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  • General Chemistry  (8)
  • Cyclophanes  (2)
  • Supramolecular chemistry  (2)
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  • 1
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Chemistry - A European Journal 2 (1996), S. 624-633 
    ISSN: 0947-6539
    Schlagwort(e): catenanes ; macrocycles ; rotaxanes ; self-assembly ; tetrathiafulvalenes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A general stepwise approach is described for the preparation of tetrathiafulvalene (TTF)-based linear and monoand dimacrocyclic compounds incorporating one or two 1,4-dioxyphenylene, 9,10-dioxyanthrylene, or 1,5- or 2,6-dioxynaphthylene units from readily available starting materials. By utilizing the π-π stacking interactions of the TTF unit with the dipyridinium dication of 1,1′-[1,4-phenylenebis (methylene)] bis-4,4′-bipyridinium bis(hexafluorophosphate), a rotaxane and two [2]catenanes were synthesized starting from the linear and monomacrocyclic compounds, respectively. From the dioxyphenylene-based dimacrocycle, three [3]pseudocatenanes (trans, cis, and a mixture of cis/trans isomers) were obtained with the trans compound as the major product. From the dioxyanthrylene dimacrocycle, only the trans-[3]pseudocatenane was obtained. Catenane products were formed quantitatively from the 1,5-dioxynaphthylene dimacrocycle in a template-directed reaction, affording a trans-[3]pseudo-catenane together with a [4]pseudocatenane (mixture of cis/trans isomers). From the 2,6-dioxynaphthylene dimacrocycle, a cis-[3]pseudocatenane was obtained as the major product and a trans-[3]pseudocatenane as the minor one. For the [3]pseudocatenanes (i.e., both the cis and trans catenanes), in which the TTF units were clamped by the tetracationic macrocycle, isomerizations were completely prevented even in the presence of trifluoroacetic acid. All new rotaxanes and catenanes were characterized by electrospray mass spectrometry, and the cis- and trans- [3]pseudocatenanes were additionally investigated by 1H NMR spectroscopy. The electrochemical and spectral properties of the rotaxane and the catenanes are reported. Catenane formation increases the redox potentials of the TTF unit. The results demonstrate the versatility of TTF as a building block in the construction of supramolecular structures.
    Zusätzliches Material: 4 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 3335-3341 
    ISSN: 1434-193X
    Schlagwort(e): Catenanes ; Donor-acceptor interactions ; Self-assembly ; Supramolecular chemistry ; Tetrathiafulvalenes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis of three novel macrocycles 3-5based on the two electron donors bis(2,5-dimethylpyrrolo)[3,4-d]tetrathiafulvalene (1) and 1,4-hydroquinone is presented. Their abilities to include the electron acceptor paraquat (6) have been investigated by UV/Vis and 1H NMR spectroscopy and an X-ray crystallographic analysis. Also, the complex formation between the cyclic acceptor cyclobis(paraquat-p-phenylene) (7) and different tetrathiafulvalene derivatives has been studied. A strong association between 1 and 7 facilitates the self-assembly of catenanes from the macrocycles 3-5. However, the preferred position of the cyclic acceptor 7in the catenanes around either the pyrrolo-annelated TTF or around the hydroquinone donor relies on a fine balance between all the individual noncovalent forces acting in cooperation.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 3
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1998 (1998), S. 1743-1757 
    ISSN: 1434-193X
    Schlagwort(e): Cyclophanes ; Electrochemistry ; Tetrathiafulvalenes ; Macrocycles ; Crystal structure ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: A series of new macrobicyclic tetrathiafulvalenophanes of type 1 and 2 with three tetrathiafulvalene bridges has been prepared under high-dilution conditions using a stepwise selective protection-deprotection of tetrathiafulvalenethiolates. All the macrobicyclic tetrathiafulvalenes, along with the intermediate compounds 5 and 6 and the unexpected tetrathiafulvalene pentamers 17, were studied by cyclic voltammetry. An electrochemical investigation using the Bard-Anson equation and thin-layer cyclic voltammetry has been carried out, allowing an estimate of the number of electrons involved in each redox process of these multi-redox compounds. The X-ray crystal structure showing the unusual crystal packing of 2a is also presented.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 4
    ISSN: 1434-193X
    Schlagwort(e): Tetrathiafulvalene ; Macrocyclic ligands ; Receptors ; Crystal structure ; Mass spectrometry ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis of new aza-macrocyclic tetrathiafulvalene (TTF) derivatives is described, with a view to limiting the structural distortion of the redox-active TTF moiety and to favour metal complexation. An X-ray diffraction determination of one of these crown systems is provided. The electrochemical properties of these redox-active macrocyclic ligands are studied by cyclic voltammetry. Their complexing ability towards silver ions is evaluated by FAB mass spectrometry.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 5
    ISSN: 1434-193X
    Schlagwort(e): Polymethines ; Dyes ; Electronic structure ; Nonlinear optics ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis of a series of new sulfur-containing polymethine dyes is reported. The linear optical properties of these bis(1,3-dithiole) (mono-, tri-, penta-, and hepta-)methine dyes show intense and narrow optical absorptions typical of cyanine dyes. The absorption maximum is increasingly red-shifted from 489 nm for the monomethine dye to 911 nm for the heptamethine compound. Based on third-harmonic generation measurements at fundamental wavelength between 1064 nm and 1907 nm, γ values were evaluated to lie in the range between 1·10-33 e.s.u. and 14·10-33 e.s.u. showing that the nonlinear response of the bis(1,3-dithiole) polymethine dyes compare well with other organic π-electron systems of similar size. Comparisons of the experimental values of γ to calculated static values obtained by ab initio and semiempirical calculations (AM1, PM3) have been made as well as comparisons to dynamic values estimated from a free-electron model. The computed dynamic values can be described by a power law; γ ≈ L5 where L denotes the length of the molecules. Our studies confirm the stabilizing effect of a carbocyclic ring in the cyanine backbone making the heptamethine dye an unusually stable and highly nonlinear polymethine chromophore possessing a strong NIR optical transition and very good transparency in the visible region.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 2807-2815 
    ISSN: 1434-193X
    Schlagwort(e): Host-guest chemistry ; Macrocycles ; Pseudorotaxanes ; “Self-complexation” ; Tetrathiafulvalene ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Two “self-complexing” macrocycles (22ab and 23ab) based on a methylthio-substituted derivative of the electron donor tetrathiafulvalene (TTF) and a cyclic bipyridinium acceptor have been prepared.[1] When “decomplexed” by fractional crystallization, the rigid compound 22b was not able to undergo “recomplexation” to any significant degree, whereas for the more flexible 23b, an equilibrium between “complexed” (23a) and “uncomplexed” (23b) compounds was slowly re-established in solution according to UV/Vis measurements. 23ab was thus seen to behave as a “thermo-switch”, although with a rather slow response. Any complexation between the two separated components, i.e. the cyclic acceptor 3 and the tetrakis(methylthio)tetrathiafulvalene 6, was not observed by 1H-NMR spectroscopy. However, 3 was able to bind unsubstituted TTF (5) in its cavity, albeit with a small association constant of only 60 M-1. Taking advantage of the tetravalency of TTF, we also report the synthesis of a “self-complexing” pyromellitic diimide/TTF macrocycle (33ab). Whereas 22ab and 23ab were prepared employing the concept of template-assisted synthesis,[2] the synthesis of 33ab did not rely on this technique.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 7
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1997 (1997), S. 2177-2187 
    ISSN: 0947-3440
    Schlagwort(e): Tetrathiafulvalene ; Cyclophanes ; Macrocycles ; Donor-acceptor systems ; Supramolecular chemistry ; Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The syntheses and some physical properties (redox potentials) of cyclic tetrathiafulvalenes (TTF) are reviewed. The ring closure is generally performed in one of two different ways: (i) by coupling of 1,3-dithiol derivatives thereby forming the central fulvene bond, or (ii) by cyclization of a preformed TTF derivative. The second route is very efficient when using the cyanoethyl protection/deprotection method and has made possible the preparation of a number of two- and three-dimensional macrocycles, e.g. mono-, bis- and tetramacrocycles, oligomeric macrocycles and cage-type molecules. The use of tetrathiafulvalenophanes in supramolecular chemistry is also exemplified in this microreview.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 8
    ISSN: 0044-8249
    Schlagwort(e): Catenane ; Kronenether ; Selbstorganisation ; Tetrathiafulvalene ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 9
    ISSN: 0570-0833
    Schlagwort(e): catenanes ; crown ethers ; self-assembly ; tetrathiafulvalenes ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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