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Molecular parameters (Mm, Mr, Kp, K, Kc, and Ks) are calculated for polysubstituted cycloveratrilenes and cyclophanes as a continuation of our series of papers on prediction
of discotic mesomorphism (DM). Histograms showing the distribution of 57 mesogenic and 28 nonmesogenic structures according
to the first three parameters are constructed. Prediction probabilities are estimated at more than 50% for Mm and Mr. This approach is used to analyze 150 hypothetical structures of polysubstituted cycloveratrilenes and cyclophanes to examine
the occurrence of a discophase. Several structures with predictable DM are selected for further research.
Ivanovo State University. Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 3, pp. 473–477, May–June, 1998. 相似文献
2.
O. B. Akopova A. A. Bronnikova A. Kruvchinskii L. N. Kotovich L. S. Shabyshev L. A. Valkova 《Journal of Structural Chemistry》1998,39(3):376-383
Molecular parameters of hexaalkoxytriphenylenes with different substituents on the periphery of the triphenylene nucleus of
known and hypothetical structures are calculated. The probability of a discophase for compounds of this series is estimated
from molecular parameters. Several compounds of this series having polar groups (NO2, NH2) in the 1 position of the triphenylene nucleus have been synthesized. The compounds synthesized were investigated by thermopolarizing
microscopy and X-ray diffraction analysis. The data on the mesomorphism of the new compounds are in good agreement with our
prediction that alkoxytriphenylenes with polar groups have a discophase. It is established that introduction of an electron-accepting
group at position 1 of the triphenylene nucleus expands the temperature range of existence of the discophase to room temperature.
On the contrary, introduction of an electron-donating group narrows this interval. Compounds of this series presumably have
a hexagonal columnar structure.
Ivanovo State University. Warsaw University. Translated fromZhurnal Strukturnoi Khimii, Vol. 39, No. 3, pp. 464–472, May–June, 1998.
This work was supported by RFFR grant No. 96-02-19036. 相似文献
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4.
A. V. Bicherov A. R. Akopova V. I. Spiglazov A. S. Morkovnik 《Russian Chemical Bulletin》2010,59(1):91-101
A new synthetic route to 2-benzhydrylsulfinylacetamide (1), a nootropic drug modafinil, is described. The synthesis includes the alkylation of sodium thiosulfate with chloroacetamide to sodium carbamoylmethyl thiosulfate, the desulfobenzhydrylation of the latter by benzhydrol in formic acid to form benzhydrylthioacetamide (3a), and the further oxidation of this thioamide with hydrogen peroxide. According to B3LYP/6-31G** DFT calculations, the key step of the synthesis, namely, desulfobenzhydrylation of salt 6a, occurs only insignificantly due to the energetically unfavorable direct attack of this salt by benzhydryl formate; the reaction mainly involves the attack by the benzhydrilium carbocation Ph2CH+. The oxidation of sulfide 3a to sulfinylacetamide 1 is efficiently catalyzed by side proton-donor molecules (constituents of the transition states of the reaction). The oxidant can be the anionic form of the reactant (HO2 - ion), which reacts with sulfide 3a via the unusual noncatalytic mechanism. At the step of transition state formation, this mechanism resembles the SN 2 substitution. 相似文献
5.
O. B. Akopova E. V. Kurbatova M. S. Gruzdev 《Russian Journal of General Chemistry》2010,80(2):268-274
The forecasting of columnar and chiral mesomorphism was done for the new series of triphenylene derivatives. The mesomorphic
properties of the two heptasubstituted triphenylenes containing chiral fragments were studied. The prediction results agreed
well with the experimental data. Anilides of 1-amino-2,3,6,7,10,11-hexa(heptyloxy)triphenylene with abietic and dihydrocholic
acids were found to exhibit the enantiotropic columnar dimesomorphism and to display the chiral columnar mesophases in the
low-temperature range. The anilides obtained possess a lower thermal stability and extended interval of the mesophase existence
than the initial amine. 相似文献
6.
T. S. Demina T. A. Akopova L. V. Vladimirov A. N. Shchegolikhin A. S. Kechek’yan N. S. Perov A. O. Chernyshenko A. N. Zelenetskii 《Polymer Science Series B》2011,53(5-6):358-370
New polymer salts and N-acetylated chitosan derivatives are prepared in an extruder by the method of solid-phase synthesis via the interaction of chitosan and 2,2-bis(hydroxymethyl)propionic acid. The effect of the initial component ratio and temperature on the yield and structure of the target products is studied. Joint deformation of solid components at room temperature is found to cause the quantitative formation of salt bonds between carboxylic groups of the acid and amino groups of chitosan. At elevated temperatures of synthesis, the corresponding acetylated derivatives with a degree of substitution of amino groups varying from 0.16 to 0.43 are prepared. The relaxation and phase transitions in the polymer salts and acetylated chitosan derivatives and their sorptional activity are studied. The films prepared from aqueous solutions of the new salt modification of chitosan are characterized by a homogeneous structure and improved mechanical characteristics relative to those of the films based on chitosan acetates. An additional thermal treatment of the products of the solid-phase synthesis leads to the formation of crosslinked and water-swollen materials that can be used for the development of novel polymeric chitosan-based membranes and sorbents. 相似文献
7.
R. I. Petrova V. P. Perelygin A. B. Akopova M. M. Gogorjan 《Radiation measurements》1995,25(1-4):329-330
The investigation of the track etching velocity dependence for nuclei with Z50 on pH of the etching solution in the olivine crystals from Marjalahti and Eagle Station meteorites, containing galactic cosmic-ray nuclear tracks and also the crystals from Marjalahti meteorite, calibrated at the UNILAC (GSI, Darmstadt) with 14.17 MeV/N 208Pb nuclei, were performed.
The pH of the etching solution were changed from 7.8 to 9.4. It is shown that the optimal track etch condition were realised at pH of etching solution in the interval from 8.4 to 8.8.
The results of the Galactic cosmic-ray nuclei tracks with Z83 revealed in olivine crystals are presented. They were additionally irradiated at 90% to the surface with accelerated 14 MeV/N 132Xe nuclei. 相似文献
8.
U. V. Chervonova M. S. Gruzdev A. M. Kolker O. B. Akopova 《Journal of Structural Chemistry》2016,57(3):478-490
New biligand complexes of iron(III) are synthesized based on 3,4,5-tri(tetradecyloxy)benzoyloxy-4-salicylidene-N′-ethyl-N-ethylenediamine azomethine with the outer sphere NO3?, PF6?, Cl?, BF4?, ClO4?, and CNS– anions. All the target compounds are characterized by gel exclusion chromatography, elemental analysis, and electron, IR, and NMR spectroscopy. The presence of complex-forming ions is confirmed by FT-IR spectra in the far region. The formation of biligand polychelate complexes with an octahedral packing of the iron ion is observed. Phase transitions in the resulting coordination compounds are studied by differential scanning calorimetry and optical polarizing thermomicroscopy. The presence of several polymorphic crystalline modifications, as well as mesophases, is established. Mesomorphic properties are found for complexes with chloride and tetrafluoroborate anions. 相似文献
9.
O. B. Akopova T. V. Frolova N. V. Usol’tseva 《Russian Journal of General Chemistry》2007,77(1):103-110
New mesogenic discotic triazine-based esters were synthesized and shown to form a low-temperature monotropic columnar mesophase. Using as examples the newly synthesized compounds and previously prepared discotic esters on the basis of benzene, biphenyl, and triphenylene, the effects of the nature and size of the central fragment and the number, position, length, and rigidity of peripheral substituents therein on the mesomorphic properties (in particular, the ability to form columnar and nematic mesophases) were examined. The main structural factors stabilizing columnar and nematic mesophases were revealed. Nematic mesomorphism was shown to be favored by increased size of the central fragment of the discogen molecule and by the presence of cyclohexane fragments in peripheral substituents. 相似文献
10.
A. N. Ozerin A. N. Zelenetskii T. A. Akopova O. B. Pavlova-Verevkina L. A. Ozerina N. M. Surin A. S. Kechek’yan 《Polymer Science Series A》2006,48(6):638-643
The effect of primary amino groups and molecular mass of chitosan on the stability of suspensions based on nanoscale TiO2 dispersions in acidic solutions of various concentrations at pH 2.5 was studied. In the case of chitosan prepared according to a commercialized process, the stability of TiO2 suspensions was low and depended on the concentration of the polymer solution. Solutions of low-molecular-mass highly deacetylated chitosan prepared by solid-phase synthesis stabilized a dispersion of nanosized TiO2 particles for a very long time. Nanocomposites based on a chitosan-PVA graft copolymer and TiO2 were prepared, in which the initial filler dispersion is retained up to very high filling ratios. A potential use of these nanocomposites in photocatalytic processes is discussed. The results of this study can be used for refining engineering procedures and processes for the manufacture of new biocompatible, bioactive, and biodegradable functional composite materials based on chitosan and synthetic polymers. 相似文献