TY - JOUR

T1 - Structure and cytotoxicity of copper(II) and zinc(II) complexes based on 2-ferrocenyl-1,10-phenanthroline

AU - Ermakova, E. A.

AU - Golubeva, Yu A.

AU - Klyushova, L. S.

AU - Smirnova, K. S.

AU - Romashev, N. F.

AU - Zaitsev, K. V.

AU - Fedin, M. V.

AU - Zyryanova, E. Yu

AU - Utepova, I. A.

AU - Lider, E. V.

N1 - E.A. Ermakova, Yu.A. Golubeva, L.S. Klyushova, K.S. Smirnova, N.F. Romashev, K.V. Zaitsev, M.V. Fedin, E.Yu. Zyryanova, I.A. Utepova, E.V. Lider, Structure and cytotoxicity of copper(II) and zinc(II) complexes based on 2-ferrocenyl-1,10-phenanthroline, Polyhedron, Volume 300, 2026, 118408, ISSN 0277-5387, https://doi.org/10.1016/j.poly.2026.118408. The research (Nikolaev Institute of Inorganic Chemistry SB RAS) was supported by the Ministry of Science and Higher Education of the Russian Federation, No. 125020401317-8. The investigation of biological activity was performed on the equipment of the Center for Collective Use “Proteomic Analysis” (FRC FTM) and supported by the Ministry of Science and Higher Education of the Russian Federation, No. 125031203556-7.

PY - 2026/12/1

Y1 - 2026/12/1

N2 - A series of copper(II) and zinc(II) complexes based on 2-ferrocenyl-1,10-phenanthroline (L) were synthesized and characterized by FT-IR, elemental, thermogravimetric, EPR and X-ray powder diffraction analysis, as well as single-crystal X-ray diffraction study. Complexes [CuLBr2]·1.3H2O (1) and [ZnLCl2] (3) crystallized in a monoclinic crystal system with P21/c and P21/n space group, respectively, and exhibited a seesaw geometry for 1 and tetrahedral one for 3. Complex [CuL2](ClO4)2·6.5H2O (2) crystallizes in triclinic crystal system with P-1 and the seesaw geometry of central atom. UV-vis spectroscopy was employed to monitor the behaviour of the complexes in various media (water and phosphate-buffered saline) over time. The observed spectral evolution indicated limited solution stability, tentatively attributed to slow ferrocenyl oxidation alongside competitive solvolysis processes. The complexes were studied using cyclic voltammetry, which revealed reversible oxidation of the complexes, attributed to the ferrocene fragment. Their cytotoxic activity was evaluated against three human tumor cell lines (Hep2, MCF7, A549) and one non-tumor fibroblast line (MRC5) using Hoechst 33342/PI double staining. The copper(II) complexes exhibited potent cytotoxicity (LC50 = 1.8–5.7 μM), outperforming cisplatin by a factor of 2–19 on Hep2 and A549 cells. In contrast, the free ligand L and the corresponding zinc(II) complex showed only weak to moderate activity. Selectivity indices (SI) calculated relative to MRC5 cells revealed that the complexes lack tumor selectivity (SI = 0.5–1.6).

AB - A series of copper(II) and zinc(II) complexes based on 2-ferrocenyl-1,10-phenanthroline (L) were synthesized and characterized by FT-IR, elemental, thermogravimetric, EPR and X-ray powder diffraction analysis, as well as single-crystal X-ray diffraction study. Complexes [CuLBr2]·1.3H2O (1) and [ZnLCl2] (3) crystallized in a monoclinic crystal system with P21/c and P21/n space group, respectively, and exhibited a seesaw geometry for 1 and tetrahedral one for 3. Complex [CuL2](ClO4)2·6.5H2O (2) crystallizes in triclinic crystal system with P-1 and the seesaw geometry of central atom. UV-vis spectroscopy was employed to monitor the behaviour of the complexes in various media (water and phosphate-buffered saline) over time. The observed spectral evolution indicated limited solution stability, tentatively attributed to slow ferrocenyl oxidation alongside competitive solvolysis processes. The complexes were studied using cyclic voltammetry, which revealed reversible oxidation of the complexes, attributed to the ferrocene fragment. Their cytotoxic activity was evaluated against three human tumor cell lines (Hep2, MCF7, A549) and one non-tumor fibroblast line (MRC5) using Hoechst 33342/PI double staining. The copper(II) complexes exhibited potent cytotoxicity (LC50 = 1.8–5.7 μM), outperforming cisplatin by a factor of 2–19 on Hep2 and A549 cells. In contrast, the free ligand L and the corresponding zinc(II) complex showed only weak to moderate activity. Selectivity indices (SI) calculated relative to MRC5 cells revealed that the complexes lack tumor selectivity (SI = 0.5–1.6).

KW - 1,10-phenanthroline

KW - Copper(II) complexes

KW - Cytotoxicity

KW - Ferrocene

KW - Zinc(II) complexes

KW - Комплексы меди(II)

KW - Комплексы цинка(II)

KW - 1,10-фенантролин

KW - Ферроцен

KW - Цитотоксичность

UR - https://www.mendeley.com/catalogue/836ed102-44e5-33b5-a727-b9a8c4032fd7/

UR - https://www.scopus.com/pages/publications/105052191529

U2 - 10.1016/j.poly.2026.118408

DO - 10.1016/j.poly.2026.118408

M3 - Article

VL - 300

JO - Polyhedron

JF - Polyhedron

SN - 0277-5387

M1 - 118408

ER -