Modeling the Proton Transport in Orthoperiodic and Orthotelluric Acids and Their Salts

Orthoperiodic and orthotelluric acids, their salts MIO₆H₄ (M = Li, Rb, Cs) and CsH₅TeO₆, and dimers of the salt · acid type are calculated within density functional theory B3LYP and basis set LanL2DZ complemented by the polarizationd,p-functions. According to calculations, the salt · acid dimerization is energetically favorable for compounds MIO₆H₄ · H₅IO₆ (M = Rb, Cs) and CsIO₆H₄ · H₆TeO₆. The dimerization energy is equal to 138–146 kJ mol^–1. With relatively small activation energies equal to 4 kJ mol^–1 (M = Li) and 11 kJ mol^–1 (M = Rb, Cs), possible is rotation of octahedron IO₆ relative to the M atom in monomers of salt molecules. The proton transfer along an octahedron occurs with activation energies of 63–84 kJ mol^–1. The activation energy for the proton transfer between neighboring octahedrons of the type salt · acid acid · salt equals 8–17 kJ mol^–1. Quantum-chemical calculations nicely conform to x-ray diffraction and electrochemical data.     

A rare multi-coordinate tellurite, NH4ATe4O9·2H2O (ARb or Cs): The occurrence of TeO3, TeO4, and TeO5 Polyhedra in the same material

Two new tellurites, NH₄RbTe₄O₉·2H₂O and NH₄CsTe₄O₉·2H₂O have been synthesized and characterized. The compounds were synthesized hydrothermally, in near quantitative yields, using the alkali metal halide, TeO₂, and NH₄OH as reagents. The iso-structural materials exhibit layered, two-dimensional structural topologies consisting of TeO_x (x=3, 4, or 5) polyhedra separated by NH₄⁺, H₂O, Rb⁺ or Cs⁺ cations. Unique to these materials is the presence of TeO₃, TeO₄, and TeO₅ polyhedra. Thermogravimetric and infrared spectroscopic data are also presented. Crystal data: NH₄RbTe₄O₉·2H₂O: Monoclinic I2/a (no. 15), a=18.917(3) Å, b=6.7002(11) Å, c=21.106(5) Å, β=101.813(2)°, V=2618.5(9) Å³, Z=8; NH₄CsTe₄O₉·2H₂O: Monoclinic I2/a (no. 15), a=18.9880(12) Å, b=6.7633(4) Å, c=21.476(2) Å, β=102.3460(10)°, V=2694.2(3) Å³, Z=8.     

Synthesis,Crystal Structure,and Properties of Mixed Salt Cs2SO4 · H6TeO6

Mixed salt Cs₂SO₄ · H₆TeO₆ (I) is synthesized and its structure and properties are studied by X-ray diffraction analysis, IR and Raman spectroscopies, impedance measurements, and differential thermal analysis. Compound I crystallizes in hexagonal system with unit cell parameters a = 7.455(1) Å, c = 33.303(7) Å, space group R3c, Z = 6. Its crystal structure consists of the H₆TeO₆ molecules and SO₄ ^2- anions united by network of hydrogen bonds and Cs⁺ cations.     

Preparation and Crystal Structures of the Hydrous Mercury Tellurates,HgII(H4TeVIO6) and HgI2(H4TeVIO6)(H6TeVIO6)·2H2O

Single crystals of Hg^II(H₄Te^VIO₆) (colourless to light‐yellow, rectangular plates) and Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O (colourless, irregular) were grown from concentrated solutions of orthotelluric acid, H₆TeO₆, and respective solutions of Hg(NO₃)₂ and Hg₂(NO₃)₂. The crystal structures were solved and refined from single crystal diffractometer data sets (Hg^II(H₄Te^VIO₆): space group Pna2₁, Z = 4, a =10.5491(17), b = 6.0706(9), c = 8.0654(13)Å, 1430 structure factors, 87 parameters, R[F² > 2σ(F²)] = 0.0180; Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O: space group P1¯, Z = 1, a = 5.7522(6), b = 6.8941(10), c = 8.5785(10)Å, α = 90.394(8), β = 103.532(11), γ = 93.289(8)°, 2875 structure factors, 108 parameters, R[F² > 2σ(F²)] = 0.0184). The structure of Hg^II(H₄Te^VIO₆) is composed of ribbons parallel to the b axis which are built of [H₄TeO₆]^2— anions and Hg²⁺ cations held together by two short Hg—O bonds with a mean distance of 2.037Å. Interpolyhedral hydrogen bonding between neighbouring [H₄TeO₆]^2— groups, as well as longer Hg—O bonds between Hg atoms of one ribbon to O atoms of adjacent ribbons lead, to an additional stabilization of the framework structure. Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O is characterized by a distorted hexagonal array made up of [H₄TeO₆]^2— and [H₆TeO₆] octahedra which spread parallel to the bc plane. Interpolyhedral hydrogen bonding between both building units stabilizes this arrangement. Adjacent planes are stacked along the a axis and are connected by Hg₂²⁺ dumbbells (d(Hg—Hg) = 2.5043(4)Å) situated in‐between the planes. Additional stabilization of the three‐dimensional network is provided by extensive hydrogen bonding between interstitial water molecules and O and OH‐groups of the [H₄TeO₆]^2— and [H₆TeO₆] octahedra. Upon heating Hg^I₂(H₄Te^VIO₆)(H₆Te^VIO₆)·2H₂O decomposes into TeO₂ under formation of the intermediate phases Hg^II₃Te^VIO₆ and the mixed‐valent Hg^IITe^IV/VI₂O₆.     

Crystal Structure and Properties of Rb4H2I2O10 · 4H2O

Single crystals of the Rb₄H₂I₂O₁₀· 4H₂O were synthesized for the first time and studied by X-ray diffraction analysis. The crystals are monoclinic, a = 7.321(6) Å, b = 12.599(8) Å, c = 8.198(8) Å, = 96.30(7)°, Z = 2, space group P2₁/c. The H₂I₂O₁₀ ^4– anion is formed by the edge-sharing IO₆ octahedra. The anions are united by hydrogen bonds into a chain running along the x axis. The chains are combined by water molecules into a three-dimensional structure through hydrogen bonds. The compound is a proton conductor. The conductivity values measured at 20–60°C vary within 10^–6 to 10^–4 ohm^–1 cm^–1.     

Ein Oxotellurat (VI) neuen Typs: Rb6[TeO5] [TeO4]

A New Type of Oxotellurates (VI): Rb₆[TeO₅] [TeO₄] For the first time single crystals of Rb₆Te₂O₉ was obtained by annealing intimate mixtures of the binary oxides (closed Ag-cylinder in supremax-glass ampoule, 680°C, 45 d). The structure elucidation (four-circle diffractometer, AgKα, 2083 I₀(hkl); R = 9.5%, R_w = 6.6%) confirms the space group C2/c with a = 1207.5(7), b = 1266.3(5), c = 1105.3(6) pm, β = 123.1(1)⁰, Z = 4 (Guinier-Simon photographs). Characteristic for this structure are ?isolated”? trigonal bipyramidal groups of [TeO₅] and ?isolated”? tetrahedral groups of [TeO₄], so we prefere to name the new compound Rb₆[TeO₅][TeO₄]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Solubility in the systems Rb2SO4-H2SO4-H2O and Cs2SO4-H2SO4-H2O at 25°

Conclusions The solubility of rubidium and cesium sulfates in aqueous solutions of sulfuric acid was studied at 25°. Rubidium sulfate forms the compounds 3Rb₂SO₄· H₂SO₄, Rb₂SO₄ · H₂SO₄, Rb₂SO₄·3H₂SO₄ and Rb₂SO₄·7H₂SO₄ with sulfuric acid, while cesium sulfate forms the compounds Cs₂SO₄·H₂SO₄; Cs₂SO₄·3H₂SO₄ and Cs₂SO₄ · 7H₂SO₄.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1166–1170, June, 1968.     

Chemie der Seltenerdmetalle, 24. Mitt.: Komplexverbindungen des dreiwertigen Cers mit Malonsäure

Zusammenfassung Durch Auflösen von Ce₂ Mal ₃·6H₂O^** in wäßr. Malonsäure wurde die Dimalonato-Ce(III)-säure in zwei Hydratformen hergestellt: HCeMal ₂·2 H₂O und HCeMal ₂·3 H₂O.Durch Auflösen von Ce₂ Mal ₃·6H₂O in konz. Malonatlösungen vom TypusM ₂ ^I Mal (M ^I=Li, Na, K, NH₄) wurden nachstehende Komplexalze gewonnen: LiCeMal ₂·3H₂O, NaCeMal ₂·2 H₂O, KCeMal ₂·2 H₂O und NH₄CeMal ₂·3 H₂O. Die Verbindungen wurden auf Grund der quantit. Analysen, Debyeogramme und IR-Spektren identifiziert. Der thermische Zerfall wurde mit Hilfe derDTA undGTA verfolgt.In neutralen und schwach sauren Lösungen kommt es bei allen Verbindungen zur hydrolytischen Spaltung unter Ausscheidung des neutralen Ce(III)-Malonates. Bei der Dimalonato-Ce(III)-säure wurde an Hand der Löslichkeitsmethode ihre Dissoziation verfolgt.

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Chemistry of the rare earth metals, XXIV: Complex Ce(III)-malonates

By dissolving Ce₂ Mal ₃·6 H₂O^** in aqueous malonic acid, the Ce(III)-dimalonic acid was prepared in two forms: HCeMal ₂·2 H₂O and HCeMal ₂·3 H₂O.When Ce₂ Mal ₃·6 H₂O is dissolved in concd. malonate solutions of the typM ₂ ^I Mal (M ^I=Li, Na, K, NH₄), the following complex salts can be isolated: LiCeMal ₂·3H₂O, NaCeMal ₂·2 H₂O, KCeMal ₂·2 H₂O and NH₄CeMal ₂·3 H₂O. The compounds where identified by quantitative analysis, X-ray powder photographs and IR spectra. The thermal decomposition was followed byDTA andGTA.In neutral and weakly acidic solutions, all these compounds are hydrolyzed with the simultaneous precipitation of the neutral Ce(III)-malonates. The dissociation of Ce(III)-dimalonic acid was followed by means of a precipitation method.

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23. Mitt.:F. Bezina, Mh. Chem.100, 1684 (1969).     

Application of NMR- and IR-spectroscopy to a study of the structure of the crystal hydrates of lanthanum molybdate and tungstate

Using the techniques of proton magnetic resonance, differential thermal analysis, and IR-spectroscopy, we have carried out a study of the structures of lanthanum molybdate and lanthanum tungstate. We have established that the hydrogen atoms are incorporated in the structure of the compounds as a component of water molecules coordinated about the lanthanum atoms and about the anions of the salts, as well as a component of OH groups. On the basis of our results the formulas of the compounds can be written as La₂(OH)₂ · · Mo₃O₁₁ · 5 H₂O and La₂(OH)₂ · W₃O₁₁ · 9 H₂O.     

Crystal structures and thermal decomposition oftrans-Pd(Creat)2Cl2·2H2O andcis-Pt(Creat)2I2·3H2O

New complexes of the formulaetrans-Pd(Creat)₂Cl₂·2H₂O (I) andcis-Pt(Creat)₂I₂·3H₂O (II) have been prepared and their structures and stabilities studied by X-ray diffraction and thermal analysis. Both compounds have a squareplanar geometry, the two Cl atoms and N1 creatinine atoms are coordinated to Pd intrans configuration, while in compoundII the I atoms and N1 atoms are coordinated incis configuration. In spite of the earlier differences, the TG and DTA curves of the complexes show that their stability is very similar. Since an extended hydrogen bond system is present in the crystals, especially inII, the possible consequences in biological media are discussed briefly.

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Kristallstrukturen und thermische Zersetzung vontrans-Pd(Creat)₂Cl₂·2H₂O undcis-Pt(Creat)₂I₂·3H₂O

Zusammenfassung Es wurden neue Komplexe der Formelntrans-Pd(Creat)₂Cl₂·2H₂O (I) undcis-Pt(Creat)₂I₂·3H₂O (II) hergestellt und ihre Strukturen und Stabilitäten mittels Röntgenstrukturanalyse bzw, thermischer Analyse untersucht. Beide Komplexe haben quadratisch-planare Struktur, die zwei Cl-Atome und die N1-Creatinin-Atome sind an Pd intrans-Konfiguration koordiniert, währenddessen in VerbindungII die I-Atome und die N1-Atome incis-Konfiguration zueinander stehen. Trotz früherer Differenzen zeigen die TG- und DTA-Kurven der Komplexe, daß ihre Stabilitäten sehr ähnlich sind. Da besonders inII ein ausgedehntes Wasserstoffbindungssystem vorhanden ist, werden auch mögliche Konsequenzen bezüglich biologischer Wirksamkeit kurz diskutiert.

     

Structural Features of Triorganylantimony Dicarboxylates R3Sb[OC(O)R′)]2

Triphenylantimony dibenzoate Ph₃Sb(O₂CPh)₂, triphenylantimony bis(methylbenzoates) Ph₃Sb(O₂CC₆H₄Me-n)₂ (n = 2, 4), and tri-p-tolylantimony bis(trichloacetate) p-Tol₃Sb(O₂CCCl₃)₂, whose Sb atoms have trigonal bipyramidal coordination, were studied using X-ray diffraction analysis. The Sb–O bond lengths are equal to 2.119(2) and 2.144(2); 2.115(2); 2.118(2) and 2.127(2); 2.133(2) Å, the Sb···O(=C) intramolecular contacts are equal to 2.797(2) and 2.698(2); 2.845(2); 2.814(2) and 3.030(2); 3.119(2) Å, respectively. The following correlation was found in the structures of triorganylantimony dicarboxylates: the shorter the Sb···O(=C) distances, the greater the equatorial angle on the side of the intramolecular contacts.     

Potassium Ion Conductivity in the Cubic Labyrinth of a Piezoelectric,Antiferromagnetic Oxoferrate(III) Tellurate(VI)

Orange-colored crystals of the oxoferrate tellurate K_12+6xFe₆Te_4−xO₂₇ [x=0.222(4)] were synthesized in a potassium hydroxide hydroflux with a molar water–base ratio n(H₂O)/n(KOH) of 1.5 starting from Fe(NO₃)₃ ⋅ 9H₂O, TeO₂ and H₂O₂ at about 200 °C. By using (NH₄)₂TeO₄ instead of TeO₂, a fine powder consisting of microcrystalline spheres of K_12+6xFe₆Te_4−xO₂₇ was obtained. K_12+6xFe₆Te_4−xO₂₇ crystallizes in the acentric cubic space group I 3d. [Fe^IIIO₅] pyramids share their apical atoms in [Fe₂O₉] groups and two of their edges with [Te^VIO₆] octahedra to form an open framework that consists of two loosely connected, but not interpenetrating, chiral networks. The flexibility of the hinged oxometalate network manifests in a piezoelectric response similar to that of LiNbO₃.The potassium cations are mobile in channels that run along the <111> directions and cross in cavities acting as nodes. The ion conductivity of cold-pressed pellets of ball-milled K_12+6xFe₆Te_4−xO₂₇ is 2.3×10⁻⁴ S ⋅ cm⁻¹ at room temperature. Magnetization measurements and neutron diffraction indicate antiferromagnetic coupling in the [Fe₂O₉] groups.     

Relationships in formation of the active surface of vanadium-containing oxide systems for hydrocarbon dehydrogenation reactions in the presence of hydrogen acceptors

A study has been made of the catalytic properties of vanadium-aluminum and vanadium-magnesium oxide systems in the reaction of ethylbenzene dehydrogenation in the presence of nitrobenzene. The catalysts were prepared from NH₄VO₃ and the complex salts K₆V₁₀O₂₈·10H₂O, 2(NH₄)₂O·V₂O₅·2CrO₃·7H₂O, and (NH₄)₄V₆O₁₇·(NH₄)₂MoO₄. It was established that catalysts prepared from complex vanadium salts and --Al₂O₃ will operate for extended periods without loss of activity. The effects of CdO, K₂SO₄, KOH, ZnO, MoO₃, and Cr₂O₃ on the catalytic activity were investigated; the addition of Cr₂O₃ has the greatest effect. The process of coke formation on these catalysts has been investigated.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1751–1757, August, 1991.     

Disordered Crystal Structure of the 1:3 Solvated Molecular Ionic Complex of 1,10-Diaza-18-crown-6 with (+)-Tartaric Acid

The disordered crystal structure of the 1:3 solvated molecular ionic complex of 1,10-diaza-18-crown-6 with (+)-tartaric acid [C₁₂H₂₈N₂O₄]²⁺·2C₄H₅O ₆ ^- ·C₄H₆O₆·1.5CH₃OH·1.7H₂O (I) was investigated by XRD analysis. Crystals I are monoclinic: space group P2 ₁, a = 9.662(2), b = 13.618(5), c = 14.316(3) , = 93.97(2)°, Z = 2. Structure I was solved by direct methods and refined by the full-matrix least-squares procedure anisotropically to R = 0.081 for all 3539 unique measured reflections (CAD-4 automatic diffractometer, CuK ). In structure I, the solvated methanol and water molecules are disordered on many sites. The DA18C6 dication is also disordered and has two different asymmetric conformations. The two tartrate anions lie on different sides of the cavity of the DA18C6 dication, whose two NH ₂ ⁺ groups each forms two H-bonds of N–H...O type with each of the tartrate anions. The (+)-tartaric acid molecule and the solvated molecules are not involved in the H-bonds with the DA18C6 dication. The molecular ionic complex I exists in crystal as a complex infinite three-dimensional supramolecular structure.     

Lanthankomplexe mit 2,2′-Bipyridin-N,N′-dioxid

Compounds of the composition La(bpyO₂ ^*)₄Cl₃·4H₂O, La(bpyO₂)₃Cl₃·5H₂O, La(bpyO₂)₂Cl₃·3H₂O, La(bpyO₂)Cl₃·3H₂O, La(bpyO₂)₄Br₃·4H₂O, La(bpyO₂)₃Br₃·8H₂O, La(bpyO₂)₂Br₃·7H₂O, La(bpyO₂)Br₃·4H₂O, La(bpyO₂)₄I₃·3H₂O, La(bpyO₂)₃(NO₃)₃·2H₂O, La(bpyO₂)₂(NO₃)₃·2H₂O, La(bpyO₂)₄(SCN)₃·3H₂O, La(bpyO₂)₃(SCN)₃·2H₂O, La(bpyO₂)₂(SCN)₃·2H₂O were isolated. They were investigated by means of thermoanalysis, I.R. spectroscopy, X-ray diffraction and molar conductivity.     

Electronic and infrared spectral studies of manganese(III) selenito complexes

Summary Selenito manganese(III) complexes of the type MMn(SeO₃)₂ · × H₂O (where M = H⁺, NH ₄ ⁺ , K⁺, Rb⁺ and Cs⁺) have been prepared, Magnetic measurements show all these complexes to be of high spin d⁴ type, On the basis of their i.r. and electronic spectral studies and other properties, a polymeric octahedral structure involving bridging oxygen atoms has been suggested.     

Open-Framework Rubidium Halides Incorporated in Cadmium Oxalate Host Lattices

The metathetic reaction between CdBr₂ and rubidium oxalate under hydrothermal conditions yields [RbBr] [Cd₆(C₂O₄)₆]·2H₂O, I, containing Cd₆O₂₄ clusters with the Br⁻ ions in the center. The RbBr moiety forms a three-dimensional Fm3m structure, but with a unit cell double that of the normal stable phase. The hydrothermal reaction between rubidium oxalate and CdCl₂ in the presence of NO⁻₃ ions gives [Rb₂Cd(NO₃)(Cl)(C₂O₄)(H₂O)], II, containing cadmium chloro-oxalate layers. The Rb⁺ ions present between the layers interact with the Cl atoms to form a one-dimensional RbCl chain decorated by NO⁻₃ groups.     

Preparation,Thermal Behaviour and Crystal Structure of the Basic Mercury(II) Tetraoxotellurate(VI), Hg2TeO5, and Redetermination of the Crystal Structure of Mercury(II) Orthotellurate(VI), Hg3TeO6

Single crystals of Hg₂TeO₅ were obtained as dark‐red parallelepipeds by reacting stoichiometric amounts of Hg(NO₃)₂ · H₂O and H₆TeO₆ under hydrothermal conditions (250 °C, 10d). The crystal structure (space group Pna2₁, Z = 4, a = 7.3462(16), b = 5.8635(12), c = 9.969(2)Å, 1261 structure factors, 50 parameters, R[F² > 2σ(F²)] = 0.0295) is characterized by corner‐sharing [TeO₆] octahedra forming isolated chains [TeO_4/1O_2/2] which extend parallel to [100]. The two crystallographically independent Hg atoms are located in‐between the chains and interconnect the chains via common oxygen atoms. Amber coloured single crystals of Hg₃TeO₆ were prepared by heating a mixture of Hg, HgO and TeO₃ together with small amounts of HgCl₂ as mineralizer in an evacuated and sealed silica glass tube (520 °C). The previously reported crystal structure has been re‐investigated by means of single crystal X‐ray data which reveal a symmetry reduction from Ia3¯d to Ia3¯ (Z = 16, a = 13.3808(6) Å, 609 structure factors, 33 parameters, R[F² > 2σ(F²)] = 0.0221). The crystal structure is made up of a body‐centred packing of [TeO₆] octahedra with the Hg atoms situated in the interstices of this arrangement. Upon heating, both title compounds decompose in a one‐step mechanism under formation of TeO₂ and loss of the appropriate amounts of elementary mercury and oxygen.     

The 1,4,7,10,13-Pentaoxacyclohexadecane-14,16-Dione Complex with Potassium Thiocyanate: Crystal Structure

The complex of 1,4,7,10,13-pentaoxacyclohexadecane-14,16-dione (L) with potassium thiocyanate, C₁₁H₁₈O₇· KNCS (I), is prepared and characterized by X-ray diffraction analysis: space group C2/c, a = 26.810 Å, b = 7.834 Å, c = 20.504 Å, = 129.19°, Z = 8. The crystal structure is solved by the direct method and refined anisotropically by the full-matrix least-squares method to R = 0.038 for all 2929 unique measured reflections (CAD4 automated diffractometer, MoK ). Structure I is built of [KL(NCS)] monomers of the host–guest type, which are united into [K₂L₂(NCS)₂] dimers containing four-membered KNKN cycles. In the crystal, the dimers are united into infinite polymeric double chains (along the b axis) by K···O=C outer bonds. The K⁺ cation (CN 8) does not lie in the plane of the L crown ligand but is located above it. The coordination polyhedron of the K⁺ cation is irregular; its vertices are occupied by five ether O atoms of one L ligand, two N atoms of two SCN ligands, and one carbonyl O atom of the adjacent L ligand.