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Hybrid iodobismuthates code: adapting the geometry of Bi polyhedra to weak interactions
Mendeleev Communications. 2021. Vol. 31. P. 166-169.
Kotov V.Yu., Buikin P.A., Ilyukhin A. B., Korlyukov A. A., Ananyev I.V., Gavrikov A. V., Medvedev M.G.
The crystal structure of the new iodobismuthate (PyPy)2(PyPyH)2Bi6I26 was found to consist of unusual hexanuclear [Bi6I26]6– anions containing the linear I4 2– unit, and the experimental Bi–I bond lengths in this anion were used to obtain the relationship between bond length and bond energy. A statistical analysis of 229 crystal structures of iodobismuthates, based on the quantum chemically estimated strength of Bi–I bonds, revealed that the total energy of the Bi3+ polyhedron remains virtually constant at 64 ± 2 kcal mol–1, regardless of its geometry within this family of materials. Thus, the polyhedron geometry flexibly adapts to the relatively weak interactions between iodobismuthate anions and embedded cations.
L.A. Surin, Astrophysical Journal 2017 Vol. 838 No. 1 P. 1-7
We report the first high resolution spectroscopic study of the NH3–H2 van der Waals molecular complex. Three different experimental techniques, a molecular beam Fourier transform microwave spectrometer, a millimeter-wave intracavity jet OROTRON spectrometer, and a submillimeter-wave jet spectrometer with multipass cell, were used to detect pure rotational transitions of NH3–H2 in the wide frequency range ...
Added: November 15, 2018
Mutisya S. M., Kalinichev A. G., Minerals 2021 Vol. 11 No. 5 Article 509
Geological carbon capture and sequestration (CCS) is a promising technology for curbing the global warming crisis by reduction of the overall carbon footprint. Degradation of cement wellbore casings due to carbonation reactions in the underground CO2 storage environment is one of the central issues in assessing the long-term success of the CCS operations. However, the ...
Added: September 5, 2021
Omelchuk O., Malyshev V., Medvedev M. et al., Journal of Organic Chemistry 2021 Vol. 86 No. 12 P. 7975-7986
Oligomycin A is a potent antibiotic and antitumor agent. However, its applications are restricted by its high toxicity and low bioavailability. In this study, we obtained Oligomycin A Diels− Alder adducts with benzoquinone and N-benzylmaleimide and determined their absolute configurations by combining 1H and ROESY NMR data with molecular mechanics conformational analysis and quantum chemical ...
Added: September 6, 2021
Комаров Н. С., Physical Chemistry Chemical Physics 2021 Vol. 23 P. 1896-1913
We use a traditional surface science approach to create and study an atomically thin NiI2 film (a promising two-dimensional ferromagnetic material) formed on nickel substrate as a result of molecular iodine adsorption. The I/Ni(100) system was examined with scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and density functional theory calculations. We found out that ...
Added: January 21, 2021
Shi R., Fang W. -., Vasenko A. et al., Nano Research 2022 Vol. 15 No. 3 P. 2112-2122
MAPbBr3 (MA = CH3NH3+) doping with bismuth increases electric conductivity, charge carrier density and photostability, reduces toxicity, and expands light absorption. However, Bi doping shortens excited-state lifetimes due to formation of DY− charge recombination centers. Using nonadiabatic molecular dynamics and time−domain density functional theory, we demonstrate that the DY− center forms a deep, highly localized ...
Added: September 29, 2021
Makhaneva A., Zakharova E., Nesterenko S. et al., Intermetallics 2023 Vol. 164 Article 108130
New ternary intermetallic Pt5Mn2Si was obtained in the form of single crystals and phase-pure polycrystalline
bulk samples. This compound is only the second one found in the Pt–Mn–Si system. Pt5Mn2Si (space group Pbam,
a = 5.4355(3) Å, b = 10.5955(7) Å, c = 4.0024(3) Å, Z = 2) is isotypic with the Rh5Ga2As structure, an ordered
ternary variation ...
Added: November 24, 2023
Tolstov K. Y., Politov B. V., Zhukov V. P. et al., Journal of Alloys and Compounds 2021 Vol. 883 Article 160821
The computational modeling within a density functional theory was applied for simulations of electronic spectra and calculations of structural and energy characteristics of the cubic double perovskite oxides Sr2Mg1−xNixMoO6–δ, where x = 0, 0.5, and 1. The oxygen stoichiometric molybdates are antiferromagnetic semiconductors with an energy gap near 2 eV. The energy-based arguments show that ...
Added: June 23, 2021
Chernyshov I. Y., Ananyev I., Pidko E. A., ChemPhysChem 2020 Vol. 21 No. 5 P. 370-376
Weak noncovalent interactions are responsible for structure and properties of almost all supramolecular systems, such as nucleic acids, enzymes, and pharmaceutical crystals. However, the analysis of their significance and structural role is not straightforward and commonly requires model studies. Herein, we describe an efficient and universal approach for the analysis of noncovalent interactions and determination ...
Added: August 11, 2020
Pouvreau M., Greathouse J. A., Cygan R. T. et al., Journal of Physical Chemistry C 2019 Vol. 123 P. 11628-11638
Toward the development of classical force fields for the accurate modeling of clay mineral-water systems, we have extended the use of metal–O–H (M–O–H) angle bending terms to describe surface Si–O–H bending for hydrated kaolinite edge structures. Kaolinite, comprising linked octahedral Al and tetrahedral Si sheets, provides a rigorous test by combining aluminol and silanol groups ...
Added: November 2, 2019
Faraonov M., Romanenko N., Mikhailenko M. et al., New Journal of Chemistry 2021 Vol. 45 P. 13599-13607
Reduction of organic dye trans-perinone (its abbreviation is perinone) in different experimental conditions allows us to obtain and characterize radical anion {cryptand(K+)}[perinone˙−] (1) and dianion {PPN+}2[perinone2−]·2C6H4Cl2 (2) salts of this dye. The salts have layered structures. Perinone˙− radical anions form π–π stacked dimers in 1 with an effective interaction between them, whereas perinone2− dianions are ...
Added: October 21, 2022
Shirokova V., Ikonnikova V., Solyev P. et al., Synthesis 2021 Vol. 53 No. 24 P. 4689-4699
Directly accessible 8-substituted tetrahydroquinolines undergo 1,5-hydride shift-triggered cyclization to provide hardly accessible julolidine derivatives in 20-98% yield under scandium (III) triflate catalysis. The scope of the reaction, several follow-up transformations and a remarkable side-process discovered during the conditions optimization are highlighted. ...
Added: July 29, 2021
Tatiana L. Kulova, Skundin A., Gavrilin I. M. et al., Batteries 2022 Vol. 8 No. 8 Article 98
Nanostructure composites Ge-Co-P with brutto-composition CoGe2P0.1, or CoGe2@GeP were manufactured via electrolysis of aqueous electrolyte. Such composites are able to reversible insertion of lithium and sodium with specific capacities up to 855 and 425 mAh/g, respectively. The main advantage of the composites consists in their excellent cycleability. ...
Added: November 25, 2022
Андрюшечкин Б. В., Eltsov K., Pavlova T. et al., Journal of Chemical Physics 2018 Vol. 148 No. 24 Article 244702
The adsorption of O-2 on Ag(111) between 300 and 500 K has been studied with temperature-programmed desorption (TPD) and scanning tunneling microscopy (STM). At the first stage of adsorption, the disordered local oxide phase (commonly looking in STM as an array of black spots) is formed on the surface irrespective of the substrate temperature. The maximum concentration of black spots was found to be approximate to 0.11 ML, which corresponds to an oxygen coverage of approximate to 0.66 ML. Taking into account that the nucleation of the Ag(111)-p(4 x 4)-O phase starts after the saturation of the disordered phase, one ...
Added: October 25, 2021
Astakhov A., Chernenko A., Kutyrev V. et al., Inorganic Chemistry Frontiers 2023 Vol. 10 No. 1 P. 218-239
C-Amino-1,2,4-triazoles are challenging polynitrogen substrates for metal-catalyzed arylation due to their multidentate character, enhanced coordinating ability and decreased nucleophilicity of the amino group. In the present study, the Buchwald–Hartwig cross-coupling of diverse 3(5)-amino-1,2,4-triazoles with aryl chlorides and bromides delivering (hetero)arylamino-1,2,4-triazoles in good-to-excellent yields under Pd/NHC catalysis was developed. The use of Pd complexes with bulky ...
Added: February 14, 2024
Svitanko I., Pivina T. S., Khakimov D. V., Journal of Molecular Modeling 2024 Vol. 30 Article 93
Using quantum chemistry and atom–atom potential methods, the molecular and crystal structures of cubane 1 and all types of unsubstituted azacubanes 2–22 were calculated. Alternative possible polymorphs of cubane 1 have been proposed. The thermochemical properties of azacubanes in the gas and solid phases were assessed. Thermodynamic aspects of stability are considered, and a significant ...
Added: March 13, 2024
Nikolaev S. A., Tsodikov M. V., A. V. Chistyakov et al., Catalysis Today 2021 Vol. 379 P. 50-61
PdCu/Al2O3 (Pd = 0.1 wt.%, Cu = 0.1 wt.%) catalyst and its monometallic analogues (Pd/Al2O3 and Cu/Al2O3) were prepared by combination of deposition-precipitation and impregnation methods. The structure of the catalysts was studied by means of XRD, TEM, EDS, TPD-NH3, and DRIFTS. In a standard run (275 ○C, 5 h), Cu/Al2O3 converts 11 % of ethanol to α-alcohols with ...
Added: November 11, 2023
Budkov Y., Kolesnikov A. L., Polymer Science - Series C 2018 Vol. 60 No. Supplement 1 P. 148-159
Theoretical models of the conformational behavior of flexible polymer chains in mixed solvents enunciated in the world literature during the last decade are critically reviewed. Models describing different mechanisms of coil-to-globule transitions in a good solvent induced by cosolvent addition are highlighted. Special attention is given to the analysis of theoretical approaches to describing the ...
Added: November 30, 2018
Wiley, 2022
Nitrogen-Rich Energetic Materials
Provides in-depth and comprehensive knowledge on both the chemistry and practical applications of nitrogen-rich energetic materials
Energetic materials, a class of material with high amounts of stored chemical energy, include explosives, pyrotechnics, and propellants. Initially used for military applications, nitrogen-rich energetic materials have become important in the civil engineering and aerospace sectors, they are ...
Added: January 31, 2023
Victoria A. Vasileva,, Daria A. Mazur, Yury A. Budkov, Journal of Chemical Physics 2023 Vol. 159 No. 2 Article 024709
In this paper, we present a continuation of our research on modeling electrolyte solutions within charged pores. We make use of the model developed by Blossey et al. [Phys. Rev. E 95, 060602 (2017)], which takes into account the structural interactions between ions through a bilinear form over the gradients of local ionic concentrations in ...
Added: July 14, 2023
Lototskyy M., Davids M. W., Sekgobela T. K. et al., Inorganics 2023 Vol. 11 No. 8 Article 319
Hydrolysis of light metals and hydrides can potentially be used for the generation of hydrogen on-board fuel cell vehicles, or, alternatively, for refilling their fuel tanks with H2 generated and pressurised without compressor on site, at near-ambient conditions. Implementation of this approach requires solution of several problems, including the possibility of controlling H2 release and ...
Added: August 11, 2023
Panina I., Krylov N., Chugunov A. et al., International Journal of Molecular Sciences 2022 Vol. 23 Article 14791
S-acylation is a post-translational linkage of long chain fatty acids to cysteines, playing a key role in normal physiology and disease. In human cells, the reaction is catalyzed by a family of 23 membrane DHHC-acyltransferases (carrying an Asp-His-His-Cys catalytic motif) in two stages: (1) acyl-CoA-mediated autoacylation of the enzyme; and (2) further transfer of the ...
Added: December 9, 2022
Yurova P., Малахова В. Р., Gerasimova E. V. et al., Polymers 2021 Vol. 13 No. 15 P. 2513
Low chemical durability of proton exchange membranes is one the main factors limiting their lifetime in fuel cells. Ceria nanoparticles are the most common free radical scavengers. In this work, hybrid membranes based on Nafion-117 membrane and sulfonic or phosphoric acid functionalized ceria synthesized from various precursors were prepared by the in situ method for ...
Added: February 3, 2022
Ivan V. Fedyanin, CrystEngComm 2022 Vol. 24 No. 14 P. 2591-2601
An approach is proposed to obtain non-centrosymmetric crystal structures using co-crystallization of specific achiral molecules. The co-formers, donors and acceptors of electron density are selected in such a way that they can form two types of supramolecular synthons: infinite H-bonded chains along a 2-fold screw axis and π-stacks propagating by translation. Geometry analysis shows that ...
Added: February 26, 2024
Trifonova E., Ankudinov N., Mikhaylov A. A. et al., Angewandte Chemie - International Edition 2018 Vol. 57 No. 26 P. 7714-7718
The rapid development of enantioselective C−H activation reactions has created a demand for new types of catalysts. Herein, we report the synthesis of a novel planar‐chiral rhodium catalyst [(C5H2tBu2CH2tBu)RhI2]2 in two steps from commercially available [(cod)RhCl]2 and tert‐butylacetylene. Pure enantiomers of the catalyst were obtained through separation of its diastereomeric adducts with natural (S)‐proline. The catalyst promoted enantioselective ...
Added: September 29, 2020