Synthesis, structure and luminescence properties of new chalcogenide octahedral rhenium cluster complexes with 4-aminopyridine [{Re₆Q₈}(4-NH₂-py)₆]²⁺

<p>Two new cationic octahedral rhenium cluster complexes [{Re₆Q₈}(4-NH₂-py)₆]²⁺ (Q=S, Se; 4-NH₂-py = 4-aminopyridine) were synthesized by reactions of cesium salts of cluster anions [{Re₆Q₈}Br₆]^4−/3− with molten 4-aminopyridine. Both complexes were separated as salts with Br⁻ as counterions and the structure of [{Re₆S₈}(4-NH₂-py)₆]Br₂·6DMF was revealed by X-ray single-crystal diffraction analysis. The compounds were characterized by elemental analysis, energy dispersive X-ray, IR, NMR, and luminescence spectroscopies.</p

The First Water-Soluble Hexarhenium Cluster Complexes with a Heterocyclic Ligand Environment: Synthesis, Luminescence, and Biological Properties

The hexarhenium cluster complexes with benzotriazolate apical ligands [{Re₆(μ₃-Q)₈}­(BTA)₆]^4– (Q = S, Se; BTA = benzotriazolate ion) were obtained by the reaction of [{Re₆(μ₃-Q)₈}­(OH)₆]^4– with molten 1<i>H</i>-BTA (1<i>H</i>-benzotriazole). The clusters were crystallized as potassium salts and characterized by X-ray single-crystal diffraction, elemental analyses, and UV–vis and luminescence spectroscopy. In addition, their cellular uptake and toxicity were evaluated. It was found that both clusters exhibited luminescence with high lifetimes and quantum yield values; they were taken up by the cells illuminating them under UV irradiation and, at the same time, did not exhibit acute cytotoxic effects

23-Electron Octahedral Molybdenum Cluster Complex [{Mo₆I₈}Cl₆]⁻

Photoactive transition metal compounds that are prone to reversible redox reactions are important for myriad applications, including catalysis, optoelectronics, and sensing. This article describes chemical and electrochemical methods to prepare cluster complex (Bu₄N)­[{Mo₆I₈}­Cl₆], a rare example of a 23 e^– cluster complex within the family of octahedral clusters of Mo, W, and Re. The low temperature and room temperature crystal structures; electronic structure; and the magnetic, optical, and electrochemical properties of this complex are described

Singlet Oxygen Production and Biological Activity of Hexanuclear Chalcocyanide Rhenium Cluster Complexes [{Re₆Q₈}(CN)₆]^4– (Q = S, Se, Te)

Octahedral rhenium cluster complexes have recently emerged as relevant building blocks for the design of singlet oxygen photosensitizing materials toward biological applications such as blue-light photodynamic therapy. However, their singlet oxygen generation ability as well as biological properties have been studied only superficially. Herein we investigate in detail the singlet oxygen photogeneration, dark and photoinduced cytotoxicity, cellular uptake kinetics, cellular localization and in vitro photoinduced oxidative stress, and photodynamic cytotoxicity of the series of octahedral rhenium cluster complexes [{Re₆Q₈}­(CN)₆]^4–, where Q = S, Se, Te. Our results demonstrate that the selenium-containing complex possesses optimal properties in terms of absorption and singlet oxygen productivity. These features coupled with the cellular internalization and low dark toxicity lead to the first photoinduced cytotoxic effect observed for a molecular [{M₆Q₈}­L₆] complex, making it a promising object for further study in terms of blue-light PDT