Sorption of strontium and lanthanum on polyantimonic acid and two phosphatoantimonic acids

The sorption of strontium and lanthanum on antimonic acid (HAP) and on two phosphatoantimonic acids, H₃Sb₃O₆(PO₄)₂ (RH3) and H₅Sb₅O₁₂(PO₄)₂ (RH5) were studied by three types of measurements: kinetics of fixation, distribution coefficients at trace level and sorption capacity. A 2H⁺/Sr²⁺ or 3H⁺/La³⁺ exchange stoichiometry and an affinity order of HAP>RH5>RH3 for Sr and RH3>HAP>RH5 for La were observed. The fixation kinetics is very fast for RH3. For HAP and RH5, there is a fast step followed by a slow diffusion-controlled step. The results are interpreted by comparing the chemical compositions and crystal structures of the three sorbents. Applications to radioactive waste treatment are discussed.     

Theoretical Study of the Reactions M++CH3F (M=Ge,As, Se,Sb)

CASSCF–MRMP2 calculations have been carried out to analyze the reactions of the methyl fluoride molecule with the atomic ions Ge⁺, As⁺, Se⁺ and Sb⁺. For these interactions, potential energy curves for the low‐lying electronic states were calculated for different approaching modes of the fragments. Particularly, those channels leading to C? H and C? F oxidative addition products, H₂FC? M? H⁺ and H₃C? M? F⁺, respectively were explored, as well as the paths which evolve to the abstraction (M? F⁺+CH₃) and the elimination (CH₂M⁺+HF) asymptotes. For the reaction Ge⁺+CH₃F the only favorable channel leads to fluorine abstraction by the ion. As⁺ and Sb⁺ can react with CH₃F along pathways yielding stable addition products. However, a viable path joining the oxidative addition product H₃C? M? F⁺ with the elimination asymptote CH₂M⁺+HF was found for the reaction of the fluorocarbon compound with As⁺. No favorable channels were detected for the interaction of fluoromethane with Se⁺. The results discussed herein allow rationalizing some of the experimental data found for these interactions through gas‐phase mass spectrometry.     

Nitrosolate und Nitrosolatokomplexe. III. Darstellung und Struktur von Nitrosolsäurederivaten organosubstituierter Antimon(V)-, Tellur(IV)- und Jod(III)-Verbindungen

Nitrosolates and Nitrosolatocompounds. III. Synthesis and Structures of Nitrosolate Derivatives of Organosubstituted Compounds of Antimony(V(, Tellurium(IV), and Iodine(III) In solution the derivatives of the nitrosolates of acetic and benzoic acids and of the ions (C₆H₅)₄Sb⁺, (CH₃),Sb⁺, (C₆H₅)₃Te⁺, and the derivative of the nitrosolate of acetic acid and of the ion C₁₂H₈I⁺ show ionic or covalent structures, depending on the polarity of the solvent. In the solid state only the derivatives of (C₁₂H₅)₄Sb⁺ unequivocally do not display salt character. The structure of (C₆H₅)₄Sb · O₂N₂C–CH₃ was determined by X-ray methods. The compound consists of separated molecules with slightly distorted trigonal-bipyramidonal environment of the antimony atom. The nitrosolato ligand is oxygen bonded to one of the apical positions. According to the electronic spectra of the solutions of the nitrosolate derivatives the nitrosolate ions react in the covalent forms either as uni-dentate ligands with O-coordination or as bidentate chelating or bridging ligands with O,O′-coordination.     

An investigation of microporous cetineite-type phases A6[B12O18][CX3]2[Dx(H2O,OH,O)6−y] I. The cetineite structure field

Hydrothermal syntheses between 120 and 200 °C have been performed to determine the chemical variability of semiconducting microporous materials with cetineite structure. The syntheses were based on the general formula A₆[B₁₂O₁₈][CX₃]₂[D_x(H₂O,OH,O)_6−y], (0≤×≤2; 0≤y≤6), which was derived from X-ray crystal structure refinements. A = Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, Tl⁺, NH₄⁺, Ca²⁺, Sr²⁺, and Ba²⁺ were introduced as hydroxides, in some cases as carbonates, B = C = As³⁺, Sb³⁺, and Bi³⁺, and X = S²⁻, Se²⁻, and Te²⁻ as elements. Only syntheses with B = C = Sb³⁺ and X = S²⁻ and Se²⁻ were successfull. Known cetineite-type phases now include the element combinations A/Sb³⁺/S²⁻ with A = Na⁺ and K⁺, and A/Sb³⁺/Se²⁻ with A = Na⁺, K⁺, Rb⁺, Sr²⁺, Ba²⁺, and probably Tl⁺. Variable amounts of Na⁺, Sb³⁺ and C⁴⁺ were found to occupy the D position of the cetineite-type structure. The chemical variability can be described by the coupled substitutions A⁺ + H₂OA²⁺ + OH⁻ mH₂OD^m+ + mOH, and nOH⁻Dⁿ⁺ + nO²⁻. The crystals obtained are orange to dark red, in agreement with their semiconducting properties.     

An Oxofluoride Catalyst Comprised of Transition Metals and a Metalloid for Application in Water Oxidation

The application of the recently discovered oxofluoride solid solution (Co_xNi_1?x)₃Sb₄O₆F₆ as a catalyst for water oxidation is demonstrated. The phase exhibits a cubic arrangement of the active metal that forms oxo bridges to the metalloid with possible catalytic participation. The Co₃Sb₄O₆F₆ compound proved to be capable of catalyzing 2H₂O→O₂+4H⁺+4e^? at 0.33 V electrochemical and ≤0.39 V chemical overpotential with a TOF of 4.4?10^?3, whereas Ni₃Sb₄O₆F₆ needs a higher overpotential. Relatively large crystal cubes (0.3–0.5 mm) are easily synthesized and readily handled as they demonstrate both chemical resistance to wear after repeated in situ tests under experimental conditions, and have a mechanical hardness of 270 V0.1 using Vickers indentation. The combined properties of this compound offer a potential technical advantage for incorporation to a catalytic interface in future sustainable fuel production.     

Formation of antimony oxide clusters by gas aggregation

Sb_xO_y clusters are produced by using a gas aggregation technique. Antimony vapor is mixed with He/O₂ or He/N₂O and cooled in a reaction channel. After photoionisation with a KrF (248 nm) or ArF (193 nm) excimer laser the products are mass analyzed in a time of flight mass spectrometer. In the presence of N₂O no oxide clusters besides SbO⁺ can be detected, while with oxygen under similar experimental conditions dramatic changes can be observed. At low oxygen partial pressure the obtained spectra are dominated by the pure Sb _x ⁺ clusters with low intensity of Sb_xO _y ⁺ , whereas at high oxygen partial pressure antimony oxides following the general sequence SbO⁺(Sb₂O₃)n are most abundant. The same stable species can furthermore be produced via aggregation of vaporised solid antimony oxide (Sb₂O₃). Within these experiments another new Series of antimony oxides tentatively assigned to (Sb₂O₃) _n ⁺ appeared in the mass spectra.     

Novel Antimony Complexes: [Ph4Sb]4 +[Sb4I16]4− · 2Me2C=O and [Ph4Sb]3 +[Sb5I18]3−

The [Ph₄Sb]₄ ⁺[Sb₄I₁₆]^4– · 2Me₂C=O and [Ph₄Sb]₃ ⁺[Sb₅I₁₈]^3– complexes were synthesized by reacting tetraphenylstibonium salts Ph₄SbX (X = I, OSO₂C₆H₄Me-4) with antimony triiodide in acetone. According to X-ray diffraction data, their tetra- and pentanuclear anions [Sb₄I₁₆]^4– and [Sb₅I₁₈]^3– have cyclic and linear structure, respectively.     

Characterization of Sb2O3 subjected to different ion and plasma surface treatments

This paper presents a study of Sb₂O₃ subjected to oxygen plasma and to ion beam bombardment (Ar⁺ and O₂⁺ ions of 4 keV) by x‐ray photoelectron and reflected electron energy‐loss spectroscopies. Changes in stoichiometry (i.e O/Sb ratio) and oxidation state of Sb have been detected and correlated with the chemical and ballistic effects of the beams used for alteration of the Sb₂O₃ surface. Thus, oxygen plasma treatments lead to a significant oxidation of the surface layers of this material with the formation of up to 51% Sb⁵⁺ species as found by Sb 4d curve‐fitting analysis. By contrast, O₂⁺ ion bombardment only produces a mild oxidation of the target with the formation of ～13% Sb⁵⁺ species. Argon ion bombardment induces a complex process where Sb⁵⁺ and Sb⁰ species are formed simultaneously. This result has been discussed in terms of a disproportionation reaction of the type Sb³⁺ → Sb⁵⁺ + Sb⁰. The changes in the electronic properties of the treated material are consistent with the loss upon oxidation to Sb⁵⁺ of the valence states associated to the 5s² electron pair of antimony. Approximate shapes of valence bands for Sb₂O₃ and Sb₂O₅ pure compounds have been extracted by applying factor analysis to valence band spectra of Sb₂O₃ subjected to different ion and plasma treatments. Copyright © 2003 John Wiley & Sons, Ltd.     

Raman spectroscopy study of species responsible for the fast proton conductivity in H2Sb4O11.3H2O

The Raman spectroscopy study of crystallized antimonic acid trihydrate powders in the 20–4000 cm⁻¹ confirme the explicit formula : (H₃O⁺)_2−x[Sb₄O_11−xOH_x]^−(2−x).(3+x−2)H₂O. Furthermore it emphasizes the presence of hydrogen bonds between either the SbOSb bridge and H₃O⁺ or the protonated Sb(OH)Sb bridge and H₂O.     

Determination of trivalent antimony

Summary A method is described for the determination of trivalent antimony. It depends on the oxidation of Sb³⁺ to Sb⁺ with KMnO₄ in sulfuric acid solutions (0.72-3.4N H₂SO₄) in the presence of fluoride ions and at temperatures below 50°. Amounts of antimony ranging from 15.7gmg to 61 mg can be determined accurately.

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Zusammenfassung Eine Methode zur Bestimmung von Sb (III) wurde beschrieben. Sie beruht auf der Oxydation zu Sb(V) mit Permanganat in schwefelsaurer Lösung (0,72-3,4N H₂SO₄) in Gegenwart von Fluorid bei Temperaturen unter 50° C. Mengen zwischen 15,7gmg und 61 mg Antimon lassen sich genau bestimmen.

     

Sb<Subscript>2</Subscript>S<Subscript>3</Subscript>-SiO<Subscript>2</Subscript> nanocomposite layers synthesized using the layer-by-layer technique

Possibility of layer-by-layer synthesis by colloidal layering of Sb₂S₃-SiO₂ nanocomposite layers from colloid solutions of {[H _x Sb₂S₅] ^m ?}mNa⁺ and SiO₂ was studied. The composition of the layers synthesized was examined by Raman spectroscopy, transmission spectroscopy in the UV and visible spectral ranges, energy-dispersion micro analysis, and scanning electron microscopy.     

Kinetic aspects and swelling changes of magnesium and cerium titano-antimonates in aqueous and mixed solvents

Magnesium titano-antimonate (MgTi₅Sb₂O₁₆·12.5H₂O) and cerium titano-antimonate (Ce₂.₇Ti₅Sb₂O₁₉·15.0H₂O) were synthesized as new cation exchangers using the in situ precipitation technique. Physico-chemical investigations showed different behaviors for the obtained materials. The materials have significant stability at high acid concentration and temperature. The ion exchange capacity for Cs⁺ in the presence of different alcoholic solvents was found to increase and generally obey the order C₂H₅OH > CH₃OH > H₂O. Diffusion coefficients (D_i) and thermodynamic parameters of Cs⁺ exchange in both magnesium and cerium titano-antimonates in aqueous and alcoholic solutions were calculated. The swelling ratios of the materials were predicted by applying modified calculations at constant values of D_i. The results showed insignificant swelling behavior in the presence of organic solvents.     

Synthesis and structure of antimony complexes [Ph3AmP] 2 + [Sb2I8 · 2DMSO]2−, [Ph3PrP] 2 + [Sb2I8 · C4H8O2]2−, and [(HOCH2CH2)3NH] 4 + [Sb4I16]4−

The reaction of equimolar amounts of triphenylamyl- and triphenylpropylphosphonium iodides and triethanolammonium iodide with antimony iodide in dimethyl sulfoxide, dioxane, or acetone gave complexes [Ph₃AmP] ₂ ⁺ [Sb₂I₈ · 2DMSO]^2?, [Ph₃PrP] ₂ ⁺ [Sb₂I₈ · C₄H₈O₂]^2?, and [(HOCH₂CH₂)₃NH] ₄ ⁺ [Sb₄I₁₆]^4?, the structure of which was established by X-ray diffraction analysis. The cations of all complexes have slightly distorted tetrahedral structure, and the antimony atoms in the anions are hexacoordinated. The crystals of the complexes have intra- and intermolecular contacts, which form the structure.     

Study on antimony oxide self-assembled inside HZSM-5

Sb/ZSM-5 was obtained by solid-state reaction with the mixture of Sb₂O₃ and zeolite HZSM-5 under a dry nitrogen flow at 773 K. Characterization of the treated zeolite was undertaken with XRD, ²⁷Al MAS NMR, BET, TGA and FT-IR. The results revealed that part of the antimony oxides migrated into the channels of zeolite, and decreased the Brönsted acid sites in Sb/ZSM-5 remarkably. The other part of antimony oxides together with the amorphous alumino-silicate in the products distributed on the external surface of zeolite ZSM-5 and modified it, while the framework of ZSM-5 in crystal phase was retained. The structure of occluded antimony oxide inside the channels of ZSM-5 was studied by XRD Rietveld method. The result showed that their structure can be described as a chain of non-perfect [Sb₅O₅(H₂O)₂]_n⁵ⁿ⁺, which is parallel to the straight channel of ZSM-5. There is about 0.6 [Sb₅O₅(H₂O)₂]⁵⁺ unit in every cell of the ZSM-5 on an average.     

Tetrakis­[phthalocyaninato(2–)­antimony(III)] hexadecaiodotetraantimony(III)

Crystals of a new antimony(III) phthalocyanine complex with the formula [Sb(C₃₂H₁₆N₈)]₄(Sb₄I₁₆), or (SbPc)·[Sb₄I₁₆]^4?, where Pc is phthalocyaninate, have been obtained by the reaction of pure powdered antimony with phthalo­nitrile under a stream of iodine vapour. The crystals are built up from separate but interacting (SbPc)⁺ cations and centrosymmetric [Sb₄I₁₆]^4? anions. Each Sb atom of two independent (SbPc)⁺ units is bonded to the four iso­indole N atoms of the phthalocyaninate(2?) macrocycle and lies 1.0 Å out of the plane defined by four iso­indole N atoms. The anionic part of the complex consists of four SbI₆ distorted octahedra joined together into a centrosymmetric [Sb₄I₁₆]^4? anion. The arrangement of oppositely charged moieties in the crystal is mainly determined by ionic attraction and by a set of distinct donor–acceptor interactions between (SbPc)⁺ and [Sb₄I₁₆]^4? ions.     

Synthesis and structure of nalidixium tetrachloroantimonate monohydrate, (C12H13N2O3)SbCl4 · H2O

Nalidixium tetrachloroantimonate monohydrate, (C₁₂H₁₃N₂O₃)SbCl₄ · H₂O, has been synthesized and its crystal structure has been determined. The structure is built of the [Sb₂Cl₈]^2? anions, C₁₂H₁₃N₂O ₃ ⁺ nalidixium cations, and H₂O molecules joint by hydrogen bonds and π-π-and Cl?Cl interactions. The [Sb₂Cl₈]^2? anion is a dimer of the SbCl₅ E distorted octahedra sharing common Cl?Cl edge (E is the lone electron pair). The Sb polyhedra contain two short Sb-Cl bonds (2.387 and 2.395 Å), one bond of a medium length (2.508 Å), and two long bridging bonds (2.745 and 3.054 Å).     

Structural Expansion of Chalcogenido Tetrelates in Ionic Liquids by Incorporation of Sulfido Antimonate Units

Multinary chalcogenido (semi)metalate salts exhibit finely tunable optical properties based on the combination of metal and chalcogenide ions in their polyanionic substructure. Here, we present the structural expansion of chalcogenido germanate(IV) or stannate(IV) architectures with Sb^III, which clearly affects the vibrational and optical absorption properties of the solid compounds. For the synthesis of the title compounds, [K₄(H₂O)₄][Ge₄S₁₀] or [K₄(H₂O)₄][SnS₄] were reacted with SbCl₃ under ionothermal conditions in imidazolium-based ionic liquids. Salt metathesis at relatively low temperatures (120 °C or 150 °C) enabled the incorporation of (formally) Sb³⁺ ions into the anionic substructure of the precursors, and their modification to form (Cat)₁₆[Ge₂Sb₂S₇]₆[GeS₄] ( 1 ) and (Cat)₆[Sn₁₀O₄S₂₀][Sb₃S₄]₂ ( 2 a and 2 b ), wherein Cat=(C₄C₁C₁Im)⁺ ( 1 and 2 a ) or (C₄C₁C₂Im)⁺ ( 2 b ). In 1 , germanium and antimony atoms are combined to form a rare noradamantane-type ternary molecular anion, six of which surround an {GeS₄} unit in a highly symmetric secondary structure, and finally crystallize in a diamond-like superstructure. In 2 , supertetrahedral oxo-sulfido stannate clusters are generated, as known from the ionothermal treatment of the stannate precursor alone, yet, linked here into unprecedented one-dimensional strands with {Sb₃S₄} units as linkers. We discuss the single-crystal structures of these uncommon salts of ternary and quaternary chalcogenido (semi)metalate anions, as well as their Raman and UV-visible spectra.     

Protonated Ethylene Carbonate: A Highly Resonance-Stabilized Cation

Salts containing the monoprotonated ethylene carbonate species of were obtained by reacting it with the superacidic systems XF/MF₅ (X=H, D; M=Sb, As). The salts in terms of [C₃H₅O₃]⁺[SbF₆]⁻, [C₃H₅O₃]⁺[AsF₆]⁻ and [C₃H₄DO₃]⁺[AsF₆]⁻ were characterized by low-temperature infrared and Raman spectroscopy. In order to generate the diprotonated species of ethylene carbonate, an excess of Lewis acid was used. However, this only led to the formation of [C₃H₅O₃]⁺[Sb₂F₁₁]⁻, which was characterized by a single-crystal X-ray structure analysis. Quantum chemical calculations on the B3LYP/aug-cc-PVTZ level of theory were carried out for the [C₃H₅O₃]⁺ cation and the results were compared with the experimental data. A Natural Bond Orbital (NBO) analysis revealed sp² hybridization of each atom belonging to the CO₃ moiety, thus containing a remarkably delocalized 6π-electron system. The delocalization is confirmed by a ¹³C NMR-spectroscopic study of [C₃H₅O₃]⁺[SbF₆]⁻.     

Antimony Trioxide as an Efficient Lewis Acid Catalyst for the Synthesis of 5-Substituted 1H-Tetrazoles

Sb₂O₃ was found to be effective as a catalyst for a smooth (2 + 3) cycloaddition of sodium azide with nitriles to afford 5-substituted 1H-tetrazoles in good yields.     

Synthesis and Crystal Structures of New Antimony Polysulfido Complexes: [P(C6H5)4]3Sb3S25 and [P(C6H5)4]2Sb2S15 · 2(C3N2H6)

Reaction of elemental antimony with sulfur under mild hydrothermal conditions yielded different polysulfido-clusters of antimony. These were isolated as tetraphenylphosphonium salts [P(C₆H₅)₄]₃Sb₃S₂₅ and [P(C₆H₅)₄]₂Sb₂S₁₅ · 2(C₃N₂H₆) and their crystal structures were determined. In the first compound two different polysulfide anions are observed, Sb₂S₁₇^2– and Sb₂S₁₆^2–, whereas the second contains the Sb₂S₁₅^2– complex. These dinuclear anions show as a common building principle two ψ-trigonal bipyramidal coordinated Sb centers bridged by two S_x^2– units and an additional S_x^2– chelate ligand bound to each Sb center giving a tricyclic structure.