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141.
B. A. Korolev L. A. Osmolovskaya Yu. V. Kuznetsov L. G. Stolyarova L. D. Smirnov 《Russian Chemical Bulletin》1992,41(2):333-336
Examination of the acid-base properties of 5-hydroxybenzimidazoles has shown them to exist in nitromethane as the 5-hydroxy-tautomers. Substituents in the 2-position have a predominantly inductive effect on the basicity of the 3-nitrogen, rationalized as in other nitrogen heterocycles by the proximity of the substituents to the reaction center.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. The Research Institute for Intermediates and Dyes, 103787 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 2, pp. 421–425, February, 1992. 相似文献
142.
143.
The structure of [CoCl2(C6H4N3CH2Ph)2] has been determined by X-ray crystallography. It is also characterized by elemental analysis, IR and electronic spectroscopy, and by thermogravimetric differential thermal analysis. It crystallizes in the monoclinic system, space group C2/c, with lattice parameters a = 16.133(3) , b = 11.355(2) , c = 15.637(3) , = 117.22(3)°, and Z = 8. The crystal structure of the title compound consists of monomeric molecules of [CoCl2(C6H4N3CH2Ph)2] with slightly distorted tetrahedron geometry for the CoCl2N2 chromophore. The thermal gravimetry (TG) data indicate that there are four decomposition steps with five endothermic peaks. The final product of the thermal decomposition is CoCl2. Elemental analysis and the electronic and IR spectra are in agreement with the structural data.Original Russian Text Copyright © 2004 by F. Jian, H. Wang, and H. XiaoTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 723–728, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
144.
145.
Diego Pallarola Luis Domenianni Graciela Priano Fernando Battaglini 《Electroanalysis》2007,19(6):690-697
In this work, two well known polymers, carboxymethyl dextran and poly(ethyleneglycol), are used for easily producing a platform for electrochemical affinity assays, avoiding nonspecific adsorption of proteins. In this way, modified electrode surfaces able to bind a recognition agent are constructed through simple and reliable reactions. 相似文献
146.
David Bevk Uroš Grošelj Anton Meden Jurij Svete Branko Stanovnik 《Helvetica chimica acta》2007,90(9):1737-1744
A simple and efficient synthesis of four new substituted pyrimidines, compounds 9a – d , from the title compound 3 is described. Conversion of 3 to methyl (E)‐3‐(dimethylamino)‐2‐(6‐methoxy‐2‐phenylpyrimidin‐4‐yl)prop‐2‐enoate ( 4 ), followed by condensation with various dinucleophiles according to the ‘enaminone methodology’, afforded the target compounds 9 in medium‐to‐good yields. 相似文献
147.
V. V. Davydov V. L. Sokol E. V. Balebanova Yu. V. Shklyaev S. V. Sergeev V. A. Nikanorov B. E. Zaitsev M. A. Porai-Koshits 《Russian Chemical Bulletin》1993,42(2):288-294
3,3-Dimethyl- and 3-methyl-1-(4,4-dimethyl-2,6-dioxocyclohex-1-yl)-3,4-dihydroisoquinolines have been synthesized. Crystal and molecular structures of the 3,3-dimethyl derivative have been determined. In the crystalline state this compound exists as a tautomeric form where a hydrogen atom is located at the N atom of the dihydroisoquinoline fragment of the molecule. The tautomeric equilibrium does not shift noticeably in solutions, as shown by IR, UV, and NMR spectroscopy.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 331–336, February, 1993. 相似文献
148.
Ewa Rudnik G. Matuschek N. Milanov A. Kettrup 《Journal of Thermal Analysis and Calorimetry》2006,85(2):279-284
Thermal behaviour of different starch derivatives, i.e. starch esters
and ethers having degree of substitution (DS) in the range of 0.02–0.18
were studied. Potato, maize and wheat starches were used. Measurements were
carried out by coupled thermal analysis/ mass spectrometry method (STA-MS)
in air atmosphere.
The major DTG peak during the investigation
for starch derivatives is observed below 300°C. The mass loss up to a
temperature of 300°C is about 50%. The most abundant ions found areH2O+
and CO2
+. For the studied
starch derivatives with a low degree of substitution (DS<0.18) no correlation
was found between thermal stability and the level of substitution regardless
of the nature of substitution. 相似文献
149.
JinXianWANG XiaoNingSHI KeHuWANG XiuQinMEN 《中国化学快报》2004,15(3):284-285
An efficient and convenient synthesis of 3, 5, 7-triaryl-4H-1, 2-diazepine from 2, 4,6-triarylpyrylium salts and hydrazine in water under microwave irradiation is reported. The same reaction can be conducted using 2, 4, 6-triarylthiopyrylium salts and hydrazine. 相似文献
150.
The halohydrin reaction of chiral N-enoyl-2-oxazolidinones 1 by halogen (Br2/I2) and water were efficiently carried out in aqueous organic solvent promoted by silver(I) with high anti- and regioselectivity and moderate to good diastereoselectivities. The alkenoyl, cinnamoyl and electron-deficient cinnamoyl substrates smoothly underwent bromohydrin reaction in aqueous acetone but no iodohydrin reaction, where as electron-rich cinnamoyl substrates preferred to undergo iodohydrin reaction in aqueous acetone with moderate diastereoselectivity and enhanced diastereoselectivity was observed in aqueous THF. 相似文献