Vol 487, No 1 (2019)

Features of the formation of porous silicon layers during anodic etching of p-Si were considered. A fundamental difference between the mechanisms of the formation of nanostructured layers on p-and n-Si was shown.

The synthesis of Boc-Gly-Pro-Dox, Boc-Gly-Pro-DOPA, and Boc-Gly-Pro-Srt and their deuterated analogues was carried out. The condensation is accompanied by side reactions, which could be minimized by optimizing the reaction conditions. The most versatile approach to the synthesis of Boc-Gly-Pro-Dox, Boc-Gly-Pro-DOPA, and Boc-Gly-Pro-Srt and their deuterated analogues is condensation of Boc-Gly-Pro or Boc-Gly-[²H]Pro with the amino groups of dopamine, serotonin, and doxorubicin. For the introduction of hydrogen isotopes into ΔPro, hydrogenation of its aqueous solution followed by condensation of the reduced proline with Boc-GlyOSu is recommended. Mass spectrometry was used to determine the content of isotopomers in the deuterated products.

Complexes [Co(solv)_n][B₁₀H₁₀], where (I: solv = H₂O, n = 6; II: solv = N₂H₄, n = 3) have been synthesized and characterized. The possibility to use them as precursors in the synthesis of binary borides has been demonstrated. The purity and homogeneity of the precursors and the products of their thermal reduction (in an inert atmosphere at 650 and 900°С) has been established by elemental analysis, X-ray powder diffraction, and IR spectroscopy; magnetochemical studies of the precursors and their annealing products have been carried out. According to the data obtained, the reduction products are structured oxide-boride and nitride-boride phases, respectively. Magnetochemical study of the phases has revealed a significant difference in their magnetic behavior: the oxide-boride phase is characterized by a significant ferromagnetic contribution to the total magnetization of the sample, while the nitride-boride phase, by a diamagnetic contribution.

A new strategy of synthesis of thiacalix[4]monothiacrown ethers in 1,3-alternate stereoisomeric form has been suggested and implemented through macrocyclization of the lower rim of 3-bromopropoxy-substituted thiacalixarenes by dithiols.

For the first time, for performing thermally coupled SHS processes, granular mixtures were used instead of powder ones. In this case, the rate of the heat transfer between the donor and the acceptor is virtually independent of the sample size and is determined only by the granule size. Therefore, an advantage of using a granular mixture is that the process optimized under laboratory conditions can be scaled without changing its characteristics and the properties of the desired synthesis product. The studied granular mixture comprised a mixture of (Ni + Al) granules (acceptor) and a mixture of (Ti + C) granules (donor), which differed in rate and temperature of combustion. It was determined that the ignition of the (Ni + Al) acceptor granules occurred in the combustion front. It was shown that using granular mixtures for performing coupled thermal reactions makes it possible to obtain the combustion products as a readily destructible sample, from which the desired product can be separated even if the melting point of the product of the interaction of the acceptor mixture is lower than the adiabatic combustion temperature.

Hydroxyapatite (HA)–polyvinylpyrrolidone (PVP) nanocomposites with the HA/PVP ratio of 3.6–14.5 were synthesized by chemical precipitation from solutions of calcium nitrate and ammonium hydrogen phosphate in a PVP solution. The phase composition, size of coherent scattering regions, and size and morphology of HA particles were determined after heat treatment of the products of synthesis. The chemical interaction of the composite components was established by ESR spectroscopy on exposure to laser radiation at 355 nm.