Synthesis and Characterization of Thiophene Cyclic Schiff Base Ligand and Metal Ion Complexes

Abstract

In this study, a new Schiff base ligand (L) containing a thiophene ring was synthesized via the reaction of thiophene-2,5-dicarbaldehyde with 5-amino-1,3,4-thiadiazole-2-thiol. The structure of the ligand was elucidated using elemental analysis, FT-IR, NMR, and UV-Vis spectroscopy. The ligand (L) reacted with metal acetate salts [M(CH₃COO)₂; M = Cu, Co, Ni] in a 1:1 molar ratio to form metal complexes with the general formula [ML(CH₃COO)₂]•nH₂O (n = 2, 3). Structural characterization of the metal complexes was performed using elemental analysis, FT-IR, UV-Vis, TGA/DTA, electrolytic conductivity, and magnetic susceptibility measurements. Based on the obtained data, it was proposed that the Cu(II), Co(II), and Ni(II) complexes adopt a tetrahedral geometry. Moreover, the molar conductivities of the complexes were found to be in the range of 1.5–2.9 μS•cm⁻¹, indicating their non-electrolytic nature.

Keywords

• Thiophene
• Thiadiazole
• Schiff base
• Metal complex
• Characterization

References

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