Physical and Physicochemical Stimuli-Responsive Arene Ruthenium Metallaprism

Unmasking Arene Ruthenium Building Blocks

We have, like many others, contributed to the development and to the popularity of arene ruthenium assemblies. From early on, our research was driven by applications, mainly biological (therapeutic, drug delivery, DNA interactions, photodynamic therapy, imaging). For nearly 15 years, we have focused on the use of arene ruthenium building block as a tool to construct added-value objects. In this account, we want to give the basic reasons behind our choice, and uncover our most successful examples, with an emphasis on the foreseen applications.

Investigation of the Anticancer Activity of Coordination-Driven Self-AssembledTwo-Dimensional Ruthenium Metalla-Rectangle

Coordination-driven self-assembly is an effective synthetic tool for the construction of spatially and electronically tunable supramolecular coordination complexes (SCCs), which are useful in various applications. Herein, we report the synthesis of a two-dimensional discrete metalla-rectangle [(η6-p-cymene)4Ru4(C6H2O4)2(2)2](CF3SO3)4 (3) by the reaction of a dinuclear half-sandwich ruthenium (II) complex [Ru2(η6-p-cymene)2(C6H2O4)Cl2] (1) and bis-pyridyl amide linker (2) in the presence of AgO3SCF3. This cationic ruthenium metalla-rectangle (3) has been isolated as its triflate salt and characterized by analytical techniques including elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance spectroscopy (1H-NMR), carbon nuclear magnetic resonance spectroscopy (13C-NMR), 1H-1H correlation spectroscopy (COSY), 1H-1H nuclear Overhauser effect spectroscopy (NOESY), diffusion ordered spectroscopy (DOSY), and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). Significantly, the 2D cationic ruthenium metalla-rectangle showed better anticancer activity towards three different cell lines (A549, Caki-1 and Lovo) as compared with the parent ruthenium complex (1) and the commercially used drug, cisplatin.

NMR spectroscopy and DFT calculations of a self-assembled arene ruthenium rectangle obtained from a combination of coordination and hydrogen bonds

Hydrogen-bonded ruthenium metalla-rectangle investigated by means of solution-phase NMR spectroscopy and DFT calculations.

Biologically relevant arene ruthenium metalla-assemblies

Arene ruthenium complexes have become popular building blocks for the preparation of metalla-assemblies with biological applications, opening a new era for arene ruthenium complexes.

One-pot synthesis of oxamidato-bridged hexarhenium trigonal prisms adorned with ester functionality

The self-assembly of hexarhenium trigonal prisms using fac-Re(CO)₃ cores (pink), bischelating oxamide ligands (green) and ester-containing tritopic linkers (blue) has been accomplished via an orthogonal bonding approach.

Exploiting natural products to build metalla-assemblies: the anticancer activity of embelin-derived Rh(III) and Ir(III) metalla-rectangles

Six new pentamethylcyclopentadienyl Rh(III) and Ir(III) metalla-rectangles ([3](CF3SO3)4-[8](CF3SO3)4) have been prepared by a self-assembly strategy using the embelin-derived metalla-clips (η5-C5Me5)2M2(μ4-C6HRO4-κO)Cl2 (M = Rh, 1; M = Ir, 2; R = (CH2)10CH3) and the linear ditopic ligands, pyrazine, 4,4'-bipyridine and 1,2-bis (4-pyridyl)ethylene. These new metalla-rectangles have been obtained in high yield and isolated as their triflate salts. The complexes have been fully characterized by standard spectroscopic techniques and the antiproliferative activity of these tetranuclear complexes was evaluated in vitro on cancerous (DU-145, A-549, HeLa) and noncancerous (HEK-293) cell lines. The biological study has showed a better activity for the rhodium derivatives over the iridium analogs and for all complexes a very good selectivity for cancerous over noncancerous cells. The presence of lipophilic side chains coupled with the positive charge of the tetranuclear complexes suggested a cytotoxic activity involving the mitochondrial machinery, as demonstrated by multiple biological experiments.

Growth Inhibitory Activity of a Bis-benzimidazole-Bridged Arene Ruthenium Metalla-Rectangle and Prism

Two new supramolecular coordination complexes (SCCs), were obtained from the self-assembly of a new bis-benzimidazole bridged Ru acceptor, 4, with dipyridyl and tripyridyl donors, respectively. As part of a growing library of anticancer-active Ru-based SCCs, metalla-prism 6 selectively showed high cytotoxicities relative to cisplatin for a series of cancer cell lines, with IC₅₀ values as low as 8.41 μM for MCF7 cells, as determined from MTS assays.