Synthesis and Structural Characterization of Half-Sandwich Arene–Ruthenium(II) Complexes with Bis(imidazol-1-yl)methane, Imidazole and Benzimidazole

Vladislava V Matveevskaya,Sergey V Baykov,Vadim P Boyarskiy,Ekaterina A Ermakova,Lyubov S Klyushova,Andrei S Potapov,Denis G Samsonenko,Dmitry I Pavlov

doi:10.3390/inorganics9050034

Abstract

Mono- and binuclear arene–ruthenium(II) complexes with imidazole-containing ligands were prepared by the reaction of the ligands (L1 = bis(imidazole-1-yl)methane; ImH = 1H-Imidazole; BImH = 1H-Benzimidazole) with [(p-cym)Ru(µ-Cl)2]2 dimers. When bis(imidazole-1-yl)methane reacted with [(p-cym)Ru(µ-Cl)2]2 in methanol, a binuclear complex of the type [Ru2(L1)2(p-cym)2Cl2]Cl2 (2) with cyclic structure was synthesized, whereas by using acetonitrile as a solvent under the same reaction conditions, an unexpected C–N bond cleavage was observed, and a complex of formula [Ru(ImH)2(p-cym)Cl]Cl (1) with coordinated imidazole molecules was obtained. Another type of arene–ruthenium complex [Ru(BImH)(p-cym)Cl2] (3) was obtained by the reaction of benzimidazole and [(p-cym)Ru(µ-Cl)2]2. All compounds were characterized by spectral (FT-IR, NMR 1H, 13C) and single-crystal X-ray diffraction methods; their catalytic activity in transfer hydrogenation and the cytotoxicity against MCF-7 and HepG2 cells were evaluated.

Highlights

Ruthenium complexes are of interest as catalysts, and they have emerged as promising nonplatinum antitumor or antimetastatic agents [1,2,3,4,5,6]
It was shown that the arene–ruthenium complex with bis(3,5-dimethylpyrazol-1-yl)methane (UNICAM-1) exhibits potent in vivo antitumor effects [14]
UNICAM-1 appears promising for the treatment of triple-negative breast cancer (TNBC), one of the most aggressive types of breast cancer [15]

Summary

Introduction

Ruthenium complexes are of interest as catalysts, and they have emerged as promising nonplatinum antitumor or antimetastatic agents [1,2,3,4,5,6]. The arene–ruthenium “piano-stool” complexes show a great promise as anticancer agents. It was shown that the arene–ruthenium complex with bis(3,5-dimethylpyrazol-1-yl)methane (UNICAM-1) exhibits potent in vivo antitumor effects [14]. UNICAM-1 appears promising for the treatment of (UNICAM-1) exhibits potent in vivo antitumor effects [14]. UNICAM-1 appears promising for the treatment of triple-negative breast cancer (TNBC), one of the most aggressive types of breast cancer [15] In this regard, arene–ruthenium complexes triple-negative breast cancerlook (TNBC), one offor theanticancer most aggressive types of breast cancer [15]

Methods

Discussion

Conclusion