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排序方式: 共有185条查询结果,搜索用时 31 毫秒
1.
2.
V. B. Vol'eva A. I. Prokofev A. Yu. Karmilov N. L. Komissarova I. S. Belostotskaya T. I. Prokofeva V. V. Ershov 《Russian Chemical Bulletin》1998,47(10):1920-1923
The formation of semiquinone and phenoxazyl radicals and metallocomplexes with semiquinone ligands was observed by ESR during
the interaction of di-tert-butylpyrocatechol with Al2O3, ZnO, SiO2, and TiO2. In the case of different modifications of SiO2, admixtures of TiO2 exhibit a higher reactivity in complex formation with the organic substrate.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1975–1978, October, 1998. 相似文献
3.
Komissarova N. L. Vol'eva V. B. Belostotskaya I. S. Kurkovskaya L. N. Starikova Z. A. 《Russian Journal of Organic Chemistry》2003,39(5):686-688
The Mannich reaction of 2,4-di-tert-butylphenol with dicyclohexylamine was found to involve formation of a stable 1:1 molecular complex between the phenol and amine. The complex does not change on melting, sublimation, and chromatography on silica gel. Its structure was determined by X-ray analysis. Stable 1:1 complexes of dicyclohexylamine with a series of substituted phenols were synthesized; exceptions were 2,6-disubstituted phenols with bulky substituents. 相似文献
4.
I. S. Belostotskaya V. B. Vol'eva N. L. Komissarova M. O. Dekaprilevich V. N. Khrustalev A. Yu. Karmilov V. V. Ershov 《Russian Chemical Bulletin》1997,46(7):1272-1280
Oxidative transformations of 2-dialkylaminomethyl-4,6-di-tert-butylphenols depend on the nature of the oxidant, the character of the substituents at the nitrogen atom, and the medium.
A mechanism of the oxidation of these compounds is suggested. The molecular structure of the compound obtained as a result
of oxidative trimerization of 2-dimethylaminomethyl-4,6-di-tert-butylphenol was established by X-ray structural analysis.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1328–1335, July, 1997. 相似文献
5.
V. B. Vol'eva T. I. Prokofeva A. I. Prokofev I. S. Belostotskaya N. L. Komissarova V. V. Ershov 《Russian Chemical Bulletin》1995,44(9):1720-1724
The interaction of 3,6-di-tert-butyl-ortho-benzoquinone (1) and 3,5-di-tert-butyl-ortho-benzoquinone (2) with NH3 in water—alcohol medium and with (NH4)2CO3 in a solid phase has been studied. Redox processes with participation of a nucleophile of the medium take place for1, while2 reacts with NH3 at the carbonyl group with transformation of the quinone imide. The mechanism of redox transformation of1 has been proposed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1789–1793, September, 1995.This work was carried out with financial support from the Russian Foundation for Basic Research (Project No. 94-03-08653). 相似文献
6.
A. V. Kulikov A. S. Komissarova A. F. Shestakov L. S. Fokeeva 《Russian Chemical Bulletin》2007,56(10):2026-2033
Solutions of the basic form of polyaniline in m-cresol were studied by ESR and optical spectroscopy in the visible region. m-Cresol can slowly (during one month) protonate polyaniline. For the first time characteristic features of spin crossover
were found: sharp changes in the magnetic susceptibility and the ESR line width of polyaniline at ∼200 and 250 K, a smooth
decrease in the susceptibility and absorption with the temperature increase from 293 to 423 K, and the temperature hysteresis.
The temperature-induced structural rearrangements of polyaniline are caused, most likely, by singlet-triplet transitions in
relatively short sections of the polymer chain. The model of short sections permits to explain the origin of the temperature-independent
part of susceptibility. Quantum-chemical calculations for the aniline dimers and tetramers describe correctly the singlet-triplet
splitting value, thermochromism, and HFS constants in the spectrum of polyaniline.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1959–1966, October, 2007. 相似文献
7.
N. G. Komissarova N. G. Belenkova L. V. Spirikhin O. V. Shitikova M. S. Yunusov 《Chemistry of Natural Compounds》2002,38(1):58-61
Oxidation of betulin by pyridinium dichromate, pyridinium chlorochromate, and K2Cr2O7 -H2SO4 in the presence of tetrabutylammonium bromide was studied. Products of regioselective C-3, C-28-, and exhaustive oxidation, 28-hydroxylup-20(29)-3-one, 3-hydroxy- and 3-oxolup-20(29)-en-28-al were obtained. 相似文献
8.
N. A. Chernova I. V. Arkhangel'skii L. N. Komissarova 《Journal of Thermal Analysis and Calorimetry》1978,13(2):315-319
A model process is considered in order to investigate the applicability of a particular statistical approach to determination of an input mechanism of topochemical reactions and of the relevant mathematical model.It is shown that the analysis of the experimental data leads to different results due to the reproducibility errors. The applied statistical approach allows one to determine the input mechanism unambiguously when has the value of 0.01.
Zusammenfassung Ein Modellverfahren wird zur Untersuchung der Anwendbarkeit einer bestimmten statistischen Näherung zur Bestimmung eines Inputmechanismus topochemischer Reaktionen und des einschlägigen mathematischen Modells herangezogen.Es wird gezeigt, daß infolge von Reproduzierbarkeitsfehlern die Analyse der Versuchsangaben zu verschiedenen Ergebnissen führt. Die angewandte statistische Annäherung gestattet die eindeutige Bestimmung des Inputmechanismus bei einem Sigma-Wert von 0.01.
Résumé On considère un processus modèle pour vérifier s'il est possible d'appliquer une approximation statistique particulière pour déterminer le mécanisme initial des réactions topochimiques et le modèle mathématique respectif.On montre que l'analyse des données expérimentales conduit à des résultats différents en raison des erreurs de reproductibilité. L'application de cette approximation statistique permet de déterminer le mécanisme initial sans équivoque, pourvu que la valeur de soit égale à 0.01.
- . , , . , 0,01.相似文献
9.
Sergeev G. B. Smirnov V. V. Rostovshchikova T. N. Komissarova N. V. Indoleva Ye. V. 《Tetrahedron》1987,43(24):5853-5863
Complexes and reactions of 2-methylbutene-2 with hydrohalogen (HCl, HBr) have been studied in solid phase at 80–150 K. It has been found that 2-methylbutene-2 forms with HX complexes of 1:1 and 1:2 composition. Hydrohalogenation proceeds via the rearrangement of complex 2HX·C5H10 into complex of the addition product with HX. Kinetic equation depends on the reagents ratio. In excess of HX (1< HX:C5H10< 10) reaction can be described by the first order kinetic equation. If the ratio HX:C5H10 is more than 10, reaction is described by polychronous kinetic law. The effective activation energy of solid phase hydrohalogenation does not exceed 20 kJ/mole. The molecular mechanism of hydrohalogenation in solid phase has been proposed. 相似文献
10.
The conditions of formation of complex lanthanide chromate(VI)-phosphates K2R(CrO4)(PO4) were found and these compounds were synthesized by solid-state synthesis with variation of the starting compounds, the temperature
of synthesis (500–800 °C), and the annealing time (6–200 h). These salts are typical of late lanthanides, R = Dy-Lu, Y. Using
lutetium derivatives as examples, it was shown that no similar compounds with lithium or sodium are formed. All the complex
chromate(VI)-phosphates obtained decompose under static conditions at temperatures above 550 °C. They are isostructural and crystallize
in the monoclinic system. The unit cell parameters for thulium, ytterbium, and lutetium compounds were calculated. It is shown
by IR spectroscopy that PO4 tetrahedra in the crystal lattice of potassium lanthanide chromate(VI)-phosphates are substantially distorted, whereas the CrO4 tetrahedra retain the regular tetrahedron symmetry (T
d
).
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 622–626, April, 2006. 相似文献