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Pardubice, Czech Republic

Svoboda J.,Czech Institute of Macromolecular Chemical | Zima V.,Czech Institute of Macromolecular Chemical | Zima V.,Joint Laboratory of Solid State Chemistry | Melanova K.,Czech Institute of Macromolecular Chemical | And 2 more authors.
Journal of Solid State Chemistry | Year: 2013

Zirconium 4-sulfophenylphosphonate is a layered material which can be employed as a host for the intercalation reactions with basic molecules. A wide range of organic compounds were chosen to represent intercalation ability of zirconium 4-sulfophenylphosphonate. These were a series of alkylamines from methylamine to dodecylamine, 1,4-phenylenediamine, p-toluidine, 1,8-diaminonaphthalene, 1-aminopyrene, imidazole, pyridine, 4,4′- bipyridine, poly(ethylene imine), and a series of amino acids from glycine to 6-aminocaproic acid. The prepared compounds were characterized by powder X-ray diffraction, thermogravimetry analysis and IR spectroscopy and probable arrangement of the guest molecules in the interlayer space of the host is proposed based on the interlayer distance of the prepared intercalates and amount of the intercalated guest molecules. © 2013 Elsevier Inc. All rights reserved. Source

Benes L.,University of Pardubice | Benes L.,Joint Laboratory of Solid State Chemistry | Melanova K.,Czech Institute of Macromolecular Chemical | Melanova K.,Joint Laboratory of Solid State Chemistry | And 4 more authors.
Journal of Inclusion Phenomena and Macrocyclic Chemistry | Year: 2012

The intercalation chemistry of layered α I modification of vanadyl phosphate and vanadyl phosphate dihydrate is reviewed. The focus is on neutral molecular guests and on metal cations used as guest species. The basic condition for the ability of the neutral molecules to be intercalated into vanadyl phosphate is a presence of an electron donor atom in them. The most commonly used guest compounds are those containing oxygen, nitrogen or sulfur as electron donor atoms. Regarding the molecules containing oxygen, various compounds were used as molecular guests starting from water to alcohols, ethers, aldehydes, ketones, carboxylic acids, lactones, and esters. An arrangement of the guest molecules in the interlayer space is discussed in connection with the data obtained by powder X-ray diffraction, thermogravimetry, IR and Raman spectroscopies, and solid-state NMR. In some cases, the local structure was suggested on the basis of quantum chemical calculations. Besides of those O-donor guests, also N-donor guests such as amines, nitriles and nitrogenous heterocycles and S-donor guests such as tetrathiafulvalene were intercalated into VOPO 4. Also intercalates of complexes like ferrocene were prepared. Intercalation of cations is accompanied by a reduction of vanadium(V) to vanadium(IV). In this kind of intercalation reactions, an iodide of the intercalated cation is often used as it serves both as a mild reduction agent and as a source of the intercalated species. Intercalates of alkali metals, hydronium and ammonium were prepared and characterized. In the case of lithium and sodium intercalates, a staging phenomenon was observed. These redox intercalated vanadyl phosphates undergo ion exchange reactions which are discussed from the point of the nature of cations involved in the exchange. Vanadyl phosphates in which a part of vanadium atom is replaced by other metals are also briefly reviewed. © 2012 Springer Science+Business Media B.V. Source

Patil D.S.,University of Pardubice | Shimakawa K.,University of Pardubice | Shimakawa K.,Gifu University | Zima V.,Czech Institute of Macromolecular Chemical | And 3 more authors.
Journal of Applied Physics | Year: 2013

Analysis of impedance spectra by a random-walk approach is proposed for the study of ionic-transport materials with a silver-containing chalcogenide glass as a case example. Through a full analysis of complex impedance spectra including the electrode polarization effect, some important physical parameters, such as the number of mobile ions in bulk and interface regions, the diffusion coefficient, etc., are extracted without using the conventional equivalent electric circuit analysis. A detailed discussion on electrode polarization, which is highly dependent on signal amplitude, is also presented. © 2013 AIP Publishing LLC. Source

Patil D.S.,University of Pardubice | Konale M.S.,University of Pardubice | Kolar J.,University of Pardubice | Shimakawa K.,University of Pardubice | And 4 more authors.
Pure and Applied Chemistry | Year: 2015

Electrical properties of a set of lithium-ion conducting sulfide glasses with general formula 20LiI-xGa2S3-(80-x)GeS2 (x = 10, 15 and 20) is studied in the present article. The experimental data obtained using impedance spectroscopy are analyzed by means of a random-walk (RW) model assuming that the conduction takes place by a random motion of Li+ ions. The influences of added gallium on the structural network and on the conductivity of prepared glasses are also analyzed using the RW model. The results are further confirmed by Raman spectral analysis. The results obtained by the random-walk model and by a conventional equivalent electric circuit model are in a good agreement. We observed that the addition of Ga2S3 contributed to phase separation in the prepared glassy system and negatively influenced the conductivity of the studied glasses. Factors contributing to the total conductivity with respect to the amount of both LiI and Ga2S3 are also reported. © 2014 IUPAC & De Gruyter. Source

Zima V.,Czech Institute of Macromolecular Chemical | Zima V.,Joint Laboratory of Solid State Chemistry | Melanova K.,Czech Institute of Macromolecular Chemical | Kovar P.,Charles University | And 4 more authors.
European Journal of Inorganic Chemistry | Year: 2015

Alcohol intercalated strontium phenylphosphonates were prepared by the addition of alcohols to an aqueous solution of strontium phenylphosphonate (SrPhP). These intercalates are unstable and de-intercalate spontaneously at ambient conditions. For the complete elucidation of their structure, a combination of a single-crystal X-ray diffraction and molecular modeling was used. The structure of the host layers in methanol (SrPhP·MeOH) and ethanol (SrPhP·EtOH) intercalates is composed of strontium atoms, which are eight-coordinate by oxygen atoms of the phosphonato groups and of water molecules. The structures of SrPhP·MeOH and SrPhP·EtOH differ in the orientation of the phenyl rings. The alcohol molecules reside in the cavities formed by the phenyl rings and are coordinated to the Sr atoms of the host layer through their oxygen atoms. On the basis of the structure of SrPhP·EtOH, the structures of propanol and butanol intercalates and of strontium phenylphosphonate dihydrate (SrPhP·2H2O) were modeled. The proposed model of SrPhP·2H2O, which features three kinds of water molecules, elucidates the temperature- and humidity-dependent behavior of the compound. Structures of alcohol intercalated strontium phenylphosphonates were suggested on the basis of a combination of single-crystal X-ray diffraction data and molecular modeling. Copyright © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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