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  • 1
    Electronic Resource
    Electronic Resource
    Isomeric Tetrakis(dimethylamino)naphthalenes: Syntheses, Structure-Dependence of Basicities, Crystal Structures, and Physical Properties (2000)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 1617-1622 
    Details
    ISSN: 1434-193X
    Keywords: Tetrakis(dimethylamino)naphthalenes ; Basicity ; Hydrogen bonds ; Cyclicvoltammetry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---For comparison to the recently described 2,3,6,7-tetrakis(dimethylamino)naphthalene (1) the three isomers 2,3, and 4 were synthesized. The basicities of this group of isomers are strongly dependent upon the different mutual orientations of the pairs of dimethylamino substituents: only the isomers 3 and, partially, 4, both with dimethylamino groups in adjacent peri-positions of the naphthalene, are strong “proton sponges”. For the isomers 1 and 2 with the same number and kind of twofold dimethylamino substituents in neighbouring ortho-positions, however, no significant basicity increase is observed. To explain this difference between the two groups of isomers it is suggested that in the ortho-pairs of 1 and 2 the C-N bonds diverge considerably, leading to an increased N···N distance and consequently to less stable [N···H···N]+ hydrogen bonds in contrast to the parallel C-N bonds in the peri-substituted isomers 3 and 4. X-ray crystal structure analyses of the bases and of some of the salts derived therefrom were solved and are discussed. Cyclic voltammetry indicates that 1 to 4 are strong electron donors, reacting easily to radical cations or dications which with suitable acids have been obtained as salts.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    π…π interactions of flavins, 5. Syntheses, structures and physical properties of flavin systems with covalent bonding to π donors and π acceptors (quinones) (1995)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1995 (1995), S. 1827-1836 
    Details
    ISSN: 0947-3440
    Keywords: Isoalloxazinophanes ; Flavins ; π Donors ; π Acceptors ; Quinones ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To study π…π interactions of flavins of different redox states with π-electron donors and acceptors, the syntheses of compounds in which such π systems are linked to flavins by using the „cyclophane concept“ were attempted and partially achieved. The syntheses of the metacyclo-isoalloxazinophanes 1 and 2 are reported as well as the X-ray structure analysis of 2. The conversion of 1 or 2 to the benzoquinono-isoalloxazinophanes 3 or 4, respectively, was not achieved, obviously due to the specific sterical shielding of the methoxy groups in the isoalloxazinophanes. Benzoquinone-isoalloxazine systems in which the two components are linked by only one triethylene chain were obtained. Spectroscopic and electrochemical properties related to intramolecular interactions are reported.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.1995199510256
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  • 3
    Electronic Resource
    Electronic Resource
    New Electron Donor-Acceptor Compounds, 51. [3](N,N′)-1,8;4,5-Naphthalenetetracarboxdiimido- [3](2,7)Pyrenophane and Its [4,4]Cyclophane Homologue (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 1551-1556 
    Details
    ISSN: 0947-3440
    Keywords: Intramolecular electron donor-acceptor interactions ; [3.3]- and [4.4]Cyclophanes of pyrene and 1,4;5,8-naphthalenetetracarboxdiimide ; Charge transfer ; Through-space interactions ; UV/Vis spectroscopy ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron donor-acceptor cyclophanes 1 and 2, consisting of pyrene as the donor component and 1,8;4,5-naphthalenete-tracarboxdiimide as the acceptor component fixed by methylene chains in parallel face-to-face orientations, have been synthesized. The structures, based on an X-ray analysis of 1 and on spectroscopic properties, are discussed with reference to intramolecular charge-transfer interactions and are compared to those of the related excimer models [3.3]- and [4.4]pyrenophanes 3 and 4.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719970735
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  • 4
    Electronic Resource
    Electronic Resource
    Photoinduced Electron-Transfer in Porphyrin-quinone Cyclophanes, 15.Part 14: Ref. Distance Dependence of Photoinduced Electron-Transfer: Syntheses and Structures of Naphthalene-Spacered Porphyrin-Quinone Cyclophanes (1997)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 2321-2336 
    Details
    ISSN: 0947-3440
    Keywords: Photoinduced electron-transfer, distance dependence ; Naphthalene-spacered porphyrin-quinone cyclophanes ; Synthesis, conformations, structural analysis ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Syntheses, conformational and structural analyses of porphyrin-quinone cyclophanes 2 with naphthalene-spacers are presented and the findings are compared with data for previously investigated analogous benzene-spacered compounds 1. In combination with data for the biphenylene- and anthracene-spacered porphyrin-quinone cyclophanes 3 and 4, to be published in following papers, the results reported herein allow some appraisal to be made of the distance dependences of photoinduced electron-transfer from porphyrin to quinone units.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199719971121
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  • 5
    Electronic Resource
    Electronic Resource
    [2.2](2,7)Pyrenophan als Excimeren-Modell: Synthese und spektroskopische Eigenschaften (1979)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 886-898 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [2.2](2,7)Pyrenophane as an Excimer Model: Synthesis and Spectroscopic Properties
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197919790618
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  • 6
    Electronic Resource
    Electronic Resource
    Elektron-Donor- Acceptor-Verbindungen, XXI. Intramolekulare Chinhydrone mit [2.2.2.21(1,2,4,5)Cyclophan- Struktur (1979)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1979 (1979), S. 1258-1269 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Electron-Donor-Acceptor Compounds, XXI. - Intramolecular Quinhydrones with [2.2.2.2](1,2,4,5)Cyclophane Structure
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.197919790817
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  • 7
    Electronic Resource
    Electronic Resource
    Elektron-Donor-Acceptor-Verbindungen, XXVII Chinhydrone der [4.4]Paracyclophan-ReiheHerrn Professor Dr. M. Seefelder zum 60. Geburtstag gewidmet. (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1052-1064 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XXVII.  -  Quinhydrones of the [4.4]Paracyclophane SeriesIn the context of the determination of the distance and orientation dependence of charge-transfer interactions the diastereomeric quinhydrones 5 and 6 of the [4.4]paracyclophane series were prepared. Cyclisation of 1,4-bis(3-bromopropyl)-2,5-dimethoxybenzene with 2,5-dimethoxy-1,4-benzenedimethanethiol yielded the diastereomeric dithia[5.5]paracyclophanes 9/10 which, via the corresponding disulfones 11/12, were converted into the 6,9,16,19-tetramethoxy-[4.4]paracyclophanes 7/8. The stereoisomers 7/8, as well as the pairs of diastereomers 9/10 and 11/12. have been separated; experiments on thermal isomerisation are reported. The assignment of 7/8 to the pseudoortho and pseudogeminal constitution was established by an X-ray structure analysis of 7 the molecular structure of which is discussed. Oxidative demethylation of 7 and 8 yielded the diastereomeric quinhydrones 5 and 6. Charge-transfer absorptions of these compounds are compared with those of the corresponding [3.3]paracyclophane quinhydrones 3b and 4b and are discussed under the aspect of the specific conformational situation present in the [4.4]paracyclophane system.
    Notes: Zur Untersuchung der Abstands- und Orientierungsabhängigkeit der Charge-Transfer-Wechsel-wirkungen wurden die diastereomeren Chinhydrone 5 und 6 der [4.4]Paracyclophan-Rehe synthetisiert. Die Cyclisierung von 1,4-Bis(3-brompropyl)-2,5-dimethoxybenzol mit 2,5-Dimethoxy-1,4-benzoldimethanthiol ergab die diastereomeren Dithia[5.5]paracyclophane 9/10, die über die entsprechenden Disulfone 11/12 in die 6,9,16,19-Tetramethoxy[4.4]paracyclophane 7/8 über-führt wurden. Ebenso wie die Diastereomeren-Paare 9/10 und 11/12 lieβen sich auch 7/8 in die Stereoisomeren trennen; über Isomerisierungsversuche wird berichtet. Die Zuordnung von 7/8 zur pseudoortho- und pseudogeminalen Reihe geschah durch Röntgen-Strukturanalyse von 7, für das die Molekülstruktur diskutiert wird. Oxidative Demethylierung von 7 und 8 diastereomeren Chinhydrone 5 und 6. Die Charge-Transfer-Absorptionen dieser Verbindungen werden mit denen der entsprechenden [3.3]Paracyclophan-Chinhydrone 3b und 4b verglichen und unter dem Gesichtspunkt der im [4.4]Paracyclophan-System vorliegenden besonderen Konformationsverhältnisse diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119810611
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  • 8
    Electronic Resource
    Electronic Resource
    Elektron-Donor-Acceptor-Verbindungen, XXVIII Synthese und Charge-Transfer-Eigenschaften von 4,7-Diaza[2.2]paracyclophanen (1981)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1981 (1981), S. 1065-1072 
    Details
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electron Donor-Acceptor Compounds, XXVIII.  -  Synthesis and Charge-Transfer Properties of 4,7-Diaza[2.2]paracyclophanes
    Notes: 2,5-Bis(brommethyl)pyrazin (3) wurde dargestellt und mit 1,4-Benzoldimethanthiol und 2,5-Dimethoxy-1,4-benzoldimethanthiol zu den entsprechenden 5,8-Diaza-2,11-dithia[3.3]paracyclophanen cyclisiert. Photochemische Schwefel-Extrusion ergab 4,7-Diaza[2.2]paracyclophan (1) und die stereoisomeren 12,15-Dimethoxy-4,7-diaza[2.2]paracyclophane 5 und 6, die chromatographisch getrennt wurden.  -  Absorptions- und Emissionsspektren von 5 und 6 beweisen die π-Acceptor-Eigenschaft eines Pyrazins, das im [2.2]Paracyclophan-System einem starken Elektron-Donor gegenübersteht. Die beobachtete Lösungsmittelabhängigkeit der Charge-Transfer-Absorptionen von 5 und 6 (Abb.) wird auf eine Änderung der Elektronenaffinität des Pyrazin-Teils durch Solvatation und Protonierung zurückgeführt. Der Vergleich von Charge-Transfer-Eigenschaften der Stereoisomeren 5 und 6 zeigt die Orientierungsabhängigkeit der Donor-Acceptor-Wechselwirkung.2,5-Bis(bromomethyl)pyrazine (3) was prepared and cyclized with 1,4-benzenedimethanethiol and 2,5-dimethoxy-1,4-benzenedimethanethiol to give the corresponding 5,8-diaza-2,11-dithia[3.3]-paracyclophanes. Photochemical sulfur extrusion yielded 4,7-diaza[2.2]paracyclophane (1) and the stereoisomeric 12,15-dimethoxy-4,7-diaza[2.2]paracyclophanes 5 and 6 which were separated by chromatography.  -  Absorption and emission spectra of 5 and 6 demonstrate the π-acceptor quality of pyrazine when linked in a [2.2]paracyclophane system vis-a-vis to a strong electron donor. The solvent dependence of charge-transfer absorptions observed for 5 and 6 (Fig.) is ascribed to the change in electron affinity of the pyrazine moiety by solvation and protonation. By comparing charge-transfer properties of the stereoisomers 5 and 6 the orientation dependence of electron donor-acceptor interactions is shown.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.198119810612
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  • 9
    Electronic Resource
    Electronic Resource
    REAKTIONSFÄHIGE HETEROCYCLISCHE AMIDE DER KOHLENSÄURE III. N.N′-Carbonyl-di-benzimidazol und N.N′ -Carbonyl-di-benztriazol (1958)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 612 (1958), S. 187-193 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: N.N'-Carbonyl-di-benzimidazol (I) und N.N'-Carbonyl-di-benztriazol (II), die sich aus Benzimidazol und Benztriazol durch Umsetzung mit Phosgen erhalten lassen, sind weniger reaktionsfähig als die früher beschriebenen N.N'-Carbonyl-Derivate des Imidazols und Triazols. Auch sie werden aber in 50-proz. wäßrigem Tetrahydrofuran schon bei Zimmertemperatur innerhalb weniger Stunden quantitativ unter CO2-Entwicklung zu Benzimidazol bzw. Benztriazol hydrolysiert. Mit Anilin setzt sich I bei Zimmertemperatur glatt zu Diphenylharnstoff um; die Aminolyse von II führt dagegen nur bis zur Stufe des N-Carbonsäureamids. Die Ursache dieses unterschiedlichen Reaktionsverhaltens ist, daß das Benzimidazol-N-carbonsäureanilid - wie IR-spektroskopisch nachgewiesen wurde  -  in Lösung schon bei Zimmertemperatur in Benzimidazol und Phenylisocyanat dissoziiert, während sich für das N-Carbonsäureanilid des Benztriazols selbst bei erhöhter Temperatur keine solche Dissoziation nachweisen läßt.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.19586120121
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  • 10
    Electronic Resource
    Electronic Resource
    Reaktionsfähige N-Carbonsäureester Und N-Carbonsäureamide Des Imidazols Und Triazols (1957)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 609 (1957), S. 83-88 
    Details
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aus Imidazol und Triazol lassen sich mit Chlorameisensäure-äthylester die N-Carbonsäure-äthylester erhalten, die mit Aminen zu Carbaminsäureestern (Urethanen) und mit Alkoholen zu Kohlensäureestern reagieren.  -  Auch die N-Carbonsäureamide, die aus Imidazol und Triazol mit Isocyanaten entstehen, zeichnen sich infolge des aktivierenden Einflusses der heterocyclischen Ringe auf die Carbonylgruppe durch eine ungewöhnliche Reaktionsfähigkeit aus: in wasserhaltigen Lösungen werden sie schon bei Zimmertemperatur unter CO2-Entwicklung hydrolysiert; mit Aminen entstehen substituierte Harnstoffe und mit Alkoholen und Phenolen Carbaminsäureester.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.19576090109
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