03 Fakultät Chemie

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/4

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Author: search.filters.author.Götz, GüntherSubject: search.filters.subject.540

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    On the spin distribution in bridged anthracene-viologen molecules : an electron-nuclear double resonance study
    (1992) Sariciftci, Serdar; Werner, Andreas; Grupp, Arthur; Mehring, Michael; Götz, Günther; Bäuerle, Peter; Effenberger, Franz
    Studies on the spin distribution in the radical state of anthracene-σ bridge viologen supermolecules with different bridge units are reported. Electronnuclear double resonance experiments (ENDOR) were performed on electrochemically reduced molecules. Proton hyperfine coupling constants at different molecular sites were obtained and are discussed in detail. The experimentally determined values are compared with quantum chemical calculations of the INDO type. The observed spin distribution depends significantly on the type of the bridging unit. The relevance of the spin distribution for electron transfer in donor-bridge-acceptor molecular complexes is discussed.
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    Synthese und Eigenschaften von σ-verbrückten Anthracen-Viologenen
    (1992) Effenberger, Franz; Götz, Günther; Bäuerle, Peter
    The synthesis of the donor-acceptor compounds 2, 7, and 12 where the anthracene donor and the viologen acceptor are linked by a saturated bridge (polymethylene or the bicyclo[2.2.2]octanyl moiety) is described. While the preparation of 2a-c is straightforward, new procedures for the synthesis of the bicyclo compounds 7 and 12 had to be developed. Unexpectedly, the viologens 13d, e could be obtained by direct nucleophilic substitution of the corresponding tertiary and neopentyl-type alkyl tosylates with 4,4-bipyridine. By comparison of the emission spectra of the compounds 2a and 12a, b the strong fluorescence quenching indicates an electron transfer from the donor to the acceptor.
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    Selective synthesis of α-substituted oligothiophenes
    (1993) Bäuerle, Peter; Würthner, Frank; Götz, Günther; Effenberger, Franz
    An improved synthesis of selectively mono- and dibrominated oligothiophenes using the system N-bromosuccinimide/dimethylformamide is reported together with the preparation of the corresponding α-alkyl and α,α-dialykl derivatives which represent potent biologically active agents.