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  • 1
    Electronic Resource
    Electronic Resource
    Anisotropic thermal expansion of potassium dinitramide: a variable-temperature crystallographic study (2001)
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 57 (2001), S. 113-118 
    Details
    ISSN: 1600-5740
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Notes: The structure of potassium dinitramide (KDN), KN3O4, has been refined in the temperature range 85–298 K from single-crystal X-ray diffraction data. The unit-cell axial lengths and the cell volume decrease linearly on cooling with the b axis being the most sensitive to the change of temperature. The β cell angle increases with decreasing temperature. The thermal expansion of KDN is significantly anisotropic, expanding along the b axis [010] more than three times the amount parallel to any other crystallographic direction. Other eigenvectors of the thermal expansion tensor lie approximately parallel to the diagonals of the ac plane. A rigid-body analysis of the dinitramide ion using the TLS formalism was performed and shows that the thermal motion of the anion is well represented by the rigid-body model. The eigenvalues of the libration tensor show significant anisotropy, whereas the translation tensor is close to isotropic. The variation of all descriptions of the thermal motion with respect to temperature indicates an anharmonic contribution to the mean field potential. The direction of greatest unit-cell expansion coincides with the largest components of the displacement tensor of the potassium ions and the direction of the largest atomic amplitudes due to the libration of the dinitramide anions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1107/S0108768100018887
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  • 2
    Electronic Resource
    Electronic Resource
    Conversion of 2,4-dihydroxybenzaldehyde to 2-benzoyloxy-4-hydroxybenzaldehyde and structural characterization of both precursor and product (1999)
    Springer
    Journal of chemical crystallography 29 (1999), S. 185-191 
    Details
    ISSN: 1572-8854
    Keywords: 2-Benzoyloxy-4-hydroxybenzaldehyde ; 2,4-dihydroxybenzaldehyde ; hydrogen bonding ; x-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract 2,4-Dihydroxybenzaldehyde can be acylated at the 2 position if the more reactive 4 position is first protected as the methylmethoxy ether. Deprotection permits isolation of 2-benzoyloxy-4-hydroxybenzaldehyde. 2,4-Dihydroxybenzaldehyde, C7H6O3, crystallizes in P21/c, with a = 7.3762(6), b = 11.7455(9), c = 7.3149(6) Å, β = 90.533(2)°, Z = 4, and D X = 1.448 g cm−3. The individual molecules are characterized by an intramolecular hydrogen bond. The molecules form sheets with additional intermolecular hydrogen bonds. 2-Benzoyloxy-4-hydroxybenzaldehyde, C14H10O2, crystallizes in Pca21, with a = 24.2629(14), b = 3.8445(2), c = 12.3727(8) Å, Z = 4, and D X = 1.394 g cm−3. The molecules consist of two planar halves twisted by 51.63(5)° about the ester linkage. Intermolecular hydrogen bonding joins the molecules into ribbons approximately parallel to c.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1009570027191
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Supramolecular Assemblies of 1,2-Dicarbadodecaborane(12) with Bowl-Shaped Calix[5]arene (1999)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 1999 (1999), S. 195-200 
    Details
    ISSN: 1434-1948
    Keywords: Calixarene ; Carboranes ; Host-guest chemistry ; Non-classical hydrogen bonding ; Supramolecular chemistry ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of globular 1,2-dicarbadodecaborane(12) (o-carborane) 1 with the bowl-shaped container molecule calix[5]arene 2 affords either the crystalline 1:1 or 1:2 host-guest complexes (o-carborane)(calix[5]arene)(CH2Cl2) 3, (o-carborane)(calix[5]arene)(toluene) 4 and (o-carborane)(calix[5]arene)2(CH2Cl2)0.55. The three complexes show a remarkable range of different supramolecular interplay beyond the common structural unit, a ball-and-socket nano-structure or supermolecule [(o-carborane)∩(calix[5]arene)]. Complex 3 forms dimeric [(o-carborane)∩(calix[5]arene)]2 units, and 5 has an additional edge on interaction between the supermolecule and a secondary calix[5]arene host.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
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