Synthesis and Characterization of New Compounds of some Dithiocarbamate Complexes and Their Ability to be Used as Scavenger for some Heavy Metal Ions

Abstract

The present study involves the synthesis and the characterization of a group of dithiocarbamate ligands and their metal(II) dithiocarbamate macrocyclic complexes. The formation of L1 was based on the preparation of the Schiff-bases. Therefore, reduction of the Schiff-bases resulted in the formation of secondary amine precursors that reacted with carbon disulphide in the presence of KOH in a medium of methanol to obtain the free ligand. While L2 and L3 ligands were prepared based on the reaction of the primary amine with an alkyl halide to obtain secondary amine that reacted with carbon disulphide in the presence of KOH in a medium of methanol to acquire the free ligands. Where: L1= potassium mono((4-(((sulfaneyl)cabonothioyl)2- hydroxybenzyl)amino)butyl)(2-hydroxybenzyl)dithiocarbamate L2= potassium propane-1,3-diylbis(butyldithiocarbamate) L3= potassium propane-1,3-diylbis(benzyldithiocarbamate) This study aims at preparing the free ligands which were complete characterized of the ligands. The reaction of the dithiocarbamate ligands with some metal ions result in the formation of macrocyclic complexes of general formula [M(Ln)]2 (where M= Fe(II), Co(II), Zn(II); Ln = L1-L3) , the second general formula [M(Ln)(H2O)2]2 (where M= Mn(II), Cu(II) ; Ln = L1-L3, Ni(II) ; Ln = L1) ,and [M(Ln)Cl2]2 (where M= Ni(II) ; Ln = L2-L3). All the prepared Ligands and their complexes are characterized by FTIR, UV-Vis, magnetic susceptibility, 1H, 13C-NMR spectroscopy, melting points, and conductance. The FTIR and 13C- NMR tests reveal that the bidentate coordination mode of the CS2 moiety with the central metal ion. The results show that the synthetic formulas for the complexes are of a tetrahedral structure with the general formula [M(Ln)]2 (where M= Fe(II), Co(II), Zn(II); n= L1, L2, L3) and of an octahedral structure with the general formula [M(Ln)X2]2 (where M= Mn(II) ,Cu(II) ; n= L1, L2, L3) and Ni(II); n= L1; X= H2O and X=Cl where M= Ni(II) ; n= L2, L3 ). Finally, the present study shows how dithiocarbamate ligands applications can be utilized in removing heavy metals from environmental systems