Synthesis, Characterization and Antibacterial Study of Zinc (II) Complex with a Schiff Base Ligand Derived from 2-Acetyl-5-Chlorothiophene and 2, 6-Diaminopyridine

Abstract

The Schiff base ligand N-[1-(5-chloro-thiophen-2-yl)-ethylidene]-pyridine-2, 6-diamine, DPACT, was synthesized by condensation reaction of 2-acetyl-5-chlorothiophene and 2, 6-diaminopyridine in the presence of concentrated hydrochloric acid as a catalyst.Zn(II) complex with the synthesized ligand was prepared by reacting zinc (II) chloride and the ligand (1:1) in methanol solvent. The purity of the synthesized compounds wasmonitored usingTLC,and characterized by melting point, solubility, conductivity measurements,atomic absorption data, and infrared spectra. The analytical data showed, the stoichiometryZn(II) to DPACT of the complex to be 1:1. Infra-red spectral data showed that the ligand behaves as bidentate with (N, S) donor sequence towards Zn(II) metal ion. The Zn(II) complex was formulated as [Zn (C11H10ClN3S) Cl2 (H2O) 2].Based on the analytical data obtained, an octahedral geometry and non-electrolyte behavior was proposed for the Zn((II)-DPACT complex.The ligand and its zinc complex were screened for their antibacterial activity against bacterial species. Activity data show that the antibacterial activity of the complex is higher than that of the parent ligand.