Fast proton conductivity of polycrystalline titanoniobates

The proton conductivity of three layer-type compounds was studied: H₃OTi₂NbO₇. H₂O, HTiNbO₅ and HTiTaO₅. Measurements were made between 20 °C and 90°C on pellets pressed from crystalline powders and soaked with pure water. The hydrated compound had the highest conductivity, (20°C)-6.3–6.9·10^–4 (cm)^–1. Acid ions from the exchange process were quite firmly retained in its layer structure and contributed significantly to the measured conductivity. Consistent results were obtained after prolonged washing with water.Dedicated to Professor Harry Thomas on the occasion of his 60th birthday     

Zur reaktionsweise von triafulvenen mit azomethinyliden

The reaction of the azomethine ylides 2a–c with cyclopropenones 3 and of 2a with methylene cyclopropenes 7 leads via (3+3)-cycloaddition to pyridones-4 5 and 1,4 - dihydro - N - methyl - 4 - methylene - pyridines 8, respectively. The merocyanine systems 8 exhibit marked solvatochromic and thermochromic properties.     

Theory of chirality functions,generalized for molecules with chiral ligands

The theory of chirality functions described in a previous publication is generalized to allow for chiral ligands. In the earlier theory, all symmetry operations of the molecular frame could be thought of as permutations of the ligands among the sites; in the present work, improper rotations not only permute the ligands, but convert them into mirror images. The group that generates all isomers from a given ordered molecule belonging to a frame with n sites is now the hyperoctahedral group of order 2ⁿ n! consisting of all possible combinations of permutations and site reflections. The representation theory of these groups is described, and applied to the problem of constructing qualitatively complete chirality functions, and of deciding which ligand partitions, and which isomer mixtures, are chiral. It is found useful to classify chiral representations of the covering group as ligand specific and class specific. The ligand specific representations describe chiral properties which are common to all frames and arise purely from the chirality of the ligands, while the class specific representations describe the chiral properties of the frame. A number of examples are explicitly worked out.     

Der Verlauf der Umlagerung von Phenacylsulfenylmorpholid zu Phenylglyoxylsäurethionmorpholid in Gegenwart von Schwefel

Zusammenfassung Bei der Einwirkung von elementarem Schwefel auf Phenacyl-sulfenylmorpholid entsteht unter H₂S-Abspaltung Phenylglyoxyl-säurethionmorpholid. Durch Einsatz von radioaktivem Schwefel wurde festgestellt, daß diese Umlagerungsreaktion über die Stufe einergem. Dimercaptoverbindung verläuft.

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Reaction of elementary sulfur with phenacylsulfenylmorpholide gives phenylglyoxylic acid thionmorpholide while hydrogen sulfide is eliminated. The rearrangement proceeds, as was shown by use of radioactive sulfur, via agem. dimercaptocompound as intermediate.

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47. Mitt.:F. Asinger, W. Schäfer undA. Saus, Mh. Chem.96, 1265 (1965).

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Teil der DissertationA. Saus, Techn. Hochsch. Aachen, 1964.     

Application of high-performance liquid chromatography of some antibiotics in clinical microbiology

During recent years high-performance liquid chromatography has become an excellent tool for the determination of antibiotics in biological fluids. Compared with biological assays, the major benefits of this method are specificity and rapidity. In particular, the determination of biologically inactive metabolites emphasizes that this technique plays an outstanding role for the analysis of antibiotics. This paper describes how the method can be used in the analysis of several antibiotics and demonstrates the efficacy of this method for clinical microbiology. Methods for the determination in biological fluids of acylaminopenicillins (azlocillin, mezlocillin, piperacillin and aspoxicillin), quinolones (ciprofloxacine, norfloxacine and ofloxacine), a penem (imipenem) and a cephalosporin (cefixime) are summarized. Furthermore, their application to in vitro studies and their trial in clinical studies are described.     

Partial Quenching of Parametrical Tetragonality of a Chromium(III) Complex by Pressure Tuning

The ligand-field spectrum of [Cr(NH(3))(4)F(2)]AsF(6) has been pressure-tuned up to 100 kbar. The parametrical analysis shows that the absolute values of the two independent tetragonalities of the chromophoric ion both decrease with increasing isotropic pressure so that the molecular ion becomes more isotropic. Moreover, the Cr-N single bonds appear to be more compressible than the Cr-F bonds, for which it is parametrically clear that they have a partial multiple-bond character. While the spectrochemical parameter for F(-), Delta(F), increases with pressure, its two components Delta(sigma)(F) and Delta(pi)(F) decrease. It is confirmed that nephelauxetism increases with pressure.