric analysis (TGA). The stability of the complexes has been calculated from quantum chemical parameters using highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) energies. The DNA binding of complexes was studied by using ultraviolet–visible (UV–Vis) spectroscopic technique; screening their ability to bind to calf thymus DNA (CT‐DNA) showed that the complexes can interact with CT‐DNA through intercalation mood, where theKbvalues are 2.59 ± 0.01 × 104, 7.43 ± 0.03 × 103, and 6.73 ± 0.02 × 104 M−1for1,2, and3, respectively. Stern–Volmer quenching constant (Ksv) values ranged from 2.32 ± 0.03 × 103to 1.66 ± 0.02 × 104 M−1were calculated for complexes from fluorescence studies. The oxidative and photolytic cleavage of supercoiled pBR322 DNA was studied and found that the complexes have cleaved this DNA effectively. The novel metal complexes have shown significant antioxidant activity against DPPH radical. The antibacterial activity of Schiff base and its metal complexes screened againstBacillus thuringiensis,Streptococcus pneumoniae,Escherichia coli, andPseudomonas putidawas investigated, and the results indicated that the metal complexes have better results than Schiff base ligand. The catalytic ability of metal complexes1,2, and3was found to be3 > 1 > 2.