Zirconium Bis Research Articles

Structural studies of oriented zirconium bis(phosphonoacetic acid) using solid-state phosphorus-31 and carbon-13 NMR

Solid-state {sup 31}P and {sup 13}C NMR spectra of uniaxially oriented films of layered zirconium bis(phosphonoacetic acid) are discussed. Prior determination of the {sup 31}P phosphonate and {sup 13}C carboxyl chemical shielding tensors in Zr(O{sub 3}PCH{sub 2}COOH){sub 2} allowed for quantitative interpretation of the chemical shift frequencies exhibited in these spectra. Structural details of the organic pendant group are elucidated by analyzing the oriented chemical shift frequency in terms of its dependence on the orientation of the chemical shielding principal axes in the static magnetic field. In Zr(O{sub 3}PCH{sub 2}COOH){sub 2}, the P-C bond was determined to lie perpendicular to the inorganic layers, and the P-C-C-O dihedral angle was calculated as 90 {+-} 15{degrees}.

The effect of the conditions of the treatment of gel on the crystallinity of the layered compound zirconium (IV) BIS(phosphite)

The conditions of treatment of gels obtained by the reaction of Zr 4+ and H 3PO 3 with the formation of layered compound Zr(HPO 3) 2. nH 2O are analyzed. An increase of the degree of crystallinity with the molar ratio H 3PO 3/Zr 4+ was observed. For conditions where the ratio is < 5:1 the X-ray patterns indicate that a non-crystalline material is formed. The FTIR spectra show that the P-H stretching mode (∼2460 cm −) is very sensitive to the organization of the layers. The temperature and time of gel treatment also increases the degree of crystallinity. The combination of these parameters allows us to modulate the crystallinity of this material.

Electrical properties of ?-zirconium phosphate and its alkali salts in a humid atmosphere

Humidity dependence of impedance was examined by using the complex impedance analysis for fine crystalline zirconium bis(monohydrogen phosphate) monohydrate and its alkali salts. The value of C0 in Cp(ω)=C0(jω/ω0)−α was hardly dependent on the relative humidity and monovalent cation species. The resistive component and its activation energy decreased with increase in the relative humidity and the former was expressed as R=R* exp (−E/kT*) exp (E/kT) The pre-exponential factor R*, was hardly influenced by the humidity and decreased when the acidic protons were replaced with monovalent alkali cations. The activation energy of conduction was strongly affected by the degree of orientation and particle size of crystal with layered structure in a whole humidity region and increased by replacing the protons by alkali cations.

Electrical properties of zirconium bis(monohydrogen phosphate) monohydrate and its related compounds in a humid atmosphere

Humidity-impedance characteristics were examined for amorphous and crystalline zirconium phosphate. The impedance of crystalline zirconium phosphate is lowered with decreasing particle size. While the impedance of amorphous zirconium phosphate increases steeply with an increase in the burning temperature, the impedance is poorly dependent on burning temperature for crystalline zirconium phosphate in a humid atmosphere. Fine-grained crystalline zirconium phosphate is a suitable material for use as a humidity sensing device because of its humidity sensitivity and response to humidity changes. The existence of amorphous phases is responsible for the increase in response time.

Zirconium–Bis(triethylamine): A New Class of Chelate Ion and Anion Exchanger

Abstract A new inorganic ion exchanger, zirconium–bis(triethylamine) has been synthesized. The material has been studied for its anion exchange capacity, sorption capacity, Kd values, composition, infrared spectrum and thermodynamic behavior. Analytically important separation of anions have been achieved. Ion exchange equilibria of Cr2O72−, CrO42−, SO42−, S2O32−, and MnO4− systems have been studied at 30, 40, 45, and 60 °C. The exchange isotherms have been measured for both forward and backward reactions with solutions of ionic strength 0.10 by batch process. The isotherms showed S shaped curves. The overall thermodynamic data are also calculated.

Synthesis and Characterization of New Three-Component Ion-Exchange Material: Zirconium(IV) Selenophosphate

Abstract Zirconium(IV) selenophosphate has been prepared by adding a mixture which is 0.05 M in sodium selenite and 0.05 M in orthophosphoric acid to a 0.05 M solution of zirconium(IV) bis(nitrate) oxide in different volume ratios at pH 1. Its ion-exchange capacity, thermal and chemical stability, pH titration curves, and chemical composition were studied. Adsorption of some of the metal ions in different solvent systems has been studied. The effect of particle size on the sorption behavior of metal ions has also been studied. The analytical importance of this material has been demonstrated by achieving the eleven quaternary separations of metal ions. A comparison of ion-exchange properties of this material has also been made with some other ion-exchangers.

Humidity sensor using amorphous zirconium phosphate and its alkali salts

It is well-known that inorganic electrolytes are formed by polybasic acids and certain hydrol3)sable polyvalent cations, and many of these salts are extremely insoluble in most reagents; a typical example is the phosphates of zirconium and titanium. Of these zirconium phosphate is known as an insoluble inorganic ion exchanger and proton conductor [1, 2]. Recently, it has been reported that the electrical conductivity of zirconium bis(monohydrogen orthophosphate)monohydrate and the sintered zircon with phosphoric acid and/or alkali phosphate is strongly affected by the moisture in the atmosphere [3-6]. Because these compounds are extremely insoluble in most reagents and the mechanically strengthened porous ceramics are easily prepared by burning at 1000°C or below, it would appear that zirconium phosphate is a suitable material for use in a humidity sensing device. In the present work the results obtained on the humidity sensitivity and its response to humidity changes of zirconium phosphate and its alkali salts are presented. Zirconylchloride was first dissolved in distilled and deionized water, then a large excess of phosphoric acid (phosphoric acid/zirconylchloride = 4 mole ratio) was added in the solution under agitation. After the white precipitate (zirconium phosphate) was separated from the solution by filtration, it was washed with distilled and deionized water and dried at 60 ° C. The sample thus obtained had no peaks in X-ray diffraction analysis. The alkali salt was obtained by titrating zirconium phosphate suspended in distilled and deionized water with the corresponding alkali hydroxide solution using the end-point titration method of up to pH --10.0. The products were washed with distilled and deionized water and dried at 60 ° C. The pulverized powder was pressed into a disc at 100 kg cm -2 and the disc was then shaped to 10ram x 10mm. The disc, ~0.5mm thick, was burned at each temperature in air. Next, gold electrodes, 4mm x 4mm, were applied to opposite faces of the disc by the vacuum evaporation method. The composition of amorphous zirconium phosphate may be expressed as ZrO(H2PO4)x(OH)2_xH20. By assuming that the dehydration goes essentially to completion by heating to ~800°C, the composition of the sample is predicted from the results of the pH titration measurements and the thermal gravimetrical analysis. These experiments suggest that the composition of starting zirconium phosphate may be expressed as ZrO(H2PO4)o3(OH)I7" H20, while no apparent plateaus are observed in the thermal TABLE I Surface area (m-'g i) of some samples

The Sodium Isotopic Exchange Rate between High-temperature Phases of Disodium Zirconium(IV) Bis(orthophosphate) and Aqueous Solutions

Abstract A monohydrate (Phase II) and three anhydrous phases prepared by the thermal treatment (at 250, 700, and 900 °C respectively for Phases III, IV, and V) of disodium zirconium(IV) bis(orthophosphate) trihydrate were studied from the sodium isotopic exchange rate between them and aqueous solutions. In Phases III and IV, which had been sufficiently adapted in water in advance, the rate was found to be controlled by the diffusion of sodium ions along the direction perpendicular to the layers consisting of zirconium atoms and the diffusion constants, and their activation energies (for Phases III and IV, 57 and 52 kJ/mol) were evaluated. When these phases were used as dried, the rate was governed by the irreversible dissociation of sodium in the solid phases. In Phase II, used as dried, and in Phase V, used as dried and wetted, the rate was controlled by neither particle diffusion, film diffusion, nor chemical reaction alone. This behavior was attributed to the complex behavior of phase transformation as the isotopic exchange proceeded.

ChemInform Abstract: SODIUM ISOTOPIC EXCHANGE RATE BETWEEN DISODIUM ZIRCONIUM(IV) BIS(ORTHOPHOSPHATE) TRIHYDRATE AND AQUEOUS SOLUTIONS

AbstractDie radiochemische Untersuchung des Na‐Austausches zwischen "Na‐markierten großen Kristallen von Na2Zr(PO4),′3 H2O und Lösungen von NaNO3, NaCl oder NaOH zeigte eine anfängliche schnelle Austauschstufe, die der Einstellung eines Gleichgewichtes zwischen unvollkommenen Oberflächenschichten der Kristalle und der Lösung entspricht.

Sodium Isotopic Exchange Rate between Disodium Zirconium(IV) Bis(orthophosphate) Trihydrate and Aqueous Solutions

Abstract The sodium isotopic exchange rate between the large crystals of disodium zirconium(IV) bis(orthophosphate) trihydrate and aqueous solutions was determined radiochemically. The exchange proceeded quickly up to 5% of the total, followed by a slow process. The first step was attributed to the instantaneous attainment of the equilibrium between the imperfect surface layers of the crystals and the solution, and the second step was found to be controlled by the diffusion of sodium ions along the direction perpendicular to the layers consisting of zirconium atoms. The diffusion constant, D, was calculated with the equation obtained by Fick’s diffusion law under the conditions of slab geometry and infinite solution volume. From the dependence of D on temperature, the activation energy for the diffusion was evaluated to be 101 kJ mol−1.

The Phases Formed by the Dehydration of Disodium Zirconium(IV) Bis(orthophosphate) Trihydrate and Their Ion-exchange Behavior

Abstract The phase transformation of Na2Zr(PO4)2·3H2O which had been obtained from zirconium(IV) bis(hydrogenphosphate) monohydrate(α-zirconium phosphate), prepared by the direct precipitation method, was studied by means of gravimetry, X-ray analysis, and acid-base titration. When the material was heated for 2 d, it was transformed to a monohydrate at 80 °C and then successively to three anhydrous phases, depending on the temperature. The monohydrate was also formed by letting the trihydrate stand over P2O5 at room temperature for longer than two weeks. The processes were confirmed to be irreversible by an examination of the rehydration behavior, from which the conditions of the storage of five modifications of disodium zirconium(IV) bis(orthophosphate) were established. It is of special interest that the second anhydrous phase reverted to the first one when it was allowed to stand at room temperature in air or in a desiccator. The rate of the reversion decreased with the temperature of heat-treatment and with a decrease in the relative humidity of the surroundings. The difference between the present results and Clearfield’s was clarified and attributed mainly to the difference in the crystallinity of the starting α-zirconium phosphate.

Ionic conductivity of anhydrous zirconium bis(monohydrogen orthophosphate) and its sodium ion forms

Conductivities have been measured by the vector impedance method for the layered compounds anhydrous α-zirconium phosphate, Zr(HPO 4) 2, and several of its sodium ion phases. The values of the ionic diffusion coefficients are of the order of 10 −6-10 −8 cm 2/s at 200°C and activation energies range from 15.6 cal/mol for Zr(HPO 4) 2 to 18.6 cal/mol for ZrHNa(PO 4) 2. Comparisons are made with literature values of conductivity and self-diffusion coefficients for Zr(NaPO 4) 2·3H 2O and kinetically determined diffusion coefficients for the phases containing both sodium and hydrogen ions.

Surface texture and crystallinity behavior of zirconium bis(methylphosphonate)

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurface texture and crystallinity behavior of zirconium bis(methylphosphonate)Martin B. Dines and Peter C. GriffithCite this: J. Phys. Chem. 1982, 86, 4, 571–576Publication Date (Print):February 1, 1982Publication History Published online1 May 2002Published inissue 1 February 1982https://doi.org/10.1021/j100393a030RIGHTS & PERMISSIONSArticle Views114Altmetric-Citations28LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (3 MB) Get e-Alerts

Exchange of interlayer hydrogen orthophosphate ions of zirconium bis(hydrogen orthophosphate) dihydrate with phenylphosphonate ions

Exchange of interlayer hydrogen orthophosphate ions of zirconium bis(hydrogen orthophosphate) dihydrate with phenylphosphonate ions

Preparation and structure of n-alkyl ester derivatives of zirconium bis (monohydrogen orthophosphate) dihydrate with a layer structure

Zirconium bis (monohydrogen orthophosphate) dihydrate with a layer structure, called γ-zirconium phosphate, has been heated with phosphoric acid esters of n-alkyl alcohols [ n-C n H 2 n+1 OPO 3H 2 ( n = 1 ∼ 18)] under reflux in a mixture of water and acetone. Half of the interlayer monohydrogen orthophosphate groups are exchanged with a phosphate esters. Only monoesters are involved in the exchange even though mixtures of mono- and di-esters are used for the reflux. X-Ray and electron microscope examinations show that the layer framework of γ-zirconium phosphate is unchanged during the reaction, while the basal spacing ( d 001) increases with increasing number ( n) of carbon atoms in the alkyl chain of the phosphate ester. The plot of d 001 vs n consists of two linear relations the slopes of which are 2.43 and 1.42 Å/carbon atoms for n ⩽ 4 and n ⩾5, respectively. When the obtained compounds are swelled with n-alkyl alcohols having the same lengths of alkyl chains as those of exchanged phosphate esters, the basal spacing increases linearly with a single slope 2.43 Å/carbon atom. The change in slope is attributed to the change in the arrangement of alkyl chains between the phosphate layers and discussed in comparison with the structure of a polyethylene crystal.

Exchange of interlayer monohydrogen orthophosphate ions of zirconium bis(monohydrogen orthophosphate) dihydrate with 1- and 2-glycero phosphate ions

The interlayer monohydrogen orthophosphate ions of zirconium bis(monohydrogen orthophosphate) dihydrate (γ-zirconium phosphate) can be reversibly exchanged with 1- and 2-glycero phosphate ions in the surrounding solutions of 1- and 2-glycero dihydrogen phosphates. When sodium ions are present in the solutions, the above exchange does not occur, instead only the hydrogen ions of the interlayer phosphate ions of γ-zirconium phosphate are exchanged with the sodium ions. The isomer ratios of the two glycero phosphates in the exchanged products as well as in the solutions were analyzed by gas chromatography as the trimethylsilyl derivatives. The ratios in the products are not so different from those in the solutions. The glycero phosphate ions in the products are also subjected to the isomerization in the interlayer spaces of γ-zirconium phosphate although the rate of the isomerization is much smaller than that in aqueous solutions.

Additions and Corrections - Competitive Oxidation Processes in the Reaction between (Dicyclopentadienyl)zirconium Bis(phosphine) Complexes and ALkyl Halides

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAdditions and Corrections - Competitive Oxidation Processes in the Reaction between (Dicyclopentadienyl)zirconium Bis(phosphine) Complexes and ALkyl HalidesG. Williams, K. Gell, and J. SchwartzCite this: J. Am. Chem. Soc. 1980, 102, 25, 7619Publication Date (Print):December 1, 1980Publication History Published online20 February 2004Published inissue 1 December 1980https://doi.org/10.1021/ja00545a614RIGHTS & PERMISSIONSArticle Views28Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (156 KB) Get e-Alerts Get e-Alerts

Competitive oxidation processes in the reaction between (dicyclopentadienyl)zirconium bis(phosphine) complexes and alkyl halides

Competitive oxidation processes in the reaction between (dicyclopentadienyl)zirconium bis(phosphine) complexes and alkyl halides

Synthesis and ion-exchange properties of zirconium bis-(carboxymethanephosphonate), a new organic-inorganic ion exchanger

By slowly decomposing zirconium fluoro-complexes in the presence of trimethylphosphonoacetate, a crystalline compound of formula Zr(HOOCCH 2PO 3) 2 has been obtained. Experimental evidence showed this compound to have a layered structure of the α-Zr(HPO 4) 2·H 2O type. Since the proton of the carboxylic group can be replaced by other cations, this compound behaves as an inorganic-organic ion exchanger with carboxylic groups fixed to the insoluble crystalline inorganic matrix. The titration curve of this compound with 0.100 M (NaCl + NaOH) solutions was investigated. Owing to the potential applications of Zr(HOOCCH 2PO 3) 2 in gas or thin-layer chromatography, the ion-exchange properties relative to the functional groups present at the surface of the micro-crystals were also studied.

Di(cyclopentadienyl)zirconium(II) bis(phosphine) complexes

Reactive di(cyclopentadienyl)zirconium(II) bis-(phosphine) complexes were prepared by phosphine ligand-induced reductive elimination from [(η5-C5H5)2-Zr(H)R], R = alkyl.