Zinc(II) Complex with 2-Ferrocenyl-1,10-phenanthroline: Synthesis, Structure, Study of Electrochemical and Cytotoxic Properties

The reaction of zinc(II) nitrate with 2-ferrocenyl-1,10-phenanthroline (L) produced the complex [ZnL(NO3)2] (I), which was analyzed by elemental analysis, powder X-ray diffraction, thermogravimetric analysis, cyclic voltammetry, and IR spectroscopy. According to the single-crystal X-ray diffraction analysis, the coordination environment of zinc(II) can be described as 5 + 1, and L acts as a chelating ligand that binds to the zinc(II) atom through the nitrogen atoms of the phenanthroline moiety. The cytotoxic properties of complex I were evaluated using the human two-dimensional cell lines Hep2 (laryngeal carcinoma cells), A549 (lung adenocarcinoma cells), and MRC5 (nontumor lung fibroblasts). Complex I exhibited cytotoxicity at concentrations between 50 and 100 μM. The activity of complex I in Hep2 spheroids (3D model) was found to be comparable to that in the two-dimensional model. The behavior of the complex in solution was studied using optical spectroscopy, conductometry, and cyclic voltammetry.