Russian Chemical Bulletin最新文献

A simple and affordable in situ synthesis of a carbon fiber@magnetite hybrid for use as a filler in shielding polymer materials is proposed. The presence of magnetic particles on the carbon fiber was confirmed by X-ray diffraction, and the effect of modification on the structural properties of the components and the magnetic properties of the system was analyzed. The analysis of the structural characteristics and the magnetic properties of the components obtained during the synthesis process was carried out. The modification of the surface of the carbon fiber with magnetite made it possible to obtain for the resulting hybrid a magnetic moment value that is three times higher than that of a mechanical mixture of carbon fiber and magnetite with the same composition.

Two complex dysprosium(iii) salts of composition Na[Dy(hfac)₄] (1) and Q[Dy(hfac)₄]₂ (2), where hfac is the hexafluoroacetylacetonate anion and Q is 1,1′-dimethyl-4,4′-bipyridinium, were synthesized and studied by X-ray diffraction. An analysis of the X-ray diffraction data using the Shape program revealed noticeable distortions of two [DyO₈] coordination polyhedra of salt 2 anions; the Dy atoms are nonequivalent and have a biaugmented trigonal prismatic (C_2v) and triangular dodecahedral (D_2d) geometry. The experimental studies and the analysis of the magnetic properties of 2 showed that this compound exhibits a field-induced slow relaxation of magnetization, which is described by the Orbach mechanism (U_eff = 23.0 K, τ₀ = 2.68 · 10⁻⁸ s).

The ultrasonic induced oxidative addition reaction of C₆₀ fullerene to tris(hydroxymethyl)-aminomethane in a toluene—DMF solvent mixture in the presence of LiOH and Pb(OAc)₄ at room temperature in an aerobic environment gave 47% yield of the C₆₀ fullerene monoadduct containing in its structure a morpholine fragment annulated to the [60]fullerene core.

New 2-(4-carboxyphenylhydrazinylidene)[1,3]thiazolo[3,2-a]pyrimidine derivatives were synthesized in high yields by the reactions of 5-aryl-6-ethoxycarbonyl-7-methyl-3-oxo-2,3-dihydro-5H-[1,3]thiazolo[3,2-a]pyrimidine with 4-carboxyphenyldiazonium chloride. The azo coupling occurs at the 2 position of the substrate. Different types of intra- and intermolecular non-covalent interactions can affect the supramolecular assembly of the molecules in the crystal structures and the molecular configuration of the synthesized compounds. The combined contribution of supramolecular non-covalent interactions leads to several types of the self-assembly in the crystalline phase, such as hydrogen-, chalcogen-, and π—π-bonded racemic dimers. In the case of compounds containing the m-chlorophenyl substituent at the C(5) position of the thiazolo[3,2-a]-pyrimidine scaffold, these interactions lead to the formation of halogen-bonded homochiral chains. Due to the π—π stacking between the electron-rich thiazolopyrimidine scaffold and the electron-deficient carboxyphenyl moiety, there occurs the formation of dense layers in the solid phase when selecting the appropriate substituents at the C(5) atom. The crystallization conditions (vapor diffusion and slow evaporation) were found to influence the configuration of the C=N-arylhydrazone moiety.

A three-components regioselective synthesis of 3-[2-formamidovinyl(phenyl)amino]-acrylic acid based on an opening of the imidazole ring under the influence of acetylene carboxylic acids esters or cyanophenylacetylene in aqueous acetonitrile in up to 86% yields has been developed.

New oleanonic acid derivatives bearing the pyridine moieties at the positions C(2) and C(28) were synthesized. Heterocyclic moieties were introduced in position C(2) of oleanonic acid by aldol condensation, and in position C(28) by N-acylation. Cytotoxicity of the synthesized compounds was evaluated against 12 tumor cell lines. Aminopyridine-derived oleanonic acid amides with 3- and 4-pyridinylmethylidene group were found to be active against a human prostate cancer cell line PC3 with half maximal inhibitory concentration (IC₅₀) values equal to 1.20 and 2.06 µmol L⁻¹, respectively.

Convenient synthesis of phosphorus-containing derivatives of succinic acid, which contain functionalized phosphonous, phosphonic, and phosphinic acid moieties have been developed. The nucleophilic addition of bis(trimethylsiloxy)phosphine to diesters of maleic, itaconic, and acetylenedicarboxylic acids proceeds regioselectively to give a number of functionalized phosphonites. Further aminomethylation of these compounds affords various target acid derivatives. The resulting compounds are of interest as promising biologically active substances and water-soluble ligands.

New (bi)pyridine derivatives of the antimicrobial drug ornidazole were synthesized by alkylation of pyridyl- and 2,2′-bipyridyl-phenolic derivatives for the first time. The proposed methodology makes it possible to expand the range of ornidazole derivatives with increased antibacterial activity.

Spiropyran containing a propylammonium moiety at the nitrogen atom in the indoline part of molecule was synthesized. Its photochromic behavior, spectral and photoluminescent properties in water, as well as cytotoxicity towards epidermoid carcinoma A431 cells were estimated. The synthesized compound exhibited positive photochromism and high stability towards photodegradation, and is capable of photoluminescence.

Information entropy is widely used in discrete mathematical chemistry as the descriptor to quantify the structural complexity of molecules. This review covers opportunities to use the information entropy parameters to evaluate changes in the complexity of molecules in both simple and multi-step chemical reactions.