Том 88, № 8 (2018)

Electronic structure and features of interatomic interactions in a series of phenylaminosilanes H_nSi(NHC₆H₅)_4–n (n = 3–0) have been studied by means of computer-based simulation (electron density functional method) in comparison with experimental (X-ray and photoelectron spectroscopy). Distributions of density of electronic states of the valence band, correlation diagrams of the energy levels, and visualizations of the isosurfaces of molecular orbitals have been obtained. Major types of interatomic electronic interactions providing the Si–NH–C₆H₅ bonds in tetraphenylaminosilane have been elucidated.

General information on the reactions of furfurals with hydrogen peroxide is given. We have discussed the Baeyer–Villiger rearrangement of furan 2-hydroxyhydroperoxides and tautomeric transformations with proton transfer of 2-hydroxyfuran and β-formylacrylic acid formed in a homogeneous reaction system furfural–Н₂О₂–solvent under the catalysis with the formed acids. The factors affecting these rearrangements and tautomeric transformations as well as their specificity in comparison with benzene type compounds, and the pathway of the reactions of furan aldehydes with Н₂О₂ in water have been analyzed. Ketoenol tautomerism of cyclic hemiacetal form of β-formylacrylic acid leading to its transformation into succinic anhydride has been described for the first time.

Formation of protonated 3,4,6-triisopropylsemiquinone radicals in solution of a mixture of 3,4,6- triisopropyl-о-benzoquinone and 3,4,6-triisopropylcatechol was shown using ESR spectroscopy. Heating the mixture to 110°С leads to the formation of the condensation products, additional amount of 3,4,6-triisopropylcatechol, and evolution of propylene. Mathematical simulation of the kinetics of the reaction was performed.

Specific features of the synthesis of polycyclic crown ethers dibenzo-18-crown-6 and dibenzo-24-crown-8 and their dinitro and diamino derivatives have been studied. A mixture of isomers of dibenzocrown ether derivatives was obtained and separated. The spectral and thermal characteristics of the synthesized compounds and the kinetics of synthesis of dibenzo-24-crown-8 by the two-component condensation of pyrocatechol with 1-chloro-2-[2-(2-chloroethoxy)ethoxy]ethane in an alcoholic medium in the presence of a KOH template agent were studied.

Synthesis of 5,7-dimethyl-3-hydroxymethyl-1-adamantanol with limited conformational mobility and of a series of esters based thereon has been performed. The physicochemical properties and thermo-oxidative stability of synthesized diesters have been studied.

The interaction of 5-arylfuran-2,3-diones with 5,6-R-benzo[d]thiazole-2-amines has resulted in 4-aryl-N-(5,6-R-benzo[d]thiazol-2-yl)-2-hydroxy-4-oxobut-2-enamides. The products structure has been confirmed by means of IR, NMR, and ¹H NMR spectroscopy as well as mass spectrometry. Analgesic and antimicrobial activities of the prepared compounds have been studied; acute toxicity of the most active compounds has been determined. The relationship between the structure and biological activity of the obtained compounds has been elucidated. The compounds acting comparably or better than the reference drugs have been found.

Hydrates of tetraphenylphosphonium carboxylates were synthesized by the reaction of equimolar amounts of pentaphenylphosphorus with 2-methoxybenzoic, 2-nitrobenzoic, and maleic acids in benzene. The product of the pentaphenylphosphorus reaction with tetrafluorophthalic acid (mole ratio 2: 1) is bis- (tetraphenylphosphonium) tetrafluorophthalate hydrate. According to the X-ray analysis data, crystals of tetraphenylphosphonim carboxylates are formed by tetraphenylphosphonim tetrahedral cations and single- or double-charged carboxylate anions. Structural organization of the crystals is determined by C–H···O weak hydrogen bonds formed with the participation of carboxylate groups and water molecules or manifold C–H···F interactions between cations and anions.

4-{[Mono/dimethyl(1,1'-biphenyl)-4-yl]oxy}phthalonitriles have been obtained by nucleophilic substitution of nitro group in 4-nitrophthalonitrile. The prepared phthalonitriles have been used for the synthesis of tetra-4-{[mono/dimethyl(1,1'-biphenyl)-4-yl]oxy}phthalocyanines and their complexes with copper, cobalt, and zinc. Spectral characteristics and thermal stability of the prepared compounds have been investigated.

Aiming at preparation of new biologically active donor‒acceptor complexes, a water-soluble manganese(III) complex with 5,10,15,20-tetrakis(N-methylpyridin-4-yl)porphine tetratosylate was synthesized and its reaction with pyridine was studied by spectrophotometry using the molar ratio method. In water a 1: 1 donor‒acceptor complex with pyridine is formed. The chemical structure of the compounds was established by spectral methods. (Acetato)[5,10,15,20-tetrakis(N-methylpyridin-4-yl)porphinato]manganese(III) tetratosylate and especially its donor‒acceptor complex with pyridine showed an antifungal activity against Candida albicans.

The state of the new antitubercular agent 1,5-bis(amidomethylsulfonyl)pentane in aqueous micellar solution of the nonionic surfactant Bridge 35 and its complexing properties toward copper(II) and iron(III) ions have been studied by spectrophotometry, pH potentiometry (25°C, variable ionic strength), and mathematical modeling. In the concentration range from 5.00 × 10^–5 to 1.00 × 10^–3 M in the presence of Bridge 35, the title compound exists in a neutral monomeric form. It forms 1: 2 mononuclear and 2: 2 binuclear complexes with copper(II) and 1: 1 and 1: 2 mononuclear and 2: 1 binuclear complexes with iron(III). The most favorable structures of 1,5-bis(amidomethylsulfonyl)pentane and its complexes have been simulated in terms of the density functional theory.

Competitive interactions in the HAuCl₄–DNA–cationic surfactant (cetyltrimethylammonium bromide) systems have been studied. Decisive role of the components binding on size and shape of gold nanoparticles obtained via reduction in these mixtures has been shown.

Thin films of aluminum nitride and oxynitride were deposited by atomic layer deposition (ALD) in the temperature range from 170 to 290°C (optimal deposition temperature 200–230°C). Tris(dimethylamido) aluminum and ammonia were used as precursors for the atomic layer deposition of aluminum nitride (AlN). The average AlN film thickness per ALD cycle (deposition rate) at 200°C was ~0.8 Å. Films were deposited on a silicon <100> substracte with a native oxide layer. The N/Al atomic concentration ratio in the obtained films was ~1.3. Aluminum oxynitride films obtained by periodical dose of water vapor in the course of atomic layer deposition of AlN at 200°C. The composition of the deposited oxynitride films was Al_0.5O_0.43N_0.07.

A series of novel substituted quinazoline derivatives are synthesized. Antibacterial tests demonstrate their high activity against Gram-positive and Gram-negative bacteria. 3-[4-(2-Bromoacetyl)-phenyl]-2-phenylquinazolin-4(3H)-one 2 and 3-oxo-3-{[4-(4-oxo-2-phenylquinazolin-3(4H)-yl]phenyl}propanenitrile 3 are used as intermediates in the synthesis of functionalized heterocyclic derivatives such as 3-[4-(2-amino-thiazol-5-yl)phenyl]-2-phenylquinazolin-4(3H)-one 4, Schiff base 5, 3-{5-(4-[4-oxo-2-phenylquinazolin-3(4H)-yl]phenyl)thiazol-2-yl}-2-phenylthiazolidin-4-one 6, and N-phenyl acetohydrazonoyl derivatives 7a, 7b. The latter react with ethyl cyanoacetate with formation of 9a, 9b. Chalcone 10 is the key intermediate in the synthesis of N-acetylpyrazole derivative 11 and 1-thiocaramoyl pyrazole derivative 12. Treatment of 12 with chloroacetyl chloride and compound 2 leads to formation of compounds 13 and 14, respectively. Treatment of compound 3 with phenyl isothiocyanate affords the corresponding quinazolin-3(4H)-yl acrylonitrile derivative 15, which reacts with phenyl hydrazine to give the corresponding product 16. The synthesized compounds are characterized by IR, MS and ¹H NMR spectra.

An operationally simple and efficient method of synthesis of novel 1,5-disubstituted tetrazoles with high yields from easily accessible 2-(2-benzamido-3-arylacrylamido)acetate under mild conditions is developed. Anticancer and anti-microbial tests of the new tetrazole derivatives have been carried out.

Thermal decomposition of triethylindium has been studied under static conditions. The temperature dependence of the thermal decomposition rate is described by the equation log k = 8.1 ± 0.4–(156 600 ± 5000)/2.3 RT. The composition of gaseous thermolysis products has been determined. The obtained data suggest radical chain mechanism of the process.

Tellurium tetrabromide readily reacted with 2-allylphenol at room temperature in acetonitrile to give previously unknown tribromo(2,3-dihydro-1-benzofuran-2-ylmethyl)-λ⁴-tellane in quantitative yield. The reduction of the product afforded bis(2,3-dihydro-1-benzofuran-2-ylmethyl)ditellane and benzyl(2,3-dihydro-1-benzofuran-2-ylmethyl)tellane.

Nanosized particles of zirconium diboride are synthesized by the reaction of ZrCl₄ with NaBH₄ in an ionic KBr melt.