Water-soluble neutral octahedral chalcogenide tungsten and molybdenum {MQ} clusters with P(CHCONH) ligand.

Developing the chemistry of octahedral chalcogenide molybdenum and tungsten cluster complexes in the context of applications in biology and medicine, in this work a series of water-soluble neutral cluster complexes [{MQ}(P(CHCONH))] (M = Mo, W; Q = S, Se) have been obtained by simultaneous replacement of inner and terminal halide ligands in [{MI}I] with chalcogenide and organic phosphine ligands and characterized by single-crystal X-ray diffraction analysis, H and P NMR spectroscopies, elemental analysis, and UV-vis spectroscopy. The amide groups of the organic ligands, on the one hand, contribute to the solubility of the resulting clusters in water and, on the other hand, are able to form an extensive network of hydrogen bonds, leading to the crystallization of the complexes from aqueous solutions. Despite this fact, the complexes have sufficient solubility and stability in aqueous solutions, which made it possible to demonstrate their low cytotoxicity on Hep-2 cells (IC were not reached even at concentration up to 4 mM).

A New Approach for the Synthesis of 2,3,4а,6,7,8а,9,10-Octaaza-4,8-dioxo-3,4,4a,7,8,8а,9,9a,10,10а-decahydroanthracene and High-Energy Performance Characterization of Its Dinitramide Salt.

A simple, one-pot regioselective method for the synthesis of a high-nitrogen tricycle, 2,3,4а,6,7,8а,9,10-octaaza-4,8-dioxo-3,4,4a,7,8,8а,9,9a,10,10а-decahydroanthracene, with a yield of 27% was developed on a starting urea basis as a result of studies focused on finding new, more efficient approaches to the synthesis of high-energy derivatives of dinitramic acid (DNA). This tricycle was further treated to furnish 2,3,4а,6,7,8а,9,10-octaaza-4,8-dioxo-3,4,4a,7,8,8а,9a,10а-octohydroanthracene-9,10-ion-bis(dinitramide). The resultant salt of dinitramic acid exhibited inhibitory properties towards the burning rate of pyrotechnic compositions, reducing it by 30%, and possessed good thermal stability due to a high decomposition temperature above 260 °C and a low sensitivity to mechanical stimuli.

Primary processes in photophysics and photochemistry of a potential light-activated anti-cancer dirhodium complex.

Photophysics and photochemistry of a potential light-activated cytotoxic dirhodium complex [Rh(µ-OCCH)(bpy)(dppz)](OCCH), where bpy = 2,2'-bipyridine, dppz = dipyrido[3,2-a:2',3'-c]phenazine (Complex 1 or Rh2) in aqueous solutions was studied by means of stationary photolysis and time-resolved methods in time range from hundreds of femtoseconds to microseconds. According to the literature, Complex 1 demonstrates both oxygen-dependent (due to singlet oxygen formation) and oxygen-independent cytotoxicity. Photoexchange of an acetate ligand to a water molecule was the only observed photochemical reaction, which rate was increased by oxygen removal from solutions.

Improved Synthesis of (TBA)[WBr] Paving the Way to Further Study of Bromide Cluster Complexes.

Octahedral cluster complexes of molybdenum and tungsten, [MXY] (M = Mo, W; X, Y = Cl, Br, I), are promising active components in various fields, including biomedicine and solar energy. Cluster complexes draw considerable attention due to their X-ray opacity, red/near-IR luminescence, and ability to convert triplet molecular oxygen to active singlet oxygen under UV and visible irradiation. Among the octahedral cluster complexes of molybdenum and tungsten, compounds with a {WBr} core are the least studied.

Unusual Square Pyramidal Chalcogenide Mo Cluster with Bridging Pyrazolate-Ligands.

The family of chalcogenide molybdenum clusters is well presented in the literature by a series of compounds of nuclearity ranging from binuclear to multinuclear articulating octahedral fragments. Clusters actively studied in the last decades were shown to be promising as components of superconducting, magnetic, and catalytic systems. Here, we report the synthesis and detailed characterization of new and unusual representatives of chalcogenide clusters: square pyramidal complexes [{Mo(μ-Se)(μ-Se)(μ-pz)}(pzH)] (pzH = pyrazole, i = inner, t = terminal).

Adducts of the Zinc Salt of Dinitramic Acid.

Herein, we describe the synthesis of coordination compounds starting from carbohydrazide ((HNHN)C=O (CHZ)) and the Zn salt of dinitramic acid (HDN), which are high-nitrogen substances that exhibit properties similar to those of a burning-rate inhibitor of pyrotechnic compositions. This study demonstrates that these compounds react with glyoxal to furnish adducts of metal-organic macrocyclic cages bearing the elements of carbohydrazide, complexing metals and the HDN anion, depending on the ratio of the starting reactants. The assembled macrocyclic cage has "host-guest" properties and is a safe container for the storage of HDN salts.

Synthesis of Nitro- and Acetyl Derivatives of 3,7,10-Trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane.

Here, we report the study results of the nitration of 3,7,10-trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane (THAP) by different nitrating agents such as nitric acid, mixed nitric/sulfuric acids, nitric anhydride, and mixed concentrated nitric acid/acetic anhydride to furnish 3,7,10-trioxo-2-nitro-2,4,6,8,9,11-hexaaza[3.

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

Despite the great potential of octahedral tungsten cluster complexes in fields of biomedical applications such as X-ray computed tomography or angiography, there is only one example of a water-soluble WQ-cluster that has been reported in the literature. Herein we present the synthesis and a detailed characterization including X-ray structural analysis, NMR, IR, UV-Vis spectroscopies, HR-MS spectrometry, and the electrochemical behavior of two new cluster complexes of the general formula WQL with phosphine ligands containing a hydrophilic carboxylic group, which makes the complexes soluble in an aqueous medium. The hydrolytic stability of the clusters' aqueous solutions allows us to investigate for the first time the influence of W-clusters on cell viability.

Highly Active Visible Light-Promoted Ir/-CN Photocatalysts for the Water Oxidation Reaction Prepared from a Halogen-Free Iridium Precursor.

A combination of the exceptional stability of -[Ir(HO)(NO)] together with thermolability of nitro and aqua ligands and high solubility in various solvents makes it promising as a brand-new chlorine-free precursor of iridium for the preparation of heterogeneous catalysts. In the current work, a new technique of -[Ir(HO)(NO)] preparation based on hydrothermal treatment of (NH)[Ir(NO)] was developed. For this purpose, the influence of reaction parameters such as the reaction time, temperature, and pH of the solution on the process of hexanitroiridate salt hydrolysis was investigated.

3,4-Unsubstituted 2--Butyl-pyrrolidine-1-oxyls with Hydrophilic Functional Groups in the Side Chains.

Pyrrolidine nitroxides with four bulky alkyl substituents adjacent to N-O group are known for their high resistance to bioreduction. The 3,4-unsubstituted 2--butyl-2-ethylpyrrolidine-1-oxyls were prepared from the corresponding 2--butyl-1-pyrroline-1-oxides via either the addition of ethinylmagnesium bromide with subsequent hydrogenation or via treatment with ethyllithium. The new nitroxides showed excellent stability to reduction with ascorbate with no evidence for additional large hyperfine couplings in the EPR spectra.

The Reactions of 6-(Hydroxymethyl)-2,2-dimethyl-1-azaspiro[4.4]nonanes with Methanesulfonyl Chloride or PPh-CBr.

Activation of a hydroxyl group towards nucleophilic substitution via reaction with methanesulfonyl chloride or PPh-CBr system is a commonly used pathway to various functional derivatives. The reactions of (5(),6())-1-X-6-(hydroxymethyl)-2,2-dimethyl- 1-azaspiro[4.4]nonanes 1- (X = O·; H; OBn, OBz) with MsCl/NR or PPh-CBr were studied.

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

Substitution of apical halide ligands in [{ReSe}X] (X = Cl, Br) by benzimidazole (bimzH) accompanied by a self-assembly process leads to the formation of microporous Re-based hydrogen-bonded organic frameworks (Re-HOFs) constructed on N-H···X hydrogen bonds and π-π-stacking interactions between bimzH ligands. Re-HOFs demonstrate sorption properties with a Brunauer-Emmett-Teller surface area of up to 443 m g and luminescence with a quantum yield and an emission lifetime of up to 0.16 and 16 μs, respectively.

New Reaction Products of Acetylacetone with Semicarbazide Derivatives.

A new approach is suggested herein for the synthesis of pyrazole derivatives by reacting 4-nitrosemicarbazide with acetylacetone. Additional studies were done on the reaction of acetylacetone with semicarbazide and its derivatives (4-aminosemicarbazide, methylsemicarbazide, and dimethylsemicarbazide). The study on the reaction with acetylacetone resulted in monocyclic 3,5-dimethyl--nitropyrazole-1-carboxamide, monocyclic 5-hydroxy-3,5-dimethyl-2-pyrazoline, and bicyclic (3,5-dimethylpyrazole-1-carbonyl)hydrazine, and conditions for the formation of acetone semicarbazone were identified.

New class of hantaan virus inhibitors based on conjugation of the isoindole fragment to (+)-camphor or (-)-fenchone hydrazonesv.

This work presents the design and synthesis of camphor, fenchone, and norcamphor N-acylhydrazone derivatives as a new class of inhibitors of the Hantaan virus, which causes haemorrhagic fever with renal syndrome (HFRS). A cytopathic model was developed for testing chemotherapeutics against the Hantaan virus, strain 76-118. In addition, a study of the antiviral activity was carried out using a pseudoviral system.

Different Reactivity of Raw Starch from Diverse Potato Genotypes.

Potato starch is one of the most important renewable sources for industrial manufacturing of organic compounds. Currently, it is produced from mixed potato varieties that often are harvested from different fields. Meanwhile, tuber starches of various potato breeds differ in their crystallinity, granule morphology, and other physical and chemical parameters.

Cyanide Complexes Based on {MoI} and {WI} Cluster Cores.

Compounds based on new cyanide cluster anions [{MoI}(CN)], -[{MoI}(CN)(MeO)] and -[{WI}(CN)(MeO)] were synthesized using mechanochemical or solvothermal synthesis. The crystal and electronic structures as well as spectroscopic properties of the anions were investigated. It was found that the new compounds exhibit red luminescence upon excitation by UV light in the solid state and solutions, as other cluster complexes based on {MoI} and {WI} cores do.

A Sterically Hindered Derivative of 2,1,3-Benzotelluradiazole: A Way to the First Structurally Characterised Monomeric Tellurium-Nitrogen Radical Anion.

Interaction of the tetradentate redox-active 6,6'-[1,2-phenylenebis(azanediyl)]bis(2,4-di-tert-butylphenol) (H L) with TeCl leads to neutral diamagnetic compound TeL (1) in high yield. The molecule of 1 has a nearly planar TeN O fragment, which suggests the formulation of 1 as Te L , in agreement with the results of DFT calculations and QTAIM and NBO analyses. Reduction of 1 with one equivalent of [CoCp ] leads to quantitative formation of the paramagnetic salt [CoCp ] [1] , which was characterised by single-crystal XRD.

Design, Synthesis and Molecular Modeling Study of Conjugates of ADP and Morpholino Nucleosides as A Novel Class of Inhibitors of PARP-1, PARP-2 and PARP-3.

We report on the design, synthesis and molecular modeling study of conjugates of adenosine diphosphate (ADP) and morpholino nucleosides as potential selective inhibitors of poly(ADP-ribose)polymerases-1, 2 and 3. Sixteen dinucleoside pyrophosphates containing natural heterocyclic bases as well as 5-haloganeted pyrimidines, and mimicking a main substrate of these enzymes, nicotinamide adenine dinucleotide (NAD+)-molecule, have been synthesized in a high yield. Morpholino nucleosides have been tethered to the β-phosphate of ADP via a phosphoester or phosphoramide bond.

Supramolecular architecture of betulin diacetate complexes with arabinogalactan from Larix sibirica.

Supramolecular ensembles of arabinogalactan (AG) and its complexes with betulin diacetate (BDA) were studied in water and dimethyl sulfoxide (DMSO) using ablation, induced by submillimeter radiation from the free electron laser. Solutions of 1wt% AG resulted in formation of aerosol particles with a maximum size of 60-70nm. In contrast, with DMSO as the solvent, the majority of particles were significantly smaller.