Neue Pyridiniumchlorometallatverbindungen der Seltenerdelemente

Summary Reaction of the rare earth chlorides with pyridinium chloride in tetrahydrofuran (THF) under anhydrous conditions gave nearly insoluble precipitates of the composition (pyH)₃ RECl₆·THF (RE=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Y, Er, Tm, Yb, and Lu). They were characterized by chemical analysis and IR spectroscopy; decompositionin vacuo was studied, yielding the hithero unknown complexes (pyH)₃ RECl₆ (RE=La, Ce, Pr, Sm, Tb, Ho, Y, Tm, and Lu).

     

Fraktionierte Kristallisation von Ammonium- und Magnesiumdoppelnitraten der Ceriterden; Bestimmung der Trennfaktoren und Vergleich der Trennwirkung

Summary The Separation Factors for Pr/La, Nd/Pr, and Sm/Nd, characterizing the crystallization of ammonium and magnesium double nitrates under practical conditions, were determined analytically and are discussed. They confirm that La and Pr can be separated better by fractional crystallization of ammonium double nitrates, whereas in the presence of Sm the magnesium double nitrates are preferable.

     

Craig-Verteilung von Seltenerdnitraten im System Tri-n-butylphosphat—Salpetersäure, 3. Mitt.: Reindarstellung von Lanthan-, Praseodym- und Neodymoxid

Zusammenfassung Die präparativeCraig-Verteilung mit einer Apparatur von 80 Elementen ergab bei Entnahme der Oberphase aus angereicherten Oxiden (Einsatz 75 g) La₂O₃, Pr₆O₁₁ und Nd₂O₃ in Reinheiten zwischen 99,9 und 99,99% (Ausbeuten 80–85%); bis 437 Verteilungsstufen gelangten zur Wirkung.

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Craig distribution of rare earth nitrates in the system tri-n-butyl phosphate—nitric acid, III. Purification of lanthanum, praseodymium and neodymium oxides

PreparativeCraig distribution using an apparatus with 80 elements and withdrawal of upper phase starting with enriched oxides (input 75 g), gave La₂O₃, Pr₆O₁₁ and Nd₂O₃ in purities from 99.9 to 99.99% (80–85% yield); up to 437 stages were effective.

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Herstellung von Seltenerdcyaniden

Zusammenfassung Seltenerd-cyanoargentateM[Ag(CN)₂]₃ wurden hergestellt (M=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er und Y), die aus wäßriger Lösung mit 3–4 Mol H₂O kristallisieren. Pr-cyanoargentat wurde entwässert und mit Li reduziert; hierbei konnte das in Tetrahydrofuran (THF) unlösliche Pr(CN)₃ im Gemisch mit anderen Stoffen erhalten werden. Da sich LiCN als inTHF löslich erwies, wurde die Herstellung aus AgCN und Li inTHF in Gegenwart von Naphthalin verbessert. LiCN wurde mit Seltenerdbromid-THF-Solvaten inTHF umgesetzt; hierbei fielen die bisher unbekannten einfachen Erdcyanide aus, die sehr zersetzlich sind und nach dem Trocknen die ZusammensetzungM(CN₃)· ·2THF besaßen (M=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm Yb, Lu und Y). Die Umsetzung verläuft bei den Verbindungen der Ceriterden schwieriger als bei denen der Yttererden; die Cyanide von La und Ce wurden nur mit überschüssigemTHF erhalten.

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Rare-earth cyanoargentatesM[Ag(CN)₂]₃ were prepared (M=La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er and Y), crystallising from aqueous solution with 3–4 moles of water. Pr-cyanoargentate was dehydrated and reduced with Li yielding some Pr(CN)₃, insoluble in tetrahydrofurane (THF), in mixture with other substances. Because LiCN proved to be soluble inTHF, the preparation from AgCN and Li inTHF in the presence of naphthalene was refined. LiCN was reacted with rare-earth bromide-THF-solvates inTHF, whereupon precipitation occured of the hitherto unknown, very sensitive to moisture simple rareearth cyanides, which after drying had the compositionM(CN)₃· ·2THF (M=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu and Y). The reaction is more difficult with the lighter lanthanon bromides than with the heavier ones; the cyanides of La and Ce were prepared only with excessTHF.

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Lie centre-by-metabelian group algebras in even characteristic, II

We complete the classification of the Lie centre-by-metabelian group algebras over arbitrary fields by solving the case of characteristic 2.     

Reindarstellung von Erbiumoxid durchCraig-Verteilung

1.6 kg of yttrium earth mixtures (4–6% Er) were concentrated to 60% erbium oxide by repeatedCraig-distributions with 4M HNO₃ lower phase for separation of yttrium, and with 11M for separation of holmium and thulium. During these experiments the optimal conditions were studied with regard to acidity and input. The 60% Er₂O₃ was further purified by using 4M followed by 11M HNO₃ lower phase several times. There resulted nearly 20 g Er₂O₃ 99.9% pure. The concept of the effective distribution coefficients characterising preparativeCraig-distributions was further verified by discussion of the values of selected separations.

Dem Vorstand des Instituts, Herrn Prof. Dr.K. L. Komarek, mit den besten Wünschen zum 60. Geburtstag gewidmet.     

Ein interaktives Verfahren zur Auswertung von Kaustiken an Trennflächenrissen

Übersicht In diesem Beitrag wird eine auf der interaktiven numerisch/graphischen Bildverarbeitung beruhende Methode zur Ermittlung der Spannungsintensitätsfaktoren, für Trennflächenrisse in Verbundmaterialien vorgestellt. Eine Anzahl von detenpunkten entlang der experimentell aufgezeichneten Kaustik wird als Eingabe verwendet. Das Verfahren überprüft die Genauigkeit und Zuverlässigkeit der Ergebnisse selbst, indem die auf der Basis des Resultats numerisch generierte Kaustik mit der experimentellen verglichen wird.

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An interactive method for data processing from crack tip caustics at interfaces

Summary An interactive numerical-graphical image processing method for the evaluation of stress intensity factors at interface cracks in composites will be presented. Based on a set of experimental data points suitably chosen along the caustic the multipoint overdeterministic data reduction technique provides reliable and rapidly coverging results by cross-checking experimental caustics with numerically generated iterative caustics.

     

Biased spectroscopic protein quantification in the presence of ionic liquids

Owing to their unique physicochemical properties, ionic liquids have gained much recognition as solvents or co-solvents in a wide variety of biochemical applications. In the context of protein analytics, four similar 1-alkyl-3-methylimidazolium-based ionic liquids have been analysed for their applicability as co-solvents. Spectroscopic bovine serum albumin (BSA) quantification experiments in the presence of ionic liquids were performed and for two ionic liquids a concentration-dependent effect has been found that can lead to biased protein quantification. It could be shown that the biased spectroscopic analysis of the tested ionic liquids is dependent on the length of the alkyl side chain (>C₄) of the 1-alkyl-3-methylimidazolium-based cation, and the chaotropicity of the anion. Once accounted for and properly calibrated when using spectroscopic methods, these effects can be avoided thus facilitating correct protein quantification in the presence of ionic liquids.     

Determination of crack-speed history and tip locations for cracks moving with nonuniform velocity

This paper describes the use of Rayleigh waves as observed with the reflected-light method of caustics to obtain information pertaining to crack speed and tip location. The basic idea is to use the Doppler-shift effect as applied to elastic-wave emission from a running crack to geometrically reconstruct crack-tip locations. In addition to the usual information pertaining to the stress-intensity factor at the time when the photograph was taken, the process yields a complete history of crack-propagation velocities even along curved-crack paths.     

Präparative Anreicherung von Yttererden durchCraig-VerteilungCraig-Verteilung von Seltenerdelementen im System Tri-n-Butylphosphat—Salpetersäure, 7. Mitt. Kurze Mitteilung

A crudeCraig-distribution in the system 11M HNO₃-TBP (input up to 200 g oxide) proved to be a rapid method to get highly enriched mixtures of yttrium earths completely free from cerium earths, which can be further separated economically, e.g. byCraig-distribution.