Synthesis, Crystal Structure and Antitumor Study of a Cobalt(II) Complex of the 2-Acetylpyrazine Thiosemicarbazone

The title complex [Co(C7H8N5S)2]·2H2O has been synthesized and characterized by IR and UV spectral studies. The structure of the compound has been determined by single-crystal X-ray diffraction. The complex consists of discrete monomeric molecules with octahedrally hexacoordinate cobalt(II) ions, where two acetylpyrazine thiosemicarbazones act as NNS tridentate ligands coordinated to the central cobalt atom via the pyrazine nitrogen, azomethine nitrogen and sulfur atoms. Hydrogen bonds link the different components to stabilize the crystal structure. The antitumor activity of the title complex was tested against A549 lung cancer cell line. The complex exhibited lower antitumor activity, as compared to the free ligand.