Research of the influence of anions in complexes [CuPhen(Hpz)₂X₂] (X = CF₃COO^-, Otf^-, Cl^-) on the structure and bioactivity

A series of copper(ii) complexes with different anions of composition [CuPhen(Hpz)(2)X-2] (Phen = 1,10-phenanthroline; Hpz = pyrazole; X = CF3COO- (1), Otf(-) (2), Cl- (3), Otf = CF3SO3) have been synthesized. The structures of all obtained complexes were determined by direct X-ray diffraction analysis. In complexes 1-3 the equatorial planes are occupied by N-donor ligands, while the axial positions belong to the anions of various acids. Crystal structures 1-3 are additionally stabilized by hydrogen bonds, the type of which depends on the nature of the anion. The stability of the complexes upon dissolution in 0.9% NaCl was confirmed by UV-vis spectroscopy. The study of the biological properties of 1-3 showed high antibacterial activity against the non-pathogenic strain of Mycolicibacterium smegmatis (MIC (minimum inhibiting concentration) = 8-10 nmol per disk). The cytotoxic effect of various concentrations of complexes 1-3 on human ovarian adenocarcinoma cells (SKOV3) and human dermal fibroblasts (HDF) was measured in vitro. All complexes exhibit high anticancer activity, exceeding the activity against healthy cells.