Spaltungen mittels Diazoniumverbindungen und Chinonimidchlorid, 6. Mitt.: Über Hydroxychalkone

Zusammenfassung Es wird über die Reaktion verschieden methylsubstituierter 4-Hydroxychalkone mittels Chinonimidchlorid berichtet und gezeigt, daß die Ausbeute an 2,6-Dimethylphenol-indophenol bei der Spaltung von 4,4-Dihydroxy-3,5,3-trimethylchalkon (VII) am RingB dreimal so groß ist als beim 4,4-Dihydroxy-3,3,5-trimethylchalkon (III) am RingA.

---

The reaction between several methyl-4-hydroxy-chalkones and p-benzoquinone-monochloroimine has been studied. It has been shown that the yield of 2.6-dimethylphenol-indophenol from the cleavage of 4.4-dihydroxy-3.5.3-trimethyl-chalkon (VII) at ringB is three times the yield resulting from the cleavage of 4.4-dihydroxy-3.3.5-trimethylchalkon (III) at ringA.

---

---

Herrn Prof. Dr.H. Bretschneider zum 60. Geburtstag gewidmet.     

Osmotic Coefficients and Activity Coefficients of Nonaqueous Electrolyte Solutions. Part 2. Lithium Perchlorate in the Aprotic Solvents Acetone, Acetonitrile, Dimethoxyethane, and Dimethylcarbonate

Vapor pressure lowering by the addition of lithium perchlorate to the aprotic solvents acetone (0.02–0.6 m), acetonitrile (0.05–1.2 m), dimethoxyethane (0.02–0.4 m), and dimethylcarbonate (0.03–1.8 m) was measured at 25°C with high precision. The experimental data for the corresponding osmotic coefficients are compared to those obtained from the Pitzer equations and chemical model calculations. Mean activity coefficients are derived from the osmotic coefficients.     

Osmotic Coefficients and Activity Coefficients of Nonaqueous Electrolyte Solutions. Part 4. Lithium Bromide, Tetrabutylammonium Bromide, and Tetrabutylammonium Perchlorate in Acetone

Vapor pressure lowering by the addition of lithium bromide (0.03–0.8m), tetrabutylammonium bromide (0.01–0.8m), and tetrabutylammonium perchlorate (0.02–3.6m) to acetone was measured at 25°C with high precision. The experimental data of the corresponding osmotic coefficients are compared to those obtained by the use of Pitzer equations and chemical model calculations. Mean activity coefficients are derived from the osmotic coefficients.     

Röntgenographische Untersuchungen an Germanaten mit Melilith-Struktur

Zusammenfassung Es wurden Germanate der Zusammensetzung Ca₂Al[AlGeO₇] und Ca₂Ga[GaGeO₇] dargestellt und mittels Einkristallaufnahmen untersucht. Die beiden Verbindungen haben Melilith-Struktur und bilden eine lückenlose Mischkristallreihe. Für erstgenannte Verbindung ergibt die Intensitätsrechnung eine statistische Al/Ge-Verteilung, analog der Al/Si-Verteilung im Gehlenit, Ca₂Al[AlSiO₇].

---

X-Ray studies on germanates of the melilite-type

Germanates of composition Ca₂Al[AlGeO₇] and Ca₂Ga[GaGeO₇] have been synthesized and studied by means of single-crystal photographs. The compounds crystallize with melilite structure and form a continuous solid solution. The intensity calculation for the first-named phase indicates a statistical Al/Ge-distribution, analogous to the Al/Si-distribution in gehlenite, Ca₂Al[AlSiO₇].

---

---

Herrn Prof. Dr.M. Pailer zum 60. Geburtstag gewidmet.