Cytotoxic Copper(II) Complexes Based on 2,2'-Bipyridine/1,10- Phenanthroline and 5-(4-Chlorophenyl)-1H-tetrazole: Synthesis and Structures

Abstract

Five coordination compounds [Cu2(Bipy)2L4]·C2H5OH (Iа, Ib), [Cu2(Dmbipy)2L4] (II),[Cu2(Phen)2L4]·H2O (IIIa), [Cu2(Dmphen)2L4] (IVa), and [Cu2(Phendione’)2L4]·2C2H5OH·2H2O (V) aresynthesized from 5-(4-chlorophenyl)-1H-tetrazole (HL), where Bipy is 2,2'-bipyridine, Dmbipy is 4,4'-dimethyl-2,2'-bipyridine, Phen is 1,10-phenanthroline, Dmphen is 4,7-dimethyl-1,10-phenanthroline, andPhendione’ is 6-ethoxy-6-hydroxy-1,10-phenanthrolin-5-one. The crystal structures of the complexes aredetermined by X-ray diffraction (XRD) of single crystals (CIF files CCDC nos. 2225368 (Ia), 2225369 (Ib),2225370 (II), 2225372 (IIIa), 2225373 (IVa), and 2225371 (V)). The compounds are binuclear due to thebridging function of the tetrazolate anion, and the coordination number of copper is five in all synthesizedcomplexes. The cytotoxic activity of the complexes against the Hep2 and HepG2 cancer cell lines and noncanceroushuman fibroblasts MRC-5 is studied. The complexes exhibit pronounced cytotoxic properties, andcompound V has the maximum selectivity index with respect to the cancer cells.