Hochdruck‐Synthese,Kristallstruktur und Eigenschaften von NaPN2

High‐Pressure Synthesis, Crystal Structure, and Properties of NaPN₂ Single phase NaPN₂ was synthesized by the reaction of NaN₃ and P₃N₅ in a multianvil assembly at 3 GPa and 1000 °C. The title compound crystallizes in a variant of the chalcopyrite structure type and is isotypic to LiPN₂. The crystal structure was refined by the Rietveld method (I 4 2d, a = 497.21(2), c = 697.60(3) pm, Z = 4, 36 observed reflections, R_p = 0.0502, wR_p = 0.0649, R_F = 0.0788).     

Einfluss der A-spannung auf die stereochemie von oximen und semicarbazonen

In piperidone-(4)-oximes, the A^1,3 strain between the substituent at the exocyclic double bond and a Me group causes the sole formation of anti-isomers. A change of the ring conformation avoids the A^1,3 strain in 1-methyl-2,6-diphenyl-3,5-dimethyl-piperidone-(4)-oxime. trans-Configuration of the Me substituents at C-3 and C-5 can be shown in a correspondingly substituted semicarbazone; in this example, the A^1,3 strain is avoided by epimerization. This semicarbazone can be transformed into the 3,5-trans-disubstituted piperidone by cerium(IV) oxidation.     

Einfluss der Partikelgeometrie auf die optischen Eigenschaften stark absorbierender Farbstoffteilchen

The extinction coefficients of spherical and ellipsoidal modelparticles of complex index of refraction have been measured. In the case of spherical particles the results are in good agreement with the predictions of the MIE theory. An empirical relationship has been worked out which relates the optical behaviour of needle-shaped ellipsoidal particles of defined eccentricity and size to an equivalent MIE diameter. The measurements have been performed in the range of size 0,2 < D₀ < 1,3 μ and eccentricity 1 ? p < 10.     

Ueber Glas und den Einfluss seiner Zusammensetzung auf seine Eigenschaften

Ohne Zusammenfassung     

Über den Einfluß von Temperatur und Fremdionen auf Eigenschaften und Bau der Natriumwasserglaslösungen

The Influence of Temperature and Impurities Addition on the Properties and the Constitution of Sodium Water Glass Solutions Sodium water glass (NaWG-)solutions of constant composition (SiO₂/Na₂O = 3,3; C_SiO2 = 6,2 M) and different concentration of impurities (Fe, Al, Ti, Cu, chloride, sulfate) were investigated in dependence on temperature by means of the dye absorption method, ¹H- and ²³Na-NMR spectroscopy. It is shown, that the differences in the dye absorption spectra of normalized technical NaWG-solutions, mainly depend on the Fe-concentration in the solutions and their thermal history. From the results follow a crosslinking of polymeric silicate species by Fe? O? Si bonds and/or hydrogen bridges and a fully or partially degradation of these bonds at higher temperatures (150°C).     

Eigenschaften von chelatbildenden Ionenaustauschern auf der Basis von Polystyrol

Zusammenfassung Selektive Chelataustauscher auf der Basis von Polystyrol mit folgenden Ankergruppen werden durch Kapazitätsbestimmung, Messung der Austauschgeschwindigkeit und Bestimmung der Verteilungskoeffizienten charakterisiert: 4,5-Dihydroxynaphthalindisulfonsäure-(2,7) (Chromotropsäure), Alizarin, 1,2,5,8-Tetrahydroxyanthrachinon (Chinalizarin), Morin, 1,5-Diphenylthiocarbazon (Dithizon), 1,5-Diphenylcarbazid, Glyoxal-bis(2-hydroxyanil), 1-[Thenoyl-(2)]-3,3,3-trifluoraceton (TTA), 5-(4-Di-methylaminobenzyliden)-rhodanin (DMABR), Ethylendiamin-N,N-bis-(o-hydroxyphenylessigsäure) (Chel I), 1,2,3-Trihydroxybenzol (Pyrogallol), 4-Methoxy-2-[thiazolyl-(2)-azo]-phenol (TAM), Bis-(salicyliden)-1,2-diaminoethan (Salen), 8-Hydroxychinolin, Brenzcatechindisulfonsäure(3,5) (Tiron) Die Werte für die Kapazität der chelatbildenden Polystyrolaustauscher mit einer Korngröße von 0,1–0,2 mm variieren zwischen 0,4 und 1,5 mmol/g. Es ist zu erwarten, daß diese Austauscher teilweise wesentlich bessere Trenneigenschaften aufweisen als der handelsübliche Austauscher Dowex A-1.

---

Properties of chelating ion-exchangers on the basis of polystyrene

Summary Selective chelating exchangers on the basis of polystyrene with the following anchor groups are characterized by capacity, determination of exchange rates and of distribution coefficients: 4,5-dihydroxynaphthalenedisulphonic acid-(2,7) (chromotropic acid), alizarin, 1,2,5,8-tetrahydroxyanthraquinone (quinalizarin), morin, 1,5-diphenylthiocarbazone (dithizone), 1,5-diphenyl-carbazide, glyoxalbis(2-hydroxyanil), 1-[thenoyl-(2)]-3,3,3-trifluoroacetone (TTA), 5-(4-dimethylaminobenzylidene)-rhodanine (DMABR), ethylenediamine-N,N-bis-(o-hydroxyphenylacetic acid) (Chel I), 1,2,3-trihydroxybenzene (pyrogallol), 4-methoxy-2-[thiazolyl-(2)-azo]-phenol (TAM), bis-salicylidene)-1,2-diaminoethane (Salen), 8-hydroxyquinoline, pyrocatecholdisulphonic acid-(3,5) (Tiron). The capacity values of the chelating polystyrene exchangers with grain sizes of 0.1–0.2 mm vary between 0.4 and 1.5 mmol/g. It can be expected that these exchangers will have more favourable separation properties than the commercially available exchanger Dowex A-1.

     

Einflu? der thermischen Kontraktion auf die Struktur und die Eigenschaften von PET-Fasern

Ohne Zusammenfassung