Uranextraktion mit Triphenylarsinoxid

Zusammenfassung Es wird eine neue extraktive Trennungsmethode für Uran beschrieben. Mit Hilfe einer Lösung von Triphenylarsinoxid in Chloroform lassen sich Uranylionen aus wäßriger Lösung im pH-Gebiet von 2 bis 3 extrahieren. Trennungen von verschiedenen anderen Metallionen sind ohne Schwierigkeiten möglich; im Falle von Mitextraktionen kann mit Äthylendiamintetraacetat maskiert werden. Trennungsbeispiele werden angegeben.

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Summary Uranyl ions can be extracted from aqueous solutions by means of triphenylarsinic oxide in chloroform within a pH range of 2 to 3. Separations from several foreign ions can be achieved without any complications; ions co-extracted with uranium can be masked by EDTA. Examples are described.

     

Synthesis and Structures of the Novel Pyridoxal Oxime Derivatives

Novel pyridoxal oxime derivatives were prepared and characterized by means of IR, ¹H and ¹³C NMR spectroscopy. The crystal structures of the 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-1,2-dimethylpyridinium iodide 1 and 3-hydroxy-4-hydroxyiminomethyl-5-hydroxymethyl-1,2-dimethylpyridinium chloride monohydrate 2 were determined by X-ray analysis. The both compounds crystallize in the triclinic crystal system, space group P . Crystal data: 1 a = 6.286(2) Å, b = 8.748(4) Å, c = 11.736(4) Å, = 104.02(3)°, = 94.70(3)°, = 107.44(6)°, V = 589.0(4) ų, Z = 2, R = 0.0526; 2 a = 6.8980(5) Å, b = 8.6409(6) Å, c = 11.1777(6) Å, = 111.138(5)°, = 93.114(6)°, = 105.158(5)°, V = 591.57(7) ų, Z = 2, R = 0.0492. The bond distances and angles in both structures agree very well. The main difference between these structures was observed in the orientation of the hydroxymethyl group with respect to the pyridinium ring. In the both structures intramolecular hydrogen bond forming six-membered ring were observed. The intermolecular OsI hydrogen bonds in the crystal structure of the compound 1 form dimers. In the crystal structure of compound 2, the water molecules and chlorines build eight-membered rings, which are also connected to pyridinium cations by OsCl and OsO intermolecular hydrogen bonds forming a three-dimensional network.     

Synthesis and Crystal Structure Determination of 6-(N-Isopropyl)Amidino-2-Methylbenzothiazole Hydrochloride Monohydrate and 2-Amino-6-(N-Isopropyl)Amidinobenzothiazole Hydrochloride

Two novel substituted amidino-benzothiazoles 6-(N-isopropyl)amidino-2-methylbenzothiazole 4 and 2-amino-6-(N-isopropyl)amidinobenzothiazole 6 were prepared in multistep synthesis in form of hydrochloride salts. They were characterized by means of IR, ¹H, and ¹³C-NMR spectroscopy and elemental analysis. The crystal structures have been also determined by X-ray analysis. Both compounds crystallize as colorless prisms in the triclinic crystal system, space group P . Crystal data: (4) a = 8.741(4) Å, b = 9.602(7) Å, c = 9.946(2) Å, = 63.94(3)°, = 79.18(2)°, = 79.68(3)°, V = 732.1(6) ų, Z = R = 0.0396; a = 8.106(1) Å, b = 9.148(2) Å, c = 9.291(2) Å, = 104.83(1)°, = 103.36(2)°, = 90.62(1)°, V = 646.2(2) ų , Z = 2, R = 0.0376. The bond distances and angles in both structures are almost similar. Between these two structures was found the difference in the orientation of the 6-(N-isopropyl)amidino moiety with respect to the benzothiazole ring. In the crystal structures of the both compounds the intermolecular hydrogen bonds form three-dimensional networks.     

Synthesis and structural studies of C-5 aryl- and C-6 alkyl-substituted pyrimidine derivatives

C-5 and C-6 disubstituted pyrimidine derivatives 2–7 were synthesized. Introduction of the aryl rings at C-5 of pyrimidine moiety in 5 and 6 was performed using palladium-catalyzed Stille cross-coupling reaction. The novel C-6 fluorophenylalkylated 5-phenylpyrimidine derivative (7) was prepared by lithiation of 5-phenylpyrimidine (6) and subsequent reaction of thus obtained organolithium intermediate with p-fluoroacetophenone. The structures of 3, 4 and 6 were determined by X-ray crystal structure analysis. Both methoxy groups in these structures adopt a synperiplanar conformation with respect to the N1 and N3 atoms of the pyrimidine ring. The molecules of 3 and 4 are linked through weak Br···Br interactions into zig-zag chains. The molecules of 6 are assembled into layers by one C–H···O hydrogen bond, C–H···π and aromatic π···π stacking interactions.     

Nuclear photodisintegration without effective charges

It is explicitly shown that the Thomas-Reiche-Kuhn electric dipole sum rule, for he case of nuclear photodisintegration, separates into a contribution due to dipole absorption by the nucleus as a whole, and a contribution representing excitation of the internal degrees of freedom (Bethe-Levinger sum rule). The concept of the “effective charge”, often employed in this connection, is not utilized in our derivation, and is seen to be not essential.     

Optical technologies for the read out and quality control of DNA and protein microarrays

Microarray formats have become an important tool for parallel (or multiplexed) monitoring of biomolecular interactions. Surface-immobilized probes like oligonucleotides, cDNA, proteins, or antibodies can be used for the screening of their complementary targets, covering different applications like gene or protein expression profiling, analysis of point mutations, or immunodiagnostics. Numerous reviews have appeared on this topic in recent years, documenting the intriguing progress of these miniaturized assay formats. Most of them highlight all aspects of microarray preparation, surface chemistry, and patterning, and try to give a systematic survey of the different kinds of applications of this new technique. This review places the emphasis on optical technologies for microarray analysis. As the fluorescent read out of microarrays is dominating the field, this topic will be the focus of the review. Basic principles of labeling and signal amplification techniques will be introduced. Recent developments in total internal reflection fluorescence, resonance energy transfer assays, and time-resolved imaging are addressed, as well as non-fluorescent imaging methods. Finally, some label-free detection modes are discussed, such as surface plasmon microscopy or ellipsometry, since these are particularly interesting for microarray development and quality control purposes.