Synthesis and structure of methyltriphenylphosphonium dicyanodibromoaurate [Ph3PCH3] [Au(CN)2Br2]

Methyltriphenylphosphonium dicyanodibromoaurate (1) [Ph3PMe]+[Au(CN)2Br2]- was synthesized by the reaction of potassium dicyanodibromoaurate with methyltriphenylphosphonium bromide in an aqueous solution and was structurally characterized. The complex is a yellow-col-ored, air-resistant crystalline substance with a clear melting point. The structure of the compound was established by IR spectroscopy, NMR spectroscopy and X-ray diffraction analysis. An intense absorption band was observed in the IR spectrum of compound at 2220 cm-1, corresponding to the stretching vibrations of cyano groups. The absorption band of the deformation vibrations of the P-SPh bonds in the IR spectrum is at 1438 cm-1. In the recorded 1N, 13S, and 31R NMR spectra, signals are observed for the number, value of chemical shifts and integral intensity that do not contradict the proposed complex structure. The X-ray diffraction analysis of crystal 1 was carried out on a Bruker D8 QUEST diffractometer (MoKα radiation, λ = 0.71073 A, graphite monochrom-ator). [C21H18AuBr2N2P, M = 686.13, crystal system triclinic, space group P-1, a = 8.802(5), b = 8.989(5), c = 15.233(11) A, V = 1143.8(13) A3, Z = 2, μ = 10.002 mm-1, F(000) = 644, crystal size 0.41x0.30x0.22 mm]. According to the X-ray diffraction analysis (XRDA) data there are two types of centrosymmetric crystallographically independent monomeric dicyanodibromoaurate anions and methyltriphenylphosphonium cations in the crystal of compound MFDDA. The cations have a distorted tetrahedral configuration: the CPC angles equal 108.8(2)°-110.0(2)°, the P-S distances are 1.791(5)-1.800(5) A. All SAuC and BrAuBr trans-angles are 180.0° in the [Au(CN)2Br2]-an-ions. The Au-C distances in anions differ from each other and equal 2.040(7), 2.024(1), 1.991(2) A. These values are close to the sum of the covalent radii of atoms (2.03 A). The Au-Br bond lengths are equal to 2.4162(14), 2.4591, 2.474(5) A in dicyanodibromoaurate anions. Formation of the crystal structure occurs due to formation of weak N···N-S hydrogen bonds between cations and anions (2.68, 2.59, 2.38 A) and Br···N-S (3.03, 3.02 A). Complete tables of coordinates of atoms, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Centre. © 2020, Ivanovo State University of Chemistry and Technology.Ministry of Education and Science of the Russian Federation, Minobrnauka: 4.6151.2017/8.9South Ural State University is grateful for the financial support of the Ministry of Education and Science of the Russian Federation (grant No. 4.6151.2017/8.9)

New pathways for the synthesis of indolyl-containing quinazoline trifluoroacetohydrazides

Received: 19.08.2020. Accepted: 28.09.2020. Published: 07.10.2020.The reactions of indole-3‑carbaldehyde arylhydrazones with quinazoline in TFA proceed at the 7’ position of the aryl part of the hydrazone molecule to form σ-adducts of quinazoline trifluoroacetohydrazides.The authors are grateful to the Russian Foundation for Basic Research (grant 18‑33‑00727 mol_a) for financial support of the research

Идентификация мономерного состава поли(стирол)акрилатов

Received: 07.09.2016; accepted: 11.10.2016; published: 01.12.2016.Поступило: 07.09.2016; приянято: 11.10.2016; опубликовано: 01.12.2016.The work is devoted to qualitative analysis of poly(styrene)acrylates, the definition of the content of styrene in them. The methods of IR, NMR spectroscopy and gas chromatography-mass spectrometry were used for analysis. It was shown that the integrated use of modern spectral methods allows unambiguous to lead identification of the components in the copolymer and to use of spectral data for quantitative determinations.Работа посвящена качественному анализу полистиролакрилатов, определению содержания в них стирола. Для проведения анализа были использованы методы ИК-, ЯМР-спектроскопии и газовой хромато-масс-спектрометрии. Было показано, что комплексное использование современных спектральных методов позволяет однозначно провести идентификацию компонентов в сополимере, а также использовать спектральные данные для количественных определений

Nematic Structure of Space-Time and its Topological Defects in 5D Kaluza-Klein Theory

We show, that classical Kaluza-Klein theory possesses hidden nematic dynamics. It appears as a consequence of 1+4-decomposition procedure, involving 4D observers 1-form \lambda. After extracting of boundary terms the, so called, "effective matter" part of 5D geometrical action becomes proportional to square of anholonomicity 3-form \lambda\wedge d\lambda. It can be interpreted as twist nematic elastic energy, responsible for elastic reaction of 5D space-time on presence of anholonomic 4D submanifold, defined by \lambda. We derive both 5D covariant and 1+4 forms of 5D nematic equilibrium equations, consider simple examples and discuss some 4D physical aspects of generic 5D nematic topological defects.Comment: Latex-2e, 14 pages, 1 Fig., submitted to GR

Two Ways of Cyclization of 5-imidazolylthioureas with Dimethyl Acetylenedicarboxylate

Two ways of cyclization of imidazolyl derivatives of thiourea with dimethylacetylene dicarboxylate (DMAD) were studied. Reaction of N,N'-disubstituted thioureas with DMAD led to formation of a thiazoline ring whereas transformation of trisubstituted thioureas under the same conditions give the novel imidazo[1,5-c][1,3,5]thiadiazine heterocyclic system. © ARKAT USA, Inc.The authors thank Russian Foundation for Basi c Research (RFBR grant 08-03-00376-a) and CRDF BRHE-2008 (grant Y5-C-05-04) for financial and material support

Synthesis of Cardanol-Containing Resols for Producing Phenolic Films: Protective Coatings for Wood Composites

Abstract: This paper investigates synthesis of impregnating phenol–formaldehyde resins in which up to 30 wt % formulation phenol is replaced by cardanol, a plant product. The resulting resins were used to make impregnated paper for laminating the plywood and particle boards. The synthesis and structure of cardanol-containing water-soluble resols were studied by IR spectroscopy and 1H NMR, and the reactivity of phenol cardanol formaldehyde resins at 80–150°C was studied by differential scanning calorimetry. The optimal amount of cardanol in relation to phenol in the resin structure was determined. It is shown that the introduction of cardanol into the composition of phenol–formaldehyde resins reduces the impregnation time of kraft paper and improves the surface quality and elasticity of the impregnated paper, with the use of such paper making it possible to decrease the water absorption of laminated particle board materials and the emission of formaldehyde. © 2021, Pleiades Publishing, Ltd

Dibenzo[ f,h]furazano[3,4- b]quinoxalines: Synthesis by Intramolecular Cyclization through Direct Transition Metal-Free C-H Functionalization and Electrochemical, Photophysical, and Charge Mobility Characterization

Herein, we describe the synthesis of unsymmetrically substituted dibenzo[f,h]furazano[3,4-b]quinoxalines by intramolecular cyclization through direct transition metal-free C-H functionalization. The electrochemical and photophysical properties for several polycycles have been measured. In thin films of the dibenzo[f,h]furazano[3,4-b]quinoxalines, hole mobility is in the order of 10-4 cm2 V-1 s-1. The results show that the HOMO and LUMO energy levels are appropriate for using the compounds as hole-transport materials in thin-film devices, in particular, organic and perovskite solar cells. Copyright © 2020 American Chemical Society.Russian Foundation for Basic Research, RFBR: 18-33-00103-mol_aRussian Science Foundation, RSF: 18-13-00409The research was financially supported by the Russian Science Foundation (project no. 18-13-00409). Y.A.K would like to acknowledge the financial support for the part of the synthetic section from the Russian Foundation for Basic Research (research project no. 18-33-00103-mol_a). The authors are grateful to Grigory A. Kim for carrying out the DFT calculations, which were performed by using “Uran” supercomputer of the Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences. NMR experiments were carried out by using equipment of the Center for Joint Use “Spectroscopy and Analysis of Organic Compounds” at the Postovsky Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences

Comparative Analysis of Self-Aggregation of Liquid Crystalline Pt(II) Complexes in Solution and in Neat Films

Two novel cycloplatinated complexes that differ by the presence/absence of a lateral fused cyclopenteno ring, respectively, were prepared. Although contributing to only a few percentage of the whole molecular volume, the presence of this aliphatic protuberance appears to be essential for the emergence of liquid crystalline behaviour. This pair of two similar compounds, non-mesomorphic complex and mesomorphic complex, was prepared as a model to assess the possible link of the self-aggregation in solution with the appearance of the liquid crystallinity in molten state. NMR dilution studies in CDCl3 solution and X-ray diffusion study in neat films show qualitative similarity of the aggregated structures formed by liquid crystalline complex. Solution studies may therefore be a useful additional tool to the characterization of the liquid crystalline properties and other self-association processes of Pt(II) complexes. © 2021We thank Northumbria University, CNRS, University of Strasbourg and Russian Foundation for Basic Research (project No. 18-03-00232A ) for the support of this work

Comparative analysis of self-aggregation of liquid crystalline Pt(II) complexes in solution and in neat films

Two novel cycloplatinated complexes that differ by the presence/absence of a lateral fused cyclopenteno ring, respectively, were prepared. Although contributing to only a few percentage of the whole molecular volume, the presence of this aliphatic protuberance appears to be essential for the emergence of liquid crystalline behaviour. This pair of two similar compounds, non-mesomorphic complex and mesomorphic complex, was prepared as a model to assess the possible link of the self-aggregation in solution with the appearance of the liquid crystallinity in molten state. NMR dilution studies in CDCl3 solution and X-ray diffusion study in neat films show qualitative similarity of the aggregated structures formed by liquid crystalline complex. Solution studies may therefore be a useful additional tool to the characterization of the liquid crystalline properties and other self-association processes of Pt(II) complexes

Quantum Turbulence

The present article reviews the recent developments in the physics of quantum turbulence. Quantum turbulence (QT) was discovered in superfluid $^4$He in the 1950s, and the research has tended toward a new direction since the mid 90s. The similarities and differences between quantum and classical turbulence have become an important area of research. QT is comprised of quantized vortices that are definite topological defects, being expected to yield a model of turbulence that is much simpler than the classical model. The general introduction of the issue and a brief review on classical turbulence are followed by a description of the dynamics of quantized vortices. Then, we discuss the energy spectrum of QT at very low temperatures. At low wavenumbers, the energy is transferred through the Richardson cascade of quantized vortices, and the spectrum obeys the Kolmogorov law, which is the most important statistical law in turbulence; this classical region shows the similarity to conventional turbulence. At higher wavenumbers, the energy is transferred by the Kelvin-wave cascade on each vortex. This quantum regime depends strongly on the nature of each quantized vortex. The possible dissipation mechanism is discussed. Finally, important new experimental studies, which include investigations into temperature-dependent transition to QT, dissipation at very low temperatures, QT created by vibrating structures, and visualization of QT, are reviewed. The present article concludes with a brief look at QT in atomic Bose-Einstein condensates.Comment: 13 pages, 5 figures, Review article to appear in J. Phys. Soc. Jp