Über die Tribromomangan(II)-Säure und deren Komplex mit Pyridin

Tribromomanganese(II) acid has been prepared for the first time and will be described. A complex of the acid with pyridine was obtained and its UV, visible, IR and¹H-NMR spectra will be reported.     

Zur Kenntnis von Natrium-hexafluoromanganat(III)

Sodium hexafluoromanganate(III) has been synthesized by heating equimolecular quantities of Na₂MnF₅ and NaF in argon atmosphere. The compound is monoclinic witha=5.56 (1) Å,b=5.84 (1) Å,c=8.10 (2) Å, =90.7 (2) andZ=2. It is a high spin complex with _eff and the deformation of the octahedra is evident from its IR-spectra. Two enantiotropic transitions (at 562 and 653°C) and the melting point at 800°C have been observed.

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8. Mitt.: Mh. Chem.106, 483 (1975).     

Die Schmelzdiagramme der Systeme CsN3/Zn(N3)2 und KN3/Zn(N3)2

The phase diagrams of the systems CsN₃/Zn(N₃)₂ and KN₃/Zn(N₃)₂ have been obtained employing the microscopic technique ofL. Kofler andA. Kofler. Within the system CsN₃/Zn(N₃)₂ three eutectics at 148°C, 142°C, and 210°C were found. Besides Cs₂Zn(N₃)₄, melting incongruently in the interval 153°C to 170°C, there exist two further compounds of the most probable composition Cs₃Zn₂(N₃)₇ and CsZn₂(N₃)₅, melting congruently at 170°C and 210°C, resp. In the system KN₃/Zn(N₃)₂ there exist two eutectics at 203°C and 172°C and two compounds, one of them, i.e. K₂Zn(N₃)₄, melting congruently at 206°C, the other one, with composition KZn₃(N₃)₇ or KZn₄(N₃)₉, melting incongruently at 210°C.

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Mit 8 Abbildungen

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Herrn Professor Dr.Heribert Grubitsch zum 70. Geburtstag gewidmet.     

Partialsynthetische Aristolochiasäuren und ihre Homologen,II. Mitt.: 3,4,6,7-Tetramethoxy-10-nitrophenanthren-1-carbonsäure

A new method for the synthesis of aristolochic acids and their homologues was presented. According to the above procedure 3,4,6,7-tetramethoxy-10-nitrophenantrenecarboxylic acid was obtained from a product of glaucine degradation and its chemical structure was proved.     

Der massenspektrometrische Zerfall von Hexamethoxydisilan und Oktamethoxytrisilan

The decomposition (70 eV, 17 eV) of Si₂(OCH₃)₆, Si₂(OCD₃)₆, and Si₃(OCH₃)₈ by electron-impact is characterized by an initial loss of the radicals CH₃, Si(OCH₃)₃, and OCH₃. For the disilanes, a typical pathway follows by successive loss of formaldehyde forming SiH-units; in the trisilane the main fragmentation path shows elimination of dimethoxysilylene previous to CH₂O-abstraction. Fragmentation schemes are given, in part metastable supported.     

Ion exchange removal of calcium carbonate and gypsum from mineral material prior to determination of cation exchange capacity using89Sr++

Summary The aim of the present work was to show that ion exchange resins can be used to remove sparingly and slightly soluble salts from calcareous and gypseous soils, which may otherwise cause serious errors in the determination of cation exchange capacity. It was shown that CaCO₃ and CaSO₄-2H₂O can be removed from a mixture with montmorillonite(Ca++) by a mixed bed resin. After resin treatment of the mixture its C.E.C. as retained Sr⁺⁺ corresponds approximately to the C.E.C. for pure montmorillonite within certain limits. Use of an anion exchange resin alone for removing these salts, however, gave an Sr⁺⁺ retention well below the C.E.C. for the mineral. It was assumed that this results from the blocking of exchange sites by resin particles.

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Zusammenfassung In kalkhaltigen und gipshaltigen B?den st?ren CaCO₃ und CaSO₄-2H₂O die Bestimmung des Kationenaustauschverm?gens. In der vorliegenden Arbeit wird gezeigt, da? Salze wie CaCO₃ und CaSO₄-2H₂O aus Mischungen mit Ca-Montmorillonit durch Ionenaustauscher herausgel?st werden k?nnen. Als Ionenaustauscher müssen jedoch Mischbettaustauscher verwendet werden; Anionenaustauscher allein liefern bei einer anschlie?enden Bestimmung des Kationenaustausches mit Sr⁺⁺ falsche Werte. Die angegebene Methode erscheint vor allem für die Untersuchung von B?den wichtig zu sein.