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  • 1
    ISSN: 0948-5023
    Keywords: Keywords Vanadyl phosphate ; Zirconium phosphate ; Molecular mechanics ; Vibrational spectroscopy ; Host-guest interaction ; Intercalates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Molecular mechanics simulations using Cerius2 modelling environment combined with vibrational spectroscopy (IR and Raman) have been used to study the host-guest interactions in zirconium and vanadyl phosphate intercalated with ethanole. The strategy of investigation is based on the comparison of vibrational spectra for the host compound, intercalate and guest species. This comparison confirmed the rigidity of VOPO4- and Zr(HPO4)2-layers during the intercalation and provided us with the basis for the strategy of modelling. Molecular mechanics simulations revealed the structure of intercalates and enabled to analyse the host-guest interaction energy and bonding geometry. The bilayer arrangement of ethanole molecules in the interlayer space with two differently bonded ethanole molecules has been found in both intercalates. The average interaction energy ethanole-layer for two differently bonded ethanole molecules is : 127.5 and 135.7 kcal·mol-1 in Zr(HPO4)2·2C2H5OH, respectively 94.0 and 104.4 kcal·mol-1 in VOPO4·2C2H5OH. The Coulombic contribution to the ethanole-layer interaction energy is predominant in all cases, but the hydrogen bonding contribution is much higher in Zr(HPO4)2·2C2H5OH than in VOPO4·2C2H5OH. Present results of modelling enabled the interpretation of vibrational spectra and explanation of small changes in positions and shapes of spectral bands, in infrared and Raman spectra, proceeding from the host structure to intercalates.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 26 (1996), S. 311-319 
    ISSN: 1573-1111
    Keywords: Intercalation ; X-ray powder diffraction ; thermomechanical analysis ; volumetry ; vanadyl ; phosphate ; ethanol ; kinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The course of intercalation of ethanol into VOPO4 has been studied by X-ray diffraction, thermomechanical analysis and a volumetric method. In all cases the kinetic curves were observed to have a sigmoidal shape. A model, based on the Avrami equation, has been proposed for description of the kinetic behavior. The activation energy of intercalation based on this model has been determined. The existence of the advancing phase boundary in the system during intercalation has been confirmed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 33 (1999), S. 391-402 
    ISSN: 1573-1111
    Keywords: intercalation ; 1-alkanols ; vanadyl phosphate ; mixed layer-type complexes ; x-ray powder diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Mixed intercalates VOPO4.C2H5 OH.C4 H9OH, VOPO4.C3H7 OH.C5H11OH, VOPO4.C3H7 OH.C6H13OH and VOPO4.C4H9 OH.C6H13OH have been prepared by reaction of polycrystalline vanadyl phosphate dihydrate with liquid mixtures of the 1-alkanols in a microwave field. The same mixed layer-type complexes were also obtained as intermediary products of exchange reactions consisting in substitution of one alkanol bound in the solid intercalate by another alkanol introduced in the form of vapour. The composition of products has been determined, and the basal spacing of all the mixed layer-type complexes prepared has been found by diffraction. A structural principle is suggested which governs the depositing of two kinds of 1-alkanol molecules (differing in the lengths of their aliphatic chains) while acting as guests in the layered structure of vanadyl phosphate.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 14 (1992), S. 19-24 
    ISSN: 1573-1111
    Keywords: Intercalation ; layered lattice ; interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The paper deals with the relations between host lattices and guest molecules. Several types of interaction of the guest molecules and the host material are explained and some conclusions are made about the arrangement of various guest molecules in the van der Waals' gap.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 31 (1998), S. 275-286 
    ISSN: 1573-1111
    Keywords: intercalation ; mechanism ; kinetics ; vanadyl phosphate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Recent knowledge of the kinetics and intercalation mechanisms are summarized and accompanied by examples of intercalation reactions of water and ethanol into anhydrous vanadyl phosphate and redox intercalation of alkali metal cations into vanadyl phosphate dihydrate. Three possible mechanisms of intercalation are presented which are based on: (i) a concept of exfoliation of layers; (ii) the formation of stages and randomly stacked layers; (iii) co-existence of intercalated and non-intercalated parts of crystals of the host separated by an advancing phase boundary. The corresponding kinetic curves are ascribed to mechanisms (ii) and (iii).
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1573-1111
    Keywords: Intercalation ; rate of intercalation ; observing intercalation processes ; change of volumes of intercalating systems ; vanadyl phosphate ; vanadyl sulfate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A new experimental method is suggested for the kinetic measurements of intercalation reactions in systems formed by a polycrystalline layered host and a liquid molecular guest. The method is based on the fact that the molecular guest decreases its molar volume on entering the space between the host layers. Hence the volume of the system in which an intercalation process takes place is measurably decreased. The time course of the intercalation process can thus be monitored by measuring the volume change of the system. The method has been used to obtain kinetic data about heterogeneous intercalations of some liquid aliphatic compounds into layered structures of anhydrous vanadyl phosphate and sulfate.
    Type of Medium: Electronic Resource
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