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  • 1
    Electronic Resource
    Electronic Resource
    The formation of solid solutions in the tetrahydrofuran-tetra(n-propyl)ammonium fluoride-water system (1994)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 99-106 
    Details
    ISSN: 1573-1111
    Keywords: Double clathrate hydrate ; solid solutions ; tertiary system ; tetra(n-propyl)ammonium fluoride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The phase diagram of the tetrahydrofuran (THF)-tetra(n-propyl)ammonium fluoride (Prp4 NF)-water system has been studied by differential thermal analysis (DTA). Solid solutions have been detected of the general formula THF·x Prp4NF·(17−2x) H2O, wherex changes from 0.06 to 0.5. The formation of solid solutions is due to the variable degree of the filling of the fragment consisting of four D-cavities in CS-II clathrate hydrates by the tetra(n-propyl)ammonium cation. The solid solution obtained is peculiar in that its vacancies are occupied by the blocks of four D-cavities each. Besides, this kind of displacement of two water molecules by an ionic pair Prp4N++F−, where only the charges of the substituting and substituted groups are equal, takes place here. It appears that this type of solid solution has been discovered for the first time.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00708004
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    The Structure–Properties Relations in Werner β-[Ni(NCS)2(4-MePy)4] Clathrates. Part 1. Sorption Equilibria and Guest to Host Influence in Solid β-[Ni(NCS)2(4-MePy)4] Clathrate – Gaseous Guest Systems (1997)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 29 (1997), S. 41-55 
    Details
    ISSN: 1573-1111
    Keywords: Werner clathrates ; sorption equilibria ; isosteric heats of sorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Sorption equilibria have been studied in the systems solid β-[Ni(NCS)2(4-MePy)4] clathrate – gaseous guest (benzene, furan,tetrahydrofuran, propane, CH2Cl2, CH2Br2, methanol). Analysis of theexperimental data shows that the solid–gas equilibrium in this systemcannot be regarded as simple physical sorption by a rigid host lattice. Itwas found that the isosteric heats of guest sorption decrease withincreasing guest uptake in all systems studied. The observed phenomena areinterpreted as the result of a guest to host influence and guest–guest repulsion. The molecular model of guest sorption by theβ-[Ni(NCS)2(4-MePy)4] host was suggested on the basis of combinedanalysis of sorption isotherms and the dependence of the isosteric heat ofsorption on clathrate composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1007957001528
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Structure–Properties Relations in Werner β-[Ni(NCS)2(4-MePy)4] Clathrates. Part 2. Host–Host Interactions as a Function of the Guest Molecular Size and Shape and the Amount of Absorbed Guest Compound (1999)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 35 (1999), S. 531-548 
    Details
    ISSN: 1573-1111
    Keywords: β-[Ni(NCS)2(4-methylpyridine)4] clathrates ; geometry of the host lattice ; host–host interactions ; guest–host interactions ; dependence of the unit cell parameters from the guest uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Careful analysis of changes in the geometry of the host lattice structure on inclusion of different guest molecules was performed for 11 β-[Ni(NCS)2(4-methylpyridine)4] clathrates reported in the literature, and specific features were established for the geometry of the host crystal lattice structure, which are characteristic for different modes of location of the guest molecules. A new method is suggested for the analysis of the volume and shape of the empty space in clathrates. Experimental data are reported on the dependence of the a and c parameters of the unit cell of clathrate phases (with furan and dichloromethane as guest components) from the guest uptake. Consideration of these data permit us to construct a model of the changes of host–host interactions in the β-[Ni(NCS)2(4-methylpyridine)4] clathrates with change of guest uptakes. Modeling of the process of diffusion of the guest molecule through the channel of the β-[Ni(NCS)2(4-methylpyridine)4] clathrate allowed the nature of the rate-determining step of diffusion to be established. Part 1 of this series has been published as [3].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1008068825957
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    New crystal structures of β-[Ni(NCS)2(4-methylpyridine)4] clathrates with furan, tetrahydrofuran, methylene chloride, benzene + ethanol and methylcellosolve as guest molecules (1996)
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 26 (1996), S. 1-20 
    Details
    ISSN: 1573-1111
    Keywords: Werner clathrates ; X-ray structure ; packing of guest molecules ; guest disordering
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Single crystal X-ray structures of clathrates of β-[Ni(NCS)2(4-methylpyridine)4] with furan, tetrahydrofuran, benzene + ethanol, methylene chloride, and methylcellosolve as guests molecules are reported. The location of the guest molecule in the partially decomposed clathrate with methylene chloride was defined by X-ray diffraction and compared with the fully occupied one. The host lattices of all clathrates studied are tetragonal (I41/a) and do not differ significantly from typical β-phase clathrates of [M(NCS)2(4-methylpyridine)4] (M = divalent metal cation). Arrangements of guest molecules represent different types of packing: one type of guest molecule occupies both possible types of positions, two different guest molecules occupy different positions, with only one type of positions occupied by one type of guest molecule. Possible stoichiometries of clathrates with β-type lattices are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01029923
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    Paper (German National Licenses)
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