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31.
32.
T. A. Danilova R. G. Aukharieva S. N. Petrov S. Ya. Grobovenko E. A. Viktorova 《Chemistry of Heterocyclic Compounds》1981,17(9):883-886
The thio-Claisen rearrangement of isomeric 3- and 1-methylallyl phenyl sulfides was investigated. It is demonstrated that the thio-Claisen rearrangement of the 3-methyl isomer is preceded by its thioallyl rearrangement to the 1-methyl isomer. The latter undergoes thio-Claisen rearrangement to o-(3-methylallyl)thiophenol, which is cyclized to 2-ethyl-2,3-dihydrobenzothiophene and 2-methylthiochroman under the reaction conditions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1191–1194, September, 1981. 相似文献
33.
E. A. Yatsynich D. V. Petrov F. A. Valeev V. A. Dokichev 《Chemistry of Natural Compounds》2003,39(4):337-339
The 1,3-dipolar cycloaddition of diazomethane to levoglucosenone was found to occur regio- and stereoselectively to form optically active 9,11-dioxa-4,5-diazatricyclo[6.2.1.02,6]undec-4-en-7-one. Levoglucosenone was found to react with methyldiazoacetate to give the 2:1 adduct. 相似文献
34.
35.
S. A. Lebedev V. S. Lopatina R. S. Sorokina S. S. Berestova E. S. Petrov I. P. Beletskaya 《Russian Chemical Bulletin》1987,36(11):2329-2332
Conclusions Condensation of aryl bromides with styrenes in acetonitrile in the presence of nickel organometallic complex catalysts and metallic zinc occurs regio- and stereoselectively to give E-stilbenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2508–2511, November, 1987. 相似文献
36.
Russian Journal of Organic Chemistry - 相似文献
37.
The formation of negative hydrogen ions in a conventional hollow cathode discharge has been investigated. A mixture of Ne and H2 proved to be more advantageous compared to pure hydrogen. The study has been performed by solving the electron Boltzmann equation, coupled with a system of balance equations for neon and hydrogen neutral and charged particles. The vibrational distribution function of hydrogen has been calculated. Our calculations show unusually high population of vibrationally excited hydrogen molecules in a Ne–H2 mixture, which explains the high density of negative hydrogen ions under optimal conditions (total gas pressure of few Torr, hydrogen number mole fraction of 1–10% and discharge current of 10–100 mA). Line intensities originating from highly excited neon states vs. hydrogen pressure have been calculated and a comparison with existing experimental results has been made. 相似文献
38.
L. Kh. Baumane R. A. Gavar Ya. P. Stradyn' O. N. Chupakhin V. L. Rusinov A. Yu. Petrov 《Chemistry of Heterocyclic Compounds》1985,21(5):582-587
1-Methyl- and 1-phenyl-substituted derivatives of 5-nitropyrazolo[3,4-b]pyridines are reduced at a dropping mercury electrode in a single one-electron wave with the formation of radical anions in interval of potentials from –0.94 to –1.06 V. Compounds unsubstituted at the N(1) nitrogen atom give an additional polarographic wave at E1/2 = –1.4 V due to the reduction of the deprotonated form (anion). The potentials and HFS constants of the ESR spectra of the corresponding electrochemically generated free radicals are given.For Communication 3, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 689–693, May, 1985. 相似文献
39.
Volodkin DV Petrov AI Prevot M Sukhorukov GB 《Langmuir : the ACS journal of surfaces and colloids》2004,20(8):3398-3406
A new approach to fabricate polyelectrolyte microcapsules is based on exploiting porous inorganic microparticles of calcium carbonate. Porous CaCO3 microparticles (4.5-5.0 microns) were synthesized and characterized by scanning electron microscopy and the Brunauer-Emmett-Teller method of nitrogen adsorption/desorption to get a surface area of 8.8 m2/g and an average pore size of 35 nm. These particles were used as templates for polyelectrolyte layer-by-layer assembly of two oppositely charged polyelectrolytes, poly(styrene sulfonate) and poly(allylamine hydrochloride). Calcium carbonate core dissolution resulted in formation ofpolyelectrolyte microcapsules with an internal matrix consisting of a polyelectrolyte complex. Microcapsules with an internal matrix were analyzed by confocal Raman spectroscopy, scanning electron microscopy, force microscopy, and confocal laser-scanning fluorescence microscopy. The structure was found to be dependent on a number of polyelectrolyte adsorption treatments. Capsules have a very high loading capacity for macromolecules, which can be incorporated into the capsules by capturing them from the surrounding medium into the capsules. In this paper, we investigated the loading by dextran and bovine serum albumin as macromolecules. The amount of entrapped macromolecules was determined by two independent methods and found to be up to 15 pg per microcapsule. 相似文献
40.
An approach for quantitative analysis of mixtures with unknown individual responses of the components is discussed. Although it is based on a resolution of overlapping bands technique, the main emphasis is not given to the computational facets of curve fitting. A logical procedure is described, allowing estimation of the unknown concentrations in the mixture, and both the number of overlapping bands and their assignment to the components in the solution to be determined automatically. A general conclusion about the precision of the method cannot be defined, because it depends on the extent of overlapping of the individual spectra of the components and their complexity. Using this procedure a complicated three-component acid-base equilibrium of a halochromic dye in solution is studied. 相似文献