Spectrophotometric determination of zirconium with 9-methyl-2,3,7-trihydroxy-6-fluorone

Summary 9-Methyl-2.3.7-trihydroxy-6-fluorone has been used as a new colorimetric reagent for zirconium. The rose-red complex shows maximum absorption, against the reagent blank, at 500 nm and obeys Beer's law from 0.1 to 2.5 ppm. The optimum concentration range is from 0.66 to 2.5 ppm, where the per cent relative analysis error is 2.96. The composition of the complex, obtained from Job's method, indicates that the complex in solution contains the metal and the reagent in a ratio of 11. The instability constant of the complex is 1.07 · 10^–6.     

Analogs of carbohydrate-metabolism coenzymes

Conclusions We synthesized two analogs of the natural coenzyme adenosine diphosphate glucose: N₆-methyl-ADPG and N₆, N₆-dimethyl-ADPG.For communication 11, see [1].The following abbreviations are used in this article: ADPG) adenosine-5'-diphosphate-a-D-glucopyranose; N₆-methyl-ADPG) N₆-methylamino-9--D-ribofuranosylpurine-5-diphosphate--D-glucopyranose; N₆, N₆-dimethyl-ADPG) N₆, Ng-dimethylamino-9--D-ribofuranosylpurine-5-diphosphate--D-glucopyranose.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2514–2521, November, 1969.     

Flammenphotometrische Bestimmung geringer Kaliummengen in Natrium und seinen Verbindungen nach Anreicherung mittels Tetraphenylborammonium

Zusammenfassung Das hier beschriebene Verfahren gestattet, in metallischem Natrium oder in Natriumsalzen bei einer Einwaage von 1 g Kaliumgehalte bis herunter zu 10^–4% mit einem mittleren Fehler von ± 5% zu bestimmen. Der flammenphotometrischen Messung geht eine Anreicherung des Kaliums durch Konzentrationsfällung mit Ttraphenylborammonium voraus.Herrn Dr. Spang, Forschungslaboratorium der Siemens-Schuckertwerke, danken wir für seine Mithilfe bei der Durchführung der radiochemischen Untersuchungen, Herrn Dr. Iwantscheff für das der Arbeit entgegengebrachte fördernde Interesse.     

Reaction of silylphosphites with secondary amines

The reaction of dialkylsilylphosphites with linear and cyclic secondary amines leads to the formation of acid alkoxydialkylamidophosphites and dialkyl phosphites. Aminolysis of pyrocatecholsilylphosphite was accomplished with retention of the phosphorus atom and formation of the corresponding amidophosphites.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 235–237, January, 1991.     

Molecular and crystal structure of the germacranolide argolide from Artemisia glabella

The new germacranolide argolide has been isolated from the epigeal part ofArtemisia glabella, and its structure has been shown by its conversion into oxopelenolide B. From the results of an x-ray investigation it is suggested that argolide has the spatial structure of 3-oxo-4α,7α,6β(H)-germacra-1(10),11(13)-dien-6,12-olide. Institute of Organic Synthesis and Coal Chemistry, Kazakh Academy of Sciences, Karaganda. A. N. Nesmeyanov Institute of Organometallic Chemistry, Russian Academy of Sciences, Moscow. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 653–657, September–October, 1991.     

Structure of subchrysin

A new sesquiterpene lactone having the structure 3-acetoxy-1-hydroxy-6, 7(H)-germacra-4,10(14), 11(13)-trien-6, 12-olide has been isolated fromArtemisia subchrysolepis Filat. and has been called subchrysin. Its stereochemistry has been established by x-ray structural analysis.Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 176–180, March–April, 1998.     

Determination of gallium in tumour-affected tissues by means of spectroscopic techniques

A comparative investigation was carried out on the suitability of atomic absorption spectrometry and of emission spectrography with arc and hollow-cathode excitation sources for determination of gallium (μg g^-1) in biological samples. The three methods give reliable results. Hollow-cathode emission spectrography was found to be influenced to a lesser extent by matrix effects and to be more precise than the other two techniques.     

Substituted dienic 1,3-dioxolan-2-ones and bis(1,3-dioxolan-2-ones)

Alkylthio-substituted dienic 1,3-dioxolan-2-ones and bis(4,4-diorganyl-5-methyli-dene-1,3-dioxolan-2-ones) were obtained in high yields by the reaction of 2-methyl-6-alkylthio-5-hexen-3-yn-2-ols and tertiary diacetylenic glycols with carbon dioxide under pressure in the presence of catalytic amounts of triethylamine and monovalent copper salts.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1617–1619, December, 1979.Original article submitted January 24, 1979.