Water‐Soluble Rhenium Clusters with Triazoles: The Effect of Chemical Structure on Cellular Internalization and the DNA Binding of the Complexes

Abstract

Here we explore the effect of the nature of organic ligandsi nr heniumc luster complexes [Re 6 Q 8 L 6 ] 4À (where Q = So rS e, and L = benzotriazole, 1,2,3-triazole or 1,2,4-triazole) on the biological properties of the complexes, in particular on the cellulart oxicity,c ellular internalizationa nd localization. Specifically,t he study describes the synthesis and detailedc haracterization of the structure, luminescence and electrochemical properties of the four new Re 6 clusters with 1,2,3-and 1,2,4-triazoles. Biological assays of these com-plexesa re also discussed in addition to those with benzotriazole using cervical cancer (HeLa) and immortalized humanf ibroblasts(CRL-4025) as model cell lines. Our study demonstrates that the presence of hydrophobic and pbondingr ich units such as the benzene ring in benzotriazole significantly enhances cellular internalization of rhenium clusters.T hese ligands facilitate binding of the clusters to DNA, whichr esults in increased cytotoxicity of the complexes.

Neutral Mo6Q8-clusters with terminal phosphane ligands – a route to water-soluble molecular units of Chevrel phases

“…10,11 Moreover, varying ligands was proved to be an efficient method to expand, manipulate or tune the properties of such compounds. [11][12][13][14][15][16][17][18] Unfortunately, due to their synthetic features, Chevrel phases did not become useful parent compounds to obtain molecular clusters. The only example of a successful synthesis was demonstrated by Mironov et al -the reaction of molybdenum selenide Mo 6 Se 8 with melted potassium cyanide resulted in water-soluble K 7 [{Mo 6 Se 8 }(CN) 6 ]Á8H 2 O.…”

Water-Soluble Chalcogenide W6-Clusters: On the Way to Biomedical Applications

“…Indeed, a series of cluster complexes, [{Re 6 Q 8 }L 6 ] (varying L), was previously shown to possess different biological effects: cytotoxicity, cellular uptake, and acute toxicity in mice depending on inner ligand [ 18 , 20 , 21 , 22 , 52 , 53 , 54 , 55 ]. For example, this tendency was observed in the cytotoxic effects of clusters with different ligand natures, namely [{Re 6 Q 8 }(CN) 6 ] 4− (Q = S, Se, Te), [ 17 , 18 ] [{Re 6 Q 8 }(trz) 6 ] 4− , [ 55 ] [{Re 6 Q 8 }(PPh 2 CH 2 CH 2 COO) 6 ] 4− [ 22 ] and [{Re 6 Q 8 }(P(CH 2 CH 2 COO) 3 ) 6 ] 16− [ 21 ] (Q = S, Se; trz = 1,2,3-triazole, 1,2,4-triazole or benzotriazole), studied in normal and cancerous cell lines. Specifically, in the case of clusters with acidic ligands, like triazoles and phosphines, the selenium-containing clusters have a more pronounced cytotoxic effect than sulfur ones.…”

Self-Assembled Microporous M-HOFs Based on an Octahedral Rhenium Cluster with Benzimidazole

“…All distances (Re–Re, Re–Se, and Re–N) in the [{Re 6 Se i 8 }­L a 6 ] 2+ cation are in good agreement with the literature data for other complexes with organic ligands (Table S2). ,, These building blocks are connected to each other via hydrogen bonds between each bimzH ligands and X anion (N–H···X), so that each X anion connects three cluster cations, with N–X distances of 3.068–3.080 and 3.220–3.278 Å for X = Cl and Br, respectively, forming infinite layers along a plane perpendicular to the crystallographic directions [1,1,1] (Figure b,c). On the other hand, stacking of the layers occurs because of parallel displaced π–π-stacking interactions (the average distances between centroids of the benzene rings are 3.730 and 3.686 Å for Re 6 -HOF-1 as and Re 6 -HOF-2 as , respectively) between three bimzH molecules in the fac positions of one cluster and the bimzH molecules of three other clusters of the adjacent layer (Figure S5).…”