Zur Struktur der Produkte der Reaktion vonE/Z-1-Benzolsulfonyl-3-(1-pentenyl)-indol mit N-Phenylmaleinimid: Ein erster Beitrag zur Konfigurations- und Konformationsanalyse in der Vinylindol-Cycloadditionsreihe

The products2,3 of the reaction ofE/Z-1-benzenesulfonyl-3-(1-pentenyl)-indole (1) and N-phenylmaleimide were analysed by¹H-NMR spectroscopy. Exemplarily, the structure elucidation of theendo-cyclo-adduct2 b was achieved by using several NMR techniques (diff. NOE-, INDOR-measurements, decoupling experiments, spectra simulation). The¹H-NMR-spectroscopically gained prediction of relative configuration and conformation of2 b was supported on X-ray analysis. The cyclohexene ring of the new cycloadducts adopts in the liquid phase and in the crystal a slightly twisted boat conformation.

     

Determination of Trace Impurities in Alkali Metals

Summary For the evaluation of compatibility studies of construction materials with liquid alkali metals at high temperatures, the knowledge of the quantity of certain impurities in the alkali metal in the ppm range is of great importance. In this paper the solubilities of several non-metals and metals in lithium, sodium and potassium are compared, according to data from literature. The methods for determination of these impurities are outlined and results are reported from analyses of lithium from a static corrosion test, sodium from long-term dynamic loop experiments, and of potassium from barrels as delivered.

---

Bestimmung von Verunreinigungen in Alkalimetallen

Zusammenfassung Zur Beurteilung von Korrosionstests im Zusammenhang mit der Materialauswahl für flüssige Alkalimetalle bei erhöhter Temperatur ist die Kenntnis der Konzentration gewisser Verunreinigungen im Alkalimetall von größter Bedeutung. Es werden einige Löslichkeitsdaten von nichtmetallischen und metallischen Verunreinigungen in Lithium, Natrium und Kalium aus der Literatur aufgezeigt. Über die Methode der quantitativen Bestimmung dieser Spurenelemente und Ergebnisse wird an Hand der Analyse von Lithium aus einem statischen Korrosionstest, von Natrium aus Langzeitversuchen eines Hochtemperaturkreislaufes und von Kalium aus Fässern im Anlieferungszustand berichtet.

---

---

Presented at the 8th International Microchemical Symposium, Graz, August 25–30, 1980.     

Alkali-hydride water cluster ions

Using a CO₂ laser we have desorbed LiOH and NaOH from a solid target into an expanding inert gas jet pulse. Subsequently the beam was ionized by photons from a UV laser. Surprisingly, we observed in mass spectra metal water clusters and metal-hydride water clusters. For the metals M=Li, Na we find that the [M(H₂O)_n]⁺ peaks are dominant for small clusters, while for large clusters (n>20) the [MH(H₂O)_n]⁺ peaks are dominant. This indicates that the clathrate (H₂O)₂₀ may play an important role in the formation of metallo-water clusters.     

Structure determination of germacrane-type sesquiterpene alcohols from an endophyte Streptomyces griseus subsp

Three germacrane-type sesquiterpene alcohols were isolated from an endophyte of mangrove plant Kandelia candel. Their structures were characterized as 1(10)E,5E-germacradiene-11-ol (1), 1(10)E,5E-germacradiene-3,11-diol (2), 1(10)E,5E-germacradiene-2,11-diol (3) based on the extensive NMR studies. Among them, 2 and 3 are identified as new compounds.     

Rapid analysis of non-esterified fatty acids as methyl esters from different biological specimens by gas chromatography after one-step esterification

A rapid gas chromatographic method for the determination of medium-chain and long-chain free fatty acids (C14:0 to C24:0 fatty acids) from different biological specimens is presented. After a rapid one-step transesterification method in methanol-acetyl chloride (50:1, v/v), fatty acid methyl esters were extracted into n-hexane and analysed on a 15-m Durabond-Wax column within a 12-min chromatographic run. The detection limit is 500 pg per injection.