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1.
| 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. |
2.
| 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. |
3.
L. F. Kozhemyakina N. I. Sheverdina I. E. Paleeva V. A. Chernoplekova K. A. Kocheshkov 《Russian Chemical Bulletin》1976,25(2):413-415
| 1. | A number of compounds of the ArSrl class were synthesized in THF solution, and the complexes of these compounds with THF were isolated. |
| 2. | Some of the reactions of these compounds were studied. |
4.
N. V. Zakatova D. R. Minkhadzhidinova M. A. Nadzhafova R. F. D'yachkovskaya N. P. Koaovalova V. A. Sharpatyi 《Russian Chemical Bulletin》1976,25(2):434-436
| 1. | We determined the reactivity of some nitrogen bases, and of a number of amino acids and bis-(diazoacetyl)alkyl derivatives toward the electron at 77°K. |
| 2. | The effect of the pH at 77°K as established on the yield of the deamination process and the reactivity of the studied amino acids toward the electron. |
| 3. | It was found that the yield for the deamination of glutamic acid is increased in the presence of inositol (acceptor of OH radicals). |
5.
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. |
6.
B. A. Arbuzov O. Éxsner A. P. Timosheva V. E. Kataev S. G. Vul'fson A. N. Vereshchagin 《Russian Chemical Bulletin》1976,25(6):1206-1212
| 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. |
7.
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. |
8.
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. |
9.
| 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. |
10.
Presently, a large variety of layered materials are synthesized that are able to intercalate neutral guest molecules or to exchange inorganic and organic ions for interlayer ions. Several of these materials are also found as minerals.The intracrystalline reactivity of a few selected compounds will be described and compared to clay minerals:
相似文献
| – | - intercalation into crystalline silicic acids; |
| – | - reactions of phosphates, arsenates, and sulfates; |
| – | - reactions of titanates, niobates, and molybdates with long chain alkylammonium ions, and |
| – | - anion exchange properties of double hydroxides. |
11.
V. M. Belikov Yu. N. Belokon' V. A. Karginov N. S. Martinkova M. B. Saporovskaya 《Russian Chemical Bulletin》1976,25(6):1233-1238
| 1. | The formation of protonated and free Schiff's bases from S-alanine and salicylaldehyde was studied quantitatively by the PMR method in the interval of pD 9.0–12.0. |
| 2. | The rate constants of the racemization of S-alanine and its Schiffs base with salicylaldehyde protonated at the nitrogen were determined, and they were compared with the analogous constants for N-salicyl-idene-S-alaninate complexes of Cr(III), Rh(III), and Co(III) and the Schiffs base from pyridoxal and S-alanine. |
| 3. | The basic role of the metal in the model reactions consists of increasing the concentration of reactive particles in solution as a result of coordination of the Schiffs base with the metal ion. |
12.
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. |
13.
M. A. Dzyubina G. N. Kuz'mina B. I. Kolobkov A. I. Nekhaev 《Russian Chemical Bulletin》1988,37(10):2057-2062
| 1. | The activation energy for the thermal decomposition of complexes with Fe2(CO)6S2 frameworks amounts to 103–144 kJ/mole. |
| 2. | Decarbonylation and splitting off of the hydrocarbon part of the molecule is the general pattern of behavior of iron carbonyl compounds with sulfur ligands on heating and under electron bombardment. |
| 3. | In complexes containing a norbornadiene fragment, a reverse Diels-Alder reaction takes place under electron bombardment, in addition to splitting off of norbornadiene. |
14.
R. G. Kostyanovskii V. P. Leshchinskaya R. K. Alekperov G. K. Kadorkina L. L. Shustova Yu. I. Él'natanov G. L. Gromova A. É. Aliev I. I. Chervin 《Russian Chemical Bulletin》1988,37(11):2315-2323
| 1. | An efficient method of aziridine dimer synthesis is presented involving reaction of aziridine with esters of strong organic acids followed by alkaline hydrolysis of the resultant N-acyl derivatives. |
| 2. | New N-acyl and carbamoyl derivatives of aziridine dimer and trimer were synthesized. |
| 3. | Linear and branched isomers of aziridine tetramer and also diastereomers of 2-methylaziridine dimer were isolated and characterized. |
| 4. | An efficient regiospecific synthesis of 2,2-dimethylaziridine dimer and trimer was developed. |
15.
Yu. V. Kuznetsov L. G. Stolyarova V. P. Lezina L. D. Smirnov 《Russian Chemical Bulletin》1989,38(7):1494-1500
| 1. | New halogen derivatives of 1-ethyl-2-methyl-, 2-methyl- and 5-hydroxybenzimidazole were obtained. |
| 2. | A method for the chlorination of aromatic compounds by an alcoholic solution of hydrogen chloride in the presence of hydrogen peroxide was proposed, which enables carrying out the reaction with a high yield. |
| 3. | The reactivity of the series of 5(6)-hydroxybenzimidazole derivatives during the electrophilic substitution (halogenation) was shown to be as follows: 1-ethyl-2-methyl-5-hydroxybenzimidazole >5(6)-hydroxybenzimidazole 2-methyl-5-hydroxybenzimidazole. |
16.
| 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. |
17.
B. K. Nefedov N. S. Sergeeva T. V. Zueva E. M. Shutkina Ya. T. Eidus 《Russian Chemical Bulletin》1976,25(3):565-569
| 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. |
18.
A. I. Kokorin L. S. Bogach A. B. Shapiro É. G. Rozantsev 《Russian Chemical Bulletin》1976,25(9):1874-1878
| 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. |
19.
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. |
20.
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. |