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  • 1990-1994  (4)
  • 1
    ISSN: 1434-4475
    Keywords: Copper clusters ; Silver clusters ; Crystal structures ; Thallium complexes ; N-Butyl-N′-phenylsulfonylthiourea ; Luminescence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Summary The acid anion of N-butyl-N′-benzenesulfonylthiourea (BuBsT) forms numerous 1/1 complexes with the univalent ions Cu(I), Ag(I) and Tl(I). The crystal structures of two different copper(I) clusters (Cu(BuBsT))x, (x=6, 4) are discussed. The hexamer containing a distorted Cu6 octahedron is luminescent, while the analogous tetramer containing a distorted Cu4 tetrahedron is not. The copper atoms of both clusters form coordinate linkages with the sulfonamide nitrogen and the thiourea sulphur of the ligands (S,N-coordination). One sulfonyl oxygen per ligand is bound to the NHC4H9 group of the same ligand through a hydrogen bond. Ag(BuBsT) forms three different luminescent modifications. One of them (Ag(BuBsT)-II) is isotype to (Cu(BuBsT))6 and therefore hexamer, too. Tl(BuBsT) mainly forms dimers in CHCl3 solution.
    Notes: Zusammenfassung Das Säureanion von N-Butyl-N′-benzolsulfonylthioharnstoff (BuBsT) bildet mit Cu(I) einen lumineszierenden hexameren und einen nicht lumineszierenden tetrameren Cluster (Cu(BuBsT))x; x=6, 4. Röntgenstrukturanalysen belegen für x=6 eine verzerrt oktaedrische und für x=4 eine verzerrt tetraedrische Anordnung der Cu-Atome. Die Liganden beider Cluster sind über den Thioharnstoff-Schwefel und den Sulfonamid-Stickstoff mit den Cu-Atomen verknüpft (S,N-Koordination). Jeweils ein Sulfonyl-Sauerstoffatom pro Ligand bildet eine intramolekulare Wasserstoffbrücke zu der NHC4H9-Gruppe der gleichen Ligandeinheit aus. Ag(BuBsT) tritt in Form von drei lumineszierenden Modifikationen auf, von denen eine (Ag(BuBsT)-II) hexamer ist (isotyp mit (Cu(BuBsT))6). Tl(BuBsT) liegt in CHCl3-Lösung überwiegend als Dimer vor.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 338 (1990), S. 717-720 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The acyl substituents of N,N-disubstituted N'-acylthioureas have a significant influence on the polarity of the chelates formed. A considerable decrease in the stability of the complexes is observed changing from aromatic to aliphatic acyl substituents. In order to separate the acylthiourea complexes, high performance thin-layer chromatography (HPTLC) methods have been used, whereby both standard methods, adsorption chromatography on silicagel layers and RP-chromatography are applicable. The strong UV-absorption properties of acylthiourea chelates allow a very sensitive detection of the separated complexes. By the method described several metals can be determined simultaneously on a migration distance of 2 to 5 cm.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 341 (1991), S. 566-568 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Benzoylthioureas are excellent reagents for the solvent extraction of gold. Very effective separations of gold from platinum group metals and base metals are possible due to control of the extraction parameters. The best results, a fast extraction and low residual gold concentrations 〈1 μg/l are obtained with N,N-Di-n-hexylbenzoylthiourea/toluene.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' Zeitschrift für analytische Chemie 339 (1991), S. 142-144 
    ISSN: 1618-2650
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The solvent extraction of Rh(III) and Pt(IV) with N,N-di-n-hexyl-N'-benzoylthiourea (DHBT)/toluene is substantially accelerated in the presence of tin(II) chloride. Low concentrations of SnCl2 from 0.02 to 0.03 mol/l and metal/ligand ratio of 1:4 (Pt) resp. 1:9 (Rh) lead to low residual metal concentrations below the detection limit of GFAAS. The extraction behaviour of Pt(II), Ru(III) and Ir(III) is not affected by the treatment with SnCl2.
    Type of Medium: Electronic Resource
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