Structural Features of Copper(II) Complexes Based on 3-(5-phenyl-2H-tetrazol-2-yl)Pyridine and 2,2′-Bipyridine/1,10-Phenanthroline

Abstract

Complex compounds [CuL(phen)(H₂O)(NO₃)]NO₃ (1), [CuL(bipy)(NO₃)₂]·2EtOH (2), [CuL₂(H₂O)₂ (NO₃)₂] (2a), [CuL(dmbipy)(NO₃)₂]·3EtOH (3), and [CuL₂(NO₃)₂] (3a), where L is 3-(5-phenyl-2H-tetrazol-2-yl)pyridine, phen is 1,10-phenanthroline, bipy is 2,2′-bipyridine, and dmbipy is 4,4′-dimethyl-2,2′-bipyridine, are obtained and structurally characterized. It is shown that L behaves as the monodentate ligand being coordinated by the nitrogen atom of the pyridine ring. The coordination polyhedron made of copper atoms is a square pyramid in complexes 1 and 3, a distorted octahedron and a distorted square in complexes 2a and 3a respectively. Complex 1 is characterized by the elemental analysis, powder X-ray diffraction, and IR spectroscopy. Furthermore, its cytotoxic properties are studied on human larynx carcinoma (Hep2), breast adenocarcinoma (MCF7), and non-tumor human fibroblast (MRC5) cell lines. Complex 1 is shown to exhibit the pronounced cytotoxic action (LC₅₀(Hep2) = 4.1±0.4 µM and LC₅₀(MCF7) = 4.9±0.1 µM), however, does not exhibit selectivity against tumor cell lines (LC₅₀(MRC5) = = 3.06 ±0.02 µM).