A. I. Smolentsev

Binuclear Bi(III) halide complexes with 4,4′-ethylenepyridinium cations: luminescence tuning by reversible solvation

Two new complexes based on 4,4′-ethylenepyridinium cations and binuclear Bi(III) anionic complexes, (H2bpe)2[Bi2X10]·2H2O (bpe = 1,2-bis(4-pyridyl)ethane; X = Cl (1), Br (2)), have been synthesized and characterized by X-ray diffractometry. In both cases, loss of solvent H2O molecules affects the luminescence behavior, resulting in increase of intensity (ca. 5-fold). Desolvation is reversible, which is of potential use in chemosensor systems.

Synthesis, Crystal Structure, and Colloidal Dispersions of Vanadium Tetrasulfide (VS4)

Although many of the layered metal chalcogenides, such as MoS2, are well-studied, some other chalcogenides have received less attention by comparison. In particular, there has been an emerging interest in vanadium tetrasulfide (VS4), which displays useful properties as a component of hybrids. However, the synthetic methods and characteristics of individual VS4 are not yet well defined, and there is no report on its solution processability. Here we have synthesized VS4 by a simple and fast direct reaction between elements. Reinvestigation of the VS4 crystal structure yielded more precise atomic coordinates and interatomic distances, thereby confirming the crystallization of VS4 in the monoclinic C2/c group and its quasi-1D chainlike structure. As the chains in VS4 are only bonded by weak van der Waals forces, we further demonstrate that bulk VS4 may be ultrasonically dispersed in appropriate solvents to form colloids, similarly to the layered chalcogenides. VS4 particles in colloids retain their phase identity and rod-shaped morphology with lengths in the range of hundreds of nanometers. Isopropanol dispersion exhibited the highest concentration and stability, which was achieved owing to the repulsion caused by high negative charges on the edges of the particles.

On the synthesis and characterisation of luminescent hybrid particles: Mo6 metal cluster complex/SiO2

Photoluminescent silica-based materials are used in applications in photonics, sensing, and biological and medical sciences. Specifically, hybrid particles based on silica doped by photoluminescent octahedral molybdenum metal cluster complexes are inexpensive and readily available via the Stober process and thus are promising materials for diverse applications. We evaluated design of photoluminescent materials based on silica and {Mo6X8}4+ clusters (where X = Cl, Br, I), including how synthesis conditions (chemical composition of metal cluster precursors (Bu4N)2[{Mo6X8}(NO3)6], loading of the precursor and presence of a surfactant) influence key parameters of the final materials, such as phase composition, size and morphology of the particles and photophysical characteristics. Our study revealed that hydrolysis of the molybdenum cluster precursors during the Stober process strongly affects both morphology and photophysical parameters of the materials, especially at high loadings. At relatively low loadings of the precursors, materials doped by {Mo6I8}4+ clusters demonstrated the most promising set of properties—the highest photoluminescence quantum yields and efficient singlet oxygen generation—while particle size and morphology remained the same as for undoped SiO2 materials.

Comprehensive study of hexarhenium cluster complex Na4[{Re6Te8}(CN)6] – In terms of a new promising luminescent and X-ray contrast agent

Octahedral rhenium cluster complexes may have considerable potential as therapeutic and diagnostic drugs due to their luminescent and X-ray contrast properties, as well as their ability to generate singlet oxygen upon photoirradiation. However, their potential biological effects and toxicity in vitro and in vivo are rather far from being understood. Thus, the aim of our research was to study cytotoxicity, intracellular localization and cellular uptake/elimination kinetics in vitro, biodistribution and acute intravenous toxicity in vivo of a complex Na4[{Re6Te8}(CN)6] as the promising compound for biomedical application. The results have demonstrated that the complex penetrates through cell membranes with the maximum accumulation in cells in 24h of incubation and have low toxic effects in vitro and in vivo. The median lethal dose (LD50) of intravenously administrated Na4[{Re6Te8}(CN)6] is equal to 1082±83mg/kg. These findings will be useful for future development of cluster-based agents for different biomedical applications.

Structure and properties of terbium(III) dipivaloylmethanate and its adducts with Bipy and Phen

The complex of terbium(III) with dipivaloylmethane (2,2,6,6-tetramethylheptane-3,5-dione = Htmhd) [Tb(tmhd)3]2 (1) and two its adducts with bipyridyl (Bipy) and phenanthroline (Tb(tmhd)3·Bipy (2) and Tb(tmhd)3·Phen (3)) are synthesized and analyzed by single crystal X-ray diffraction. The crystals of [Tb(tmhd)3]2 (1) belong to the monoclinic crystal system: P21/n space group, a = 12.2238(2) Å, b = 27.6369(5) Å, c = 21.8740(4) Å, β = 105.146(1)°, V = 7133.0(2)Å3, Z = 4; the crystals of Tb(tmhd)3·Bipy (2) and Tb(tmhd)3·Phen (3) belong to the triclinic crystal system with unit cell parameters: (2)

Selective Two-Step Oxidation of μ2-S Ligands in Trigonal Prismatic Unit {Re3(μ6-C)(μ2-S)3Re3} of the Bioctahedral Cluster Anion [Re12CS17(CN)6]6–

P\bar 1

Synthesis, supramolecular self-organization, and thermal behavior of the heteropolynuclear complex ([H3O][Au{S2CN(CH2)6}2][Au2{S2CN(CH2)6}4][ZnCl4]2)n

space group, a = 11.0554(6) Å, b = 12.2761(7) Å, c = 17.7096(8) Å, α = 77.457(2)°, β = 85.557(2)°, γ = 69.659(2)°, V = 2199.8(2) Å3, Z = 2; (3)

Synthesis and structure investigation of Co(III) complex salts with the perrhenate anion

P\bar 1

Structure of a new molecular rhenium cluster complex: trans-{[Ni(NH3)5]2×[Re6Se8(CN)4(OH)2]}·6H2O

space group, a = 10.8814(3) Å, b = 12.2852(4) Å, c = 18.3590(6) Å, α = 80.463(1)°, β = 87.587(1)°, γ = 68.640(1)°, V = 2253.6(1) Å3, Z = 2. The structures of the complexes are molecular and involve isolated [Tb2(tmhd)6] (1), Tb(tmhd)3·Bipy (2), and Tb(tmhd)3·Phen (3) molecules. The thermal properties of the obtained terbium complexes are studied by TG-DTA.

A 1-D cyano-bridged coordination polymer, [Ni(NH3)6]2[{Ni(NH3)4}{Re12CS17(CN)6}] · 8H2O: reactivity studies of dodecanuclear rhenium cluster anion [Re12CS17(CN)6]6− in Ni(II)-ammonia system

An oxidation of cluster anion [Re(12)CS(17)(CN)(6)](6-) by H(2)O(2) in water has been investigated. It was shown that selective two-step oxidation of bridging μ(2)-S-ligands in trigonal prismatic unit {Re(3)(μ(6)-C)(μ(2)-S)(3)Re(3)} takes place. The first stage runs rapidly, whereas the speed of the second stage depends on intensity of ultraviolet irradiation of the reaction mixture. Each stage of the reaction is accompanied by a change in the solutions color. In the first stage of the oxidation, the cluster anion [Re(12)CS(14)(SO(2))(3)(CN)(6)](6-) is produced, in which all bridging S-ligands are turned into bridging SO(2)-ligands. The second stage of the oxidation leads to formation of the anion [Re(12)CS(14)(SO(2))(2)(SO(3))(CN)(6)](6-), in which one of the SO(2)-ligands underwent further oxidation forming the bridging SO(3)-ligand. Seven compounds containing these anions were synthesized and characterized by a set of different methods, elemental analyses, IR and UV/vis spectroscopy, and quantum-chemical calculations. Structures of some compounds based on similar cluster anions, [Cu(NH(3))(5)](3)[Re(12)CS(14)(SO(2))(3)(CN)(6)]·9.5H(2)O, [Ni(NH(3))(6)](3)[Re(12)CS(14)(SO(2))(3)(CN)(6)]·4H(2)O, and [Cu(NH(3))(5)](2.6)[Re(12)CS(14)(SO(2))(3)(CN)(6)](0.6)[{Re(12)CS(14)(SO(2))(2)(SO(3))(CN)(5)(μ-CN)}{Cu(NH(3))(4)}](0.4)·5H(2)O, were investigated by X-ray analysis of single crystals.