Spectroscopic and Theoretical Studies of Some Bivalent Metal Complexes of a Quinoline Schiff Base Derivative

Interaction of M(II) ions, M=Co, Ni, Cu, Zn, and Pd, with a Schiff base ligand (HL), derived from the condensation of 2-hydroxy-5-nitrobenzaldehyde and 8-aminoquinoline, gave the complexes [Co(L)2(H2O)2], [Ni(L)2(H2O)2], [Cu(L)(H2O)]CH3COO, [Zn(L)(H2O)]CH3COO, and [Pd(HL)Cl2]. The ligand and its complexes were characterized by means of elemental and thermal analyses, molar conductance, and magnetic moment measurements along with the different spectroscopic techniques. Theoretical calculations based on DFT were carried out to verify the optimized structures of ligand and complexes. The relative reactivity of the compounds was estimated from chemical descriptors analysis using the HOMO and LUMO frontier orbitals. Molecular docking of ligand and its zinc complex revealed that the interaction of Zn(L) with DNA is comparable to that of HL due to the presence of water OH groups instead of the hydroxyl group of ligand.