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 46 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.  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   

3.
1.  The catalytic activity of new complexes of Pt (II)-Sn (II) with dimethylacetamide and DMF in isomerization and hydrogenation reactions of compounds containing a C=C bond is greater than the activity of the Pt-SnCl3 complex by a factor of 4–5.
2.  All the examined complexes catalyzed the selective hydrogenation of phenylacetylene to styrene, and diphenylacetylene to diphenylethane passing through the stilbene stage.
  相似文献   

4.
1.  It has been shown by PMR spectroscopy that in a solution of RYbI there exists an equilibrium similar to that established by Schenk for Grignard reagents.
2.  The compound formed by the action of an equimolar mixture of PhI and LiI on Yb metal in THF differs in reactivity from PhYbI in its reaction with CF2=CF2.
3.  The reaction of PhSmI with 1,2,2-trifluorostyrene differs from the reactions of PhEuI and PhYbI in that it gives an equimolar mixture of the cis and trans isomers of 5,6-difluoro-4,6-diphenyl-5-hexene-1-ol.
4.  PHCeI does not react with 1,2,2-trifluorostyrene. However, the organocerium complex formed by the oxidatlve addition of Ce to PhI in the presence of an equivalent quantity of LiI reacts with 1,2,2-trifluorostyrene to form an equimolar mixture of the cis and trans isomers of 5.6-difluoro-4,6-diphenyl-5-hexene-1-ol.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khicheskaya, No. 2, pp. 445–450, February, 1988.  相似文献   

5.
1.  The dipole moments of the two kinds of C-O bonds in acetals and their analogs are not identical.
2.  In formal molecules and the dimethylketal of acetone the C-O-C-O -C chains have gauche-gauche conformation, with the methyl groups lying on different sides of the O-C-O plane.
3.  The dimethylketal of tetrachlorocyclopentadienone is represented by a mixture of trans-gauche and gauche-gauche conformers.
  相似文献   

6.
1.  Nitroxyl biradicals of the triazine, N,N-bis(triazinyl)ethylenediamine, N,N-bis(triazinyl)piperazine, and s-nitropyrimidine series have been prepared.
2.  The ESR spectra of liquid and frozen solutions of these biradicals have been obtained and N. - O group separations calculated.
3.  Toluene solutions of (II), (V), (VI), and (X) biradicals contain at least four different conformations, each with its own value of the exchange integral.
4.  In one of the biradical (V) conformations, spin interaction exchange is through the chain of atoms linking the N.-O fragments.
  相似文献   

7.
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   

8.
1.  3,6-Di-tert-butyl-o-quinone (I) forms both hydrogen-bonded and donor-acceptor complexes with 3,6-di-tert-butylpyrocatechol (II) and 3,5-di-tert-butylpyrocatechol (III) in CCl4, and n-hexane solutions. The concentrations of these two types of complexes are approximately equal.
2.  Photoreduction of quinone (I) at 77 K occurs in both the H-bonded and donor-acceptor complexes.
3.  A new mechanism has been proposed to account for radical formation and stabilization in mixed complexes with both H-bonding and donor-acceptor interactions.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2756–2760, December, 1988.  相似文献   

9.
1.  Methanol, containing 10–20 mole % of CH3I, is carbonylated to methyl acetate in the presence of impregnated Eh-zeolite NaX catalyst at 230–250° and atmospheric pressure.
2.  The specific (per gram of Rh) rate of methyl acetate formation is antibatic to the Rh content in the catalyst, it increases with increase in the methanol contact time, and shows little change in the range 230–250°.
3.  The rate of forming the sole secondary product, namely dimethyl ether, decreases with increase in the amount of Rh and the methanol contact time.
4.  CH2I is an astoichiometric component of the reaction.
  相似文献   

10.
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   

11.
1.  Protonated, neutral (mixed), and binuclear Cu(II), Ni(II), Co(II), Zn(II), and Mn(II) iminodisuccinate complexes have been synthesized.
2.  Based on the results of IR-spectroscopic, thermal, and other methods of analysis, various conclusions have been drawn concerning the structures of these complexes; for instance, in the case of complexes of composition H2ML·nH2O both carboxyl groups are protonated, and one of them is coordinated to the metal ion.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1468–1472, July, 1988.  相似文献   

12.
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   

13.
1.  Dimethyl, diphenyl, and tetramethylene sulfoxide hydrochlorides react with methylheptenyl, citronellyl, and geranyl acetates to give predominantly the allylic chlorination products.
2.  These findings are preferably to be regarded as involving AdE reactions between the weakly electrophlic hydroxy and (or) chlorosulfonium cation and the trisubstituted C=C bond in these olefins at the key stage.
3.  The addition of lithium perchlorate has been found to accelerate this reaction.
4.  Sulfoxide hydrobromides are highly selective brominating agents for the terminal grouping in isopropenoid oligoolefins.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1797–1803, August, 1988.  相似文献   

14.
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   

15.
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   

16.
1.  New cationic o-tolyl and o-fluorophenyl complexes of Ni containing Ph3P, MeCN, or THF ligands have been synthesized.
2.  Reaction of these compounds with potassium carboxylates gave the novel o-tolyl and o-fluorophenylbis(triphenylphosphinyl)nickel carboxylates.
3.  According to19F NMR data o-tolylbis(triphenylphosphinyl)nickel p-fluorobetizoate contained a highly polarized Ni-O bond.
Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 166–170, January, 1988.  相似文献   

17.
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   

18.
1.  The authors have studied the formation of electron and hole paramagnetic centers in gamma-irradiated magnesium hydroxide and oxide with various degrees of dehydration.
2.  Rise in the temperature of preliminary heat treatment of the magnesium oxide causes an increase in the radiation-chemical yield of FS + centers and a decrease in that of V su centers.
3.  The thermal stability of paramagnetic centers in magnesium oxide increases as the hydroxyl group content decreases.
  相似文献   

19.
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   

20.
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   

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