1,302 results match your criteria: "Institute of Organoelement Compounds[Affiliation]"

Copper is an important metal micronutrient, required for the balanced growth and normal physiological functions of human organism. Copper-related toxicity and dysbalanced metabolism were associated with the disruption of intracellular respiration and the development of various diseases, including cancer. Notably, copper-induced cell death was defined as cuproptosis which was also observed in malignant cells, representing an attractive anti-cancer instrument.

View Article and Find Full Text PDF

The present computational study provides a benchmark of density functional theory (DFT) methods in describing hydrogen evolution processes catalyzed by [Cp*Rh]-containing organometallic complexes. A test set was composed of 26 elementary reactions featuring chemical transformations and bonding situations essential for the field, including the emerging concept of non-innocent Cp* behavior. Reference values were obtained from a highly accurate 3/4 complete basis set and 6/7 complete PNO space extrapolated DLPNO-CCSD(T) energies.

View Article and Find Full Text PDF

Molecules with chiral boron atoms have been scarcely studied due to limited synthetic access. Herein, we report a new method for their synthesis asymmetric insertion of arydiazoacetates into the B-H bonds of prochiral carbene-boranes NHC-BHR. The reaction is catalyzed by the rhodium(I) complex with the chiral diene ligand Bu-TFB, which can be conveniently prepared by diastereoselective coordination of the racemic diene with (-Salox)Rh(CO).

View Article and Find Full Text PDF

Positively charged ligands are scarce. Here, we report the synthesis of unprecedented cationic selenium-containing triazapentadiene ligand framework. The reaction between 2-pyridylselenyl reagents and NaN(CN) in a 2:1 ratio produces the sodium complexes featuring the cationic selenium-containing triazapentadiene (SeTAP) ligand.

View Article and Find Full Text PDF

Coatings with xenogenic materials, made of detonation nanodiamonds, provide additional strength and increase elasticity. A functionally developed surface of nanodiamonds makes it possible to apply antibiotics. Previous experiments show the stability of such coatings; however, studies on stability in the bloodstream and calcification of the material in natural conditions have yet to be conducted.

View Article and Find Full Text PDF

Despite the significance of HO-metal adducts in catalysis, materials science and biotechnology, the nature of the interactions between HO and metal cations remains elusive and debatable. This is primarily due to the extremely weak coordinating ability of HO, which poses challenges in characterizing and understanding the specific nature of these interactions. Herein, we present an approach to obtain HO-metal complexes that employs neat HO as both solvent and ligand.

View Article and Find Full Text PDF

Vanadium-Silsesquioxane Nanocages as Heterogeneous Catalysts for Synthesis of Quinazolinones.

Inorg Chem

July 2024

Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology, School of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252000, People's Republic of China.

The functionalization of polyoxovanadate clusters is promising but of great challenge due to the versatile coordination geometry and oxidation state of vanadium. Here, two unprecedented silsesquioxane ligand-protected "fully reduced" polyoxovanadate clusters were fabricated via a facial solvothermal methodology. The initial mixture of the two polyoxovanadate clusters with different colors and morphologies (green plate and blue block ) was successfully separated as pure phases by meticulously controlling the assembly conditions.

View Article and Find Full Text PDF

Manganese complexes [(arene)Mn(CO)] were prepared in one step from arenes and Mn(CO)Br. They were found to be efficient catalysts in the carbonyl cyanation with TMSCN, CO fixation by epoxides, and direct reductive amination in the presence of syngas. The amination reaction tolerated various reducible functional groups.

View Article and Find Full Text PDF

In this study, we report an easy approach for the production of aqueous dispersions of C fullerene with good stability. Maleic acid copolymers, poly(styrene--maleic acid) (SM), poly(N-vinyl-2-pyrrolidone--maleic acid) (VM) and poly(ethylene--maleic acid) (EM) were used to stabilize C fullerene molecules in an aqueous environment by forming non-covalent complexes. Polymer conjugates were prepared by mixing a solution of fullerene in N-methylpyrrolidone (NMP) with an aqueous solution of the copolymer, followed by exhaustive dialysis against water.

View Article and Find Full Text PDF

In recent years, researchers have often encountered the significance of the aberrant metabolism of tumor cells in the pathogenesis of malignant neoplasms. This phenomenon, known as the Warburg effect, provides a number of advantages in the survival of neoplastic cells, and its application is considered a potential strategy in the search for antitumor agents. With the aim of developing a promising platform for designing antitumor therapeutics, we synthesized a library of conjugates of 3,5-bis(arylidene)-4-piperidone and sesquiterpene lactones.

View Article and Find Full Text PDF

It is found that the reaction of dimethyl 2-phenylcyclopropane-1,1-dicarboxylate with 2 equivalents each of aromatic aldehydes and TaCl in 1,2-dichloroethane at 23 °C for 24 h after hydrolysis gives substituted 4-phenyl-3,4-dihydronaphtalene-2,2(1)-dicarboxylates in good yield. This represents a new type of reactions between 2-arylcyclopropane-1,1-dicarboxylates and aromatic aldehydes, yielding chlorinated tetrahydronaphthalenes with a arrangement of the aryl and chlorine substituents in the cyclohexene moiety. A plausible reaction mechanism is proposed.

View Article and Find Full Text PDF

Copolymers based on vinylidene fluoride are potential materials for ferroelectric memory elements. The trend in studies showing that a decrease in the degree of crystallinity can lead to an unexpected increase in the electric breakdown field is noted. An analysis of the literature data reveals that in fluorine-containing ferroelectric polymers, when using a bipolar triangular field, the hysteresis loop has an unclosed shape, with each subsequent loop being accompanied by a decrease in the dielectric response.

View Article and Find Full Text PDF

Ditopic bis-pyrazolylpyridine ligands usually react with divalent metal ions (M) to produce dinuclear triple-stranded helicates [ML] or, π⋯π interactions, dimers of monoatomic complexes ([ML]). The introduction of an additional benzene ring at each end of ligand L increases the number of aromatic contacts within the supramolecular aggregate by 40%, driving the self-recognition process in an irreversible manner. Consequently, the mixing of new bis-pyrazolylquinoline L2 with FeX salts leads to crystallization of the tripartite high-spin assemblies (X@[Fe(L2)]) (X = Cl, Br or I).

View Article and Find Full Text PDF

High-temperature polymer-electrolyte membrane fuel cells (HT-PEMFCs) are a very important type of fuel cells since they operate at 150-200 °C, making it possible to use hydrogen contaminated with CO. However, the need to improve the stability and other properties of gas-diffusion electrodes still impedes their distribution. Self-supporting anodes based on carbon nanofibers (CNF) are prepared using the electrospinning method from a polyacrylonitrile solution containing zirconium salt, followed by pyrolysis.

View Article and Find Full Text PDF

The development and technological applications of molecular spin systems require versatile experimental techniques to characterize and control their static and dynamic magnetic properties. In the latter case, bulk spectroscopic and magnetometric techniques, such as AC magnetometry and pulsed electron paramagnetic resonance, are usually employed, showing high sensitivity, wide dynamic range, and flexibility. They are based on creating a nonequilibrium state either by changing the magnetic field or by applying resonant microwave radiation.

View Article and Find Full Text PDF

A New 2-Aminospiropyrazolylammonium Cation with Possible Uses in the Topical Areas of Ionic Liquids.

Molecules

May 2024

X-ray Diffraction Laboratory, A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, 28 Vavilov Str., B-334, 119334 Moscow, Russia.

Based on the fact that 2-aminospiropyrazolinium compounds and structurally related azoniaspiro compounds belong, in a broad sense, to the class of ionic liquids, we have reviewed them and studied their practical applications. To search for possible uses of a new 2-aminospiropyrazolinium compounds, it is necessary to undertake a comparison with the related class of azoniaspiro compounds based on available information. The structures of the well-studied class of azoniaspiro compounds and the related but little-studied class of 2-aminospiropyrazolinium have rigid frameworks, limited conformational freedom, and a salt nature.

View Article and Find Full Text PDF

The development of photocurable compositions is in high demand for the manufacture of functional materials for electronics, optics, medicine, energy, etc. The properties of the final photo-cured material are primarily determined by the initial mixture, which needs to be tuned for each application. In this study we propose to use simple systems based on di(meth)acrylate, polyimide and photoinitiator for the preparation of new photo-curable compositions.

View Article and Find Full Text PDF

Herein, we describe in first the application of squid pens for the preparation of pharmaceutical-grade oligochitosan hydrochloride with the physicochemical characteristics corresponding with the requirements of the European Pharmacopoeia. It is shown that the use of specific properties of squid pens as a source of parent chitosan allows preparing the product with a high yield at relatively moderate process conditions used for squid pens treatments and chitosan depolymerization.

View Article and Find Full Text PDF

An efficient access to the novel 5-(aryl)amino-1,2,3-triazole-containing 2,1,3-benzothiadiazole derivatives has been developed. The method is based on 1,3-dipolar azide-nitrile cycloaddition followed by Buchwald-Hartwig cross-coupling to afford the corresponding -aryl and ,-diaryl substituted 5-amino-1,2,3-triazolyl 2,1,3-benzothiadiazoles under NHC-Pd catalysis. The one-pot diarylative Pd-catalyzed heterocyclization opens the straightforward route to triazole-linked carbazole-benzothiadiazole D-A systems.

View Article and Find Full Text PDF

A three-component condensation of 2-unsubstituted imidazole -oxides, 3-ketonitriles, and aldehydes is described. The reaction proceeds sequential Knoevenagel condensation/Michael addition under mild, catalyst-free conditions with various substrates. Furthermore, the corresponding 2-functionalized imidazole -oxides can be further dehydrated to ()-2-aroyl-3-(1-imidazol-2-yl)-acrylonitriles, which may also be directly prepared by changing the reaction conditions as a cascade of Knoevenagel condensation/Michael addition/dehydration.

View Article and Find Full Text PDF

The implementation of selective catalytic processes with highly active reagents is an attractive strategy that meets the modern principles of sustainable development of chemistry. In the current study, we for the first time describe the method and general principles of Cu(I)-catalyzed allylation of imines with amine adducts of allylic triorganoboranes. Triallylborane is an extremely reactive compound and cannot be used for the catalytic allylation of imines, whereas its amine adducts are ideal substrates for catalysis.

View Article and Find Full Text PDF

High-spin organic tetraradicals with significant intramolecular exchange interactions have high potential for advanced technological applications and fundamental research, but examples reported to date exhibit limited stability and processability. In this work, we designed the first tetraradical based on an oxoverdazyl core and nitronyl nitroxide radicals and successfully synthesized it using a palladium-catalyzed cross-coupling reaction of an oxoverdazyl radical bearing three iodo-phenylene moieties with a gold(I) nitronyl nitroxide-2-ide complex in the presence of a recently developed efficient catalytic system. The molecular and crystal structures of the tetraradical were confirmed by single crystal X-ray diffraction analysis.

View Article and Find Full Text PDF

In this study, we provide a theoretical explanation for the experimentally observed decrease in the organocatalytic activity of -aryl imidazolylidenes methylated at the C4/5-H positions in the benzoin condensation of aromatic aldehydes. A comparative quantum chemical study of energy profiles for the NHC-mediated benzoin condensation of furfural has revealed a high energy barrier to the formation of the IPr-based furanic Breslow intermediate that can be attributed to the negative steric interactions between the imidazole backbone methyl groups and -aryl substituents.

View Article and Find Full Text PDF

Hydrogels from natural polysaccharides are of great interest for tissue engineering. This study aims (1) to prepare hydroxyapatite-loaded macroporous calcium alginate hydrogels by novel one-step technique using internal gelation in water-frozen solutions; (2) to evaluate their physicochemical properties; (3) to estimate their ability to support cell growth and proliferation in vitro. The structure of the hydrogel samples in a swollen state was studied by confocal laser scanning microscopy and was shown to represent a system of interconnected macropores with sizes of tens micron.

View Article and Find Full Text PDF

Isocyanates play an essential role in modern manufacturing processes, especially in polyurethane production. There are numerous synthesis strategies for isocyanates both under industrial and laboratory conditions, which do not prevent searching for alternative highly efficient synthetic protocols. Here, we report a detailed theoretical investigation of the mechanism of sulfur dioxide-catalyzed rearrangement of phenylnitrile oxide into phenyl isocyanate, which was first reported in 1977.

View Article and Find Full Text PDF