Beiträge zum chemischen Transport oxidischer Metallverbindungen. V. Der Transport ternärer und quaternärer Mischferrite über ihre Metallchloride

Contributions to the Chemical Transport of Metal Oxides. V. Transport of Ternary and Quaternary Mixed Ferrites by their Chlorides The transport by means of HCl as transporting gas in a closed system in the case of the ternary mixed ferrites (Ni_0,8Fe_2,2O₄, Mn_0,75Fe_2,25O₄, Mn_1,286Fe_1,714O₄) and the quaternary mixed ferrites (Mg_0,5Mn_0,5Fe₂O₄, Mg_0,75Mn_0,536Fe_1,714O₄, Mg_0,281Mn_0,469Fe_2,25O₄, Mn_0,5Zn_0,5Fe₂O₄, Mn_0,5Zn_0,45Fe_2,05O₄, Ni_0,5Zn_0,5Fe₂O₄) between T₂ = 1100?1000°C and T₁ = 1000?800°C was investigated. Transported crystals were characterized by chemical analysis and the saturation magnetization, the transport rate has been checked. In the case of Mn_0,5Zn_0,45Fe_2,05O₄ two phases were transported. By discussing the phase diagram an explanation is given.     

Beitrag zur Analyse von Stibin

Zusammenfassung Es wird ein Verfahren zur Bestimmung von Stibin beschrieben, das sich sowohl zur Analyse von SbH₃ in organischen Lösungsmitteln als auch zur Bestimmung von flüssigem oder festem SbH₃ eignet. Hierbei wird das Stibin mit überschüssigem Brom zu Sb^V oxydiert, danach mit SO₂ zu Sb^III reduziert und dieses oxydimetrisch mit Jod oder Bromat titriert.

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Summary A method is proposed for the determination of stibine, applicable to its solutions in organic solvents and also to the solvent-free liquid or solid substance. The procedure involves oxidation of SbH₃ with an excess of bromine to Sb^V, reduction to Sb^III with SO₂, and oxidimetric titration of the trivalent antimony with iodine or bromate.

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Herrn Professor Dr. C. Mahr zum 65. Geburtstag gewidmet.     

On stable geometries

Within the concept of projective lattice geometry we are considering the class of stable geometries which have also been introduced in [14]. The investigation of their basic properties will result in fundamental structure theorems which especially give a lattice-geometric characterization of free left modules of rank 6 over proper right Bezout rings of stable rank 2. This yields a proper generalization of previous results of ours.     

Cyclisierungsreaktionen zu Pyrano[3,2-c]pyridinen und pyrano[3,2-c]chinolinen unter Verwendung von Ethoxymethylen-malodinitril bzw.-cyanessigester Synthesen mit Nitrilen, 50. Mitt. pyrano[3,2-c]quinolines with ethoxymethylene-malonitrile and-ethyl cyanoacetate,resp.

Reaction of ethoxymethylene-malonitrile and ethoxymethyleneethyl cyanoacetate, resp., with 4-hydroxy-2-pyridones (1a–b) and 4-hydroxy-2-quinolones (3a–b) leads to 2,5-dioxo-5,6-dihydro-2 H-pyrano[3,2-c]pyridine-(2a–d) and 2,5-dioxo-5,6-dihydro-pyrano[3.2-c]quinoline-derivatives (4a–d), resp.2a–d and4a–d exhibit remarkable visible fluorescence. Absorption- and emmission-data in different solvents are reported.     

Zur Verwendung von Quecksilber(I)-nitrat als reduktometrisches Reagens

Ohne ZusammenfassungVgl. diese Z. 137, 129 (1952/53); 138, 118 (1953)