Synthesis and study of complexes of cobalt(II), nickel(II), and copper(II) halides with 2-(3,5-dimethylpyrazol-1-yl)benzimidazole

New coordination compounds of cobalt(II), nickel(II), and copper(II) halides with 2-(3,5-dimethylpyrazol-1-yl)benzimidazole (L) of the composition [CoLCl2] (1), CoL2Cl2 · 2H2O · EtOH (2), [NiL(H2O)4]Cl2 · H2O · EtOH (3), NiL2Cl2 · 2H2O · EtOH (4), and [CuL2Br]Br · H2O (5) were synthesized. The compounds were characterized by electronic (diffuse reflectance) spectroscopy, IR spectroscopy, and powder X-ray diffraction. The crystal structures of compounds 1, 3, and 5 were determined by single-crystal X-ray diffraction. The cytotoxic properties of the ligand and compound 5 were evaluated in the Hep-2 cell line.