Extraktion von Sb(III) aus sauren L?sungen und Extraktions-Atomabsorptionsbestimmung von Sb in Kupfer, Blei, Zink und Cadmium

Ohne Zusammenfassung

---

Extraction of Sb(III) from strongly acid media and determination of Sb in copper, lead, zinc and cadmium by means of extraction/atomic-absorption spectrophotometry

     

Desoxy-nitrozucker 14. Mitteilung 1-C-Nitroglycale. Herstellung und Umsetzung mit einigen Stickstoff-Nucleophilen

1-C-Nitroglycals. Preparation and Reaction with Some Nitrogen Nucleophiles Acetylation of the 1-deoxy-1-nitromannopyranoses 2 and 6 was accompagnied by spontanous β-elimination to give the 1-C-nitroglucals 3 and 7 , respectively, while acetylation of the gluco- and galacto-configurated 1-deoxy-1-nitropyranoses 8 and 14 gave the acetates 9 and 15 , respectively (Scheme 1). The acetylation of the ribo- and arabino-configurated 1-deoxy-1-nitrofuranoses 19 and 21 also occurred without β-elimination to give the acetates 20 and 22 , respectively (Scheme 2). Mild base treatment of the previously described O-acetylnitro-β-D -glucose 4 , the O-acetylnitro-β-D -pyranoses 9 and 15 , and the O-acetylnitro-β-D -furanoses 17 , 20 , and 22 gave the 1-C-nitroglycals 3 , 10 , 16 , 18 and 23 , respectively (Scheme 1 and 2). The previously obtained 1-C-nitroglucal 3 was deacetylated by treatment with MeOH in the presence of KCN or sodium m-nitrophenolate to give the free nitroglucal 5 . Deacetylation of the benzylidene protected 1-C-nitroglucal 10 (MeOH, NaOMe) gave the 4,6-O-benzylidene-1-C-nitroglucal 11 and traces of the 2-O-methyl-1-C-nitromannoses 12 and 13 . The UV, IR, ¹H-NMR and ¹³C-NMR spectra of the 1-C-nitroglycals are discussed. In solution, the 1-C-nitroglycals 1 , 5 , 7 , 10 , 11 , and 16 adopt approximately a ⁴H_5? and 3 a flattened ⁴H₅ conformation. The structure of 5 was established by X-ray analysis. In the solid state, 5 adopts a sofa conformation, which is stabilized by an intramolecular H-bond. The β-addition of NH₃ to the 1-C-nitroglucals 7 and 10 was followed by an O→ N acetyl migration to give exclusively anomeric pairs of the N-acetyl-1-nitromannosamine derivatives 24 / 25 and 26/27 , respectively (Scheme 3). The β-addition of methylamine, octadecylamine, and tryptamine to the 1-C-nitroglucal 11 also stereoelectronically controlled and gave the crystalline N-alkyl-1-nitromannosamines 28 , 29 , and 30 , respectively. The stereoelectronically controlled β-addition of NH₃ to the 1-C-nitrogalactal 16 , followed by acetylation, yielded exclusively the talosamine derivative 31 , while the reversible β-addition of azide ions to 16 gave the anomeric 2-azido-1-nitrogalactoses 32 and 33 . The β-addition of azide ions to the 1-C-nitroglucal 1 led to the 2-azido-1-nitromannose 34 . In the presence of excess formaldehyde, this addition was followed by a Henry reaction. Chromatography of the crude product was accompagnied by solvolytic removal of the NO₂ group to give the 3-azidomannoheptulose 35 in high yields (Scheme 4).     

Anwendung von Detergentien zur direkten Bestimmung von Fe, Zn und Cu in Milch mit Hilfe der Flammen-Atomabsorptions-Spektralphotometrie

Ohne Zusammenfassung

---

Application of detergents to the direct determination of Fe, Zn and Cu in milk by means of flame atomic-absorption spectrophotometry

     

Herstellung hochgereinigtermyo-Inosit-1-phosphat-Synthase aus stierhoden und Vergleich mit dem entsprechenden Enzym aus Rattenhoden

Using the method of affinity chromatography on NAD-Sepharose, themyo-inositol-1-phosphate synthase (EC 5.5.1.4) from testicles of the bull could be purified to homogeneity. Although its specificity, its activity and its molecular weight are all very similar to the corresponding properties of the enzyme from rat testicles, there are also some considerable differences between the two enzyme proteins. Whereas the rat enzyme consists of two different pairs of subunits with the molecular weights of 3.5×10⁴ and 7.2×10⁴, respectively, the bull enzyme consists of four subunits, all of them apparently having the same molecular weight of 5.45×10⁴. The isoelectric points of the two enzyme proteins are also different; with the help of the method of isoelectric focussing they were determined as 3.95 for the rat enzyme and 4.59 for the enzyme from the bull.     

Umsetzung von gemischten Siliciumhalogeniden und von Halogendisilanen mit Pyridin und 1,10-Phenanthrolin

Zusammenfassung Die Reaktion gemischter Siliciumhalogenide mit Pyridin (=py) oder 1,10-Phenanthrolin (=phen) führte zu den Additionsverbindungen SiClBr₃(py)₂, SiClBr₃(phen), SiCl₃Br(py)₂, SiCl₃Br(phen), SiCl₂J₂(py)₄, SiCl₂J₂(phen), SiCl₃J(py)₃ und SiCl₃J(phen). Eine Dismutation der gemischten Siliciumhalogenide wurde dabei nicht beobachtet. Ihre Darstellung erfolgte durch Umsetzung von ClSi(Net ₂)₃, Cl₂Si(Net ₂)₂ und Cl₃Si(Net ₂) (et=C₂H₅) mit HBr oder HJ. Si₂Cl₆ reagierte mit 3py zu SiCl₄(py)₂ und 1/n [SiCl₂(py)] _n , Si₂Br₆ analog zu SiBr₄(py)₂ und 1/n [SiBr₂(py)] _n , Si₃Cl₈ mit 4py zu SiCl₄(py)₂ und 2/n [SiCl₂(py)] _n .

---

The reactions of mixed silicon halogenides with pyridine (=py), or 1.10-phenanthroline (=phen) resulted in the addition compounds SiClBr₃(py)₂, SiClBr₃(phen), SiCl₃Br(py)₂, SiCl₃Br(phen), SiCl₂I₂(py)₄, SiCl₂I₂(phen), SiCl₃I(py)₃ and SiCl₃I(phen). Dismutation of the mixed silicon halogenides in these reactions was not observed. Their preparation was achieved by cleaving of Si–N-bonds in ClSi(Net ₂)₃, Cl₂Si(Net ₂)₂ and Cl₃Si(Net ₂) (et=C₂H₅) with HBr or HI. Si₂Cl₆ reacted with 3py forming SiCl₄(py)₂ and 1/n [SiCl₂(py)] _n . The analogous reaction of Si₂Br₆ resulted in SiBr₄(py)₂ and 1/n [SiBr₂(py)] _n . Si₃Cl₈ and 4py formed SiCl₄(py)₂ and 2/n [SiCl₂(py)] _n .

---

---

Mit 1 Abbildung

---

66. Mitt.:U. Wannagat, K. Hensen, P. Petesch undF. Vielberg, Mh. Chem.98, 1415 (1967).

---

Zugleich 7. Mitt. über Verbindungen von Nichtmetallhalogeniden mit Pyridin und seinen Homologen; 6. Mitt.:U. Wannagat, K. Hensen undP. Petesch, Mh. Chem.98, 1423 (1967).

---

Mit Auszügen aus den DissertationenF. Vielberg, Techn. Hochsch. Aachen 1956, undK. Hensen, T. H. Aachen 1962.