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1.
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. |
2.
| 1. | On Raney Cu and Co catalysts modified with D-(+)-tartaric acid acetoacetic ester is hydrogenated asymmetrically. |
| 2. | The optical yield of (-)-ethyl-3-hydroxybutyrate depends on the nature of the catalyst and the experimental conditions: on Cu catalyst the optical yield reaches 20–24% and is close to the optical yield obtained on modified Ni catalyst: on Co catalyst the optical yield is considerably less (2–8%). With increase in the quantity of catalyst the optical yield on these catalysts passes through a maximum. |
3.
L. S. Isaeva G. I. Drogunova A. S. Peregudov D. N. Kravtsov 《Russian Chemical Bulletin》1988,37(1):153-157
| 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. |
4.
M. M. Ermilova N. V. Orekhova E. V. Skakunova V. M. Gryaznov 《Russian Chemical Bulletin》1988,37(4):637-640
| 1. | In the course of catalytic hydrogenation reactions of cyclopentadiene, cyclooctadiene, and isoprene; and in the catalytic hydrogenolysis of propane, all of which proceed at 373–573 K, a.catalytic etching of a palladium-ruthenium membrane catalyst is taking place; it is determined by the nature of the reagents. |
| 2. | An oxidative-reductive treatment changes the surface structure, the catalytic activity, and the hydrogen permeability to a much lesser degree than when such a treatment is alternated with actual catalytic reactions. |
| 3. | A heat treatment followed by a subsequent rapid cooling from temperatures above the recrystallization temperature, increases significantly the activity of a palladium-ruthenium membrane catalyst in the hydrogenolysis of propane. |
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.
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. |
7.
Yu. V. Maksimov P. Ya. Kolotyrkin Yu. V. Baldokhin A. V. Krylova 《Russian Chemical Bulletin》1989,38(7):1344-1349
| 1. | The protective layer of microcrystalline iron consists of crystallites of hematite magnetically ordered at 20C and 0.1 m in size, and the phase composition of the surface and bulk of the sample is qualitatively the same in all conditions of oxidation. |
| 2. | The passivating film of the promoted catalyst of synthesis of ammonia is formed from small clusters of iron oxide with an effective size of 0.005–0.01 m; the composition of the surface and bulk of the stabilized catalyst is qualitatively different. |
| 3. | The role of the defects in the promoted catalyst in the mechanism of formation of oxide clusters was discussed. |
8.
| 1. | Complexes of platinum with polyethyleneimine have been synthesized and characterized by spectroscopic methods. |
| 2. | It has been shown that the complex Pt(II)-PEI, reduced with sodium borohydride, is an active and selective catalyst for the hydrogenation of aromatic nitro-compounds. |
9.
A. Teies Gonsalo A. I. Donskikh V. N. Kulagin Yu. V. Moiseev G. M. Tseitlin 《Russian Chemical Bulletin》1976,25(5):1156-1158
| 1. | The hydrolysis rate of N-benzoylanthranilic acid was studied at a KOH concentration of 2.2–44.6% and a temperature of 25–95°. |
| 2. | The limiting step of the process is the reaction of the singly ionized form of the reagent with a molecule of water. |
| 3. | The equilibrium constant for the addition of hydroxyl ion to the carbonyl atom of the amido group of N-benzoylanthranilic acid is 267, and the true rate constant for the reaction of the ionized form with a molecule of H2O at 25° is 0.13 min–1. |
10.
In conclusion, let us note the principal results of the calculation.
Institute of Catalysis, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 33, No. 2, pp. 35–41, March-April, 1992. 相似文献
| 1. | On a clean Ni(100) surface, only molecular adsorption of water is realized. Partial dissociation of H2O is thermodynamically allowed process; however, dissociation of water is impossible because of kinetic limitations. |
| 2. | Modification of the nickel surface by oxygen stabilizes the donor-acceptor pair (H2O/O) on the surface and removes the kinetic limitation in decomposition of water, through a substantial reduction of the activation energy of dissociation. |
| 3. | The promoting role of oxygen is manifested in an increase in the nonuniformity of electron density on the nickel surface in the vicinity of the [Ni]–OH2 bond, which makes it possible to open up a new channel of the reaction in which a high degree of energy compensation in the water dissociation reaction is possible. |
11.
| 1. | The (Cp2TiCl)2-LiAlH4 system with Al/Ti from 0.25 to 1.5 catalyzes both the homogeneous hydrogenation and isomerization of allylbenzene. |
| 2. | In an argon atmosphere, allylbenzene is isomerized to trans-propenylbenzene with 90–92% selectivity when Al/Ti=1–1.5. |
| 3. | The possibility was demonstrated for reactivation of this catalytic system by its retreatment with LiAlH4. |
12.
O. S. Morozova A. A. Kadushin V. A. Khalif E. L. Aptekar' L. Ya. Margolis O. V. Krylov 《Russian Chemical Bulletin》1976,25(4):722-725
| 1. | The surface of a SnO2-Sb2O4 catalyst is uniformly homogeneous with respect to the heats of adsorption of isobutylene. The heats vary from 50 to 20 kcal/mole as the degree of coverage is increased to 18% of a monolayer. |
| 2. | Isobutylene is adsorbed on SnO2-Sb2O4 in two forms: reversible (desorbed in the range 79–100° with Edes=21 kcal/mole) and irreversible. |
| 3. | Irreversibly chemisorbed isobutylene exists on the surface primarily in the form of the-methallyl complex. |
13.
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. |
14.
S. P. Freidman N. I. Medvedeva G. S. Nazarova V. A. Gubanov 《Journal of Structural Chemistry》1991,32(5):631-636
| 1. | The Al–O and P–O chemical bonds in variscite are mainly covalent in nature. The degree of covalency of the P–Ob chemical bond is substantially greater than that of Al–Ob. |
| 2. | The presence of nonequivalent bonds of oxygen atoms in water molecules in variscite (H–OW–H) and bonds of bridge oxygen atoms (P–Ob–Al) leads to splitting of the 02s and 02p states of the OW and Ob atoms amounting to 7 eV. |
| 3. | The strength of the Al–OW bond is considerably lower than that of the Al–Ob bond. |
| 4. | The H11, H21, and H22 hydrogen atoms form hydrogen bonds with the bridge oxygen atoms, but H12 does not participate in hydrogen bonding. |
| 5. | The results from cluster calculations of the electronic structure of variscite provide a basis for interpreting the experimental x-ray photoelectron spectrum and for determining the influence of structural molecules of water on the XPS line shape and structure. |
15.
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. |
16.
M. N. élinson S. K. Fedukovich S. V. Lindeman M. S. Aleksanyan Yu. T. Struchkov G. I. Nikishin 《Russian Chemical Bulletin》1989,38(7):1467-1471
| 1. | On electrolysis in methanol in the presence of the catalyst carrier NaI, tetramethyl propane-1,1,3,3-tetracarboxylate cyclizes with the exclusive formation of tetramethyl cyclopropane-1,1,2,2-tetracarboxylate with the yield up to 98%. |
| 2. | In the presence of NaBr and LiCl, hexamethyl pentane-1,1,3,3,5,5-hexacarboxylate, hexamethyl cyclopentane-1,1,2,2,4,4-hexacarboxylate, and tetramethyl tetrahydrofuran-2,2,4,4-tetracarboxylate are also formed; the last may be obtained with the yield up to 60%. |
17.
| 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. |
18.
V. I. Avdeev I. I. Zakharov G. M. Zhidomirov N. M. Neshev E. I. Proinov 《Journal of Structural Chemistry》1992,33(2):179-185
| 1. | Upon interaction of OH with Ni(100)m Ni(111), and Ni(110), stable, many-center forms of OH adsorption are produced. One-center and bridge forms of OH adsorption on nickel are kinetically unstable for the lowest surface coverages. |
| 2. | On Ni(100) and Ni(111), a linear form of adsorption of OH is realized; on Ni(110), an angular form is realized, with a polar angle 0 = 20°. |
| 3. | In the course of adsorption, there is a significant transfer of electron density from the metal to the OH, leading to an increase in the work function of the electrons and a decrease in the frequency of the (O–H) vibration. For the angular forms of adsorption, bending vibrations (O–H–Ni) are active. |
| 4. | Upon adsorption of OH, a strong -bond Ni(110)–OH is formed, as manifested in the UV photoelectron spectra by absorption in the 9.2 eV energy region. |
19.
B. A. Kazanskii M. I. Rozengart V. L. Polinin V. G. Bryukhanov L. V. Kravtsova N. I. Kolpakova 《Russian Chemical Bulletin》1976,25(8):1685-1690
| 1. | Cyclohexadiene, bensene, and methylcyclopentadienes are mainly formed from the hexatriene in the presence of silica gel and Al2O3 at 300–450°C. Increase in temperature (from 550 to 1100°C) and in the length of calcination of the silica gel (1–6 h) reduces the specific surface area and acidity of the catalyst and the degree of 1–5 and 1–6 cyclization of the triene. |
| 2. | In the presence of ZnO and Bi2O3, 1–6 cyclization of hexatriene to cyclohexadiene and benzene mostly occurs; methylcyclopentadienes are formed in insignificant amounts. |
| 3. | The 1–5 cyclization of hexatriene on silica gel and Al2O3 evidently takes place by a mechanism of acidic intramolecular alkylation. At 300–450°C, catalytic 1–6 cyclization of hexatriene is observed in addition to the thermal reaction. The idea was put forward that the catalytic 1–6 cyclization is facilitated by acceleration of the isomerization of the trans-triene to the cis isomer and by the effect of the catalyst surface on the conformation of the cis-hexatriene molecules. |
20.
D. D. Gogoladze E. S. Levitina L. F. Godunova E. I. Karpeiskaya E. I. Klabunovskii G. O. Chivadze 《Russian Chemical Bulletin》1988,37(6):1207-1210
| 1. | Hydrogenation of -nitrpcaprolactam by treatment with a Pd catalyst in the presence of S--phenylethylamine in aprotic solvents proceeds via azoxycaprolactam as an intermediate. |
| 2. | The asymmetric effect in the enantioselecive hydrogenation of nitrocaprolactam on a chiral Pd catalyst occurs at the stage where azoxycaprolactam is reduced. |