Synthesis and Structural Characterization of Schiff Base-Based Transition Metal Complexes

In this study, two complexes [Co(C7H9N3S2)2Cl2]Cl2, and [Ni(C7H9N3S2)2Cl2]Cl2 were synthesized from the ligands known as 2-Acetyl thiophene thiosemicarbazone (C7H9N3S2), respectively. C7H9N3S2 was characterized using various characterization techniques. The study of magnetic moment values (4.92 B.M. for [Co(C7H9N3S2)2Cl2]Cl2 and (2.93 for [Ni(C7H9N3S2)2Cl2]Cl2) shows that the complexes are paramagnetic with octahedral geometry. The value of electrical conductance (184 Ohm−1 cm2 mole−1 for [Co(C7H9N3S2)2Cl2]Cl2 and (173 Ohm−1 cm2 mole−1 for [Ni(C7H9N3S2)2Cl2]Cl2) suggested that ligand to metal ratio is 2:1 in its structure. In addition, the electronic spectrum analysis (8000–8650, 20,800–21,580, and 16,200–17,500 cm−1 suggested that the [Co(C7H9N3S2)2Cl2]Cl2 is spin-free octahedral complex. Similar way, the electronic spectrum values (9500–10,415, 14,200–14,940, and 23,500–24,000 cm−1 suggested that the [Ni(C7H9N3S2)2Cl2]Cl2 is in octahedral geometry. An infrared spectroscopy study showed that each equivalent ligand was attached to the metal with C=N, and C=S moiety using nitrogen and sulfur atoms. The vibration bands of νM-Cl were also observed at 325 for [Co(C7H9N3S2)2Cl2]Cl2 and 350 cm−1 [Ni(C7H9N3S2)2Cl2]Cl2. This observation confirms that Cl− ion is also coordinated with the metal ion. The article shows the synthesis and structure of new metal complexes [Co(C7H9N3S2)2Cl2]Cl2 and [Ni(C7H9N3S2)2Cl2]Cl2 based on 2-Acetyl thiophene thiosemicarbazone ligands.