Coordination Compounds of Cobalt(II), Nickel(II), and Copper(II) Halides with 2-Methyl-1,2,4-Triazolo[1,5-a]benzimidazole

New coordination compounds of Co(II), Ni(II), and Cu(II) halides with 2-methyl-1,2,4-triazolo[1,5-a]benzimidazole (L), [Co(L)(2)Cl-2] (Ia), [Ni(L)(2)(H2O)(4)]Cl-2 4H(2)O (II), and [Cu-2(L)(4)(mu-Br)(2)Br-2] (IIIa), are synthesized. The complexes are studied by X-ray structure analysis (CIF files CCDC nos. 1825006-1825008), electronic (diffuse reflectance) spectroscopy, and IR spectroscopy. In compounds Ia, II, and IIIa, ligand L is coordinated to the metal by the N-4 atom of the triazole fragment. The study of the cytotoxic effect of the ligand and synthesized complexes on the Hep-2 line (laryngeal cancer cells) shows a considerably higher activity of the copper(II) complex than that of the ligand.