Browsing by Author "Krüger, Carl"

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    Modelle für Amin-Aromaten-Exciplexe: π-π- versus n-π-Wechselwirkung bei isomeren [2]Naphthalino[2](2,6)pyridinophanen und [2]Naphthalino[2](2,6)pyridinophan-1,11-dienen (Transanulare Wechselwirkung bei [m.n]Phanen ; 29)
    (1985) Haenel, Matthias; Lintner, Birgit; Benn, Reinhard; Rufinska, Anna; Schroth, Gerhard; Krüger, Carl; Hirsch, Susanne; Irngartinger, Hermann; Schweitzer, Dieter
    Als Exciplex-Modelle wurden die [2.2]Naphthalinopyridinophane 5, 6 und die entsprechenden Diene 3, 4 synthetisiert. Die Molekülstrukturen von 3, 5 und 6 wurden durch Röntgenstrukturanalyse bestimmt. Absorptionsspektren und vor allem die für Exciplexe typisch rot verschobenen und strukturlosen Fluoreszenz-Emissionen von 3 - 6 zeigen Orientierungsabhängigkeiten und werden mit n-π-Wechselwirkung zwischen dem Pyridin-Stickstoff und Naphthalin in 3,4 und π-π-Wechselwirkung zwischen den Aromaten-Einheiten in 5, 6 interpretiert.
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    Novel (imino-η6-arene)chromium-complexes and their diastereoselective intramolecular hetero-Diels-Alder reactions
    (1993) Laschat, Sabine; Noe, Ralf; Riedel, Michael; Krüger, Carl
    Novel (imino-η6-arene)chromium complexes 3 with nonactivated olefins tethered to the 2-azadiene system were prepared and further used in a new diastereoselective intramolecular Lewis-acid-catalyzed hetero-Diels-Alder reaction to give (η6-octahydroacridine)chromium complexes 4. The trans selectivity of the cyclization reaction is mainly controlled by the Cr- (CO)3 fragment and to a minor extent by the catalyst, solvent, and substituents. Complexes 4 also could be obtained by a one-pot reaction starting from aldehyde 1, (o-toluidine)Cr(CO)3 (2), and Lewis acid. The stereochemistry of 4a was established by single-crystal X-ray structure analysis.
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    X-ray investigations of the low-temperature phases of the organic metals α- and β-(BEDT-TTF)2I3
    (1986) Endres, Helmut; Keller, Heimo J.; Swietlik, Roman; Schweitzer, Dieter; Angermund, Klaus; Krüger, Carl
    The structure of single crystals of the organic metals α- and β-(BEDT-TTF) was determined at 100 K, well below the phase transitions indicated by resistivity and thermopower measurements as well as by differential thermal analysis. In the α-phase no unusual change of the room temperature unit cell but a slight variation in the triiodide network and especially a more pronounced dimerization in one of the two donor stacks have been found. The β-phase develops a superstructure with a unit cell volume three times as large as that at room temperature and with pronounced distortions of the I3--ions.