Preparation and Characterization of New Four Coordinate Complexes and their Application in Removing Some Metal Contaminants from their Media

Abstract

synthesize and characterize a variety of dithiocarbamate (dtc) ligands and associated dinuclear metal(II) dithiocarbamate macrocyclic complexes. The complexes are made by reacting the free ligand with the metal ion . This is based on the Schiff-bases' preparation. Following that, reduction of the Schiff-bases produced amine precursors, which interacted with carbon disulfide in the presence of potassium hydroxide in Methanol to produce free ligands (L1 , L2 and, L3 ). Where: L 1 = Potassium 1,4-phenylenebis (methylene)bis(3-chlorophenyl)carbamodithioate. L 2 = Potassium 1,4-phenylenebis (methylene)bis (hexachlor-3-ylcarbamodithioate). L 3 = Potassium ethan-1,2-diylbis((2-bromobenzyl)carbamodithioate). The secondary diamine, carbon disulfide, and potassium hydroxide are mixed in (methanol or Ethanol)/DCM to make all of the free ligands. The aim of the preparation of the free ligands is to give us a full characterization of the ligands. The one-pot template reaction of the dtc ligands with some metal ions resulted in the formation of macrocyclic complexes of the general formula: [M(Ln )]2 (where M=Mn(II) , Fe(II), Co(II), Ni(II) , Zn(II), L n = L 1 -L 3 ). Melting points, conductance, FTIR, Mass spectra, UV-Vis, and 1H-NMR spectroscopy are used to characterize ligands and their complexes. FTIR and 1H-NMR analyses revealed that the CS2 moiety is in a bidentate coordination state with the central metal ion. Physico-chemical analysis revealed the coordination mode around the center of metal ions for the prepared macrocyclic complexes indicated a tetrahedral structure for Mn(II), Fe(II), Co(II), Cu(II), and Zn(II), and square planar geometry with Ni(II) complexes. The prepared ligands were also used in the ecosystem by removing heavy polluting elements in the water. The biological activity of the ligands and some of their prepared complexes was also tested on two types of bacteria, namely: (Staphylococcus aureus, Escherichia coli