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121.
Olga N. Kataeva Aidar T. Gubaidullin Igor A. Litvinov Olga A. Lodochnikova Lenar R. Islamov Alexander I. Movchan Galina A. Chmutova 《Journal of Molecular Structure》2002,610(1-3):175-179
Crystal and molecular structure of 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one as a product of the benzoylation of 1-phenyl-3-benzoylaminopyrazol-2-in-5-one was characterised by X-ray single crystal diffraction. It is shown that 1-phenyl-3-benzoylamino-4-benzoylpyrazol-2-in-5-one exists in the solid phase in an NH-tautomeric form, which is stabilised by two intramolecular hydrogen bonds and one intermolecular bond with the solvate dioxane molecule, the latter being used as a solvent for recrystallisation. 相似文献
122.
A. A. Ponomarev A. S. Chegolya N. S. Smirnova V. N. Dyukareva 《Chemistry of Heterocyclic Compounds》1967,2(2):113-117
This paper gives the results obtained by liquid phase catalytic hydrogenation under pressure, over ruthenium catalysts, of furan aldehydes, ketones, and carboxylic acids. It is shown that the ruthenium catalysts are highly effective for hydrogenating the furan ring, ethylenic double bonds, and the carbonyl group, though they are not selective with respect to them. At room temperature the furan ring is mostly reduced to a tetrahydrofuran one. It is confirmed that compounds containing the 1, 6-dioxaspiro [4, 4]-nonane grouping are formed by hydrogenating furfurylidene aldehydes and ketones, and -furylalkanols.For Part XXX see [15]. 相似文献
123.
A facile seven-step sequence was developed from 4′-bromopropiophenone, utilizing a Suzuki-type coupling with an alkene, to give several novel 5-substituted pyrazole derivatives in overall yields of 11-31%. They are potent CB1 antagonists and have binding affinities similar to SR 141716A. Like SR 141716A, they may prove to be clinically useful for the treatment of obesity. 相似文献
124.
Josep Castells Elisabet Duñach Fernando Geijo Francisco López-Calahorra Margarita Prats Olga Sanahuja Laura Villanova 《Tetrahedron letters》1980,21(23):2291-2294
Triethylamine catalyzed Michael additions of benzoins to chalcone can prevail over the expected Michael-Stetter additions when certain thiazolium ion conjugate bases - prepared from the pertinent thiazolium salts and triethylamine- are used as catalysts. 相似文献
125.
Hay Robert W. Pujari Mahesh P. Hideg Kaiman Hankovszky Olga H. 《Transition Metal Chemistry》1985,10(5):188-191
Summary The new macrocyclic ligand 7,14-o-hydroxyphenyl-5,12-dimethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene (1=L) has been prepared and complexes with copper(II), nickel(II) and cobalt(III) characterised. The nickel(II) complex is a yellow square-planar species, while the purple-red copper(II) complex is probably tetragonal in both the solid state and solution. The complexes appear to have an N-meso arrangement of the chiral nitrogen centres with the HOC6H4 groups occupying equatorial sites so that axial interactions with the metal do not occur. A variety oftrans-[CoLX2]ClO4 complexes (X=Cl, Br, NO2, or N3) have been characterised. 相似文献
126.
Olga V. Boltalina Lev N. Sidorov Ekaterina V. Sukhanova Igor D. Sorokin 《Chemical physics letters》1994,230(6):567-570
Difluorinated higher fullerenes have been studied by Knudsen cell mass spectrometry. Thermal negative ions CnF2− (n=60, 70, 72, 74, 76 and 78) were produced inside the effusion cell as well as the neutral molecules C60F2 and C70F2. From the equilibrium constants for the electron exchange reactions between difluorinated fullerenes and their parents electron affinity values were derived for C60F2 (2.74 eV) and C70F2 (2.80 eV). 相似文献
127.
Anna Katafias Olga Impert Przemysław Kita Grzegorz Wrzeszcz 《Transition Metal Chemistry》2004,29(8):855-860
Oxidation of the trans-[Cr(cyca)(OH)2]+ complex, where cyca = meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, by [Fe(CN)6 ]3- ion in strongly alkaline media, leading to [CrV O(cycaox )]3+ ion, has been studied using electronic and e.p.r. spectroscopy. The kinetics of the CrIII → CrIV transformation have been studied using a large excess of the reductant and OH- ion over the oxidant. The reaction is a second order process: first order in [CrIII] and [FeIII] at constant [OH-]. The second order rate constant is higher than linearly dependent on the OH- concentration. The mechanism of the reaction has been discussed. A relatively inert intermediate chromium(V) species was detected based on characteristic bands in the visible region and the e.p.r. signal at giso = 1.987 for the systems where an excess of oxidant was used. The hyperfine structure of the main e.p.r. signal is consistent with the d1 -electron interactions with four equivalent nitrogen nuclei and [CrV = O(cycaox)]3+ formula, where cycaox = oxidized cyca, can be postulated for the intermediate CrV complex. 相似文献
128.
Olga Hadžija 《Mikrochimica acta》1968,56(5):917-921
Summary Körbl-catalyst and manganese dioxide absorb chlorine and bromine quantitatively at room temperature. This property is applied to simultaneous microanalytical determination of carbon, hydrogen and chlorine or bromine in compounds containing carbon, hydrogen, oxygen, chlorine or bromine, but not nitrogen or sulphur.
Zusammenfassung Der Körbl-Katalysator und Mangandioxid absorbieren Chlor und Brom bei Raumtemperatur quantitativ. Sie wurden daher zur gleichzeitigen Bestimmung von C, H sowie Cl oder Br in Verbindungen verwendet, die C, H, O, Cl (oder Br), nicht aber N oder S enthalten.相似文献
129.
Olga V. Vorobyeva Tatyana A. Samoylova Vladimir I. Yusupov 《Photochemistry and photobiology》2020,96(5):1116-1123
This paper deals with the effect of photobiomodulation (PBM) on Daphnia magna S. and their sensitivity to cadmium sulfate, a known high toxic pollutant. In a first series of experiments, the effect of different He-Ne laser fluences irradiation (range 0.9-4300 mJ cm−2) on the fertility of both parent and filial generations (F1–F3) of the crustacean was studied. It was found that PBM in some cases significantly influenced the fertility of both irradiated crustaceans and their nonirradiated offspring. By selecting two fluences (9 ± 2 mJ cm−2 reducing fertility and 4.3 ± 0.9 J cm−2 increasing it), the effect of these on toxicity of cadmium sulfate was evaluated. These experiments have shown that prior irradiation with low-intensity light of a helium–neon laser with 632.8 nm wavelength can change the sensitivity of aquatic organisms to toxin cadmium sulfate. The degree and direction of changes depend on the toxicant concentration and the irradiation dose. 相似文献
130.
The thermodynamic properties of styrenetricarbonylchromium, -methylstyrenetricarbonylchromium, and p-methylstyrenetricarbonylchromium were studied with adiabatic vacuum and dynamic calorimeters. The heat capacity in the range 5-450 K (error about 0.3% in most cases) and the temperatures and enthalpies of the phase transitions were determined. The experimental data were used to calculate the thermodynamic functions C
0
p(T), H
0(T) - H
0(0), S
0(T), and G
0(T) - H
0(0) for the range from 0 to 330-400 K, and also the isochoric heat capacity C
v and its lattice (Cv,latt) and atomic (C
v,at) contributions for the range from 0 K to T
0
m; the parameters = C
0
p/C
v were evaluated. The thermodynamic properties were considered in relation to the composition and structure of the compounds. 相似文献