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41.
I. Yu. Kargapolova K. S. Shmuilovich I. V. Beregovaya N. A. Orlova 《Russian Chemical Bulletin》2010,59(7):1414-1418
Reactions of α-perfluorophenylpyrylium salts with hydrazine hydrate in ethanol afforded derivatives of 1,2-diazepine, dihydro-1H-pyrazole, and/or 1-aminopyridinium salts, depending on the steric characteristics of the substituent in the second α-position.
1-Amino-2-methyl-6-perfluorophenyl-4-phenylpyridinium perchlorate was used to obtain various pyridocyanines. 相似文献
42.
R. Stanoeva D. A. Artemenkov V. Bradnova S. Vokál L. A. Goncharova P. I. Zarubin I. G. Zarubina N. A. Kachalova A. D. Kovalenko D. O. Krivenkov A. I. Malakhov G. I. Orlova N. G. Peresadko N. G. Polukhina P. A. Rukoyatkin V. V. Rusakova M. Haiduc S. P. Kharlamov M. M. Chernyavsky T. V. Shchedrina 《Physics of Atomic Nuclei》2009,72(4):690-701
Experimental data on fragmentation channels in peripheral interactions of 8B nuclei in nuclear track emulsions are presented. A detailed analysis made it possible to justify selections of events of the electromagnetic-dissociation process 8B → 7Be + p and to estimate its cross section. Events of 10C peripheral dissociation that were observed in the same exposure are described. 相似文献
43.
V. I. Pet’kov V. S. Kurazhkovskaya A. I. Orlova M. L. Spiridonova 《Crystallography Reports》2002,47(5):736-743
Double phosphates of zirconium and metals with an oxidation degree of +2 of the composition M0.5Zr2(PO4)3 (M = Mg, Ca, Mn, Co, Ni, Cu, Zn, Sr, Cd, and Ba) are synthesized and characterized by X-ray diffraction methods and IR spectroscopy. The crystal structures of all the compounds are based on three-dimensional frameworks of corner-sharing PO4-tetrahedra and ZrO6-octahedra. Phosphates with large Cd2+, Ca2+, Sr2+, and Ba2+ cations octahedrally coordinated with oxygen atoms form rhombohedral structures (space group R3), whereas phosphates with small tetrahedrally coordinated Mg2+, Ni2+, Cu2+, Co2+, Zn 2+, and Mn2+-cations are monoclinic (space group P21/n). The effect of various structure-forming factors on the M0.5Zr2(PO4)3 compounds with a common structural motif but different symmetries are discussed. 相似文献
44.
Chung MK Orlova G Goddard JD Schlaf M Harris R Beveridge TJ White G Hallett FR 《Journal of the American Chemical Society》2002,124(35):10508-10518
Palladium(0)-catalyzed silane alcoholysis was applied to sugars for the first time using tert-butyldimethylsilane (TBDMS-H) and Ph(3)SiH as the silanes. The catalyst is a colloidal solution of Pd(0) generated in situ from PdX(2) (X = Cl(-), OAc(-)) and TBDMS-H in N,N-dimethylacetamide. The colloid has been characterized by dynamic light scattering and transmission electron microscopy and consists of catalytically highly active nanoparticles of approximately 2 nm diameter. The silane alcoholysis reaction is an effective method for the regioselective silylation of methyl and phenyl glycosides and generates hydrogen gas as the only side product. For many of the sugar substrates investigated, the distribution of regioisomers obtained is complementary to that of the traditional R(3)SiCl/base (base = pyridine, imidazole) methodology and gives convenient access to the 3,6- rather than the 2,6-silylated pyranosides, obtained as the main product by the silyl chloride method. The method also allows a selective axial silylation of levoglucosan and 1,3,5-O-methylidene-myo-inositol. In an attempt to rationalize the observed regioselectivities, ab initio predictions (HF/3-21G) have been made on the relative energies of some of the silylated products. They suggest that the observed regioselectivities do not reflect a kinetic vs thermodynamic product distribution but are induced by the silylation agent employed. Models for the possible origin of the observed regioselectivity in both silylation methods (silane- and silyl chloride-based) are discussed. 相似文献
45.
The electron binding energy in negative ions of the alkaline-earth atoms Ca and Sr is calculated on the basis of the polarization-potential
formalism and relativistic perturbation theory with a zeroth-order model potential. The results improve the data available
in the literature for these negative ions.
Odessa Hydrometeorological Institute. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 27–31, September,
1996. 相似文献
46.
47.
Reaction of -chloroethers with zinc in the presence of thiophene and furan derivatives gives the corresponding diheterylalkanes.For Part IX, see [1].Translated from Khimiya Geterotsikicheskikh Soedinenii, No. 9, pp. 1181–1182, September, 1970. 相似文献
48.
49.
50.
S. N. Bondarenko T. V. Khokhlova S. A. Orlova O. I. Tuzhikov 《Russian Journal of Applied Chemistry》2004,77(10):1715-1720
Polyurethanes were prepared from diphenylmethane-4,4-diisocyanate, poly(tetramethylene ether) glycol, and B,P-containing polyols. The structure and properties of these polyurethanes were studied in relation to the synthesis conditions, including the functional group ratio and temperature. The heat resistance of the polyurethanes was evaluated.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 10, 2004, pp. 1729–1734.Original Russian Text Copyright © 2004 by Bondarenko, Khokhlova, Orlova, Tuzhikov. 相似文献