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1.
L. G. Vorontsova V. M. Shitkin O. S. Chizhov I. M. Petrova I. E. Chlenov V. A. Tartakovskii 《Russian Chemical Bulletin》1976,25(4):790-794
| 1. | We have determined the confirmations and accurate geometrical parameters for the two isomers of 8-p-bromophenyl-6-cyano-2,9-dioxa-1-azabicyclo[4.3.0]nonane. |
| 2. | Replacement of the nitro group by the cyano group proceeds mainly with inversion of configuration at the center of substitution. |
2.
I. E. Chlenov I. M. Petrova V. M. Shitkin V. A. Tartakovskii 《Russian Chemical Bulletin》1976,25(6):1347-1350
| 1. | The reaction of 6-nitro-2,9-dioxa-1-azabicyclo[4.3.0]nonane derivatives with alcohols and alcoholates leads to remplacement of the nitro group by the corresponding alkoxy group. |
| 2. | The reaction proceeds with either a complete (for the case of the alcoholates) or predominant (for the case of alcohols) inversion of the configuration at the substitution center. |
| 3. | The reaction proceeds via the intermediately formed bicyclic immonium cation. |
3.
V. A. Ermolaeva G. A. Marchenko V. I. Markovskii V. I. Slovetskii S. S. Novikov 《Russian Chemical Bulletin》1976,25(12):2495-2498
| 1. | Study has been made of the IR spectra of N--polynitroalkylhydrazine derivatives, band assignments being made for stretching vibrations in the NH, C=O, and NO2 groups. |
| 2. | Integral intensities for NO2 antisymmetrical stretching absorption bands are additive. Splitting of these bands is characteristic of nitro compounds containing a hydrazine radical in the -position with respect to the nitro group. |
| 3. | It has been shown that intermolecular hydrogen bonding exists in the N--polynitro-alkylhydrazines, in the crystalline state and in concentrated solution. |
4.
I. V. Anonimova N. A. Chadaeva L. K. Yuldasheva S. G. Vul'fson A. N. Vereshchagin B. A. Arbuzov 《Russian Chemical Bulletin》1976,25(12):2519-2524
| 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. |
5.
| 1. | The authors suggest a model to explain the axial symmetry of the hole center V– in magnesium oxide. |
| 2. | Using the model they consider the possible alternatives for localization of the hydroxyl groups of the hole center. |
| 3. | In analytic form, they express the values of the g factors for the V– center in terms of the parameters of the method of molecular orbits. The experimental values of the g factors can be explained if we assume localization of one or two hydroxyl groups in the first or second layer from the O– radical ion in the MgO lattice. |
6.
| 1. | The relation of the adsorption values of standard benzene vapor at 293 K to the parameters of the Dubinin-Stokley adsorption equation was considered for the case of model microporous carbon adsorbents. |
| 2. | Active carbons with low characteristic standard-vapor adsorption energies and a wide micropore-volume size distribution are characterized by higher filling of the micropore volume at low equilibrium pressures in comparison with active carbons with homogeneous microporous structure. |
| 3. | Fillings were calculated for micropores under various adsorption conditions for estimation of the adsorption properties of active carbons and selection of adsorbents with parameters most suitable for practical use. |
7.
M. M. Dubinin O. Kadlets L. I. Kataeva B. A. Onusaitis 《Russian Chemical Bulletin》1988,37(5):849-854
| 1. | The adsorption properties with respect to benzene vapors and the pore structure of carbon adsorbents with almost maximum development of the microporosity were studied. |
| 2. | The position of the micropore volume distribution curves whose maxima correspond to a size (halfwidth) of 1.2–1.4 nm and micropore volumes 1.5 cm3/g is a characteristic feature of the adsorbents studied. The difference between ordinary active carbons and the active carbons investigated is only quantitative in the values of the parameters of the Dubinin-Stockley adsorption equation. |
| 3. | The adsorption isotherms are described by the adsorption equation from the theory of volume filling of micropores in a wide range of equilibrium relative pressures and temperatures of 293–353 K with totally satisfactory precision. |
| 4. | The question of the upper limit of the micropores of carbon adsorbents is discussed. |
8.
| 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%. |
9.
| 1. | A study was made of the irreversible heat inactivation of free trypsin, and of trypsin in the complex with poly-4(5)-vinylimidazole, in aqueous solution, at pH 6.1, in the temperature range 33–50°. |
| 2. | The inactivation rate of trypsin decreases in the presence of the polymer, and its activation enthalpy increases when compared with the values of these parameters for free trypsin. |
10.
| 1. | The observed change, with change in temperature, in the components of the tensor of the hyperfine interaction and in the relative intensity of the corresponding ESR lines is due to the anisotropic vibrational motion. |
| 2. | The observed anisotropy of the motion makes it possible to relate the values of the magnetic parameters to the molecular axes of the complex in nonoriented systems. |
11.
B. A. Arbuzov S. G. Vul'fson G. G. Butenko O. A. Samarina A. B. Teitel'baum A. N. Vereshchagin 《Russian Chemical Bulletin》1976,25(1):75-81
| 1. | The ellipsoids of polarizability of dimethylsulfone, sulfuryl chloride, and methanesulfonyl chloride were determined, and the nonadditivity of the parameters of the bonds in the sulfonyl chloride group was demonstrated. |
| 2. | Substituted methane sulfonyl chloride exist in gauche conformations. |
| 3. | In benzenesulfonyl chloride and a series of its para-substituted derivatives, the aryls are situated in the C-S-Cl plane; the para-nitro group induces a 35° rotation. |
12.
| 1. | N-Ethyl and N-isopropyl-3-piperidones were synthesized and the stereochemistry of their reduction was studied. |
| 2. | The dependenceof stereochemistryof a series of reactions at the carbonyl center on bulk of the substituent on nitrogen was established. |
| 3. | Pure a- and e-epimers of N-ethyl- and N-isopropyl-3-piperidols were separated. |
13.
| 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. |
14.
| 1. | The structures and stability constants of outer-sphere adducts of Co(HBpz3)2 with aromatic nitro compounds have been determined. |
| 2. | The process of outer-sphere solvation of Co(HBpz3)2 has been shown to lie outside the framework of a simple donor-acceptor model for adduct formation. |
15.
L. F. Chertanova G. A. Marchenko A. A. Gazikasheva Yu. T. Struchkov V. F. Sopin L. N. Punegova A. S. Mukhametzyanov 《Russian Chemical Bulletin》1989,38(2):250-253
| 1. | The planar alkoxydiazinoxide fragments are shown to have the Z-configuration and be orthogonal to each other by an x-ray structure study of a series of alkoxydiazinoxides. |
| 2. | In the oxydiazinoxide fragments, p- conjugation occurs. |
| 3. | The molecules of the compounds in the crystals studied are joined by hydrogen bonds. |
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. |
17.
B. A. Glazun R. N. Kurnosova M. M. Dubinin I. V. Zhilenkov S. S. Levchenko 《Russian Chemical Bulletin》1976,25(1):8-11
| 1. | In NaA zeolite a homocharge is formed by charges deposited on the surface of the zeolite from the gas gap between the electrode and the specimen. |
| 2. | The existence of thermoelectret effects has been found in the systems NaA-zeolite -air, NaA-helium, NaA-nitrogen, and NaA-oxygen. |
| 3. | The thermoelectret effects are caused by both the accumulation of charges in the specimen and the adsorption of molecules in the electric field. |
| 4. | A low mobility has been noted for adsorbed molecules in the electret state of the system. |
18.
| 1. | The results of calculations of the first ionization potentials of the anions of the dihydrides of 3d metals by the discrete variation X method are in good agreement with the available experimental values. |
| 2. | The electron affinities of the MH2 molecules are close to the first ionization potentials of the corresponding anions on account of the small values of the adiabatic corrections, and vary noniaonotonically on passing along the series of 3d metals. |
| 3. | The electron affinity of the dihydrides of the 3d metals always exceeds the electron affinity of the central atom, but varies in parallel with the latter quantity along the series. |
19.
L. A. Rozov Yu. V. Zeifman N. P. Gambaryan Yu. A. Cheburkov I. L. Knunyants 《Russian Chemical Bulletin》1976,25(12):2560-2566
| 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. |
20.
| 1. | Study has been made of the kinetics of the-elimination of alcohol from 3-carbethoxy-4-ethoxy-2-pentanone in benzene and under the catalytic action of acetic acid. |
| 2. | This reaction involves formation of a complex between substrate and acetic acid. |
| 3. | The equilibrium constant for the reaction of forming the complex between substrate and acetic acid, and the rate constant for complex formation, have both been determined. |