Perrhenate Ion Research Articles

ReO2(dppp)2]Ix[ReO4]1-x.xH2O.CH3OH forx= 0.17 (1), 0.36 (1) and 1 [dppp is 1,3-bis(diphenylphosphino)propane

The crystal structures of [ReO 2 (dppp) 2 ]I x [ReO 4 ] 1-x -xH 2 O.CH 3 OH, where x = 0.17(1), 0.36(1) and 1, i.e. dioxo[propane-1,2-diylbis(diphenylphosphine)-P,P']-rhenium iodide perrhenate hydrate methanol solvate, with iodide partially substituted by the perrhenate ion, are described. The compositions studied correspond to x = 0.17 (1), 0.36 (1) and 1. A solvent water molecule participates in the crystallization in a 1: 1 stoichiometric ratio with the iodide ion. The iodide ion and the water molecule together occupy nearly the same space and volume as the perrhenate ion and this facilitates their substitution. The three compositions studied are isostructural and crystallize in space group P2 1 /n. A contraction of the unit cell is detected as the iodide-ion concentration increases.

Base Hydrolysis of Methyltrioxorhenium. The Mechanism Revised and Extended: A Novel Application of Electrospray Mass Spectrometry.

The full kinetic pH profile for the base-promoted decomposition of MTO to CH(4) and ReO(4)(-) was examined with the inclusion of new data at pH 7-10. Spectroscopic and kinetic data gave evidence for mono- and dihydroxo complexes: MTO(OH(-)) and MTO(OH(-))(2). Parallel unimolecular eliminations of methane from these species account for the rate-pH profile; the respective rate constants are MTO(OH(-)), k = 4.56 x 10(-)(5) s(-)(1) and MTO(OH(-))(2), k = 2.29 x 10(-)(4) s(-)(1) at 25 degrees C. Some kinetic data were acquired with electrospray mass spectrometry to monitor the buildup in the concentration of perrhenate ions. Reliable signals for each of the isotopomers of ReO(4)(-) were obtained by this method with initial MTO concentrations of 160 &mgr;M.

Preparation and Crystal Structure of (Sb4O5)(ReO4)2 with Cationic Antimony Oxide Layers

A new layered compound (Sb4O5)(ReO4)2 was prepared by thermal decomposition of SbOReO4·2H2O. The structure contains cationic layers of (Sb4O5)2+ in which each antimony atom is coordinated by three oxygen atoms in a trigonal-pyramid geometry. Tetrahedral perrhenate ions are between these cationic layers.

Experience with aluminum perrhenate targets for reactor production of high specific activity Re-186

An alternative method for the production of multicurie quantities of (n, gamma) Re-186 has been investigated utilizing irradiation of sub-milligram-sized targets of water-soluble, Re-185-enriched aluminum perrhenate in high neutron fluxes (∼4 × 10 14 cm 2 s −1) for up to 2 weeks. These targets can be accurately aliquoted from solution and dried in quartz vials prior to irradiation, immobilizing them and preventing their dispersal upon opening. Aluminum functions as an excellent counterion because of its high valence and because it forms only short-lived radioactivities under neutron bombardment. Approximately 190, multi-curie-sized Re-186 targets have been irradiated and processed, recovering typically ∼85% of the Re-186 activity in 0.5 ml water and employing only glove box techniques. This product exhibits >98% of the radiorhenium in the chemical form of perrhenate ion by ITLC and has a specific activity of about 3 Ci/mg Re. Similar experience has been obtained using Re-187-enriched aluminum perrhenate for the production of Re-188. Aluminum perrhenate is thus a suitable target for a high flux reactor, permitting easy recovery of rhenium activities in suitable chemical form in an oxidant-free, neutral aqueous solution which is practical for development of radiopharmaceutical kits for new applications. In addition, the short processing time and simple manipulations required by this target contribute to radiation safety.

A Saturated Heterocycle Formed from Ethane-1,2-diamine, Formaldehyde and Nitroethane: Crystal Structure of 6-Methyl-6-nitro-1,4-bis(2′-nitropropan-1′-yl)-1,4-diazacycloheptane

The substituted saturated seven-membered heterocycle 6-methyl-6-nitro-1,4-bis(2′-nitropropan-1′-yl)- 1,4-diazacycloheptane crystallizes readily as a product from the reaction between [Re(en)2O2]+ (en = ethane-1,2-diamine), formaldehyde and nitroethane in basic solution. The complex apparently acts as a ‘molecular tap’, releasing en very slowly for reaction and favouring formation of discrete molecules rather than polymers, which form when free en alone is employed in the presence or absence of perrhenate ion. The trinitro cycloalkane crystallizes in the space group Pbca, with a 11·131(2), b 14·919(3), c 20·662(4) Å. A-CH2-C(CH3)(NO2)-CH2- chain links the two original primary amines of the ethane-1,2-diamine, in the same way that this type of chain links two primary amines of different ethane-1,2-diamine molecules in related metal-directed reactions. Further condensation involving the two secondary amines in the heterocycle intermediate leads to two -CH2-CH(NO2)-CH3 pendants being formed, the relatively insoluble final product crystallizing readily from aqueous solution.

Perrhenate ion uptake by aluminium hydroxide gels

The adsorption of perrhenate ions onto aluminium hydroxide gels was investigated. These gels were prepared by the sol-gel method in non aqueous solutions using a tertiary amine as template. They were amorphous and presented high specific surface areas. The amount of perrhenate ions adsorbed from aqueous solutions depended on the specific surface area of the gels. Removal of perrhenate ions up to 84% could be achieved without reaching saturation.

Preparation of Pt [sbnd]Re/Al 2O 3 catalysts by surface redox reactions II. Influence of the acid medium on Re deposition and Pt [sbnd]Re interaction

Bimetallic Pt Re/Al 2O 3 catalysts are prepared under hydrogen atmosphere by a surface redox reaction between hydrogen adsorbed on a parent platinum/alumina catalyst and the perrhenate ion ReO 4 −. This reaction, called catalytic reduction, occurs only in an acidic medium, with a maximum rhenium deposition appearing as a function of the concentration of the acid solution. The preparation of bimetallic Pt Re/Al 2O 3 catalysts by catalytic reduction of the rhenium salt on a highly dispersed platinum catalyst leads to bimetallic particles after activation by direct reduction under hydrogen. The calcination at 450°C partially destroys the interaction between the two metals, the effect being more obvious on chloride containing samples. The activation procedure produces the reverse effect at high rhenium loading deposited on a parent catalyst of low dispersion.

Preparation of [formula omitted] catalysts by surface redox reactions II. Influence of the acid medium on Re deposition and PtRe interaction

Bimetallic PtRe Al 2O 3 catalysts are prepared under hydrogen atmosphere by a surface redox reaction between hydrogen adsorbed on a parent platinum/alumina catalyst and the perrhenate ion ReO 4 −. This reaction, called catalytic reduction, occurs only in an acidic medium, a maximum rhenium deposition appearing as a function of the concentration of the acid solution. The preparation of bimetallic PtRe Al 2O 3 catalysts by catalytic reduction of the rhenium salt on a highly dispersed platinum catalyst leads to bimetallic particles after activation by direct reduction under hydrogen. The calcination at 450°C partially destroys the interaction between the two metals, the effect being more obvious on chloride containing samples. The activation procedure produces the reverse effect at high rhenium loading deposited on a parent catalyst of low dispersion.

SORPTION BEHAVIOR OF PERRHENATE ION ON REILLEX™-HP ANION EXCHANGE RESIN FROM NITRIC ACID AND SODIUM NITRATE/HYDROXIDE SOLUTIONS

ABSTRACT The distribution coefficients (K' d) are reported for perrhenate on the nitrate form of Reillex™-HP, a weak base anion exchange resin, as a function of nitric acid concentration from 0.100 to 10.0 M. Perrhenate K' d values were determined in 1.00 M NaNO3 from pH 2 to 13. The K'd values were determined in solutions containing 1.35 M NaNO3 and variable NaOH, 0.155 to 4.66 M, and in solutions containing 0.655 M NaOH and variable NaNO3,0.46 to 5.35 M. Maximum perrhenate loadings were <2.7% of theoretical capacity. The K' d is defined by the following equation: The total mmol of rhenium initially added is Retotal and [Re]sol is the analytical molarity of rhenium in Vsot mL of solution after a batch contact. At 1.0 M HNO3 the value of K'd is 73 mL/g. The behavior of the perrhenate system in acid can be described by assuming that perrhenic acid, HReO4, is formed with a derived acid dissociation constant of about 6.5 M. In 1.00M NaNO3from pH 2 to 13 the sorption behavior is initially what is expected for a weak base resin with an acid dissociation constant of 1.24 × 10−55 M. Thus, the K' d value decreases with pH values above the pKa value. However, instead of the value of K' d decreasing to zero at higher pH values, it becomes constant at 15 mL/g. In a solution containing 1.00 M NaOH and 1.00 M NaNO3, the value of K'd is 25 mL/g. The unusual behavior of the Reillex™-HP anion exchange resin suggests that the resin's unprotonated pyridine functionality is solvating a {Na+,ReO4 −} ion pair. The interaction of the perrhenate ion with Reillex™-HP is more involved than a simple ion exchange phenomenon and the presence of NaOH affects the resin-perrhenate interactions.

Simultaneous reduction of perrhenate and nickel ions by hypophosphite

Reduction of water by hypophosphite during Ni-P-Re alloy deposition proceeds in nearly the same proportion as that in the case of Ni-P deposition according to the mass spectrometric analysis of the gas evolved in deuterium-labelled electroless plating solutions. Perrhenate ion is reduced to metal rhenium as shown by the XPS analysis of the electrolessly deposited Ni-P-Re coating. Atomic hydrogen is expected to tkae part in perrhenate reduction at the catalyst surface resulting in a high hypophosphite efficiency in the overall electroless Ni-P-Re deposition process.

Deactivation of Methylrhenium Trioxide−Peroxide Catalysts by Diverse and Competing Pathways

The peroxides from methylrhenium trioxide (MTO) and hydrogen peroxide, CH3ReO2(η2-O2), A, and CH3Re(O)(η2-O2)2(H2O), B, have been fully characterized in both organic and aqueous media by spectroscopic means (NMR and UV−vis). In aqueous solution, the equilibrium constants for their formation are K1 = 16.1 ± 0.2 L mol-1 and K2 = 132 ± 2 L mol-1 at pH 0, μ = 2.0 M, and 25 °C. In the presence of hydrogen peroxide the catalyst decomposes to methanol and perrhenate ions with a rate that is dependent on [H2O2] and [H3O+]. The complex peroxide and pH dependences could be explained by one of two possible pathways: attack of either hydroxide on A or HO2- on MTO. The respective second-order rate constants for these reactions which were deduced from comprehensive kinetic treatments are kA = (6.2 ± 0.3) × 109 and kMTO = (4.1 ± 0.2) × 108 L mol-1 s-1 at μ = 0.01 M and 25 °C. The plot of log kψ versus pH for the decomposition reaction is linear with a unit slope in the pH range 1.77−6.50. The diperoxide B decomposes much more slowly to yield O2 and CH3ReO3. This is a minor pathway, however, amounting to <1% of the methanol and perrhenate ions produced from the irreversible deactivation at any given pH. Within the limited precision for this rate constant, it appears to vary linearly with [OH-] with k = 3 × 10-4 s-1 at pH 3.21, μ = 0.10 M, and 25 °C. Without peroxide, CH3ReO3 is stable below pH 7, but decomposes in alkaline aqueous solution to yield CH4 and ReO4-. As a consequence, the decomposition rate rises sharply with [H2O2], peaking at the concentration at which [A] is a maximum, and then falling to a much smaller value. Variable-temperature 1H NMR experiments revealed the presence of a labile coordinated water in B, but supported the anhydride form for A.

A Novel Tetranuclear Compound: Crystal Structure and Mass Spectra of [Re4(C6H5NCOCH3)6(Cl)(μ-O)(μ-OH)(MeOH)3][ReO4]2

The reaction between Re2(C6H5NCOCH3)4Cl2 and water in air yields a blue compound [Re4(C6H5NCOCH3)6(Cl)(μ-O)(μ-OH)(MeOH)3][ReO4]2. It crystallizes in a triclinic cell with a = 12.356(3) A, b = 14.820(6) A, c = 20.064(6) A, α = 103.38(3)°, β = 91.61(2)°, γ = 110.37(2)°, V = 3327(2) A3, and Z = 2. The X-ray crystallography revealed an unprecedented tetranuclear structure together with two perrhenate ions. The tetranuclear dication is formed by two quadruply bonded dirhenium units linked through an oxygen ligand and a hydroxy ligand. One unit uses two rhenium atoms and the other unit uses only one rhenium atom to form a Re−Re−O−Re−OH five-membered ring. The formula of this compound was further confirmed by mass spectral analysis.

Adsorption of Perrhenate on Modified Aluminas

Series of rhenium catalysts were prepared by equilibrium adsorption on unmodified alumina and alumina containing F and Mg additives. The uptake of perrhenate on alumina was dependent on the pH and the concentration of nitrate in the impregnation solution. Uptake of perrhenate at pH 6.5 on F modified alumina decreased with increasing F loading; for Mg-modified aluminas, perrhenate uptake at pH 9.3 increased with increasing Mg content. A correlation was observed between perrhenate uptake and the isoelectric point (IEP) of the modified supports. These data are interpreted on the basis of electrostatic attractions which occur between perrhenate ions in solution and alumina surfaces. Competition between nitrate and perrhenate for adsorption sites satisfactorily accounts for the effect of nitrate on perrhenate adsorption.

XAS and XRD Studies on Graphite Intercalation Compounds of Re2O7

Abstract Re2O7 was used as starting material for the preparation of pure low-stage graphite intercalation compounds (GICs). X-ray absorption measurements were carried out at the Re LIII and L1 absorption edges. The EXAFS analysis resulted in a coordination number of four and a Re-O bond length of 173.5 pm for the GICs. In the Re L1 XANES the analysis of the strong pre peak confirmed a slight distorted tetrahedral symmetry. Further XANES features indicated a variation of long-range order for the intercalate. Therefore the XAS measurements determined the tetrahedral perrhenate ion as the intercalated species. The majority of synthesized compounds showed sharp hk0 diffraction patterns. Only some compounds showed first diffuse rings and after several days sharp reflections of an ordered “in-plane” lattice. The analysis of the hk0 diffraction pattern yielded a lattice with the constants a = 652 pm, b = 764 pm, γ = 100°, δ a = 0.6° and δ b = 19.4°.

Determination of rhenium and platinum in natural waters and sediments, and iridium in sediments by flow injection isotope dilution inductively coupled plasma mass spectrometry

Methods have been developed to measure Re, Ir, and Pt in natural waters and sediments by isotope dilution inductively coupled plasma mass spectrometry (ID-ICPMS). The techniques have been applied to determination of the three elements in sediments, Pt in seawater, and Re in seawater, sediment pore waters, and river waters. In each case, a stable isotope-enriched spike is added to the sample before processing. Sediments are dissolved in all-Teflon digestion vessels using a modified standard kitchen microwave oven. Anion exchange of the chloro complexes of Ir and Pt and of the perrhenate ion (ReO 4 - ) is used to preconcentrate the elements and to separate them from concomitants which produce molecular ions in the argon plasma resulting in isobaric interferences

Microdetermination of Rhenium with Sodium Pentacyanonitrosylferrate(III) and Thiocyanate

Abstract A highly simple and sensitive method for the microdetermination of perrhenate ion was developed which is based on the formation of a mixed ligand complex with thiocyanate and pentacyanonitrosylferrate(III) (nitroprusside) in the presence of tin(II) chloride as reductant. The dark yellowish-brown species thus obtained was quantitatively extractable into 3-methyl-1-butanol whose absorption was measured at 410 nm. A large number of transition elements including Pt-metals do not cause any interference in the method and the results obtained are quite reproducible with a standard deviation of 0.002. The method obeys Beer’s law in the range of 0.91–2.57 ppm of Re with molar absorptivity and Sandell’s sensitivity of 3.86 × 104 dm3 mol−1 cm−1 and 0.0048 μg-Re cm−2, respectively. The method handles satisfactorily the analysis of a wide variety of samples. Rhenium, thiocyanate and nitroprusside in the extracted species were found to be in a respective ratio of 2 : 3 : 1.

Structural, magnetic, and charge transport properties of bis[(5,10,15,20-tetramethylporphyrinato)palladium(II)] perrhenate, [Pd(tmp)]2[ReO4

Electrochemical oxidation of Pd(tmp), in the presence of the perrhenate ion affords the new molecular conductor [Pd(tmp)] 2 [ReO 4 ]. The compound is composed of partially oxidized (+1/2) Pd(tmp) cations stacked metal-over-metal and surrounded by chains of ReO 4 anions. Single-crystal room-temperature conductivity along the needle axis averages 30 Ω −1 cm −1 and may be fit to an expression that describes a semiconductor with temperature-dependent carrier mobility. ESR measurements confirm the tmp ligand as the site of oxidation

Thermally activated magnetic interactions in a one-dimensional semiconductor. Structural, charge-transport, and magnetic studies of bis[(tetramethylporphyrinato)copper] perrhenate

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThermally activated magnetic interactions in a one-dimensional semiconductor. Structural, charge-transport, and magnetic studies of bis[(tetramethylporphyrinato)copper] perrhenateEllen M. McGhee, Martin R. Godfrey, Brian M. Hoffman, and James A. IbersCite this: Inorg. Chem. 1991, 30, 4, 803–808Publication Date (Print):February 1, 1991Publication History Published online1 May 2002Published inissue 1 February 1991https://doi.org/10.1021/ic00004a036RIGHTS & PERMISSIONSArticle Views67Altmetric-Citations14LEARN 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 (678 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Spin pairing and magnetic coupling in quasi one-dimensional semiconductors with a trimeric stacking structure. Structural, charge-transport, and magnetic studies of [Ni(tatbp)]3[ReO4]2.cntdot.C10H7Cl and [Cu(tatbp)]3[ReO4]2.cntdot.C10H7Cl

Electrochemical oxidation of (triazatetrabenzoporphyrinato)nickel(II) or (triazatetrabenzoporphyrinato)copper(II), Ni(tatbp) or Cu(tatbp), dissolved in 1-chloronaphthalene in the presence of the perrhenate ion affords the new molecular conductors (Ni(tatbp)){sub 3}(ReO{sub 4}){sub 2}{center dot}C{sub 10}H{sub 7}Cl and (Cu(tatbp)){sub 3}(ReO{sub 4}){sub 2}{center dot}C{sup 10}H{sub 7}Cl. The isostructural compounds are composed of partially ligand-oxidized (+2/3) M(tatbp) molecules that form trimerized stacks. Trimerization of the conducting stacks renders the compounds semiconductors with conductivity along the needle axis (crystallographic a) in the range of 2.5 {times} 10{sup {minus}4}-3.0 {times} 10{sup {minus}4} {Omega}{sup {minus}1} cm{sup {minus}1} and an activation energy for conduction in the range of 0.24-0.26 eV. Magnetic susceptibility measurements on the Ni(II) derivative show that the valence band has the diamagnetic ground state expected for a semiconductor. Nonetheless, the valence-band electrons are shown to mediate a strong intratrimer Cu-Cu coupling characterized by a Weiss constant {Theta} = {minus}5.2 K in the Cu(II) analogue. The magnetic properties are rationalized in terms of a band structure derived by considering the trimers as weakly interacting supermolecules, with {Theta} dominated by intratrimer interactions. A structure determination was performed on the Cu(II) analogue.

ChemInform Abstract: Structural and Charge Transport Properties of Bis((5,10,15,20‐tetramethylporphyrinato)nickel(II)) Perrhenate, (Ni(tmp))2(ReO4).

AbstractElectrochemical oxidation of tetramethylporphyrinatonickel(II) in the presence of the perrhenate ion affords the title compound (P4/n, Z=2), a new molecular conductor, which is composed of planar molecules of the Ni complex stacked metal‐over‐metal.