Mononuclear Cu(II), Zn(II) Complexes with 2-Aminoethylpyridine and carboxylate ligands: Structure, DFT, DNA binding, Docking and Catecholase Like Activities

Abstract

Abstract Mononuclear copper(II) and zinc(II) complexes of composition [Cu(2-AEP)(BA)2] 1, [Cu(2-AEP)(TPAA)2] 2, [Zn(2-AEP)(Cl)2] 3, [Zn(2-AEP)2](ClO4)2 4, and [Zn(2-AEP)(TPAA)2] 5, were synthesized by using, 2-aminoethylpyridine (2-AEP) as ligand, benzoic acid (BA) and triphenylaceticacid (TPAA) as ancillary ligands. Complexes 1-5 were characterized using elemental study, UV-Vis, FT-IR, ESI-MS, and ESR spectroscopy (incase of Cu). Single crystal XRD of complexes revealed 1 in octahedral, 2 & 5 in square pyramidal and 3 & 4 in tetrahedral geometry. The interactions towards DNA with complexes 1-5 were studied by spectral titration, electrochemical techniques, and CD measurements. These complexes were interacted strongly via groove binding with CT-DNA with binding efficacy in the range kb = 0.45-4.69 × 104 M-1. Among the complexes, zinc(II) complex 4 showed higher binding affinity than remaining complexes (1-3, 5). The binding affinity order is 4 > 5 > 3 > 1 > 2. In addition, copper(II) complexes (1 and 2) showed catecholase like activity with reaction rate, k = 2.68 × 10-3 M s-1 and 2.63 × 10-3 M s-1 respectively.