Chalkogenolat-lonen und ihre Derivate. I. Darstellung und Eigenschaften salzartiger Chalkogenophenolate

Chalcogenolates and their Derivatives. I. Syntheses and Properties of Ionic Chalcogenophenolates The syntheses and properties of ionic chalcogenophenolates are described. Using liquid ammonia as solvent the alkali chalcogenophenolates M[EPh] (M = Na, K; E = Se, Te; Ph = C₆H₅) have been synthesized via reduction of the diphenyl dichalcogenides with alkali metals. Similarly, the tetraphenylphosphonium chalcogenophenolates [Ph₄P][EPh] (E = S, Se, Te) have been obtained by reacting alkali chalcogenophenolates with tetraphenylphosphonium chloride.     

Determination of sub microgram amounts of selenium in rocks by atomic-absorption spectroscopy

Atomic-absorption spectroscopy was used to determine trace amounts of selenium accurately in U.S. Geological Survey standard rocks, GSP-1, W-1 and BCR-1. The results obtained were compared with those obtained by neutron-activation analysis and excellent agreement was found; in addition, the selenium:sulphur ratio was calculated and agreed with results obtained by other workers.     

Thiapyrylium salts (review)

The literature data touching upon the synthesis of thiapyrylium salts and the stability of the thiapyrylium cation as compared with its isoelectronic analogs, as well as the nucleophilic, oxidation, anion-exchange, and other reactions of the salts with substituted and unsubstituted thiapyrylium cations are examined in this review.     

Cyclisations par l'intermédiaire de fonctions phénylthioet phénoxy-carbamyle. I. Diphényl-1,2-alcoyl-5-dioxo-3,6-hexahydro-triazines-1,2,4

The N-(p-nitrophenoxy-carbonyl) and N-(phenylthio-carbonyl) derivatives of α-amino-acyl-hydrazides cyclize in presence of diazomethane, yielding hexahydro-1, 2, 4-triazines with simultaneous formation of p-nitro-anisole or thio-anisole respectively. The molecules with a phenoxycarbonyl function such as N-(phenoxycarbonyl)-glycyl-(N, N′-diphenylhydrazide) give the corresponding ring products and anisole only in solvents with high dielectric constant (e.g. nitromethane). The phenylthio-carbonyl derivatives give the same ring products in presence of lead acetate by the intervention of HO^?. The p-nitrophenoxycarbonyl derivatives give rise to the same cyclisations in the presence of pyridine by the intermediate of carbamyle-pyridinium ion acting as electrophile. These different types of intramolecular reactions are illustrated by the formation of 1, 2-diphenyl-5-alcoyl-3, 6-dioxo-1, 2, 4-hexahydro-triazines.     

Non-destructive neutron-activation analysis for determining the chlorine content of paper-pulp

Non-destructive neutron-activation analysis is used for determining chlorine in paper-pulp. Numerical data have been obtained for bleached and unbleached paper-pulps of different types and origins. The sensitivity of this method is 100 ppm for an irradiation time of 30 min and a neutron flux of 6 x 10(10) neutrons.cm(-2).sec(-1) and 10 ppm for an irradiation time of 1 min and a neutron flux of 2 x 10(12) neutrons.cm(-2).sec(-1). In both cases the amount of chlorine that can be determined depends on the presence of the interfering elements manganese and sodium in the paper-pulp. The time required for a complete analysis, after irradiation, is 5 min.     

Triterpene glycosides ofSapindus mukorossi

Conclusions The structure of two triterpone glycosides fromSapindus mukorossi Gaertn. has been established. It has been shown that sapindoside A is hederagenin 3-O--L-arabinosyl-(2 1)--L-rhamnopyranoside and sapindoside B is the 3-O--L-arabopyranosyl-(2 1)-O--L-rhamnopyranosyl-(3 1)--D-xylopyranoside.     

High-performance liquid chromatographic determination of benzodiazepines in human plasma

A simple and sensitive method for determination of benzodiazepines in plasma has been developed using high-performance liquid chromatography in a reverse-phase mode. The method is illustrated by application to plasma samples containing diazepam and N-desmethyldiazepam at concentrations which would be encountered during therapy, with limits of detection of 10 ng/ml and 2 ng/ml for diazepam and N-desmethyldiazepam, respectively.     

Electrophilic reactions of 3-hydroxyisonicotinic acid

Conclusions The aminomethylation, azo-coupling, and nitration of 3-hydroxyisonicotinic acid and its ester are directed to the 2 position, whereas their iodination proceeds with the formation of the 2-iodo and 2,6-diiodo derivatives.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 452–454, February, 1977.     

Preconcentration of manganese,cobalt, yttrium,zirconium, niobium,ruthenium, europium and protactinium by various hydroxides

Summary The removal of trace elements from dilute water solutions by hydroxide precipitates was investigated. The co-precipitation yields of manganese, cobalt, ruthenium, europium and protactinium onto beryllium, zinc, iron, lanthanum and titanium hydroxides were studied in the pH region from 3 to 11, while those of manganese, cobalt, yttrium, zirconium, niobium, ruthenium, europium, and protactinium onto the same hydroxides were investigated in sea-water media. The influence of some other factors, such as the presence of neutral electrolyte and NH₄ ⁺ ions, aging of hydroxide precipitates etc. on the co-precipitation yields were also examined.

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Zusammenfassung Die Entfernung von Spurenelementen aus verdünnten wäßrigen Lösungen durch Hydroxidniederschläge wurde untersucht. Die mitgefällten Anteile Mn, Co, Ru, Eu und Pa in den Hydroxiden von Be, Zn, Fe, La und Ti wurden im pH-Bereich 3–11 untersucht, während die Anteile von Mn, Co, Yt, Zr, Nb, Ru, Eu und Pa in den gleichen Hydroxiden in Meerwasser studiert wurden. Der Einfluß einiger anderer Faktoren auf die Mitfällung, wie die Anwesenheit neutraler Elektrolyte und von NH₄-Ionen, die Alterung der Hydroxidniederschläge usw. wurden ebenfalls geprüft.