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41.
Summary Methyl -nitrocrotonate has been synthesized by the condensation of methyl nitroacetate with acetaldehyde, acetylation of the methyl -nitro--hydroxybutyrate, and subsequent deacetylation of the resulting product. 相似文献
42.
43.
R. K. Alekseenko L. S. Ivanova D. I. Shvets 《Theoretical and Experimental Chemistry》1991,26(6):694-697
In order to establish the interrelation between the electronic characteristics of carbons that are manifested in the EPR spectra and their ability to adsorb complex gold and silver ions, the EPR spectra of carbon adsorbents from phenol-formaldehyde resins of various nature, unactivated and activated under various conditions, and the adsorption of [Au(CN)2]– and [Ag(CN)2]– from cyanide solutions on these same adsorbents were investigated. A parallel relation was observed between the amount of paramagnetic centers on carbon and its adsorption capacity and selectivity in relation to these anions.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 26, No. 6, pp. 742–745, November–December, 1990. 相似文献
44.
Sheinin V. B. Ivanova Yu. B. Berezin B. D. 《Russian Journal of General Chemistry》2002,72(7):1128-1131
The association equilibrium of porphyrinium ions of mesoporphyrin IX dimethyl ester (H2MP) with iodide ions in acetonitrile was studied by spectropotentiometric titration. Two associates were revealed: (H4MP2
+)(I-) and (H4MP2
+)(I-)2; the electronic absorption spectra of these species were measured, and their formation constants were determined. 相似文献
45.
E. A. Amelina I. V. Videnskii N. I. Ivanova A. M. Parfenova V. V. Pelekh N. V. Altukhova E. D. Shchukin 《Colloid Journal》2001,63(5):527-531
The effect of cationic surfactants (cetyltrimethylammonium bromide and tetrabutylammonium iodide) and cationic polyelectrolyte polyethylenimine on the coefficient of friction and adhesion force p(during shear and tensile testing, respectively) at the point contacts between the individual fibers of cellulose, viscose, and cellulose acetate was studied. The comparison of these data with the results of -potential and adsorption measurements enabled us to relate the nonmonotonic dependence of parameters and pon the surfactant concentration to the changes in electrosurface properties and the hydrophilicity or hydrophobicity of the fibers. The specific free energy of interaction U[mJ/m2] was estimated for cellulose acetate fibers. 相似文献
46.
Droplet growth in thin layers of water-alcohol solutions under the effect of a concentration-induced capillary flow, which is governed by a laser electromagnetic radiation, is investigated. It is established that an increase in water concentration in a solution accelerates the droplet growth. In low-concentrated solutions, a droplet may reach a quasi-steady state, in which its diameter is no larger than the diameter of the light beam projection onto the layer. A rise in the radiation power above an optimal magnitude decelerates the droplet growth. In low-concentrated solutions, this deceleration results from a decrease in the flow that feeds the droplet, while in high-concentrated solutions, it is due to a droplet constriction and an increase in its curvature radius. 相似文献
47.
Akat'eva M. E. Erofeeva O. S. Dobrynina N. A. Ivanova N. A. Efimenko I. A. 《Russian Journal of Coordination Chemistry》2004,30(8):584-590
Pd(II) complexes with glutamic acid of the composition K[Pd(HGlu)Cl2] (I) and [Pd(HGlu)2] (II) were synthesized and studied by IR and electronic absorption spectroscopy methods. Pd2+–H2O–Cl– and Pd2+–H2O–Cl––H2Glu systems were analyzed by pH-metric titration. The most essential Pd(II) complex forms were established by mathematical modeling and their formation constants were calculated. The electronic absorption spectra of complexes I and II were measured in aqueous and physiological solutions. Complex I was found to be biologically active and to exhibit antimetastatic properties. 相似文献
48.
L. V. Grishchuk E. I. Ivanov V. E. Kuz'min A. M. Turyanskaya R. Yu. Ivanova 《Chemistry of Heterocyclic Compounds》2003,39(3):340-343
The reaction of 4-aryl-2-hydrazino-3-nitro-6-R-quinolines with NaNO2 in AcOH gives the corresponding tetrazolo[1,5-a]quinolines. In contrast to tetrazolo[1,5-c]pyrimidines they cannot be converted to 6-R-4-phenyl[1,2,5]oxadiazolo[3,4-b]quinoline-3-oxides by heating in THF, toluene, or AcOH. Total energy quantum-chemical calculations using the MINDO/3 and MNDO methods show that [1,2,5]oxadiazolo[3,4-b]quinoline-3-oxides are significantly higher in energy (230-280 kcal/mol) than the mentioned tetrazolo[1,5-a]quinolines and hence their formation is unlikely. 相似文献
49.
A. B. Sheremetev E. A. Ivanova D. E. Dmitriev V. O. Kulagina Boris B. Averkiev Mikhail Yu. Antipin 《Journal of heterocyclic chemistry》2005,42(5):803-810
A series of macrocycles containing four furazan rings bonded by three azo bonds 2, 5 and 7 have been synthesized from the common precursor, 3‐amino‐3′‐nitro(azofurazan) 3 . The macrocycles closure is a result of N?N bond formation at oxidative cyclization of corresponding bis(3‐aminofurazan‐4‐yl) precursors. X‐Ray crystal structures of macrocycles 2, 2 ?AcOH, 11 and 13 are reported. 相似文献
50.
G. G. Zapesochnaya S. Z. Ivanova V. I. Sheichenko N. A. Tyukavkina S. A. Medvedeva 《Chemistry of Natural Compounds》1980,16(2):141-145
Two monoacylated glycosides have been isolated from the needles ofPicea obovata — the previously unknown 3-p-coumaroylastragalin (I) and 6-p-coumaroylastragalin (II). It has been established that under the conditions of mild saponification and acid hydrolysis isomerization of (I) into (II) and the splitting out of the acy1 residue takes place. The position of the acy1 substituent has been shown by PMR spectroscopy using the INDOR method. The physicochemical characteristics of the acylated glycosides and of their heptaacetates are given.All-Union Scientific-Research Institute of Medicinal Plants, Moscow. Irkutsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR, Moscow. I. M. Sechenov First Moscow Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 186–190, March–April, 1980. 相似文献