Synthesis and characterization of complexes of schiff base ligands thiadiazole derivative

This study has been occured in four stages. In the first stage, the 2-amino-5-(2-amino-1,3,4-thiadiazole-yl)-1,3,4-thiadiazole (L1) compound, as stated in the experimental section was synthesized according with literature. Then, the N-[5?-amino?2,2?-bis(1,3,4-thiadiazole)-5-yl]-2-hydroxybenzaldehyde imine (L1H) was obtained by the reaction of 2-amino-5-(2-amino-1,3,4-thiadiazoleyl)-1,3,4-thiadiazole (L1) and salicylaldehyde. In the second stage, the N-(5-ethyl-1,3,4-thiadiazole-2-yl)terephthalaldehyde imine (L2) compound was synthesized by the reaction terephthalaldehyde and 2-amino-5-ethyl-1,3,4-thiadiazole, which provided from the chemical company. In the third stage, the N,N?-bis[5-(4-nitrophenyl)-1,3,4-thiadiazole-2-yl]terephthalaldehydediimine (L3) compound was synthesized by the reaction 5-nitrophenyl-1,3,4-thiadiazole-2-amine and terephthalaldehyde. In the last stage, the complexes were synthesized by the reaction of these ligands (L1H, L2, L3) with CoCI2.6H2O, CuCI2.2H2O, NiCI2.6H2O, CdCI2.H2O, ZnCI2, MnCI2.4H2O and FeCI2.6H2O metal salts.The suggested structures for the L1H complexes of Fe(II), Co(II), Zn(II) and Cd(II) are octahedral, for the Ni(II) complex is tetrahedral and for the Cu(II) complex is square-planar. The structures all of the L2 complexes are octahedral. Octahedral structures are suggested for the Fe(II), Ni(II) and Mn(II) complexes, whereas the Co(II) and Cu(II) complexes of the L3 are tetrahedral.The structure of synthesized ligands and their complexes were characterized by using IR, 1H-NMR spectra, elemental analysis, magnetic susceptibility, UV-Vis. and thermogravimetry-differential thermal analysis (TGA-DTA).