Synthesis and characterization of some transition metal complexes with Schiff base derived from 2,6-diaminopyridine

Abstract

Schiff base labeled as H2L1 was synthesized, which was derived from pyridine-2,6-diamine and 2-hydroxynaphthaldehyde. Types of complexes [ML]Cl2 and [ML(py)2]Cl2, were formed with Co2+, Ni2+, Cu2+, and Zn2+. Additionally, adduct complexes [ML(py)2] were prepared  in a ratio of 2:1. Diverse analytical techniques, elemental analyses, (FT-IR, UV-Vis, 1H NMR), conductance measurements, and magnetic susceptibility, were employed to characterize these complexes and adducts. The data acquired validated that the ligands donor atoms act as (ONNO) tetra-dentate bibasic chelating ligands with metal ions. Depending on spectral and magnetic measurements, the suggested shapes of these complexes were reported to be either tetrahedral/octahedral in geometry. Density functional theory (DFT) was used to get some theoretical data about the generated complexes. The data obtained includes the energy of the highest and lowest occupied molecular orbitals (HOMO and LUMO), electron density, ionization potential (IP), electron affinity (EA), electronegativity (En), electrophilicity (ὠ), chemical hardness (η), and dipole moment (μ). Different characteristics of the complexes have been investigated and explained based on these studied parameters. The molecular docking of target microorganisms of these complexes will be studied. The interaction of DNA gyrase 4ckk with the compounds visualized by LigPlot software. KEY WORDS: 2,6-Diaminopyridine, 2-Hydroxynaphthaldehyde, Metal complexes, Spectral studies Bull. Chem. Soc. Ethiop. 2024, 38(5), 1337-1350.                                                           DOI: https://dx.doi.org/10.4314/bcse.v38i5.12