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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1101-1106 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Structure of Triarylmethyl DimersStructure 3 is confirmed for the dimer of triphenylmethyl (1) by 13C. n.m.r. spectra of [α-13C]triphenylmethyl dimer, the synthesis of which is described. The interpretation given for the proton resonance of 1-dimer2 is also supported by the 1H. n.m.r. spectrum of tris-(4-deuterophenyl)methyl dimer. However, for 9-phenylfluorenyl dimer the hexaarylethane structure 4 is proposed on the basis of the 1H. n.m.r. spectrum.
    Notes: 13C-NMR-Spektren des [α-13C]Triphenylmethyl-Dimeren, dessen Synthese beschrieben wird, beweisen die Struktur 3 für das dimere Triphenylmethyl (1). Das 1H-NMR-Spektrum des Tris-[4-deutero-phenyl]-methyl-Dimeren bestätigt ebenfalls die Interpretation der Protonenresonanz des 1-Dimeren2 im Sinne der Formel 3. Für das 9-Phenyl-fluorenyl-Dimere wird dagegen auf Grund des 1H-NMR-Spektrums die Struktur eines echten Hexaaryläthans 4 vorgeschlagen.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conjugation in Macrocyclic Systems, XVIII. Benzo[12]annulenes: 5,6,11,12-Tetradehydrotribenzo[a,e,i]cyclododecene, 11,12,15,16-Tetradehydrotribenzo[a,e]cyclododecene and 5,6,11,12,15,16-Hexadehydrodibenzo[a,e]cyclododeceneThe syntheses of the title compounds 2, 6 and 5 are reported. In 2 and 6 the resonance of the inner olefinic hydrogen is shifted to τ -0.1 and τ -0.5. The relevance of this finding for the assumption of an induced paramagnetic ring current in the geometrically analogous monocyclic dehydro[12]annulene 4 is discussed.
    Notes: Über die Synthese der Titel-Verbindungen 2, 6 und 5 wird berichtet. Bei 2 und 6 ist die Resonanz des inneren olefinischen Protons durch den Anisotropie-Effekt der beiden Drei-fachbindungen bis τ -0.1 bzw. τ -0.5 verschoben. Die Relevanz dieses Befundes für die Annahme eines induzierten paramagnetischen Ringstroms in dem geometrisch analogen monocyclischen Dehydro [12]annulen 4 wird diskutiert.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1095-1100 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: [1-13C]Naphthalene: Synthesis, n.m.r. Spectra, e.s.r. Spectrum of the Radical Anion and the Automerization Problem„13C-NMR-Untersuchungen organisch-chemischer Reaktionen, I“.[1-13C]Naphthalene was prepared via [1-13C]-4-phenylbutanoic acid (from 1-bromo-3-phenylpropane and [13C]carbon dioxide), [1-13C]tetralone and [1-13C]tetraline. 1H n. m. r. and 13C n. m. r. spectra are discussed as well as the e. s. r. spectrum of the [1-13C]naphthalene radical anion. By these magnetic resonance measurements it is shown that an automerization of naphthalene catalyzed by aluminium chloride does not occur under the conditions mentioned in literature10,12.
    Notes: [1-13C]Naphthalin wurde über [1-13C]-4-Phenyl-buttersäure (aus 1-Brom-3-phenyl-propan und [13C] Kohlendioxid), [1-13C]Tetralon und [1-13C]Tetralin synthetisiert. 1H-HMR-und 13C-NMR-Spektren sowie das ESR-Spektrum des Radikalanions werden diskutiert. Mit Hilfe der genannten drei magnetischen Resonanzmethoden wurde gezeigt, daß eine durch Aluminiumchlorid katalysierte Automerisation des Naphthalins unter den in der Literatur angegebenen10,12 Bedingungen nicht erfolgt.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 1993-2008 
    ISSN: 0009-2940
    Keywords: Electron donor-acceptor cyclophanes ; Charge-transfer compounds ; Crown ethers ; Oligooxaparacyclophane metal complexes, charge-transfer absorption of, crystal structures of ; Cyclophanes, electron donor-acceptor ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The intramolecular oligooxa[3n.3]paracyclophane quinhy-drones 2-5 (with n = 3 to 6) were synthesized and their interactions with alkali and alkaline earth metal and mercury(II) ions were studied by electron absorption and NMR spectroscopy. Remarkable enhancements of the CT absorptions were observed by complexation with metal ions of the pentaoxa[15.3]paracyclophane quinhydrone 4 and the hexaoxa[18.3]paracyclophane quinhydrone 5 to the corresponding complexes 6a-e and 7, respectively. The various donor-acceptor orientations and the crown ether-like complexation in the calcium complex 6d, the mercury complex 6e and the barium complex 7 were determined by X-ray analysis. Moreover, the X-ray structures of the tetramethoxy-2,5,8-trioxa[9.3]paracyclophane 8a, a precursor of the quinhydrone 2, and of the pentaoxa[15.3](2,5)-p-benzoquinonophane 20, the product of oxidative demethylation of the quinhydrone 4, are given. For comparison with the cyclic quinhydrones acyclic analogs are also described.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0009-2940
    Keywords: Flavin-flavin interactions ; Isoalloxazinophanes ; Bis(isoalloxazinyl)arenes ; Bis(isoalloxazines), absorption spectra and cyclovoltammetry ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to study the orientation and distance dependence of π … π interactions between flavins in various redox states, two approaches to bis(isoalloxazine) model compounds are presented: The [3.3]isoalloxazinophanes 2 and 4 and the rigid single-bridged 1,8-naphthalene- and 1,8-anthracene-linked bis(isoalloxazine) systems 6, 8 and 26 were synthesized, characterized, and studied by spectroscopic methods and cyclic voltammetry. The experimental data are discussed in comparison with “monomeric” isoalloxazines and flexible single-chain trimethylene-linked bis(isoalloxazine) reference compounds. X-Ray structure analyses are reported for the 1,8-bis(isoalloxazinyl)-9,10-dihydroanthracene 26 and for 22 as an example of 1,8-disubstituted naphthalenes with strongly polar substituents comparable to 6.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0009-2940
    Keywords: Isoalloxazinocyclophanes ; Pyridinio-isoalloxazinophanes ; Nicotinic ester and nicotinic acid isoalloxazinophanes, intramolecular interactions of, X-ray structure analyses of ; Flavin-nicotinamide models ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: As model systems for active site complexes in flavoenzymes, flavin and nicotinamide analogues were linked together in cyclophane skeletons of specific sterical structures. Elaborating this concept, we prepared [4]metacyclo[3](10,6)isoalloxazinophane (3), [4](3,1)pyridino[3](10,6)isoalloxazinophane (4), as well as the 16-methoxycarbonyl and the 16-carboxylato derivatives (2 and 34, resp.), of 4 by multistep syntheses. For the isoalloxazinophanes 2, 3, 4, and 34 X-ray structure analyses were performed and are discussed with regard to intramolecular interactions. Preliminary UV/Vis-spectroscopic results related to π…π interactions in these isoalloxazinophanes are reported.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 223-229 
    ISSN: 0009-2940
    Keywords: Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Absorption and emission spectra of porphyrin-quinone cyclophanes ; Photosynthesis models ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses and spectroscopic properties of the porphyrin-quinone cyclophanes 1, 2 and 3 of which structural and/or conformational studies have recently reported[1] are described. Physical properties related to photoinduced electron-transfer reactions like redox potentials, absorption and emission spectra were determined for these compounds.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 231-236 
    ISSN: 0009-2940
    Keywords: Zinc porphyrin complexes ; Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Electron-transfer mechanism in metalloporphyrin-quinone cyclophanes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to increase the driving force for photoinduced electron-transfer reactions of porphyrin-quinone cyclophanes, the zinc complexes 3a-e and 4a-e were prepared from the corresponding cyclophanes of the 1 and 2 series. Electron-transfer-related properties like redox potentials and fluorescence spectra were determined for 3a-e and 4a-e. The X-ray structure analysis of 4a indicates that for the very fast and solvent-independent electron transfer in these systems a specific mechanism involving an interaction of a quinone carbonyl group with the zinc might be considered as an alternative to through-space electron-transfer.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1107-1118 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conjugation in Macrocyclic Systems, XV. Benzo[12]annulenes: 5,6,11,12,17,18-Hexadehydrotribenzo[a, e, i]cyclododecene5.6-Didehydrotribenzo[a,e,i]cyclododecen (6) was obtained by a double Wittig reaction with phthaldialdehyde starting from 2.2′-bis-(bromomethyl)diphenylacetylene. Bromination of 6 and HBr elimination yielded 5,6,11,12,17,18-hexadehydrotribenzo[a, e, i]cyclododecene (1). U.v., i.r., Raman and 1 H n.m.r. spectra of 1 and the e.s.r. spectrum of 1-radicalanion are discussed with regard to the rigid planar benzo[12]annulene structure of 1 and to the intramolecular interactions between the triple bonds. Experiments on isomerisation and complex formation of 1 are reported.
    Notes: 5.6-Didehydro-tribenzo[a.e.i]cyclododecen (6) wurde ausgehend von 2.2′- Bis-brommethyl-diphenylacetylen durch doppelte Wittig-Reaktion mit Phthaldehyd erhalten. Bromierung von 6 und HBr-Eliminierung ergab 5.6.11.12.17.18-Hexadehydro-tribenzo[a.e.i]cyclododecen (1). UV-, IR-, Raman-und 1H-NMR-Spektren von 1 sowie das ESR-Spektrum des 1-Radikal-anions werden unter dem Gesichtspunkt der starren ebenen Tribenzo[12]annulen-Struktur von 1 und der Intramolekularen Wechselwirkung zwischen den Dreifachbindungen diskutiert. Über Isomerisierungs-und Komplexbildungsversuche mit 1 wird berichtet.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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