首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
1.  The kinetics of reactions of alkali metal salts of 9-carbomethoxy- and 9-cyanofluorene with para-nitrofluorobenzene and of Me3SnM with pentafluoropyridine have been studied.
2.  In the case of carbanions the free anions are more reactive, while in the case of Me3SnM the corresponding tight (contact) ion pairs are more reactive.
3.  The effect of the leaving group (on reactivity) was investigated using the reactions of pentafluorochlorobenzene with the K salts of 9-carbomethoxyfluorene and cyclopentadienylirondicarbonyl anions as examples.
4.  The reaction mechanism has been shown to depend on the nature of the nucleophile.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2826–2832, December, 1988.  相似文献   

2.
1.  Indium atoms have been obtained in aqueous solutions of univalent indium by pulse radiolysis.
2.  In0 reacts with In+ to form the dimer In 2 + .
3.  The optical characteristics of these particles, the rate constants for their formation and loss, as well as the oxidation-reduction potentials have been determined.
We thank A. G. Egorova for providing the InBr salt.  相似文献   

3.
1.  It has been shown that 2-bromo-l,3,2-dioxaarsenanes exist in chair conformation with axially oriented As-Br bonds.
2.  Polarity and polarizability parameters have been found for the As-O and As-Br bonds in 2-bromo-l,3,2-dioxaarsenanes.
3.  The so-called -effect is stronger in the O2AsBr group than in the O2AsCl group.
  相似文献   

4.
1.  Complexes of the REE, Y, and Sc with hydroxyethylethylenediaminetriacetic acid have been isolated in solid form. The hydrate compositions of the complexes have been determined.
2.  The La and Pr complexes form hydrates of different compositions. The LnL hydrates form slightly nonisostructural groups in the series La-Lu.
3.  According to thermographic analysis data, the hydrate water in the LnL·nH2O complexes of different hydrate compositions is not bonded with the same firmness.
  相似文献   

5.
1.  Polarizability parameters have been obtained for the C6H5-C group in benzylidene bromides, and it has been shown that the bromine atom in these compounds interacts with the aromatic system.
2.  The conformations of the nonsterically hindered benzylidene bromides are close to those in which the ring plane is shielded by the C-Br bond.
  相似文献   

6.
1.  The condensation of 1,2-hydroxylamino oximes with biacetyl leads to 1-hydroxy-2-acetyl-2,4,5,5-tetrasubstituted 3-imidazoline 3-oxides.
2.  When 1-hydroxy-2-acetyl-2,5,5-trimethyl-4-phenyl-3-imidazoline 3-oxide is oxidized the CH3CO group is cleaved to give the 5H-imidazole 1,3-dioxide.
3.  Stable nitroxyl radicals were obtained when the 1-hydroxy-2-oximiaoethyl-2,4,5,5-tetrasubstituted 3-imidazoline 3-oxides are oxidized.
  相似文献   

7.
To mitigate CO2 discharged from thermal power plants, studies on CO2 fixation by the photosynthesis of microalgae using actual exhaust gas have been carried out. The results are as follows.
1.  A method is proposed for evaluating the maximum photosynthesis rate in the raceway cultivator using only the algal physical properties;
2.  Outdoor cultivation tests taking actual flue gas were performed with no trouble or break throughout 1 yr using the strain collected in the test;
3.  The produced microalgae is effective as solid fuel; and
4.  The feasibility studies of this system were performed. The system required large land area, but the area is smaller than that required for other biomass systems, such as tree farms.
  相似文献   

8.
1.  A method has been developed for the intercalation of solid substances from solutions in organic solvents into graphite fluoride C2Fx.
2.  Molecules of inserted paramagnetic copper complexes and nitroxyl radicals assume oriented positions between the structural layers in graphite fluoride.
3.  The planes of molecules of bis-chelate Cu(II) complexes with acetylacetone, o-hydroxyquinoline, and phenylsalicylaldimine were determined to lie parallel to the C2Fx planes.
4.  A method has also been suggested for the preparation of samples from C2Fx·yA compounds with a higher degree of texturizing (more nearly complete orientation) than can be achieved by pelletizing.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 272–276, February, 1988.  相似文献   

9.
1.  The molecular-sieve properties of a number of synthetic and natural chabazites have been investigated.
2.  Characteristic differences have been revealed in the molecular-sieve properties, thermal stability, and x-ray characteristics between the two groups of the zeolites studied.
3.  A reversal of the molecular-sieve effect on passing from the calcium to the sodium-calcium forms of certain synthetic and natural chabazites has been observed.
  相似文献   

10.
1.  The absorption of electromagnetic radiation ( 1.05 mm) by solutions of DMSO in water and DMSO and water in dioxane has been measured in the whole interval of relative concentrations.
2.  The additivity of the absorption in systems containing dioxane, and its absence in the system H2O-DMSO, have been demonstrated.
3.  The possibility of using the absorption of radiation in the millimeter range for the study of solvation in solutions has been shown.
  相似文献   

11.
1.  Potentiometric titration in nitromethane at 25°C has been used to determine dissociation constants for 16 mono-substituted benzoic acids.
2.  Brönsted and Hammett equations have been set up for the compound series under study here.
3.  The data of the literature have been used to evaluate the nitromethane autoprotolysis constant, pKS24.
4.  The relative differentiating action of nitromethane with respect to other solvents has been evaluated from the slopes of the Brönsted and Hammett plots and the values of the autoprotolysis constant. The differentiating action of nitromethane with respect to acids is greater than that of acids with respect to alcohols and acetone, but less than that of DMSO, acetonitrile, and DMF.
5.  Study has been made of the dissociation of the aminobenzoic acids in nitromethane. Solutions of p-aminobenzoic acid are free of zwitterions, while solutions of the m-aminobenzoic acid contain these ions to the extent of 50%.
  相似文献   

12.
1.  A procedure has been developed for carrying out the reaction between ozone and paraffins directly in an EPR resonator.
2.  EPR signals of the products of the reaction between ozone and paraffins in the liquid phase have been obtained.
  相似文献   

13.
1.  A new method of analysis of autocatalytic reactions was developed which permits determining the rate constants of noncatalytic and catalytic reaction pathways with the data from one kinetic curve.
2.  The reverse reaction of acylation has an autocatalytic character.
3.  In comparison to CHCl3, in CH3CN, all of the rate constants increase by 2–4 times, and the noncatalytic reaction pathways are more sensitive to the nature of the solvent.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1978–1984, September, 1988.  相似文献   

14.
1.  The previously unknown aminooxyalkylcelluloses have been synthesized by alkylation of cellulose with N-substituted -haloalkylhydroxylamines.
2.  The prepared aminooxyalkylcelluloses are weak ion-exchangers, readily react with many classes of organic compounds, and are stable during storage.
3.  Methods have been developed for the preparation of aminooxyalkylcelluloses with different lengths of the pendant H2NO group on the polysaccharide framework.
4.  Sorbents were prepared, based on the aminooxyalkylcelluloses, which contained a covalently bonded coenzyme (pyridoxal-5-phosphate), a substrate (-ketoglutaric acid) and functional groups, able to react with certain functional groups of biopolymers.
  相似文献   

15.
1.  The reaction of bis (-allyl)dipalladium dichloride with diethylcadmium, bis(triethylgermyl)cadinium, and bis (triethylgermyl)mercury was studied. The reaction proceeds with the initial formation of the 11 adduct and subsequent exchange reaction.
2.  The decomposition of the intermediate [AllPdR] compounds depends on the nature of the E group. When R=Et the decomposition proceeds via the intermediate formation of the -olefin complex and the subsequent liberation of ethylene. When R=Et3Ge the decomposition includes the disproportionation reaction and the radical decomposition of the disproportionation products.
  相似文献   

16.
1.  Polarizability parameters have been determined for the selenocyanate group.
2.  Selenobenzene cyanate, and derivatives of this compound with donor substituants in the p position, have planar conformations; introduction of acceptor substituents breaks down the coplanarity of the C6H4-SeCN fragment.
  相似文献   

17.
1.  The possibility of polymerizing 1,2-dimethylenecyclobutane with organolithium initiators has been demonstrated. The microstructure of the polymers obtained is determined by the nature of the solvent; in a hydrocarbon medium the 1,4-structural unit is mainly. formed, while in a polar solvent the 1,2-structural unit predominates.
2.  The anionic copolymerization constants of 1,2-dimethylenecyclobutane with butadiene in hydrocarbon and polar media have been determined.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1993–1995, September, 1988.  相似文献   

18.
1.  Depending on the nature of the substituent in the 2 position, l-fluoro-l-(-hydrohexafluoroisopropyl)ethylenes are dehydrofluorinated to either allenes or 1,3-dienes.
2.  It was shown that allylic substitution is possible in the reactions of perfluoroisobutylene with carbanions; the mutual transformations of the allyl and vinyl isomers were studied.
3.  The perfluoroalkenylation product was obtained when perfluoroisobutylene is reacted with ketene acetal.
  相似文献   

19.
1.  By14C labeling, it has been shown that carbon dioxide will adsorb differently on various synthetic Ca2+-ion-containing zeolites (CaNaY, and dealuminated CaNaY and CaNdNaY) on which benzene is being alkylated by ethylene. The promoting action of CO2 is due to the presence of a weakly adsorbed form of the compound which can be readily displaced by N2 at the reaction temperature.
2.  The CO2 content of the catalyst and its time variation are dependent on the zeolite composition, the re-action temperature, and the moisture content of the CO2.
3.  Under fixed operating conditions, the CO2 content of zeolite 0.67CaNaY and its time variation are the same for C6H6 alkylation by ethylene and for toluene disproportionation.
  相似文献   

20.
1.  The activity of cobalt-group II metal oxide catalysts in the hydropolymerization reactions of C2-C4 olefins, initiated by CO at 190°, depends on the nature of the oxide and decreases when going from BeO to BaO.
2.  In their reactivity the olefins fall into the order: C2 > C3H6 >-C4H8 > i-C4H8.
3.  The degree of reduction of the cobalt found in the catalyst depends on the nature of the employed oxide and (toes not determine its activity.
  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号