Reaction of carbon dioxide with a bimetallic octadienylbridged palladium complex

Reaction of equimolar amounts of μ-1–3-η:6–8-η-octadienatobis(1,1,1,5,5,5-hexafluoroacetylacetonatopalladium) and triisopropylphosphine gives a bimetallic octadienyl-bridged complex, in which one palladium atom is η¹ -bound to the terminal carbon of the octadienyl chain. Insertion of CO₂ into this PdC bond gives a carboxylate complex; acidic decomposition and hydrogenation of the carboxylate complex gives pelargonic acid. The results are discussed in relation to the mechanism of the palladium-catalyzed reaction between butadiene and carbon dioxide.     

Das Vorkommen von Aconits?ure im Zuckerrohrsaft und Colonialzucker

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The role of the endpoint in weighted polynomial approximation with varying weights

For a weight functionw: [a, b]→(0, ∞), we consider weighted polynomials of the formw ⁿ P_n where the degree ofP _n is at mostn. The class of functions that can be approximated with such polynomials depends on the behavior of the densityv(t) of the extremal measure associated withw. We show that every approximable function must vanish at the endpointa ifv(t) behaves like (t?a) ^β ast→a with β>?1/2. We also present an analogous result for internal points. Our results solve some open problems posed by V. Totik and disprove a conjecture of G.G. Lorentz on incomplete polynomials.     

Eine verbesserte Schleifvorrichtung zur Herstellung von Kugeln aus harten Materialien

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Die Elektronenemission bei Röntgenbestrahlten Ferriten

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Untersuchungen über die photometrische Bestimmung von Tantal mit Pyrogallol

The optimum conditions for the photometric determination of tantalum with pyrogallol in sulphuric acid solution at 405 nm have been elaborated. The method has been checked statistically.