Bidentate Schiff base coordinated square planer nickel(II) complexes: Synthesis, crystal structure, DFT/TD-DFT calculation and DNA/protein binding

Two mononuclear square planer Ni(II) complexes, [Ni(L1)2] (1) and [Ni(L2)2] (2) [HL1 = 2-[(2-Methoxy-ethylimino)-methyl]-phenol; HL2 = 2-Methoxy-6-[(2-methoxy-ethylimino)-methyl]-phenol] have been synthesized and characterized through X-ray single crystal structure determination and DFT/TDDFT calculation. Both the complexes crystallize with P21/c space group. C-H…π interactions results 2D and 1D supramolecular network of complexes 1 and 2, respectively. Interaction of complexes with calf thymus DNA (CT-DNA), bovine serum albumin (BSA) and human serum albumin (HSA) were studied by using both UV–vis absorption and emission spectroscopic techniques, and the calculated values of intrinsic binding constants with CT-DNA are (1.43 ± 0.56) × 106 M−1 (for 1) and (1.25 ± 0.79) × 106 M−1 (for 2).