Molecular structures of new 2-(quinoline-2-yl)-1,3-tropolones

The molecular structures of 5,7-di(tert-butyl)-2-(6,8-dimethyl-4-piperidinoquinoline-2-yl)-3-hydroxytropone and 5,7-di(tert-butyl)-2-(5,8-dimethyl-4-piperidinoquinoline-2-yl)-3-hydroxytropone are determined by the single crystal X-ray diffraction analysis.     

New polyfunctional spiropyran of 1,3-benzoxazin-4-one series with carbonyl-containing substituents in the [2H]-chromene moiety

A polyfunctional spiropyran of 1,3-benzoxazin-4-one series containing one hydroxy and two carbonyl substituents in the [2H]-chromene moiety was synthesized on the basis of a new analogue of 2,4-dihydroxyisophthalic aldehyde, methyl 3,5-diformyl-2,4-dihydroxybenzoate. The structure of resulting 6'-carbomethoxy-3,7-dimethyl-8'-formyl-5'-hydroxy-4-oxo-spiro-(1,3-benzoxazine-2,2'-[2H]-chromene) was unambiguously established by single crystal X-ray diffraction analysis. These data allowed us to reveal the route for the reaction of the new polyfunctional aldehyde with 1,3-benzoxazin-4-onium perchlorate.     

Crystal structure of fluorosulfate complex compounds of indium(III) M<Subscript>2</Subscript>[InF<Subscript>3</Subscript>(SO<Subscript>4</Subscript>)H<Subscript>2</Subscript>O] (M = K,NH<Subscript>4</Subscript>)

The crystal structures of isostructural mixed-ligand fluorosulfate complex compounds of indium(III) M₂[InF₃(SO₄)H₂O] (M = K, NH₄), formed of K⁺ cations, NH₄ ⁺ respectively, and complex [InF₃(SO₄)H₂O]^2– anions are determined. In the complex anion, the indium atom surrounded by three F atoms, the oxygen atom of the coordinated H₂O molecule, and two oxygen atoms of the bridging sulfate group forms a slightly distorted octahedron (CN 6). Via alternating bridging SO₄ groups, the polyhedra of In(III) atoms are arranged in polymer chains. The O–H???F hydrogen bonds organize the chains in a three-dimensional network. The K⁺ and NH₄ ⁺ cations are located in the structure framework and additionally strengthen it.     

Estimation of the Thermodynamic Quality of Alkylbenzenes with Respect to Low Density Polyethylene

The original optical method was used for the first time to obtain complete diagrams of the state of mixtures of low-density polyethylene with o-xylene and ethylbenzene. The diagrams are of the type describing the phase state of systems partially crystalline polymer–good solvent. In contrast to the diagrams described in the literature, the diagrams described here contain an additional boundary curve for the solubility of the liquid in the polymer. Using the coordinates of the intersection of this line with the curve of complete amorphization of the polymer, five alkyl benzenes were ranked according to their thermodynamic affinity to low-density polyethylene.     

Stability of tetraoxides of chemical elements

Published data on the synthesis of eight-valence iridium and some other elements, and also works casting doubt on the fact of preparing iron and some 5f-elements in the oxidation state +8 were analyzed. Supposed methods (nuclear-chemical and pulse radiolysis methods) for Pu(VIII) and Am(VIII) detection and the method of matrix isolation at a temperature of 4–6 K for stabilization of eight-valence in Fe, Pu, and Am were considered.     

Regularities of formation of emboli of liquid polymer solutions in aqueous medium

Work on creating the basis for embolic compositions for the treatment of a wide range of pathologies of various organs was conducted. This basis is a solution of a biocompatible water-insoluble polymer in a biocompatible water-soluble solvent. Formation of the embolus in such an aqueous medium takes place in the transition of the solvent into the aqueous phase and the formation of a solid polymer clot occluding a blood vessel. Criteria for selection of the polymer and the solvent for the basis were formulated, and a number of polymers and solvents that meet these criteria were selected for further research. Research on the solubility of the selected polymers in solvents was carried out, and the rheoviscometric characteristics of polymer solutions, as well as parameters of solid emboli formation of polymer solutions in aqueous media, were found. The solution of cellulose acetate plasticized with OPADRY CA 500F190000 polyethylene glycol in dimethylsulfoxide with concentration of no less than 60 g/L was recognized as optimal for further studies.     

Photochromic properties of perfluorosulfonic membranes modified by sodium molybdate

Transfer of a perfluorosulfonic membrane from the hydrogen form into the sodium form provides accessibility of pore space to sodium molybdate aqueous solution. Charge transfer spectra make it possible to judge the course of polymerization of capsulated molybdate ions and its intensification when the membranes are held in HCl vapor. The UV irradiation of the modified membranes causes a progressing absorption in the visible spectral region. The rate and depth of photoreduction increase as the concentration and degree of polymerization of molybdate ions increase. The scheme of the process was offered, which is based on taking into account a possibility of delocalization of 4d ¹ electrons of molybdenum(V) over the system of metal-metal bonds.     

Relaxation in the photoelectric and photovoltaic responses of thin-film Pb(Zr0.25, Ti0.75)O3 ferroelectric

We study the relaxation of photoresponses in self-polarized Pb(Zr_0.25, Ti_0.75)O₃ film structures with a semitransparent NiCr top electrode under focused laser illumination with a wavelength of 0.63 μm and a power of about 40 mW. Dependences of the relaxation times of the photoresponses on the field directed both along the self-polarization vector and opposite to it are experimentally obtained. The dependences are found to be qualitatively different. We assume that in the structure under study, a screening charge occurs due to the capturing of photoinduced carriers in deep traps localized in the contact region.     

The parametric Doppler effect in quartz glass

Transformation of frequency is analyzed under the parametric Doppler effect in quartz glass in the “optic collider” scheme. In this scheme, intense laser radiation induces moving inhomogeneities of the refractive index in the glass and the probe radiation undergoes the Doppler frequency shift when being reflected from them. The possibilities of transforming the frequency both within the main transparent region and from the main transparent region to the low- and high-frequency regions separated from the main region by absorption peaks in the infrared and ultraviolet spectral ranges are demonstrated.