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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2265-2277 
    ISSN: 0009-2940
    Keywords: Inositol ethers ; Mesogens ; Liquid crystals, thermotropic ; Hydrogen bonding ; Supramolecular structures ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis and Liquid-Crystalline Properties of myo- and scyllo-Inositol Multi EthersSelectively alkylated myo- and scyllo-inositol ethers were obtained by multi-step syntheses starting from commercially available myo-inositol. Necessary conversions of axial hydroxy groups into equatorial ones were achieved using either potassium superoxide (KO2) or potassium nitrite (KNO2) as oxygen nucleophiles for the transformation of myo- into scyllo- inositol derivatives. Polarizing microscopic and thermoanalytical studies of numerous members of three families (6, 13, and 20) of inositol ethers reveal for most of them thermotropic liquid-crystalline behavior. Furthermore, in case of the two long-chain scyllitol tetraethers 13d and e an unusual thermopolymorphism has been found. The number, position, and stereochemical arrangement of alkyl chains attached to the inositol cores strongly influence the mesogenic properties of these biomolecule derivatives, chemically vicinal diols and tetrols. The self-assembly of the studied inositol multi ethers to columnar mesophases of “supramolecular structures” is discussed considering geometrical features of these molecules and their capabilities to aggregate by hydrogen bonding.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1707-1712 
    ISSN: 0009-2940
    Keywords: Amphiphiles ; Carbohydrates ; Fluoro-D-glucoses ; Fluoro Sugars ; Liquid crystals ; Mesogens ; Scyllitol derivatives ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Liquid Crystalline Compounds, 79[1a].-Amphiphilic and Mesogenic Carbohydrates, V[1b].-Amphiphilic Fluoroglucose and Fluoroscyllitol DerivativesIn order to look at the influence of the OH-F substitution in the cyclic, hydrophilic section (head group) of amphiphilic sugars and of scyllitol derivatives on their liquid crystalline properties for the first time, we synthesized various differently structured fluoro-D-glucose derivatives [2-O-decyl-α-D-glucopyranosyl fluoride (4), 4-O-tetradecyl-α-D-glucopyranosyl fluoride (5), 6-O-hexadecyl-α-D-glucopyranosyl fluoride (6), 6-deoxy-6-fluoro-2,3-di-O-hexadecyl-D-glucopyranose (9), 2-deoxy-2-fluoro-4,6-O-alkyliden-D-glucopyranosen (11a-d), 3-deoxy-3-fluoro-5,6-di-O-tetradecyl-D-glucofuranose (15)] as well as the 2-deoxy-2-fluoro-2,3,4,5,6-tetra-O-hexyl-scyllo-in-osit (19). Substitution of an OH group for a fluorine atom in amphiphilic derivatives destabilizes the thermotropic mesophase as it was to be expected so that either no or only narrowrange mesophases result. Both thermotropic and lyotropic liquid crystal phases occur in the series of 2-deoxy-2-fluoro-D-glucopyranose acetals 11 which are discussed in detail and which are compared with the analogous 2-hydroxy derivatives 12. Only 11c-d are thermotropic fluoro mesogens.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 24 (1996), S. 19-41 
    ISSN: 1573-1111
    Keywords: Arenes ; electron donor-acceptor complexes ; heterocycles ; induction phenomena ; liquid ; crystals ; metallomesogens ; radial multiynes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract We describe here an overview on the formation of mesophases by the interaction between large flat aromatic cored molecules and relatively small organic electron acceptors which form stacked, sandwich-like columnar π-π electron donor-acceptor complexes. The inclusion of suitable donor and acceptor components may be used to induce columnar mesophases in mixtures of compounds which can be either mesomorphic or non-mesomorphic in the pure state. With judicious choice of donor and acceptor partners, induced mesophases of remarkable range and thermal stability can be prepared.
    Type of Medium: Electronic Resource
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