Perrhenate Anion Research Articles

Bis[glycinium(0.5+)] perrhenate

All the residues of the title compound, (C2H5.5NO2)2[ReO4], are located in general crystallographic positions. The glycine mol­ecules have usual conformations [Rodrigues Matos Beja et al. (2006 ▶). Acta Cryst. C62, o71–o72] with the H atom of the carboxylate group half-occupied, thus bearing a formal half-positive charge per molecule. The perrhenate anion has nearly ideal tetra­hedral geometry. A large number of strong hydrogen bonds give rise to the overall three-dimensional network. A two-dimensional network, parallel to (100), is made up of strong O—H⋯O hydrogen bonds with a donor acceptor distance of 2.445 (2) Å. A large number of weaker O—H⋯O and N—H⋯O hydrogen bonds consolidates the structure into an overall three-dimensional network.

Excited states of [formula omitted]: A comprehensive time-dependent relativistic density functional theory study

The perrhenate anion, ReO4-, is taken as a showcase of heavy transition metal complexes, to examine the performance of time-dependent relativistic density functional linear response theory for electronic excitations, which is based on a newly proposed exact two-component Hamiltonian resulting from the symmetrized elimination of the small component. In total 30 scalar and 63 spinor excited states are investigated and the results are grossly in good agreement with those by the singles and doubles coupled-cluster linear response theory. It is found that only a few scalar states of 3T1 and 3T2 symmetries are split significantly by the spin–orbit coupling, whereas only those excited states involving the Rydberg-type virtual orbital are affected by the solvent effects. The nature of the optical absorption spectra is also highlighted.

CRYSTAL STRUCTURE OF A NEW BISMUTH PERRHENATE Bi(Re0(4))3H(2)0

ABSTRACT Monoaquatris(tetraoxorhenate (VII)) bismuth(III), Bi(ReO 4 ) 3 (H 2 O) was prepared by reaction of (BiO) 2 CO 3 /Bi 2 (CO 3 ) 3 with concentrated HReO 4 at room temperature. The pale yellow compound crystallize triclinic in the space group P1;, (No. 2); with two formula units per unit cell (a = 746.0(1) pm, b = 777.1(2) pm, c = 990.5(2) pm, α = 100.99(3)°, β = 99.88(3)°, γ = 100.17(3)° ). The main feature of the crystal structure is a distorted bicapped trigonal prism of Bi[(ReO 4 ) 3/2 (ReO 4 ) 2/2 (ReO 4 ) 2/2 (H 2 O)], which are connected each other through [ReO 4 ]-tetrahedra to form a three-dimensional network. In the titled compound, the cation Bi 3+ is eightfold coordinated which agree with the tendency observed in other compounds of the family. Keywords: crystal structure, perrhenate anions, X-ray diffraction, coordination number INTRODUCTION In previous publications we reported the synthesis and crystal structure of tetraoxorhenates (VII) of some rare earth metals like Gd, Sm, Eu, Yb, La

Use of the Oak Ridge National Laboratory Tungsten-188/Rhenium-188 Generator for Preparation of the Rhenium-188 HDD/Lipiodol Complex for Trans-Arterial Liver Cancer Therapy

This work describes the installation, use, and quality control (QC) of the alumina-based tungsten-188 ((188)W)/rhenium-188 ((188)Re) generators provided by the Oak Ridge National Laboratory (ORNL). In addition, methods used for concentration of the (188)Re-perrhenate bolus and preparation of (188)Re-labeled HDD (4-hexadecyl-2,2,9,9-tetramethyl-4,7-diaza-1,10-decanethiol) for trans-arterial administration for therapy of nonresectable liver cancer also are described. The (188)W/(188)Re generator has a long useful shelf-life of several months and is a convenient on-site (188)Re production system. (188)Re has excellent therapeutic and imaging properties (T(1/2) 16.9 hours; E(betamax) 2.12 MeV; 155-keV gamma ray, 15%) and is cost effectively obtained on demand by saline elution of the generator. The clinical efficacy of a variety of (188)Re-labeled agents has been demonstrated for several therapeutic applications. Because of the favorable physical properties of (188)Re, several (188)Re-labeled agents are being developed and evaluated for the treatment of nonresectable/refractory liver cancer. (188)Re-labeled HDD has been the most widely studied of these agents for this application and has been introduced into clinical trials at a number of institutions. The trans-arterial administration of (188)Re-labeled agents for treatment of inoperable liver cancer requires use of high-level (1-2 Ci) (188)W/(188)Re generators. The handling of such high levels of (188)Re imposes radiological precautions normally not encountered in a radiopharmacy and adequate care and ALARA (ie, "As Low As Reasonably Achievable") principles must be followed. The ORNL generator provides consistently high (188)Re yields (>75%) and low (188)W parent breakthrough (<10(-3)%) over an extended shelf-life of several months. However, the high elution volumes (20-40 mL for 1-2 Ci generators) can require concentration of the (188)Re bolus by postelution passage through silver cation chloride trapping columns used in the cost-effective tandem cation/anion column system. The silver column removes the high levels of chloride anion as insoluble AgCl, thus allowing subsequent specific trapping of the perrhenate anion on the small (QMA SeaPak) anion column. This method permits subsequent elution of (188)Re-perrhenate with a small volume of saline, providing a very high activity-concentration solution. Because the (188)Re-specific volume-activity concentration continually decreases with time, the tandem system is especially effective method for extending the useful generator shelf-life. Low elution flow rates (<1 mL/min) minimize any high back pressure which may be encountered during generator/tandem column elution when using tightly packed, small-particle-size commercial columns. In-house preparation of silver cation columns is recommended since the chloride trapping capacity is essentially unlimited, it is inexpensive and not limited in availability to any one supplier, and back pressure can be eliminated by the use of larger particles. Methods for the preparation of (188)Re-HDD have been optimized and this agent can be obtained in high yield (80%).

Synthesis of perrhenic acid using ion exchange method

The paper presents results of the study for obtaining perrhenic acid from aqueous ammonium perrhenate solutions by ion exchange. Two ways of perrhenic acid synthesis have been examined: sorption of perrhenate anion on selected anion exchange resins (followed by elution of the sorbed rhenium as HReO4), and sorption of ammonium ion on selected cation exchange resins. The method of ammonium ion sorption on cation exchange resins has proved to be more effective. Using C 160 (H) cation exchange resin, perrhenic acid containing >300 g/L of Re (after performing concentration in vacuum evaporator) has been obtained, with impurities concentration at the level of: <1.0 mg/L NH4, ≤0.05 mg/L sodium, ≤0.20 mg/L potassium, ≤0.10 mg/L magnesium and ≤0.20 mg/L calcium.

Separation of tungsten and rhenium on alumina in dynamic conditions

The separation of tungstate and perrhenate anions on alumina from aqueous solutions of sodium chloride was investigated in dynamic conditions. The breakthrough curves for W and Re as the function of the ratio of their concentrations in the solution, were determined. The flow rate (3 ml/min), pH 2 and NaCl concentration (0.15 mol/l) were kept constant throughout the experiments. The breakthrough capacities Q0.05, the capacities at C/C0 = 0.5, the total column sorption capacities Q0.9 and the utilization degrees or column efficiencies E, were determined. According to the obtained data the separation factors αW/Re = Qw/QRe were calculated.

Bipyrrole- and Dipyrromethane-Based Amido-imine Hybrid Macrocycles. New Receptors for Oxoanions

Three new amido-imine-type hybrid macrocycles based on substituted pyrrole units have been synthesized and shown to act as effective receptors for oxoanions in the solid state and in acetonitrile solution. One of the macrocycles in question, compound 15, was characterized by X-ray diffraction analysis as the free macrocycle and as a complex with sulfuric acid. A comparison of the resulting structures reveals that this receptor is capable of undergoing a conformational change and, as a consequence, varying the number of donor sites that can interact with a bound substrate. This system and the other two new receptors described in this work (macrocycles 14 and 16, respectively) display a high affinity toward oxoanions (studied as their tetrabutylammonium (TBA) salts), with association constants on the order of 10(7) M-1 being determined in acetonitrile solution using standard UV-vis spectroscopic titration methods. A competitive titration method was used to determine affinity constants in excess of ca. 10(6) M-1. Two of the receptors (14 and 15) were found to bind acetate, hydrogen sulfate, and dihydrogen phosphate anion well, and the bipyrrole-based receptor (14) was also found to bind the perrhenate anion. In contrast, the bis-dipyrromethane-derived receptor (16) was found to bind chloride anion preferentially. The unusual selectivity displayed by 16 for this spherical anion was rationalized on the basis of single-crystal X-ray diffraction data and DFT modeling calculations, which revealed a rigid structure appropriately suited for chloride anion recognition.

P523 Evaluation of three commercial assays for the detection of Giardia and Cryptosporidium organisms in stool specimens

Fluorescent sensor for the perrhenate/pertechnetate anions in aqueous media are rarely reported in literature as their large size and low charge density poses great challenge to their detection. Herein, we report the first fluorescent turn-on ratiometric sensor for perrhenate anion, exploiting its weak hydration property which leads to an advantageous formation of a contact ion-pair of perrhenate anion with a well-known cationic ultrafast molecular rotor dye, Auramine O. This ion-pair formation, in turn, leads to a fluorescent aggregate assembly that provides an excellent opportunity to detect perrhenate anion in aqueous solution.

Sorption of rhenium on alumina under dynamic conditions

The sorption of perrhenate anion on alumina from aqueous solutions of sodium chloride was investigated under dynamic conditions. The initial concentrations of rhenium were in the range of 2.7x10-2-2.7 mmol/dm3. The breakthrough curves as the function of Re and NaCl concentrations (0.12-0.20 mol/dm3), pH 2-6 and flow rate 3-10 ml/min were determined. According to the experimental results, it was concluded that the breakthrough capacities, the capacities at c/c0 = 0.5, the total column capacities and the utilization degrees (column efficiency) increase with increasing Re and NaCl concentrations and decreasing pH. The optimal flow rate was found to be 3 ml/min. At pH2 and c0 = 2.7 mmol Re/dm3, the total capacity was found to be Q 0.9 max = 2.1x10-2 mmol Re/g Al2O3. The data for perrhenate anions fit with a Henry-type isotherm. It was found that, under the above mentioned conditions, the value of the Henry constant K H was 7.8x10-3 dm3/g and the Gibbs energy change, ?G was -0.5 kJ/mol.

PbCl(ReO4), a derivative of the matlockite (PbFCl) structure

Single crystals of lead(II) chloride perrhenate(VII), (I), were obtained from a reaction of PbCl2 and Pb(ReO4)2. Its structure can be considered as an alternation of lead–chlorine slices, [Pb2Cl2]2+, formed of edge-sharing ClPb4 tetra­hedra, and double layers of perrhenate anions, [ReO4−]2. Except for one O atom, all other atoms in (I) are situated on mirror planes. The arrangement is derived from a distorted matlockite (PbFCl) structure by replacing F with Cl, and introducing the ReO4 group instead of Cl. The structure of (I) is the first PbFCl derivative containing tetra­hedral anions.

Electrochemical and Spectroelectrochemical Properties of Poly-o-phenylenediamine: The Effect of the Perrhenate Anion

Poly-o-phenylenediamine films applied to ITO are modified by rhenium oxides using cyclic voltammetry in an ammonium perrhenate sulfate solution. Electrochemical and spectroelectrochemical properties of the composite thus obtained are studied. It is shown that all its components undergo reversible redox conversion.

Synthesis and Characterization of Periodic Mesoporous Organosilicas as Anion Exchange Resins for Perrhenate Adsorption

A new methodology to immobilize ionic liquids through the use of a bridged silsesquioxane N-(3-triethoxysilylpropyl), N(3)-(3-trimethoxysilylpropyl-4,5-dihydroimidazolium iodide that incorporates an ionic functionality for the assembly of novel periodic mesoporous organosilica (PMO) materials has been developed. The resulting PMO materials were investigated for use as novel anion exchange resins for the separation of perrhenate anions in aqueous solution. As compared with cetyltrimethylammonium chloride, 1-hexadecane-3-methylimidazolium bromide has been demonstrated to be a more efficient surfactant template for the generation of mesopores and surface areas for such PMO materials.

Ethyltriphenylphosphonium perrhenate and (iodomethyl)triphenylphosphonium perrhenate

Ethyltriphenylphosphonium perrhenate, (C(20)H(20)P)[ReO(4)], and (iodomethyl)triphenylphosphonium perrhenate, (C(19)H(17)IP)[ReO(4)], have been crystallized from 2-propanol. Both crystal structures consist of phosphonium cations and perrhenate anions. The cations show the typical propeller-like geometry. In both crystals, the positions of the nearly tetrahedral anions are stabilized by weak C-H...O hydrogen bonds, and for the latter compound, I...pi interactions also occur.

Separation of tungsten and rhenium on alumina

The conditions for the efficient separation of tungsten(VI) and rhenium (VII) on alumina were established. The distribution coefficients K d for tungstate and perrhenate anions, as well as the separation factors ?(? = KdWO42-/Kd ReO4-) were determined using hydrochloric or nitric acid as the aqueous media. Asolution of sodium chloride in the pH range 2?6 was also examined. Under all the tested experimental conditions, alumina is a much better adsorbent for tungsten than for rhenium. The obtained results indicated that the best separation of these two elements is achieved when 0.01? 0.1 mol dm-3HCl or 1.0mol dm-3 HNO3 are used as the aqueous media. If NaCl is used as the aqueous phase, the best separation is achieved with 0.20 mol dm-3 NaCl pH 4?6. Under these experimental conditions, the breakthrough and saturation capacities of alumina for tungsten at pH4 are 17 and 26 mg W/g Al2O3 respectively. With increasing pH, these values decrease. Thus, at pH 6 they are only 4 and 13 mg W/g Al2O3, respectively.

High intensity perrhenate anion (ReO 4−) emitters

Various materials have been investigated for ReO 4 − (perrhenate anion) emission with the goal of producing a high output emitter for application as a primary ion source in secondary ion mass spectrometry (SIMS) analysis. A new emitter consisting of Re powder/BaSO 4 packed in Pt tubes has been found to have superior properties. This system produces in the order of 200 nA/mm 2 for over 100 h when heated between 1100 and 1300 °C. Total currents of over several hundred nano-amperes have been sustained (three orders of magnitude higher than previous emitters, >100 h). Lower currents (5–100 nA) persist for hundreds of hours. These emitters have been used in several SIMS guns for over a year, and have proven to be extremely reliable and relatively easy to operate. As the ReO 4 − ion has previously been shown to be a highly effective projectile for many SIMS applications, the development of this improved high output emitter makes it feasible to extend the range of its application to imaging and depth profiling.

Synthesis and Characterization of Organic−Inorganic Hybrid Mesoporous Anion-Exchange Resins for Perrhenate (ReO4-) Anion Adsorption

Organic−inorganic hybrid mesoporous anion-exchange resins based on either pure silica or organosilica support materials were prepared and tested for the adsorption of perrhenate (ReO4-) anions in aqueous solutions. The prepared samples were characterized using nitrogen adsorption−desorption measurements, Fourier transform infrared spectroscopy, Raman spectroscopy, small-angle X-ray scattering, 29Si cross-polarization/magic-angle-spinning nuclear magnetic resonance, and scanning transmission electron microscopy. Among the prepared samples, the hybrid mesoporous anion-exchange resins functionalized with N-((trimethoxysilyl)propyl)-N,N,N-tri-n-butylammonium ions showed higher affinities for perrhenate ions than did the resins functionalized with N-((trimethoxysilyl)propyl)-N,N,N-trimethylammonium ions. The enhancement by the bulky ammonium functional ligand is consistent with Hofmeister selectivity.

X-Ray Absorption Studies of Poly(vinylferrocene) Polymers for Anion Separation

X-ray absorption spectroscopy (XAS) was used to study the electrochemical incorporation of perrhenate anion, from a 0.1 M solution, into poly(vinylferrocene) (PVFc) and a modified PVFc (a copolymer of 30% t-butyl acetylferrocene and 70% t-butyl divinyl ferrocene). The polymers were deposited on a carbon cloth current collector from a solution of the polymers in In situ XAS measurements were done at the Fe K edge on the reduced polymers and at 0.9 V vs. Ag/AgCl. Ex situ XAS was done at the edge after oxidation of the polymers at 0.9 V. The oxidized electrodes were washed in water to remove dissolved in the electrode pores. XAS was done both on wet-washed electrodes and on electrodes that were dried. XAS showed that at 0.9 V the Fe was oxidized from a ferrocene to a ferrocenium moiety and the bond distance increased from 2.05 to 2.08 Å. Both the X-ray absorption near-edge spectroscopy and extended X-ray absorption fine structure (EXAFS) results are consistent with having of the ferrocene moieties in the polymer oxidized at 0.9 V. The Fe K-edge EXAFS showed no direct indication of interaction of Fe with At the edge the only indication of interaction of with the polymers was a slight change in the XANES features. © 2002 The Electrochemical Society. All rights reserved.

Singly and Doubly Oxidized Phthalocyanine (pc) Rings: [Cu(pc)(ReO4 )] and [Cu(pc)(ReO4 )2

One ring, two oxidations: The first doubly ring-oxidized metal phthalocyanine complex has been synthesized by galvanostatic electrocrystallization. Copper phthalocyanine was oxidized in the presence of perrhenate anions to form the new molecular compounds [Cu(pc)(ReO4)] and [Cu(pc)(ReO4)2] (structure shown). Single-crystal EPR results show that the oxidation of [Cu(pc)(ReO4)2] is entirely ring-based.

Electrochemical quartz crystal microbalance study of perchlorate and perrhenate anion adsorption on polycrystalline gold electrode

The electrochemical quartz crystal microbalance (EQCM) was used to study adsorption/desorption of perchlorate and perrhenate ions on a bare polycrystalline gold electrode. An electrode mass change in perrhenate solution was about double that of perchlorate. The equivalent mass of adsorbed anions (about 260 and 120 g F −1 respectively) suggests adsorption of perchlorate and perrhenate anions on a polycrystalline gold electrode in the double-layer region. Water molecules are partially expelled from the gold surface during the initial stages of anion adsorption. The water loss is about three times larger for perrhenate compared to perchlorate due to the bigger ionic radius (volume) of the perrhenate anion.

ChemInform Abstract: Cooperative Halide, Perrhenate Anion—Sodium Cation Binding and Pertechnetate Extraction and Transport by a Novel Tripodal Tris(amido benzo‐15‐crown‐5) Ligand.

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