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1.
S. P. Kolesnikov A. I. Ioffe B. L. Perl'mutter O. M. Nefedov 《Russian Chemical Bulletin》1976,25(4):736-739
| 1. | We have used the extended Hückel method to examine the interaction of singlet methylene with water and found the existence of a molecular complex CH2·H2O with an energy of stabilization of 5.6 kcal/mole and a complex CH2·2H2O with an energy of stabilization of 2.1 kcal/mole, which tends to lose one water molecule during simultaneous approach of the other. |
| 2. | The structure of these complexes is determined by the interaction of the unoccupied methylene p orbital with the lone-pair orbitals of the water molecules. |
2.
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. |
3.
A. A. Fomkin N. I. Regent V. Yu. Gusev S. G. Tkachenko V. A. Eroshenko V. V. Serpinskii 《Russian Chemical Bulletin》1989,38(6):1268-1270
| 1. | The absolute differential calorimetric heats of adsorption were measured for Xe and Kr on NaX zeolite at 304.5 K and pressures up to 10 MPa. |
| 2. | Good agreement was found between the measured heats of adsorption and the calculated isosteric heats within experimental error. |
4.
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. |
5.
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. |
6.
T. M. Guliev A. A. Isirikyan D. I. Mirzai V. V. Serpinskii 《Russian Chemical Bulletin》1988,37(12):2576-2578
| 1. | Stilbite and heulandite begin to undergo sintering upon heating in vacuum at 200 ± 5°C and undergo about 80% dehydration. |
| 2. | The rehydration energy (heat of immersion in water) of stilbite and heulandite reach maximal values of 350 ± 15 and 215 ± 15 J/g after pumping at 230 ± 20 and 200 ± 20°C, respectively. Maximum half-width values are reached at 250 and 300°C, respectively. |
| 3. | The maximal integral mean-molar heats of adsorption of water vapor on stilbite and heulandite after pumping at 230 and 200°C, respectively, are 76 ± 3 and 69 ± 3 kJ/mole. |
7.
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. |
8.
| 1. | The existence of synergism is demonstrated; the activity of Pd-Tc/carrier catalysts in the dehydrogenation of hydrocarbons considerably exceeds that of monometallic catalysts. The most active catalysts are those with PdTc ratios from 11 to 23. |
| 2. | In terms of reactivity on Pd-Tc catalysts, the hydrocarbons are arranged as follows: cyclohexene > cyclohexane > methylcyclohexane > ethylcyclohexane > n-hexane. |
| 3. | Activity in the dehydrogenation of cyclohexane varies as follows: Pd-Tc/-Al2O3 > Pd-Tc/MgO > Pd-Tc/TiO2 > Pd-Tc/Y2O3 > Pd-Tc/SiO2. |
| 4. | A decrease in CO chemisorptive capacity on bimetallic catalysts compared to monometallic catalysts is established. |
9.
A. M. Voloshchuk M. M. Dubinin T. A. Moskovskaya A. O. Larionova L. A. Shilkova 《Russian Chemical Bulletin》1988,37(10):1979-1983
| 1. | The adsorption isotherms of N2 at 77 K on the surface of carbonaceous adsorbents in the region of low relative pressures are satisfactorily described by the Dubinin-Radushkevich (DR) equation. However, the a0 parameter of the DR equation is not related to the monolayer capacity, and for samples with the most homogeneous surface the quantity a0 substantially exceeds the BET monolayer capacity. |
| 2. | The adsorption isotherms calculated per unit surface area of adsorbent can be grouped in terms of the E0 value of the DR equation; this can be regarded as a measure of the degree of energetic heterogeneity of the samples. |
| 3. | For samples with E0 < 15.5="" kj/mole,="" the="" specific="" surface="" areas="" calculated="" by="" the="" bet="" method="" and="" by="" the=""> and methods are similar. |
| 4. | The samples of carbonaceous adsorbents with E0 > 15.5 kJ/mole are characterized by surface heterogeneity associated with the presence of micropores. |
10.
| 1. | Using seven independent methods it was found that the concentration of the active centers on the surface of-Al2O3, which are responsible for the dehydration, is (9±1)×1017 centers/m2. The catalytically active centers are identical with adsorption centers. |
| 2. | A method of calculating the stochiometry, concentration, and thermodynamics of the surface association reactions has been developed. |
| 3. | The first reaction step proceeds according to the associative bimolecular substitution mechanism, with the formation of an associative intermediate compound. The association enthalpy and entropy have been calculated. |
11.
| 1. | From MNDO quantum chemical calculations, opening of the episulfonium ion ring by neutral nucleophiles X (X=NH3 and HCN) and related SN2 reactions of protonated methylthiol (PMT) with X proceed through formation of pre-reaction complexes in which X is coordinated either at the reacting C atom or (only in opening of episulfonium ion rings) at the center of the C-C bond. |
| 2. | In their electronic structure, the transition states for the reactions are reminiscent of a carbocation simultaneously reacting with the attacking and the leaving nucleophilic fragments (X S). |
| 3. | Opening of episulfonium ion rings proceeds slightly more easily (Ea 10–12 kcal/mole) than substitution in PMT (Ea 22–25 kcal/mole). The ease of ring opening for episulfonium ions is due to the large exothermicity of the reaction and the lower internal activation barrier compared with SN2 reactions in PMT. |
12.
| 1. | An increase in the SiO2/Al2O3 ratio (x) in type Y zeolites through dealuminization with ethylenediaminetetraacetic acid leads to an increase in their catalytic activity during the alkylation of benzene with ethylene. |
| 2. | The properties of CaNaY zeolites of the same composition prepared from NaY obtained by hydrothermal synthesis and by dealuminization of samples with a small value of x are identical. |
| 3. | Carbon dioxide exerts an accelerating effect on the Ca forms of dealuminized type Y zeolites of various compositions and has no effect on the properties of NaY'. |
13.
Yu. M. Kiselev N. E. Fadeeva M. V. Korobov V. I. Spitsyn 《Russian Chemical Bulletin》1989,38(5):913-920
| 1. | The heats of the reactions of xenon difluoride with fluoro complexes of RE(III) have been determined experimentally by the methods of DTA and mass spectrometry. The values of ArH for the thermolysis of MI 3MIVF7 to MI 3MIIIFI 6 and F2have been found. |
| 2. | The values of the enthalpy changes according the transition of KHF2, the melting of KHF2, and the melting of XeF2 have been refined and found to be equal to 41.4±1.25, 26.7±2.60, and 19.0 ± 2.0 kJ/mole, respectively. |
| 3. | The series of the thermodynamic stability of the fluoro complexes of RE(IV) toward the elimination of a fluoride ion has been established. |
14.
| 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. |
15.
A. I. Nesmelov A. V. Orlinkov V. B. Murachev I. S. Akhrem V. S. Byrikhin M. E. Vol'pin 《Russian Chemical Bulletin》1988,37(10):2006-2011
| 1. | The complexes AcBr·AlBr3 and AcBr·2AlBr3 initiate cationic polymerization of isobutylene in hydrocarbon medium at –78°C and the complex AcBr·2AlBr3 is more active. |
| 2. | Initiation of polymerization under the effect of the AcBr·2AlBr3 complex in hexane at –78°C takes place exclusively with Ac+ and the initiating capacity of the AcBr·AlBr3 complex is due to generation of a proton in the reaction of this complex with the monomer. |
| 3. | Under the effect of AcBr·AlBr3 and AcBr·2AlBr3 complexes, chain breaking takes place with the formation of the same C-Br and C=C terminal groups with similar ratios equal to 21. |
16.
K. M. Gitis V. N. Kornyshev E. S. Shpiro A. A. Grigoryan G. V. Isagulyants Kh. M. Minachev D. P. Shashkin 《Russian Chemical Bulletin》1989,38(7):1349-1354
| 1. | Selective hydrogenation of piperylene into n-amylenes (300C) on applied nickel sulfide was studied in the pulsed mode. It was found that NiS/SiO2 is more selective than NiS/Al2O3. |
| 2. | Treatment of applied NiS with air at 300–500C oxidizes a significant portion of NiS into NiSO4, which gives the catalyst hydroisomerizing properties and permits obtaining up to 44% isoamylenes from piperylene. In contrast to oxidized NiS/SiO2, oxidized NiS/Al2O3 retains hydroisomerizing activity for a much longer time, which is due to the higher resistance of NiSO4 to reduction on Al2O3 than on SiO2. |
| 3. | The data obtained indicate that reduced nickel atoms are the active sites of selective hydrogenation, while sulfur, sulfide or sulfate, is the surface modifier. |
17.
Yu. N. Belokon' V. M. Belikov V. A. Karginov V. I. Tararov 《Russian Chemical Bulletin》1976,25(11):2390-2395
| 1. | Three complexes of sodium bis[N-3-substituted-salicylidene-S-valinato]cobaltate(III) were synthesized where the salicylaldehyde residue was substituted in position 3 with the NO2, i-C3H7, and t-C4H9 groups. The (SS)- and (SS)-diastereomers of the complexes were separated and their structure and configuration were demonstrated by elemental analysis and physical methods. |
| 2. | The stereoselective effects in these compounds were studied and it was shown that by varying the bulk and electronic effects of groups in the salicylaldehyde ring (from 5-NO2 to 3-t-C4H9) the relative energy of diastereomers can be changed in the interval of 2.6 kcal/mole. |
| 3. | Stereoselective effects were studied in the complexes potassium - and -bis[N-salicyliden-S-alaninato ]cobaltate(III) and potassium - and -bis[N-salicylidene-S-valinato]cobaltate(III) in various solvents and it was shown that the solvent has at least no less an effect on the energy difference of diastereomers than do the substituants introduced into the complex molecule. |
| 4. | The energy difference of diastereomers in a series of alcohols correlates with the dielectric constant of the solvent, which indicates the important role of electrostatic interactions in complexes. |
18.
É. D. Filippova N. D. Mitrofanova L. I. Martynenko V. I. Spitsyn 《Russian Chemical Bulletin》1976,25(1):4-7
| 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. |
19.
| 1. | CF3OOCF3 and CF3OOOCF3 are the principal products from the photochemical fluorination of fluoroform in the presence of oxygen. A possible mechanism for the formation of these products is suggested. |
| 2. | Rate constants have been obtained for the interaction of CF3 radicals with O2 and F2, at room temperature and a total pressure of 100 torr. |
20.
R. B. Akhverdiev I. A. Timakov R. G. Sarmurzina V. I. Yakerson M. I. Rustamov M. K. Guseinova Sh. K. Seitzhanova 《Russian Chemical Bulletin》1989,38(3):455-458
| 1. | Aluminum hydroxide and oxide supports, obtained by interaction with water of aluminum activated by indium or gallium, are multiphasic systems containing in the first case PB, BR, and In, and in the second, -Al2O3, In2O3, and In. |
| 2. | The presence of Co and Ni as alloys with activated aluminum determined the x-ray amorphous character of the Co- and Ni-containing phases at all stages, including the thermal treatment of the hydroxide and oxide systems. In the case of the copper alloy, only with thermal treatment does the partial crystallization of the CuO phase occur. |
| 3. | Introduction of the Co, Ni, and Cu ions into the aluminum oxide or hydroxide matrices, obtained from activated aluminum, show a definite effect on the formation of the Co3O4, CoAl2O4, and NiAl2O4 phases after thermal treatment. For the Cu-containing catalysts, the Cu2O and CuO phases are formed even before thermal treatment. |