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41.
I. V. Sterkhova V. V. Astakhova B. А. Shainyan 《Russian Journal of General Chemistry》2017,87(8):1680-1684
The methods of IR spectroscopy and quantum chemistry (B3LYP/DGDZVP) were applied to investigation of the types of self-associates formed in solutions of N-(2-hydroxy-3,8-diiodocyclooctyl)trifluoroacetamide and N-(4-iodo-2,2,5,5-tetramethyltetrahydrofuran-3-yl)trifluoroacetamide in CCl4 by means of hydrogen bonding. The ОН group of N-(2-hydroxy-3,8-diiodocyclooctyl)trifluoroacetamide participates in the formation of intramolecular hydrogen bond ОH···О=С, while chain dimers are formed due to interactions between the NH and С=О groups of the neighboring molecules. Due to the formation of the intramolecular bond, the dimers of N-(2-hydroxy-3,8-diiodocyclooctyl)trifluoroacetamide are energetically less stable than the chain dimer of N-(4-iodo-2,2,5,5-tetramethyltetrahydrofuran-3-yl)trifluoroacetamide. 相似文献
42.
N. M. Makarova E. G. Kulapina А. А. Skaptsov 《Russian Journal of General Chemistry》2017,87(10):2320-2326
Compounds of alkyl sulfates and cationic copper(II) complexes with some organic reagents (pyridine, 1,10-phenanthroline, 2,2'-dipyridyl) were prepared, and their physicochemical characteristics (composition, thermal stability, solubility) were determined. The synthesized compounds are poorly soluble (solubility product KS = n×10–20–n×10–22) and thermally stable (90–260°С). An effect of the hydrophobilicity of alkyl sulfates on the UV characteristics of the copper(II)–organic reagent systems and on the solubility of the studied compounds was evaluated. 相似文献
43.
Е. N. Chernova Ia. V. Russkikh E. I. Afonina О. А. Keltsieva V. A. Ostrovskii Е. P. Podolskaya Z. А. Zhakovskaya 《Russian Journal of General Chemistry》2017,87(13):3123-3132
The sample preparation procedure for determination of microcystins from biomass by the LC–MS method was optimized. Treatment of freeze-dried biomass samples with acetonitrile prior to the main extraction was effectively used for decreasing the amount of protein-like matrix compounds in extracts. Use of acetonitrile–water mixtures during the main ultrasound-assisted extraction allowed increasing the total microcystins amount in the resultant extracts compared to the traditional extraction using 75% methanol. 相似文献
44.
А.?А.?AleksandrovEmail author М.?М.?El’chaninov 《Russian Journal of General Chemistry》2017,87(8):1716-1720
N-(1-Naphthyl)furan-2-carboxamide was synthesized by the coupling of naphthalen-1-amine with furan-2-carbonyl chloride in propan-2-ol and then treated with excess P2S5 in anhydrous toluene to obtain the corresponding thioamide. The latter was oxidized with potassium ferricyanide in an alkaline medium by the Jakobson procedure to synthesize 2-(furan-2-yl)benzo[e][1,3]benzothiazole which was subjected to electrophilic substitution reactions: nitration, bromination, formylation, and acylation. 相似文献
45.
D.?S.?Yambulatov А.?А.?Skatova A.?V.?Cherkasov I.?L.?FedushkinEmail author 《Russian Chemical Bulletin》2017,66(7):1187-1195
The reduction of 1,2-bis[(2,6-diisopropylphenyl)imino]acenaphthene (dpp-bian) with an excess of europium metal in 1,2-dimethoxyethane (dme) produces a divalent europium complex with the dpp-bian dianion, [(dpp-bian)Eu(dme)2] (1). The reactions of 1 with phenyl-acetylene and camphor proceed via protonation of the diimine ligand to form the monomeric amido-amino complexes of divalent europium — [H(dpp-bian)Eu(C≡CPh)(dme)2] (2) and [H(dpp-bian)Eu(camphor)(dme)2] (3), respectively. Compounds 2 and 3 were characterized by IR spectroscopy and elemental analysis. Their molecular structures were determined by X-ray diffraction. Compounds 2 and 3 were shown to be monomeric seven-coordinate europium(ii) complexes with terminal phenylethynyl and enol ligands, respectively. According to the IR spectroscopic data, the terminal ligands in complexes 2 and 3 undergo tautomerization involving backward proton transfer from the amido-amino ligand to the substrate. The magnetic moment of compound 2 (8.03 μB) remains constant in the temperature range of 4—300 К and confirms the presence of divalent europium. 相似文献
46.
V. B. Sokolov А. Yu. Aksinenko Т. А. Epishina Т. V. Goreva S. О. Bachurin 《Russian Chemical Bulletin》2017,66(9):1607-1610
An efficient synthetic procedure to combine biologically active indole derivatives by the triazole-containing spacer in a molecule has been proposed. The procedure was based on a copper-catalyzed alkyne-azide cycloaddition of azide-containing carbazoles and N-propargyl-containing carbazoles, tetrahydrocarbazoles, and tetrahydro-γ-carbolines. 相似文献
47.
In connection with the development of nanotechnology in the last 15—20 years, the method of molecular layering (ML), created in the middle of the last century in the USSR, has attracted increasing attention. The features of structural-dimensional effects in the products obtained by new chemical nanotechnology and promising directions of their practical application in "core—nanoshell" compositions are considered in the review. In accordance with the synthetic capabilities of the ML method, the functional properties of the "core—nanoshell" type materials are affected by the "monolayer effect" and the substrate shielding effect, as well as the multicomponent nature of the system, and mutual structural coordination effect of the substrate and the build-up nanolayer. The review presents theoretical and experimental data on the application of the observed effects in the creation of shell pigments and fillers, modified sorbents, catalytic membrane reactors, nanodoped ceramic materials, polymers, quartz fibers with adjustable optical characteristics, electrets, etc. 相似文献
48.
I.?A.?Os’kinaEmail author А.?Ya.?Tikhonov 《Russian Journal of Organic Chemistry》2017,53(8):1239-1242
Reaction of 2-(hydroxyamino)-1-R-propan-1-one oximes with furfural in methanol afforded the corresponding α-furylnitrones. The cyclization of α-furylnitrones in alkaline medium results in the formation of 5-aryl(hetaryl)-2-(furan-2-yl)-1H-imidazol-1-oles. 相似文献
49.
提出结合àtrous算法与Retinex算法的医学图像增强.方法在二进小波理论基础上,利用推广的二维àtrous算法对医学图像进行处理,对经过多级分解后的医学图像的低频利用连续非线性函数增强,而对分解后的多个高频采用改进的Retinex算法进行增强;最后,对增强后的低频和高频进行重构.经过反复仿真试验结果表明:方法在去除噪声的同时更好地保留了图像边缘特征,增强了图像细节信息和凸显图像的轮廓,并克服对比度下降的不足,较好地去除光晕现象,视觉效果好,层次感更丰富. 相似文献
50.
在零售市场,专业零售商与厂家直售商的价格竞争日益突起,再次背景下构建了专业零售商和厂家直售商组成的多渠道供应链价格博弈模型。利用管理学、经济学以及混沌动力学有关理论,对多渠道供应链中各渠道间长期价格博弈的动态演化过程进行理论验证和数据仿真,研究了专业零售商和厂家直售商的价格决策变量的变化给市场带来的影响。研究表明,双方价格决策变量的不断增加,市场从稳定进入混沌无序状态。采用调整参数可以对混沌进行有效的控制,研究结果具有较好的理论和实际应用价值。 相似文献