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  • 1
    Digitale Medien
    Digitale Medien
    Struktur der Triarymethyl-Dimeren (1970)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1101-1106 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19701030414
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  • 2
    Digitale Medien
    Digitale Medien
    Zur Konjugation in makrocyclischen Bindungssystemen, XVIII. Benzo[12]annulene: 5.6.11.12-Tetradehydro-tribenzo[a.e.i]cyclododecen, 11.12.15.16-Tetradehydro-dibenzo[a.e]cyclododecen und 5.6.11.12.15.16-Hexadehydro-dibenzo[a.e]cyclododecen (1970)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 103 (1970), S. 1157-1167 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: 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.
    Notizen: 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.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19701030418
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  • 3
    Digitale Medien
    Digitale Medien
    Intramolekulare Wechselwirkungen zwischen Dreifachbindungen, XII. 2.2′-Bis-[alkin-(1)-yl]-biphenyle (1972)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 105 (1972), S. 2310-2319 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Intramolecular Interactions of Triple Bonds, XII. 2.2′-Bis(1-alkynyl)biphenylsThe preparation of 2.2′-diethynylbiphenyl (2, R = H) was achieved by double Wittig reaction from 2.2′-bis(bromomethyl)biphenyl via 2.2′-divinylbiphenyl which by bromine addition and elimination of hydrogen bromide yielded 2 (R = H). Two other syntheses of 2 (R = H) are reported. 2 (R = H) reacted with hydrogen bromide under cross-linkage of the triple bonds to 9.10-bis(bromomethyl)phenanthrene (6). By catalytic hydrogenation 9.10-dimethylphenanthrene (5) was obtained in small yields in addition to the normal hydrogenation product 4.2.2′-Bis(1-propynyl)biphenyl (2, R = CH3) and the cyclic diacetylenes 3 (n = 2, 3 and 4) were obtained from 2 (R = H) via the dilithium acetylide by alkylation with the corresponding alkyl iodides.For 3 (n = 2) the potential barrier for the ring inversion was determined from temperature dependent 1H n.m.r. to be 17.9 ± 0.2 kcal/mole at TC = 87° (in 1-chloronaphthalene). The conformational stability of 3 (n = 2) is discussed in comparison to 1.
    Notizen: Zur Darstellung von 2.2′-Diäthinyl-biphenyl (2, R = H) wurde durch doppelte Wittig-Reaktion aus 2.2′-Bis-brommethyl-biphenyl und Formaldehyd 2.2′-Divinyl-biphenyl dargestellt, das durch Brom-Addition und Bromwasserstoff-Eliminierung 2 (R = H) ergab. Zwei weitere Synthesen von 2 (R = H) werden angegeben. 2 (R = H) reagierte bei der Bromwasserstoff-Addition unter Wechselwirkung der Dreifachbindungen zu 9.10-Bis-brommethyl-phenanthren (6). Ebenso entstand bei der katalytischen Hydrierung neben dem normalen Hydrierungsprodukt 4 in geringer Ausbeute 9.10-Dimethyl-phenanthren (5).Aus 2 (R = H) wurden über das Dilithiumacetylid durch Alkylierung mit den betreffenden Alkyljodiden 2.2′-Bis-[propin-(1)-yl]-biphenyl (2, R = CH3) und die cyclischen Diacetylene 3 (n = 2, 3 und 4) erhalten.Aus der Temperaturabhängigkeit des 1H-NMR-Spektrums wurde für 3 (n = 2) die Potentialbarriere für die Ringinversion zu 17.9 ± 0.2 kcal/Mol bei TC = 87° (in 1-Chlor-naphthalin) bestimmt. Die konformative Stabilität von 3 (n = 2) im Vergleich zu 1 wird diskutiert.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19721050724
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  • 4
    Digitale Medien
    Digitale Medien
    [2.2](2,6)- and [2.2](2,5)Pyrazinophanes: Synthesis and Molecular Structure (1990)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 523-533 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Hofman 1,6-elimination / Pyrazine derivatives / [2.2]Pyrazinophanes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The title compounds 1-3 and their methyl derivatives 4-7 were synthesized 2,11-dithia[3.3]pyrazinophanes 24-26 or by Hofmann 1,6-elimination of the appropriate [(5-methyl-2-pyrazinyl)methyl]trimethylammonium hydroxides followed by dimerization of the generated 2,5-dihydro-2,5-dimethylenepyrazines. α-Chlorination of the methylpyrazines 8-10 with N-chlorosuccinimide gave the required precursors 11, 12, 14, 17 and 18. The results of the X-ray structure determinations for 1-4 and 7 which indicate an unequivocal isomer assignment are discussed with regard to steric strain in these molecules. The electronic spectra of the pyrazinophanes 7-7 are reported and compared with those of the parent methylpyrazines.
    Zusätzliches Material: 6 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19901230319
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  • 5
    Digitale Medien
    Digitale Medien
    Photoinduced electron transfer in porphyrin-quinone cyclophanes, 5. Quinone-porphyrin-quinone and quinone-porphyrin-donor cyclophanes: Syntheses, structures and electron-transfer-related properties (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 2275-2283 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Photosynthesis models ; Photoinduced electron transfer ; Porphyrin-quinone cyclophanes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: To study the structure dependence of photoinduced electron transfer between porphyrins and quinones the concept of a new family of porphyrin-quinone cyclophanes with vertical arrangements of porphyrin and quinone units is presented. The syntheses of the quinone-porphyrin-quinone cyclophane 1, the prototype of this series, and of the quinone-porphyrindonor cyclophanes 12 and 14 are described. Spectroscopic data are discussed with regard to the structures involved and in relation to electron-transfer reactions occurring in these systems.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19921251016
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  • 6
    Digitale Medien
    Digitale Medien
    Photoinduced electron transfer in porphyrin-quinone cyclophanes, 7. Porphyrin-quinone cyclophanes with gradually varied acceptor strength: Physical properties related to electron transfer (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 2303-2310 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Porphyrin-quinone cyclophanes ; Photoinduced electron transfer in porphyrin-quinone cyclophanes ; Absorption and emission spectra of porphyrin-quinone cyclophanes ; Redox potentials and electron transfer in intramolecular porphyrin-quinone systems ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Absorption and emission spectra of the doubly quinone-bridged porphyrin cyclophanes 1-4 with gradually varied acceptor strength as well as of the single-bridged analogues 5-9 and 10-13 are reported. Reduction and oxidation potentials of these intramolecular porphyrin-quinone systems have been determined. Based on these data, fluorescence quenching as well as time-resolved fluorescence lifetime measurements are discussed in terms of photoinduced electron transfer to the charge-separated zwitterionic state.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19921251018
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  • 7
    Digitale Medien
    Digitale Medien
    Zinc Complexes of Porphyrin-Quinone Cyclophanes: Syntheses, Structures and Electron-Transfer-Related Properties (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 231-236 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Zinc porphyrin complexes ; Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Electron-transfer mechanism in metalloporphyrin-quinone cyclophanes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: 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.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19941270133
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  • 8
    Digitale Medien
    Digitale Medien
    Photoinduced electron transfer in porphyrin-quinone cyclophanes, 6. Porphyrin-quinone cyclophanes with gradually varied acceptor strength: Syntheses and characterizations (1992)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 125 (1992), S. 2285-2301 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Porphyrin cyclophane syntheses ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: For studying intramolecular electron-transfer reactions, three groups of double- and single-bridged porphyrin-quinone cyclophanes 1-4, 5-9, and 11-14, resp., with gradual variation of quinone acceptor strengths were synthesized. As key intermediates for building up the porphyrin-cyclophane skeleton the correspondingly 3,6-substituted 1,4-bis[4-(2-formylphenyl)-butyl]-2,5-dimethoxybenzenes 15-20 were synthesized. Condensation with pyrrole yielded the doubly bridged porphyrin cyclophanes 42-45; via the bis(dipyrrolylmethyl) derivatives 46-51 and 64-67 the single-bridged porphyrin cyclophanes 58-63 and 72-75 were obtained by acidic condensation with triethyl formate. Cleavage of the methoxy groups and oxidation yielded the corresponding porphyrin-quinone systems. Some magnesium and zinc complexes of these cyclophanes are described. Spectroscopic data (MS, 1H NMR) are reported in support of the proposed structures.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19921251017
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  • 9
    Digitale Medien
    Digitale Medien
    Syntheses and Properties of New Quinone-Bridged Diphenyl- and Tetraphenylporphyrins (1994)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 223-229 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Absorption and emission spectra of porphyrin-quinone cyclophanes ; Photosynthesis models ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: 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.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19941270132
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  • 10
    Digitale Medien
    Digitale Medien
    Photoinduced Electron Transfer in Porphyrin-Quinone Cyclophanes, 8 Conformational Mobility and Crystal Structures of Porphyrin-Quinone Cyclophanes (1993)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 811-821 
    Details
    ISSN: 0009-2940
    Schlagwort(e): Porphyrin-quinone cyclophanes ; Photoinduced electron transfer ; Porphyrin cyclophanes, conformational mobility of, crystal structures of ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: In order to correlate photoinduced electron-transfer in porphyrin-quinone cyclophanes to specific molecular conformations, the internal mobility of single-and double-bridged porphyrin-quinone cyclophanes was studied by low-temperature 1H-NMR measurements. The dynamic processes observed are discussed in terms of N-H/N tautomerisation, of the rotation of the rings in the bridges, and of a specific “swinging bridge” process back and forth between two equivalent unsymmetrical conformations with a tilted orientation of the porphyrin and quinone ring planes. For comparison with the conformational situation in solution the results of X-ray structure analyses of 3(X=OMe) and 6, as representative examples of single-bridged quinone-porphyrin cyclophanes, and of the corresponding tetramethoxybenzene-bridged octamethylporphyrin cyclophane 4(X=OMe) are reported and discussed. In contrast to the previously solved crystal structure of the quinone-porphyrin-quinone cyclophane 1(X=H), all three X-ray structure analyses of the single-bridged porphyrin cyclophanes proved the existence of unsymmetrical, tilted-plane structures similar to those discussed as the stable conformations in the “swinging bridge” process.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/cber.19931260336
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