3β-Methoxyolean-18-ene (miliacin) from the marine fungus Chaetomium olivaceum

A pentacyclic tritepenoid, 3-methoxyolean-18-ene (miliacin), was isolated for the first time from the marine fungus Chaetomium olivaceum. Its structure was determined on the basis of 2D NMR spectroscopy and X-ray diffraction data.     

Untersuchung des Wachstumsmechanismus und der Vbertragungsreaktionen bei der Olefin-Polymerisation mit Ziegler-Natta-Katalysatoren. 1. Mitt. Bestimmung der Zahl der Wachstumszentren und der Geschwindigkeitskonstante

Ohne Zusammenfassung     

Crystal and molecular structures of Si-(iodomethyl)silatranes with methyl substituents in β-position relative to the nitrogen atom

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Some regularities of the surfactant adsorption accumulation in the foam with high capillary pressure in Platean-Gibbs borders

Summary Some regularities of the surfactant adsorption accumulation in a foam with high capillary pressure in the Plateau-Gibbs borders are investigated. The dependencies of the accumulation ratio on the surfactant adsorption, on the dispersity and the expansion factor of the foam, and on the capillary pressure are obtained theoretically. The surfactant accumulation is investigatet in a static and in a dynamic foam. The experimental data are in a good agreement with the theoretical dependencies. The accumulation ratio reaches values up to 1000–2000.

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Zusammenfassung Es wurden die Gesetzmäßigkeiten der Adsorptionskonzentrierung von Tensiden in einem Schaum mit hohem Kapillardruck in den Plateau-Gibbsschen Grenzen untersucht. Die Abhängigkeit des Konzentrierungskoeffizienten von der Tensidadsorption, von der Dispersität und Verschäumungszahl des Schaumes und von dem Kapillardruck wurden theoretisch erhalten. Die Konzentrierung des Tensides wurde in einem statischen und in einem dynamischen Schaum untersucht. Die experimentellen Ergebnisse stimmen gut mit den theoretischen Abhängigkeiten überein. Die Konzentrierungskoeffizienten können Werte von 1000–2000 erreichen.

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With 3 figures     

Thermal stability of organosilica and their forms modified by ions of copper(II)

Thermal stability of two-component organosilica sorbents – silico-polymethylsiloxanes with the ratio of hydrophilic and hydrophobic components of 50:50 and 70:30 mass%, and their forms, modified by copper(II), was investigated using thermal analysis (DTG, DTA, TG). The influence of the composition of modified organosilica sorbents and copper(II) content on the endothermic (removal of adsorbed water) and exothermic (decomposition by oxidation of methyl groups, possible hydration of surface) peak temperatures and on mass loss is shown. It was found that thermal stability of organosilica modified by copper(II) was lower than that of initial sorbents and depends on the content of modifying component and ratio of silanol and methylsilil groups in organosilica composition.     

New experimental data on the proton electromagnetic polarizabilities

The γp-elastic scattering cross section has been measured in the photon energy range 70–110 MeV. As a monitor process the electron Compton-scattering was simultaneously measured. The values of the electric ($\text{α}$) and magnetic ($\text{β}$) polarizabilities of the proton were obtained from the experimental data: $\text{α}\text{= (10.7 ± 1.1) × 10}{}^{\mathrm{?43}}\text{cm}{}^3$; $\text{β}\text{= (?0.7 ± 1.6) × 10}{}^{\mathrm{?43}}\text{cm}{}^3$.     

Aminoalkylated Calix[4]resorcinarenes as pH Sensitive “hosts” for Charged Metallocomplexes

On the basis of RCA, pH-potentiometry and EPR-spectroscopy data aminoalkylated derivatives were proved to bind metal ion complexes both in alkaline and in acidic media. Outer-sphere coordination is the only interaction mode in these host-guest complexes.