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1.
N. K. Tatarskaya M. A. Zhurav S. M. Smirnov I. A. Degterev V. F. Tarasov Yu. E. Borisevich G. E. Zaikov 《Russian Chemical Bulletin》1989,38(4):722-726
| 1. | The decomposition of khinifur in aqueous solutions proceeds according to two parallel paths: direct photodecomposition from the first singlet activated state (monomolecular path) and reaction of the molecule in the triplet state with a molecule in the initial state (bimolecular path). |
| 2. | The first path does not depend on the pressure of oxygen in the solution, while the second path is inhibited by oxygen. |
2.
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. |
3.
| 1. | The dependence of the rate of decomposition in aqueous solutions of dialkyl substituted nitrosoureas based on monoquaternary alkylammonium salts on pH conforms to the ElcB mechanism of decomposition. |
| 2. | A new compound of the chloroethylnitrosourea class has been discovered. Its rate of decomposition in neutral and weakly alkaline media is independent of pH. |
4.
P. P. Levin V. A. Kuz'min R. M. Fatkulbayanov M. F. Budyka M. V. Alfimov 《Russian Chemical Bulletin》1989,38(2):225-231
| 1. | Molecules of acridine and chloroacridine in the triplet state form triplet exciplexes of the radical ion pair type with tertiary aromatic amines. Proton transfer from the radical cation to the radical anion with formation of neutral radicals is the basic pathway of quenching of these exciplexes in a nonsolvating medium. In the presence of an alcohol, the triplet exciplexes disappear due to protonation of the radical anion in the exciplex. |
| 2. | Quenching of triplet states of acridine and chloroacridine by secondary aromatic amines take place by transfer of an H atom from the amine regardless of the nature of the solvent. |
| 3. | The singlet excited state is the most probable reactive state of 9-chloroacridine in photoreduction and photosubstitution reactions with aromatic amines. |
5.
G. Grossman G. Komber G. Kroshvitts P. A. Kirpichnikov N. A. Mukmeneva D. G. Pobedimskii 《Russian Chemical Bulletin》1989,38(1):26-32
| 1. | Dithiophosphoric acids are either not catalysts or only act as moderate catalysts as a function of the structure in reactions of decomposition of CHP. |
| 2. | The real catalyst of decomposition of CHP in the presence of dithiophosphoric acids is the sulfuric acid formed during the oxidation of the dithiophosphoric acids, or the combination of the sulfuric acid with phosphours-containing acids. |
| 3. | Slow and fast stages of kinetic decomposition of CHP were detected, and the kinetic parameters of the fast stage were determined. |
6.
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. |
7.
| 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. |
8.
G. A. Artamkina A. Yu. Mil'chenko I. P. Beletskaya O. A. Reutov 《Russian Chemical Bulletin》1988,37(12):2550-2556
| 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. |
9.
| 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%. |
10.
K. L. Rogozhin A. N. Rodionov S. G. Smirnov D. N. Shigorin O. P. Syutkina V. I. Lodochnikova K. A. Kocheshkov 《Russian Chemical Bulletin》1976,25(2):319-322
| 1. | There is a regular increase in the energy of the lowest singlet and triplet excited levels in the aromatic derivatives of the elements C, Si, Ge, Sn and N, P, As, Sb, Bi, which is consistent with the quantum-mechanical model of the mixing of the electronic states of the aromatic system with states involving p and s orbitals of the heteroatom with different energies and symmetries. |
| 2. | The yields of the radiative electronic transitions regularly decrease, and the probabilities of nonradiative intramolecular electronic transitions increase. |
| 3. | The temperature effects inthe 300–77°K range in the electronic absorption spectra have been found and are associated with a postulated change in the spatial configuration of the compounds investigated. |
11.
Zh. A. Krasnaya T. S. Stytsenko V. I. Avdeeva D. Ya. Shagalova 《Russian Chemical Bulletin》1989,38(1):80-86
| 1. | A series of tetracyanopolymethines has been synthesized by condensation of aminals and aminal-acetals of conjugated -dimethylaminoaldehydes with malonodinitrile. |
| 2. | These tetracyanopolymethines can be used as the anionic components in cation-anion cyanine dyes. |
| 3. | The electronic absorption spectra of these newly synthesized dyes were studied in both polar and nonpolar solvents. Specific cation-anion interaction and complex formation has been shown to occur in several of these cation-anion dyes in nonpolar solvents. |
12.
| 1. | It has been shown that bifunctional agents have high activity in catalyzing -elimination reactions; study has been made of the effect of the concentration of such agents on the specific rate of -elimination from methyl-substituted ethoxy--ketoesters. |
| 2. | Study has been made of the state of 2- and 3-oxypyridines in benzene solution at 80°C. A value has been obtained for the 2-oxypyridine dimerization constant. |
| 3. | A mechanism has been proposed for the action of 2-oxypyridine in catalyzing -elimination reactions, and equilibrium constants and rate constants calculated for the various mechanism steps. The factors responsible for the low catalytic activity of 8-oxyquinoline are discussed. |
13.
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. |
14.
A. K. Mal'tsev N. D. Kagramanov I. O. Bragilevskii N. G. Komalenkova S. A. Bashkirova D. A. Zagorets M. Ya. Kel'man E. A. Chernyshev O. M. Nefedov 《Russian Chemical Bulletin》1989,38(5):950-956
| 1. | Differences have been shown in the mass spectra of isomeric 1,1-difluoro- and 1,1-dichloro-1-silacyclopentenes, and also 1,1-dichloro-, 1,1-dihydro-, and 1,1-dideuterio-1-silacyclohexadienes, differences that make it possible to identify the isomers. |
| 2. | Mass spectrometry has been used to identify the intermediates formed in the vacuum pyrolysis of these silicon-containing cyclic compounds, and it has been established that all of the dihalo derivatives dissociate selectively, splitting off the corresponding dihalosilylene. |
| 3. | In the thermal dissociation of sila-2,5-cyclohexadiene, hydrogen splits off selectively from the silicon atom and one of the carbon atoms, forming silabenzene — a molecule with a multiple carbon-silicon bond. The mass spectrum of silabenzene has been obtained for the first time. |
15.
B. E. Ivanov L. A. Valitova V. I. Gaidai T. G. Bykova N. I. Kuchma S. V. Samurina 《Russian Chemical Bulletin》1976,25(11):2386-2389
| 1. | An intermediate alkoxyphosphorane with two pentacoordinated phosphorus atoms was isolated and characterized during the reaction of 2,5-bis(diethylaminomethyl)hydroquinone with trialkyl phosphites. |
| 2. | A method has been developed for the synthesis of phosphorylated dihydric phenols. |
| 3. | The triethylether of 3-ethoxy-6-hydroxy-1,4-xylyenediphosphonic acid was prepared by the interaction of 2,5-bis(diethylaminomethyl)hydroquinone with diethylphosphorous acid in the presence of triethyl phosphite. |
16.
B. L. Korsunskii G. V. Sitonina B. S. Fedorov F. I. Dubovitskii L. T. Eremenko 《Russian Chemical Bulletin》1989,38(4):710-713
| 1. | The thermal decomposition of N,N-dinitroamines is homogeneous and unimolecular in the gas phase. The limiting step of the process is the rupture of the N-NO2 bond. |
| 2. | The activation parameters of the process imply that the dinitroamine group is more reactive than the mononitroamine group in thermal decomposition. The energy of dissociation of the N-NO2 bond in dinitroamines is 42 kJ/mole less than in mononitroamines. |
| 3. | Nitrogen dioxide and acetaldehyde do not influence the kinetics of thermal decomposition of dinitroamines due to their high reactivity. |
17.
A. M. Moiseenkov V. A. Dragan A. V. Lozanova V. V. Veselovskii 《Russian Chemical Bulletin》1988,37(8):1603-1609
| 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. |
18.
| 1. | The kinetics of the Cannizzaro reaction of benzaldehyde in aqueous KOH solution have been studied spectrophotometrically, working at 25°C and at concentrations ranging from 19.1 to 37.9%. |
| 2. | Reaction proceeds through the formation of an activated complex consisting of the doubly ionized and the un-ionized forms of benzaldehyde and the hydroxide cation. |
| 3. | The spectrophotometric data and the kinetic data have been combined to give an estimate of the benzaldehyde ionization constant in aqueous KOH solution at 25°C. |
| 4. | Analysis of the kinetic data for benzaldehyde reduction by formaldehyde has shown the activated complex for this reaction to be composed of an un-ionized benzaldehyde molecule and a doubly ionized formaldehyde molecule, with or without participation of the hydroxide cation. |
19.
Lagerge S. Kamyshny A. Magdassi S. Partyka S. 《Journal of Thermal Analysis and Calorimetry》2003,71(1):291-310
A new batch titration microcalorimeter has been used for estimation of thermodynamic properties in various investigated colloidal systems. As examples, we present enthalpic and kinetic data obtained from this calorimetric device for four different processes widely encountered in colloid science:
This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
| (i) | The dilution/micellization process of cationic gemini surfactants in aqueous solution. |
| (ii) | The hydration process of non ionic surfactants in organic solution, i.e. the mechanism of micellar solubilization of water in the aggregates. |
| (iii) | The complexation of calcium ions by polyacrylates sodium salts (PaNa). |
| (iv) | The adsorption phenomenon of PaNa molecules on the calcium carbonate surface. |
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. |