Synthesis, spectroscopy, x-ray structures, DNA binding and photocatalytic properties of two Ni(II) and Co(II) complexes of a pyrazolyl Schiff-base ligand

Two new nickel(II) and cobalt(II) complexes, [Ni(MPAFA)3](BF4)2 (I) and [Co(MPAFA)3](BF4)2 (II) were synthesized from a pyrazole containing ‘NN’ bidentate Schiff-base ligand, N-(furan-2-ylmethyl)-1-(5-methyl-1H-pyrazol-3-yl)methanimine, (MPAFA) (L). The complexes I and II were characterized by various physico-chemical and spectral parameters. Both I and II were 1:3 (M:L) coordination complexes and behaving as 1:2 electrolytes. Single crystal X-ray diffraction studies revealed that both of them were distorted octahedral in nature with a N6 donor set. The binding interactions of the complexes with CT-DNA were studied by UV-Vis and fluorescence spectroscopic methods. I was found to bind with CT-DNA in a partial intercalative mode, whereas II bound via the groove-like manner in solutions. The ligand and the complexes were shown to have potential photocatalytic activity in degrading methylene-blue (MB) under UV-Vis light irradiation.