scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Studies of layered uranium(VI) compounds. IV. Proton conductivity in single-crystal hydrogen uranyl phosphate tetrahydrate (HUP) and in polycrystalline hydrogen uranyl arsenate tetrahydrate (HUAs)

01 Sep 1980-Journal of Solid State Chemistry (Academic Press)-Vol. 34, Iss: 2, pp 149-155
TL;DR: In this paper, single-crystal measurements on hydrogen uranyl phosphate tetrahydrate, HUO 2 PO 4 ·4H 2 O (HUP), have confirmed that the high proton conductivity is a bulk characteristic.
About: This article is published in Journal of Solid State Chemistry.The article was published on 1980-09-01. It has received 76 citations till now. The article focuses on the topics: Tetrahydrate & Uranyl.
Citations
More filters
Journal ArticleDOI
07 Aug 1992-Science
TL;DR: A Citrobacter sp.4H2O grown by chemical methods has a high capacity for accumulating metal phosphate, attributable to biomineralization; uranyl phosphate accumulates as polycrystalline HUO2PO4 at the cell surface.
Abstract: A Citrobacter sp. accumulates heavy deposits of metal phosphate, derived from an enzymically liberated phosphate ligand. The cells are not subject to saturation constraints and can accumulate several times their own weight of precipitated metal. This high capacity is attributable to biomineralization; uranyl phosphate accumulates as polycrystalline HUO2PO4 at the cell surface. The precipitated metal is indistinguishable from crystalline HUO2PO4.4H2O grown by chemical methods.

277 citations

Journal ArticleDOI
TL;DR: The oxalate-bridged bimetallic complexes with hydrophilic tri(3-hydroxypropyl)ammonium with NH(prol)(3)(+) ions are prepared by a new synthetic procedure, and the effects of the NH( prol)( 3)(+) ion upon the structure, magnetism, and electrical conduction were studied.
Abstract: The oxalate-bridged bimetallic complexes {NH(prol)3}[MIICrIII(ox)3] (MII = MnII, FeII, CoII) with hydrophilic tri(3-hydroxypropyl)ammonium (NH(prol)3+) were prepared by a new synthetic procedure, and the effects of the NH(prol)3+ ion upon the structure, magnetism, and electrical conduction were studied. An X-ray crystallographic study of the MnCr dihydrate, {NH(prol)3}[MnCr(ox)3]·2H2O, was performed. Crystal data: hexagonal, P63, a = b = 9.3808(14) A, c = 15.8006(14) A, Z = 2. The structure comprises oxalate-bridged bimetallic layers interleaved by NH(prol)3+ ions. The ions assume a tripodal configuration and are hydrogen bonded to the bimetallic layers together with water molecules, giving rise to a short interlayer separation (7.90 A) and unsymmetrical faces to the bimetallic layer. Cryomagnetic studies demonstrate ferromagnetic ordering with transition temperature of 5.5 K for the MnCr complex, 9.0 K for the FeCr complex, and 10.0 K for the CoCr complex. The interlayer magnetic interaction is negligibl...

235 citations

Journal ArticleDOI
TL;DR: Together with water adsorption isotherm studies, the significance of the carboxyl residues as proton carriers is revealed and the R-MnCr and R-FeFe MOFs are the first examples of coexistent Néel N-type ferrimagnetism and proton conduction.
Abstract: Proton-conductive magnetic metal–organic frameworks (MOFs), {NR3(CH2COOH)}[MaIIMbIII(ox)3] (abbreviated as R–MaMb: R = ethyl (Et), n-butyl (Bu); MaMb = MnCr, FeCr, FeFe) have been studied. The following six MOFs were prepared: Et–MnCr·2H2O, Et–FeCr·2H2O, Et–FeFe·2H2O, Bu–MnCr, Bu–FeCr, and Bu–FeFe. The structure of Bu–MnCr was determined by X-ray crystallography. Crystal data: trigonal, R3c (#161), a = 9.3928(13) A, c = 51.0080(13) A, Z = 6. The crystal consists of oxalate-bridged bimetallic layers interleaved by {NBu3(CH2COOH)}+ ions. Et–MnCr·2H2O and Bu–MnCr (R–MnCr MOFs) show a ferromagnetic ordering with TC of 5.5–5.9 K, and Et–FeCr·2H2O and Bu–FeCr (R–FeCr MOFs) also show a ferromagnetic ordering with TC of 11.0–11.5 K. Et–FeFe·2H2O and Bu–FeFe (R–FeFe MOFs) belong to the class II of mixed-valence compounds and show the magnetism characteristic of Neel N-type ferrimagnets. The Et-MOFs (Et–MnCr·2H2O, Et–FeCr·2H2O and Et–FeFe·2H2O) show high proton conduction, whereas the Bu–MOFs (Bu–MnCr, Bu–FeCr, and...

199 citations

Journal ArticleDOI
TL;DR: This work synthesized a cation-substituted MOF, K2(H2adp)[Zn2(ox)3]·3H2O, where the ammonium ions in a well-defined hydrogen-bonding network are substituted with non-hydrogen-b bonding potassium ions, without any apparent change in the crystal structure.
Abstract: Proton conductivity through two-dimensional (2-D) hydrogen-bonding networks within a layered metal–organic framework (MOF) (NH4)2(H2adp)[Zn2(ox)3]·3H2O (H2adp = adipic acid; ox = oxalate) has been successfully controlled by cation substitution. We synthesized a cation-substituted MOF, K2(H2adp)[Zn2(ox)3]·3H2O, where the ammonium ions in a well-defined hydrogen-bonding network are substituted with non-hydrogen-bonding potassium ions, without any apparent change in the crystal structure. We successfully controlled the proton conductivity by cleavage of the hydrogen bonds in a proton-conducting pathway, showing that the 2-D hydrogen-bonding networks in the MOF truly contribute to the high proton conductivity. This is the first example of the control of proton conductivity by ion substitution in a well-defined hydrogen-bonding network within a MOF.

192 citations

References
More filters
Journal ArticleDOI
TL;DR: In this article, it was shown that the layered hydrate HUO2PO4 is a rapid proton conductor with a room temperature conductivity of 4 × 10−3ohm−1cm−1.

136 citations

Journal ArticleDOI
TL;DR: In this paper, a Grotthus-type mechanism of conduction is proposed which involves intermolecular transfer steps (hopping) and inter-parallel transfer steps in comparable numbers, the former facilitated by the high concentration of H 3 O + ions in the structure, and the latter most likely facilitated by high H-bond vacancies.

132 citations

Journal ArticleDOI
TL;DR: In this article, the authors measured the relaxation times in hydrogen uranyl phosphate and arsenate, which are fast proton conductors, and found that the two compounds undergo a phase transition resulting in discontinuities in T/sub 1/ and t/sub 2/ and a DTA peak.

58 citations

Journal ArticleDOI
TL;DR: In this article, it was shown that the structural ordering within the water layers of HUO 2 PO 4 ·4H 2 O (HUP) can change from tetragonal to orthorhombic symmetry below these temperatures.

33 citations