An efficient method has been developed for the synthesis of resorcinol–formaldehyde hybrid aerogels with ferrocene subunit fragments embedded in their polymer structure. For gelation preceding the synthesis of aerogels, dioxane was used for the first time as the main reaction solvent. The gels were converted into aerogels using SC-CO2. The aerogel samples were characterized in detail by Mössbauer spectroscopy, nitrogen adsorption, and atomic absorption spectroscopy. The density of the materials was determined. The iron content in the resulting aerogels varies from 1.5 to 11 wt

The first example of intramolecular diastereoselective domino reaction of ferrocene 1,1'-bis-enone to [5]ferrocenophane initiated with sodium ethoxide was found. The product is [5]ferrocenophane with two pyridyl and one ethoxy substituents arranged asymmetrically in a five-carbon bridge. Diffraction studies showed that ferrocene is in almost ideal eclipsed conformation. The fan conformation found in the crystal is also preserved in solution, which was determined by NMR spectroscopy.

The reaction of ferrocene-containing alkenes and alkynes with HSi(OEt)3 and HSiMe(OMe)2 in the presence of Karstedt catalyst (Pt2[(Me2SiCH=CH2)2O]3) was studied. It was found that only terminal alkenes underwent hydrosilylation, while alkynes entered this reaction even in the case of a disubstituted C≡C bond. The synthesized silicon-containing ferrocene derivatives were used as precursors for the preparation of siloxane aerogels, which were characterized by low-temperature nitrogen adsorption, scanning electron microscopy, and Mössbauer spectroscopy.

Based on carbonate-substituted hydroxyapatite (HAP) containing vancomycin, a method is developed for the preparation of macroporous matrices that combine bioresorbability, osteoconductivity, and the possibility for the volumetric impregnation of antibiotics without loss of their activity and their prolonged release. The technology includes treatment with supercritical CO2 as the final stage in the preparation of a matrix, which makes it possible to completely remove the organic solvent that serves as an extractant for the pore formation additive, i.e., polyethylene glycol (PEG) granules, and to increase the biocompatibility of the matrix, as confirmed by the results of histological tests during subcutaneous implantation. The activity of vancomycin after its volumetric incorporation into the calcium phosphate matrix is demonstrated in the regions of inhibiting the growth of bacterial cultures. As proven in in vivo experiments on the implantation of bones, the matrix is a therapeutically effective carrier of antibacterial substances in the treatment of septic purulent inflammations of bone tissues.

Из плодового тела трутового гриба Fomes fomentarius методами суб- и сверхкритической флюидной экстракции этанолом получены хитинсодержащие комплексы с выходом 57—88 % и содержанием хитина до 18,7 %. Оценено влияние продолжительности, температуры и давления экстракции на выход и свойства получаемых хитинсодержащих комплексов, которые охарактеризованы по элементному и функциональному (ИК-спектроскопия) составу. Показана высокая сорбционная емкость полученных комплексов по отношению к основному — метиленовому синему (ло 312 мг/г) и кислотному — конго красному (до 170 мг/г) красителям, что указывает на полиамфолитную природу полученных комплексов — биосорбентов. Chitin-containing complexes were obtained from the fruiting body of the tinder fungus Fomes fomentarius using sub- and supercritical fluid extraction with ethanol with a yield of 57—88 % and a chitin content of up to 18.7 %. The influence of the duration, temperature, and pressure of extraction on the yield and properties of the resulting chitin containing complexes has been evaluated. Chitin-containing complexes were characterized by elemental and functional (by IR spectroscopy) composition. The high sorption capacity of the obtained complexes in relation to the basic — methylene blue (up to 312 mg/g) and acid — congo red (up to 170 mg/g) dyes is shown. Sorption activity relative to both basic and acid dyes indicates the polyampholytic nature of the resulting complexes-biosorbents.

— We have developed a method for the preparation of macroporous carbonate hydroxyapatite-based matrices with the use of the technology of self-setting cements for surgical osteology. Macroporosity of osteoconductive calcium phosphate matrices was produced by adding paraffin granules to a dry cement mixture, followed by organic solvent extraction of the granules from matrices hydrated in an aqueous solution. In vivo tests of the resultant materials demonstrated high biocompatibility with pronounced angiogenesis, which was achieved via additional treatment with supercritical carbon dioxide.

A method for producing a new generation of high-purity xenogenic biomatrixes suitable for implantation in a living organism is proposed. Special biocompatibility can be achieved by additional treatment with supercritical carbon dioxide and the introduction of dosed amounts of polylactides with molecular weight of 20 and 40 kDa in the porous space of the matrix. In vivo testing of the obtained materials showed their high biocompatibility with varying degrees of integration with surrounding tissues.

Two approaches for the syntheses of bispidine-ferrocene cyclophanes were reported. Both include the acylation of 1,5-dimethylbispidin-9-one (H(2)Bp) or its pendant amino-armed derivative by 1,1'-ferrocenoyl (Fc(CO)(2)) dichloride. The first approach allowed to isolate di-, tri-and pentameric cyclic oligomers of composition (BpFc(CO)(2))(n). The second one included the preliminary functionalization of H(2)Bp by N-protected glycine followed by deprotection and cyclization with Fc(COCl)(2). The crystal structure of two new bispidine-ferrocene cyclophanes was established by single-crystal X-ray study. This study revealed the anti-conformation of amido-groups attached to the bispidine nitrogen atoms for both molecules. Various NMR techniques were applied to study the solution behavior of the macrocycles; the predominant anti-conformation in solution was also proved. The acyclic model compound Bp(FcCO)(2) also showed only anti-conformer as revealed by VT-NMR and X-ray studies. Cyclic voltammetry study showed the difference in oxidation potentials of the Fc moiety within the row Bp(FcCO)(2)-(BpFc(CO)(2))(2) -(BpFc(CO)(2))(3) with splitting of the oxidation curve in two later cases. The results obtained in this work will find an application in design and study of novel bispidine-ferrocene cyclophanes for the purposes of supramolecular sensing and catalysis. (C) 2021 Elsevier B.V. All rights reserved.

Предложен способ получения высокочистых ксеногенных биоматриц нового поколения, пригодных для имплантации в живой организм. Особая биосовместимость может быть достигнута путем дополнительной обработки сверхкритическим диоксидом углерода и введения дозированных количеств полилактидов с молекулярной массой 20 и 40 кДа в пористое пространство матрицы. Испытания in vivo полученных материалов показали их высокую биосовместимость с различной степенью интеграции с окружающими тканями. A method for producing new generation of xenogenic biomatrixes, which are characterized by their special purity and suitable for implantation in a living organism, is proposed by additional treatment with supercritical carbon dioxide. The obtained highly pure biomatrixes were modified by introducing dosed amounts of polylactides with a molecular weight of 20 and 40 KDa into their pore space. In vivo testing of the obtained materials showed their high biocompatibility with varying degrees of integration with surrounding tissues.

—It is demonstrated that tin(II) 2-ethylhexanoate and tin(II) oxide are effective catalysts for the reaction of cyclization of model arylamines o -NH 2 (C 6 H 4 )XH (X = NH, O, S, CH 2 NH) in supercritical carbon dioxide with the formation of benzo-1,3-azol-2-ones and 3,4-dihydroquinazolin-2-one. Optimal conditions for these reactions are found. Possible mechanisms for these processes are proposed, depending on the catalyst used.

The structure of zirconocene is determined experimentally. Zirconocene is found to catalyze effectively the copolymerization of α-olefins with nonconjugated dienes in the presence of minimal amounts of methylalumoxane as an organoaluminum activator. On the basis of a highly ferromagnetic carrier (a product of the reaction between Fe3O4 microparticles and Si(OEt)4), a deposited zirconocene catalyst is obtained. Using the latter, copolymers of α-olefins (1-hexene, 1-octene, and 1-decene) with 1,7-octadiene and 1,4- di(3-butenyl)benzene are synthesized. The obtained ferromagnetic copolymers demonstrate properties of effective absorbents of hydrocarbons, namely, oil sponges. A copolymer of 1-octene and 1,4-di(3-butenyl) benzene is found to possess the maximum adsorption capacity (up to 8) in the studied series.

The bromination of (E)-4,4-dimethyl-6-isobutylidenecyclohex-2-en-1-one with molecular bromine occurs first at endocyclic double bond and next at the exocyclic one.

A new series of dicarboxylic derivatives of bispidines have been synthesized to develop novel copper(II) complexes suitable as imaging agents for positron emission tomography. For characterization purposes, copper complexes of bispidines were synthesized in the pure form and in quantitative yields by neutralization of ligands with malachite. The formation of complexes and their stoichiometries were studied by potentiometric titration, cyclic voltammetry, and spectroscopic methods. The stability constants were found to be fairly suitable for copper cation fixation inside dianionic chelate molecules.

A series of cross-conjugated dienones was synthesized to study the dependence of physicochemical characteristics on the nature of substituents in the aromatic groups of symmetric cyclopentanone dibenzylidene derivatives. The structure of compounds was established by electronic, IR, and NMR spectroscopy and X-ray diffraction study. All the compounds obtained possess the E,E-geometry. In the crystalline state, the arrangement of the dienone molecules is unfavorable for the intermolecular [2+2] photocycloaddition to take place. The low-temperature phases transition for unsubstituted diphenyl derivative of cyclopentanone was detected using variable-temperature X-ray diffraction and differential scanning calorimetry. Oxidation and reduction potentials of the dienones were measured by cyclic voltammetry. Their dependence on the nature and placement of substituents in the benzene rings was demonstrated. A linear correlation (R = 0.9343) between the difference of electrochemical oxidation and reduction potentials and the energy of the long-wavelength absorption maximum was found, that allows us to recommend the use of the data obtained in the correlation analysis of other compounds of this class.

Ternary copolymers of acrylonitrile with methylacrylate, itaconic acid (IA), and its derivatives, namely, monomethyl ester (MME), monoethyl ester (MEE), monoamide, and mono- n -octylamide, were synthesized in a supercritical carbon dioxide medium. The morphology of the synthesized copolymers was studied by scanning electron microscopy. Copolymers with IA, MME, and MEE were obtained in the form of regularly shaped particles of nearly 1 μm in size without the addition of stabilizers.