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  • 1
    ISSN: 0009-2940
    Keywords: Cyclophane anions ; Indene derivatives ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyclophane, XXVII. - [2.2]Indenophan-Mono-und Dianionen: Darstellung und kernmagnetische Resonanz-SpektrenDie Darstellung, chemischen und physikalischen Eigenschaften negativ geladener polycyclischer Cyclophane werden beschrieben. Through-space-elektronische Wechselwirkungen und through-space-Anisotropieeffekte werden aus den Protonen- und Kohlenstoffkernresonanzspektren abgeleitet. Die untersuchten Systeme gehören zu zwei Hauptgruppen: a) paratrope 4nπ-polycyclische Dianionen, z. B. [2.2]Benzo[g]chrysenocyclophan-Dianion (122-) und b) (4n + 2)π-polycyclische Mono- und Dianionen, die diatrop sind. In den Dianionen sind beide Decks geladen: z. B. syn-[2.2]Indenocyclophan-Dianion (132-) und sein anti-Isomer (142-). Bei den untersuchten Monoanionen handelt es sich um die des [2.2]-Benzoindenocyclophans (151-), 4,5,17,18-Tetramethyl[2.2]benzoindenocyclophans (161-) und des 12-Methyl[2.2]benzoindenocyclophans (171-). Die spektroskopischen Eigenschaften der lagigen Anionen werden mit denjenigen von 1,4-Dimethylindenyl-Anion (111-) und mit Literaturwerten der neutralen Cyclophane 1-11 verglichen. Es wird eine Trennung von Anisotropie- und chargetransfer-Effekten durchgeführt, die es erlaubt, die Netto-through-space-Wechselwirkung abzuschätzen.
    Notes: The preparation and chemical and physical properties of negatively charged polycyclic cyclophanes are reported. The throughspace electronic interactions and the through-space anisotropy effects were deduced from proton and carbon nuclear magnetic resonance data. The systems studied belong to two main groups: a) 4nπ-polycyclic dianions which are paratropic, e.g. [2.2]benzo-[g]chrysenophane dianion (122-), and b) (4n + 2)π-polycyclic mono- and dianions, which are diatropic. In the dianions both layers are charged, e. g. syn-[2.2]indenocyclophane (132-) and its anti isomer (142-). The monoanions studied are [2.2]benzoindenocyclophane (151-), 4,5,17,18-tetramethyl[2.2]benzoindenocyclophane (161-), and 12-methyl[2.2]benzoindenocyclophane (171-). The spectroscopic properties of the layered anions were compared with those of 1,4-dimethylindenyl anion (111-) and with literature data of neutral cyclophanes, viz. 1-11. A differentiation between the anisotropy and charge-transfer effects has been made and it enables the estimation of the net through-space interaction.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0009-2940
    Keywords: Cyclophanes ; Indenyl anions ; Iron complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: [2.2]Metacyclophane can be directly formylated according to the Rieche method to give 4-formyl[2.2]metacyclophane (12) in 44% yield. The synthesis of the [2]metacyclo[2]indenophane 8 from the aldehyde 12 by the pathway previously employed for the corresponding [2.2]paracyclophanes failed due to the harsh conditions of the cyclization step. An alternative synthesis of 8 and its isomer 9 involving the construction of the five-membered ring prior to that of the cyclophane unit succeeded. Compounds 8 and 9 were obtained as an 82:18 mixture, deprotonation of which afforded the anion 10, which shows long-term stability. The 1H-NMR spectrum of this anion does not exhibit a through-space charge transfer due to its structure. The 1H-NMR parameters and molecular mechanics calculations are discussed. Both faces of 10 react in the presence of FeCl2 · 2 THF and a twentyfold excess of LiCp to give a 70:30 mixture of the ferrocene derivatives 7 and 35.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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