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991.
The reaction takes place on Cd-containing Lewis sites, whereas the irreversible adsorption and condensation of product acetaldehyde on acidic OH groups of Cd-X, FAU catalyst results in deactivation. Preadsorbed ammonia moderates the deactivation, because it reacts with acetylene, and pyridine homologues are formed which block the accessible OH groups. Since in divalent cationic forms of clinoptilolite no OH groups are generated, Cd-clinoptilolite proved to be a catalyst of permanent activity.
, Cd, — OH FAU, Cd-X. , .. , OH . OH, Cd- .相似文献
992.
The kinetics of oxidation of isopropanol (IPA) by IO
4
–
in the presence of Os(VIII), Ru(III) and mixture of Os(VIII) and Ru(III) has been studied. The catalytic effect was found to be in the order Os(VIII)
IO 4 – Os(VIII), Ru(III) Os(VIII) Ru(III), . : Os(VIII)相似文献
993.
Ruthenium halides (Cl and Br) react with monotertiary arsines-Ph2RAs (R=Me, Et, Pr
n
) in methoxyethanol, in the presence of aq. formaldehyde to give monocarbonyl complexes of ruthenium(II) of the type RuX2(CO) (Ph2RAs)3. Carbonylation of an ethanolic solution containing ruthenium trichloride and the arsine at room temperature yieldtrans dicarbonyl compounds of the formula RuCl2(CO)2 (Ph2RAs)2. The osmium monocarbonyls OsX2(CO) (Ph2RAs)3 (X=Cl, Br; R=Me, Et) react with NaBH4 in methanol to yield complexes of the composition OsHX(CO) (Ph2RAs)3. The ruthenium analogues RuHCl(CO) (Ph2RAs)3 have also been made. Structures have been assigned to all these compounds on the basis of IR and NMR spectral results. 相似文献
994.
P. Vitarelli S. Cavallaro R. Ottaná L. M. Saija N. Giordano 《Reaction Kinetics and Catalysis Letters》1984,25(1-2):79-82
The isomerization-disproportionation of m-xylene has been investigated over a series of dealuminated mordenites characterized by Si/Al ratios varying from 5 to 15. Catalytic activity increases with the Si/Al ratio and correspondingly also the products of disproportionation. This behavior is interpreted in terms of increasing acid strength leading to a higher activity and selectivity to disproportionation through a common mechanism which involves both a parallel and a consecutive route.
- - , Si/Al, 5 15. Si/Al, . , , , , .相似文献
995.
É. Kh. Batirov S. A. Khamidkhodzhaev V. M. Malikov S. Yu. Yunusov 《Chemistry of Natural Compounds》1977,12(1):50-52
Summary In addition to three known alkaloids, the seeds ofL. cuneatum have yielded N-formylloline, N-acetylnorloline, and the new alkaloids N-methylloline and N-formylloline methiodide.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 60–63, January–February, 1976. 相似文献
996.
Decomposition of isopropanol on V2O5 and the bonzes Li0.02V2O5, Na0.02V2O5, Na0.06V2O5, Li0.33V2O5, and Na0.33V2O5 has been studied in the temperature range 168–300°C. The main reaction was found to be dehydration to propene with negligible dehydrogenation to acetone on the first four catalysts. Dehydration on these catalysts increased with the alkali metal content, but the energy of activation remained unchanged. On the last two catalysts, dehydration and dehydrogenation proceeded at comparable rates. A tentative mechanism for the dehydration of isopropanol is proposed, based on the effect of the product on the initial rate, the electric conductivity of the catalysts and their ESR spectra.
V2O5 : Li0,02V2O5, Na0,02V2O5, Na0,06V2O5, Li0,33V2O5 Na0,33V2O5 186–300°C. . , . . , , .相似文献
997.
Summary The diphenylmethyl and triphenylmethyl esters of uridine-3'phosphate have been obtained and their stability under various conditions has been studied.Khimiya Prirodnykh Soedinenii, Vol. 2, No. 1, pp. 48–51, 1966 相似文献
998.
Summary A simple isolation and cleanup procedure for the determination of organophosphorus insecticides and their oxones in animal tissues has been developed. This procedure unites partly extraction of organophosphorus pesticides and their oxones with cleanup by column chromatography. Most polar coextracts remain on the column and in its further processing the eluate does not tend to form emulsion. The process has been studied on model mixtures of 32P- and 14C-labelled pesticides with tissues as well as after application of pesticides to white rats. The average recovery of the method is 90.5%, with a standard deviation of ±5.1%.
Isolierung und Reinigung von Organophosphorinsecticiden und ihren Oxonen aus tierischen Gewehen
Zusammenfassung Ein einfaches Isolations- und Reinigungsverfahren wurde ausgearbeitet. Die Extraktion der Insecticide aus einer Homogenatsäule, die aus Kieselgel und Tiergewebe besteht, umfaßt zum Teil auch die Reinigung der Extrakte, da die polaren Verbindungen an die Säule gebunden bleiben. Der Mittelwert der Ausbeute des Verfahrens wurde im Modellversuch mit 14C- und 32P-markierten Insecticiden zu 90,5% festgestellt. Die Standardabweichung beträgt ± 5,1%.相似文献
999.
1000.
In this review an analysis is made of literature information on the synthesis of protoberberine alkaloids during 1980–1990.Institute of Chemistry of Plant Substances, Uzbekistan Republic Academy of Sciences, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 449–468, September–October, 1992. 相似文献