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  • 1980-1984  (6)
  • Inorganic Chemistry  (5)
  • New reversed stationary LG-phases  (1)
  • General Chemistry
  • crystal structure
  • 1
    ISSN: 1612-1112
    Keywords: New reversed stationary LG-phases ; Crosslinking of oligomers by γ-radiation ; Shielding of silanol-groups ; Surface deactivation ; Characterization methods
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Continuing our work on new silanization reagents for producing chemically-modified small-particle, silica support material exhibiting improved chromatographic performance and especially good shielding of silanol groups in respect of solute-stationary phase interaction, we have developed new silica-based polymer phases with different “polarities” by crosslinking or polymerization reactions induced by γ-radiation. Polybutadienes or polysiloxanes were immobilized on non-, or specially presilanized, 5μm silica particles by using different dose-rates of γ-radiation and by addition of different amounts of allylmethacrylate as a radical stabilizer. The materials obtained were tested by elemental analysis, scanning electron microscopy, ESCA and IR-reflexion measurements as well as by chemical Si−OH determinations. Chromatographic testing has been carried out with different, especially strongly basic solutes, under normal and reversed phase conditions. The dual retention mechanism model of Nahum and Horvath [1] was applied to the usual commercially available phases and those phases produced by ourselves. The influences of mobile phase additives such as acetonitrile or tetrahydrofuran were also investigated following the chromatographic test procedures for characterization of the support materials synthesized. The silicas obtained show excellent long term stability to all types of HPLC solvents. Their inertness with respect to irreversible adsorption of polar, especially basic, compounds can only be compared with that of reticular bulk polymer stationary phases without any silica skeleton. Unlike pure polymer particles these materials exhibit high pressure stability, only moderate shrinking and swelling effects, and most importantly, high plate numbers, comparable with normal brushtype stationary phases.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 495 (1982), S. 7-15 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The First Nesogallate with Different Counter-cations: Li3Na2[GaO4]We prepared hitherto unknown Li3Na2[GaO4] [Heating mixtures of Na8Ga2O7 and Li2O gives single crystals (Ag-cylinders, 700°C, 14 d), from binary oxides Li2O, Na2O and β-Ga2O3 the compound is obtained as powder (like above, 680°C, 7 d)]. The single crystals are colourless and transparent, the powders are white. A new type of structure is found. The single crystal data are: Pnnm, a = 8.260, b = 7.946, c = 6.515 Å, Z = 4, dx = 3.117, dpyk = 3.073 g · cm-3 [4-circle-diffractometer data, MoKα, 679 from 709 I0(hkl), R = 3.97% and RW = 3.88%, Parameter see text, anisotropic refinement]. The Madelung Part of Lattice Energy, MAPLE, is calculated and discussed.
    Notes: Neu dargestellt wurde Li3Na2[GaO4] [Tempern inniger Gemenge von Na8Ga2O7 mit Li2O liefert Einkristalle (Ag-Bömbchen, 700°C, 14 d), aus den binären Oxiden Li2O, Na2O und β-Ga2O3 erhält man entsprechende Pulverpräparate (wie oben, 680°C, 7 d)]. Die Einkristalle sind farblos und transparent, die Pulver weiß. Der neue Strukturtyp wird durch Einkristalldaten belegt: Pnnm; a = 8,260, b = 7,946, c = 6,515 Å; Z = 4; drö = 3,117, dpyk = 3,073 g · cm-3 [Vierkreisdiffraktometerdaten PW 1100, MoKα; 679 von 709 I0(hkl); R = 3,97% und RW = 3,88%; Parameter siehe Text; anisotrope Verfeinerung].Der Madelunganteil der Gitterenergie, MAPLE, wird berechnet und diskutiert.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 507 (1983), S. 155-162 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The First Oligo-Oxo-Aluminate: Na14[Al4O13]Colourless single crystals of Na14[Al4O13] are formed by reaction of Na2O and Al2O3 in a closed Ni-cylinder at 980 K. The compound is very sensitive against moisture. Na14[Al4O13] crystalizes in the monoclinic space group P21/c with 2 formula units (a = 599.7, b = 2704.0, c = 596.9 pm, β = 120.1°). The characteristic feature of the structure, the anion [Al4O13]14-, is built of four AlO4-tetrahedra, sharing vertices. The connection of these groups by the counter-cations is discussed.
    Notes: Farblose Einkristalle von Na14[Al4O13] bilden sich bei der Reaktion von Na2O mit Al2O3 bei 780 K im geschlossenen Ni-Bömbchen. Die Substanz ist stark feuchtigkeitsempfindlich. Na14[Al4O13] kristallisiert in der monoklinen Raumgruppe P21/c mit 2 Formeleinheiten (a = 599,7, b = 2704,0, c = 596,9 pm, β = 120,1°). Die charakteristische Baugruppe der Struktur ist das erstmals erhaltene Anion [Al4O13]14-, welches von vier über Ecken verknüpften AlO4-Tetraedern gebildet wird. Die Verknüpfung dieser Gruppen durch die Gegenkationen wird besprochen.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 511 (1984), S. 201-211 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: About the Na5[GaO4]-Relationship: KNa4[GaO4] and CsK4[GaO4]KNa4[GaO4] was newly prepared from binary oxides (powders) and also from KGaO2/Na2O/K2O (colourless columnar single crystals) in a closed Ag-cylinder at 600 and 650°C. Space group Pbca with a = 1046.1(2), b = 596.3(1), c = 1871.1(3) pm, Z = 8 [Four-circle-diffractometer data, 1138 I0(hkl), MoKα, R = 8.29, Rw = 6.76%, anisotropic refinement] (Parameter s. text).Colourless cubic single crystals of hitherto unknown CsK4[GaO4] are formed by reaction of K2O, CsGaO2, and Cs2O (surplus) in a closed Au-tube at 580°C. Space group Pbca with a = 1154.7, b = 667.7, c = 2096.6 pm, Z = 8 [Four-circle-diffractometer data, 1798 I0(hkl), MoKα, R = 7.62, Rw = 7.68%, anisotropic refinement] (Parameter s. text). Both crystal structures belong to the Na5[GaO4] type. Structural aspects, ECoN, and MAPLE of KNa4[GaO4] and CsK4[GaO4] in relation with Na5[GaO4] are discussed.
    Notes: Neu dargestellt wurde KNa4[GaO4] aus den binären Oxiden (Pulver) bzw. aus Gemengen von KGaO2/K2O/Na2O (säulenförmige farblose Einkristalle) in einem geschlossenen Ag-Bömbchen bei 600 bzw. 650°C. Es liegt die RGr. Pbca mit a = 1046,1(2), b = 596,3(1), c = 1871,1(3) pm, Z = 8 vor. [Vierkreisdiffraktometerdaten, 1138 I0(hkl), MoKα, R = 8,29%, Rw = 6,76%, anisotrope Verfeinerung] (Parameter s. Text).Farblose würfelförmige Einkristalle von bislang unbekanntem CsK4[GaO4] entstehen aus K2O, CsGaO2 und Cs2O (überschuß) im zugeschweißten Au-Rohr bei 580°C. RGr. Pbca mit a = 1154,7, b = 667,7, c = 2096,6 pm, Z = 8 [Vierkreisdiffraktometerdaten, 1798 I0(hkl), MoKα, R = 7,62%, Rw = 7,68%, anisotrope Verfeinerung] (Parameter s. Text). Beide Kristallstrukturen gehören zum Na5[GaO4]-Typ. Strukturelle Aspekte, ECoN und MAPLE von KNa4[GaO4] und CsK4[GaO4] werden im Vergleich zu Na5[GaO4] diskutiert.
    Additional Material: 1 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 512 (1984), S. 240-240 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 517 (1984), S. 67-74 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The First Oxide with the Formula Type K5[MO4]: K5[TlO4]Light yellow powder and pale yellow transparent single crystals of K5[TlO4] were newly prepared from mixtures of binary oxides (K2O/Tl2O3) preheated and levigated several times [closed Ag-cylinder, 580°C, 24 h and 600°C, 20 d]. Space group Pbca with a = 1170.4(3), b = 686.1(1), c = 2079.2(5) pm, Z = 8 [four-circle-diffraktometer data, 997 I0(hkl), R = 7.87%, Rw = 5.63%, MoKα] (parameter s. text). The crystal structure belongs to the Na5[GaO4] type. Structural aspects, ECoN and MAPLE are discussed.
    Notes: Neu dargestellt wurden hellgelbes Pulver und blaßgelbe durchsichtige Einkristalle von K5[TIO4] aus mehrmals innig verriebenen, vorgetemperten Gemengen der binären Oxide (K2O/Tl2O3) [geschlossenes Ag-Bömbchen, 580°C, 24 h bzw. bei 600°C, 20 d]. Es liegt die Raumgruppe Pbca mit a = 1170,4(3), b = 686,1(1), c = 2079,2(5) pm, Z = 8 vor. [Vierkreisdiffraktometerdaten, 997 I0(hkl), R = 7,87%, Rw = 5,63%, MoKα] (Parameter s. Text). K5[TlO4] ist isotyp zu Na5[GaO4]. Strukturelle Aspekte, ECoN und MAPLE werden diskutiert.
    Additional Material: 11 Ill.
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