Volume 88, Nº 5 (2018)

Products of oxidation of HfB₂ particles with mean size 50–55 and 20–25 nm with air oxygen under polythermal and isothermal conditions have been studied by means of thermal analysis, scanning electron microscopy, X-ray energy-dispersive analysis, and elemental analysis. Rate constants of oxidation of the HfB₂ nanoparticles have been determined.

A method of synthesis of aminobicycloheptanols by the hydroxyhalogenation of bicyclo[2.2.1]- heptene and its alkyl derivatives in a cycloolefin‒oxidant‒hydrogen halide system to induce electrophilic intermediates followed by substitution of the halogen atoms by amino groups of different compositions and structures. It was found that the selectivity of the reaction depends on the formation/consumption rate ratio for the electrophilic intermediate. A high selectivity with respect to hydroxyhalides takes place, when the consumption rate of the latter intermediate is higher than its formation rate. An increase in the pH of the medium becomes higher than 10.5 decreases the yield of amino alcohols and changes the reaction direction due to acceleration of dehydrohalogenation and formation of the corresponding epoxides.

Conditions were found which allow 2-alkyl-substituted imidazole-4,5-dicarboxylic acids to be synthesized in preparative quantities by the oxidation of 2-alkylbenzimidazoles with hydrogen peroxide. It was shown that optimal results can be obtained at the concentration of 2-alkylimidazole in sulfuric acid of 1 M and the hydrogen peroxide: 2-alkylbenzimidazole molar ratio of 11: 1. Oxidation under these conditions results in higher yields of the target 2-alkylimidazole-4,5-dicarboxylic acids, including those with a branched alkyl group.

Cyclohexenes functionalized by nitro and trihalomethyl groups were produced by condensation of 1-nitro- and 1-bromo-1-nitro-3,3,3-trifluoro(chloro)propenes with 2-methyl- and 2,3-dimethyl-1,3-butadienes; their structure was characterized by IR, ¹H, ¹³C, ¹⁹F NMR spectroscopy, and X-ray diffraction method.

New amination reactions of 5-chloro-4-nitrobenzofurazane with different amines were studied. The reactions of 5-chloro-4-nitrobenzofurazane with 2,4,6-trichloro-, para-acetyl-, and para-carboxyethylanilines gave the products of aromatic nucleophilic substitution of the chlorine substituent in the nitrogenous heterocycle, the composition and structure of which was established by chemical, physical, and physicochemical methods and X-ray diffraction analysis. The thermal stability was studied by synchronous thermogravimetry and differential scanning calorimetry (TG‒DSC). The synthesized compounds showed a high antibacterial and antimycotic activity against human and animal pathogenic microflora.

5-Aryl-4-aroyl-3-hydroxy-1-cyanomethyl-3-pyrrolin-2-ones were synthesized by a three-component reaction of methyl aroylpyruvate with a mixture of aromatic aldehyde and 2-aminoacetonitrile sulfate in glacial acetic acid in the presence of anhydrous sodium acetate.

Flash vacuum thermolysis of trimethylsilyl tert-butylphosphonohalidates involved elimination of halo(trimethyl)silane with the formation of tert-butyl-λ⁵-phosphanedione whose structure was confirmed by chemical reactions. tert-Butyl-λ⁵-phosphanedione readily undergoes trimerization, reacts with 2-phenyloxirane to give cycloaddition product, and takes up alcohols.

DFT PBE/3ζ study of relative stability of the R- and S-isomers of α-alanine in open carbon nanotubes with chirality indices (5,5), P,M-(5,1) and P,M-(5,2) has shown that the encapsulated molecule of the amino acid notably changes its geometrical and electronic characteristics. Besides, for the clusters α-alanine@nano (5,2) the most stable are practically degenerate in energy adducts S-alanine@P-(5,2) and R-alanine@М-(5,2). All this indicates the ability of chiral nanotubes to recognize encapsulated molecules of the R- and S-isomers.

Condensation of para-dibromoxylene and ortho-phenylenediamine in glass ampule at 150°С in an alkaline aqueous solution has yielded polymer with completely substituted N–H hydrogen atoms, capable of formation of polymeric cation-radicals. Complexes of this polymer and N,N,N',N'-tetrabenzyl-o-phenylenediamine with Co(II), Ni(II), Cu(II), and Ag(I) have been obtained, and their structure has been studied.

Enthalpy of the complex formation between diglycine (HL^±) and Ce³⁺ or La³⁺ at 308.15 K and ionic strength of 0.5 mol/L (KNO₃) has been determined by means of calorimetry. Thermodynamic parameters of the diglycine complexes formation with Ce³⁺ and La³⁺ at different metal to ligand molar ratios have been determined.

By the reaction of 2-chloroindole-3-carbaldehyde with acylhydrazones new acylhydrazones of the indole series have been synthesized, and their structure, the possibility of cyclization to pyrazoloindoles, and complexing properties have been studied. By means of quantum chemical DFT calculations taking into account the solvent effect it was shown that the reaction of 2-chloroindole-3-carbaldehyde and the corresponding acylhydrazine is an exothermic process, irrespective of which final product is formed, indolemethylenehydrazide or pyrazoloindole. Therefore, both possible transformations in the studied reacting system are controlled kinetically and not thermodynamically.

Kinetics of the formation reactions of palladium complexes of meso-nitro-substituted 5-phenyl-β- octaalkylporphine derivatives in the Pd(OAc)₂–acetonitrile system at 303–323 K was studied by spectrophotometry. The kinetic parameters of the formation reaction of complexes of porphyrins under study with palladium and zinc previously prepared, as well as their corresponding fluorescence spectra, were subjected to a comparative analysis. The parameters of electron absorption spectra of all palladium porphyrinates obtained were determined.

A new iridium(III) cyclometalated complex NBEpzIr(Tiq)₂ {NBEpzH is 4-[(bicyclo[2.2.1]hept-5- en-2-yl)hydroxymethylidene]-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazole-3-on and TiqH is 1-(thien-2-yl)isoquinoline} was synthesized. Copolymers with carbazole and iridium-containing fragments in side chains were obtained on the basis of the synthesized monomer by the method of ring-opening metathesis polymerization. The copolymers exhibit intense photoluminescence and electroluminescence of deep red color.

A series of M(II) ternary complexes [M(L)Phen] and [M(L)Oxine], where M = Co(II), Ni(II), Cu(II), and Zn(II), L = ((2-hydroxynaphthalen-1-yl)methylene)-4-nitrobenzohydrazide, Phen = 1,10-phenanthroline and Oxine = 8-hydroxy chloroquinoline, were synthesized and characterized by UV-Vis, ESR, IR, mass spectra, and TG-DTA data. Morphology and crystallinity of the complex [Ni(L)Phen] were studied by scanning electron microscopy. The crystal systems of Cu(II) complexes were determined by powder X-ray diffraction. Biological activity of the ligand and its metal complexes has been screened against four bacterial strains.

New chromanone and aurone hybrids have been synthesized by conventional and microwave induced methods from substituted (E)-7-hydroxy-6-[3-(p-tolyl)acryloyl]spiro[chroman-2,1'-cyclohexan]-4-one with high yields. Structures of the synthesized compounds have been elucidated from IR, ¹H and ¹³C NMR, and mass spectra. All newly synthesized compounds were tested in vitro for their antimicrobial activity. Methoxysubstituted spirochromanones revealed the best antimicrobial profile.

As a continuous study, a set of 23 new 6-substituted 1,4-naphthoquinone oxime derivatives are synthesized and screened for their in vitro cytotoxic activity. Four of those oxime derivatives demonstrate more potent cytotoxic activity towards K562, HCT-15, and HCT-116 cell lines than a reference drug 5-Fu. In particular, compound 21g exhibits the strongest inhibitory activity against K562 cell lines with IC₅₀ values of 1.25 μM. According to flow cytometry data, compound 21g can arrest cell cycle at S phase and induce a strong apoptotic response in K562 cells. The preliminary structure-activity relationship study shows that the nature of substituents in positions 6 and 1' of 1,4-naphthoquinone derivatives significantly affect their cytotoxic activity.

3-Alkyl-1-methoxycarbonylmethyl-5-dialkylaminomethylpyrazolines have been synthesized by the reaction of 3-alkyl-5-dialkylaminomethylpyrazolines with methyl monochloroacetate. The reaction of the synthesized compounds with hydrazine hydrate and KOH afforded new functional derivatives of 3-alkyl-5- dialkylaminomethylpyrazolines. The biological activity of the synthesized functional derivatives of pyrazolines was investigated.

Tricymantrenylantimony dibromide [C₅H₄Mn(CO)₃]₃SbBr₂ and dichloride [C₅H₄Mn(CO)₃]₃SbCl₂ were synthesized by the reaction of tricymantrenylantimony with bromine and chlorine in chloroform; the products are transformed into tricymantrenylantimony dihydroxide [C₅H₄Mn(CO)₃]₃Sb(OH)₂ by the action of potassium hydroxide in ethanol. Antimony atoms in the dihydroxide have a distorted trigonal–pyramidal coordination with oxygen atoms in axial positions [OSbO 175.66(8)°; Sb–O 1.987(2), 2.049(2), Sb–C 2.086(2), 2.101(2), and 2.105(2) Å].

Results of studying zinc sulfide catalytic activity in the reaction of methylene blue photodegradation are presented. It was found that the process rate increases when the catalyst is doped with titanium(IV) oxide. The rate depends on the ratio of anatase/rutile crystal phases.

The article published in volume 85, no. 8, pp. 1939–1944, DOI: 10.1134/S107036321508023X has been retracted by the Editor-in-Chief. After careful investigation it was found that experimental data made by a laboratory not cited as a reference were taken over by error. The experimental data was taken from Liang Liao, Doctoral Thesis, Laboratory of Molecular Chemistry and Thio-Organic Caen-France, 1999. (https://doi.org/www.theses.fr/1999CAEN2021). All authors are informed on the retraction and agree with it.