Die neuen gemischtvalenten Chalkogenoindate MIn7X9 (M = Rb,Cs; X = S,Se): Strukturchemie,Röntgenund HRTEM‐Untersuchungen

The New Mixed Valent Chalcogenoindates MIn₇X₉ (M = Rb, Cs; X = S, Se): Structural Chemistry, X‐Ray and HRTEM Investigations Systematic X‐ray and HRTEM investigations on the ternary systems alkali metal (or thallium)–indium–chalcogen proved the existence of mixed valent solids with the simultaneous occurrence of indium species in different states of oxidation. Additionally to the earlier described solids MIn₅S₇ (M: Na, K, Tl: isotypic to InIn₅S₇ = In₆S₇ and TlIn₅S₇) and KIn₅S₆ (isotyp to TlIn₅S₆) in the actual work we present with MIn₇X₉ (M: Rb, Cs; X: S, Se) a new structure type which also contains indium in the states of oxidation +3 and +2. The formal state of oxidation In²⁺ corresponds to (In₂)⁴⁺ ions. A reasonable ionic formulation of these structures is given by: MIn₅S₇ = M⁺ 3[In³⁺] [(In₂)⁴⁺] 7[S^2–] (M = Na, K, Tl), MIn₅S₆ = M⁺ [In³⁺] 2[(In₂)⁴⁺] 6[S^2–] (M = K, Tl), MIn₇X₉ = M⁺ 3[In³⁺] 2[(In₂)⁴⁺] 9[S^2–]. The three structure types show common two dimensional structure elements which contain ethane analogous In₂X₆ units and cis and trans edge sharing double octahedron chains. The main interest of this work is a crystalchemical discussion taking into account the new compounds MIn₇X₉ and the results of special HRTEM investigations on MIn₇X₉. The HRTEM investigations aim on the identification and subsequent preparation of new phases which initially might be visible as nano size crystals or inclusions in the HRTEM only.     

Structure-determining role of Tl+ in natural and synthetic sulfides

A crystallographic analysis is performed for the structures of TlCu₂S₂, TlCu₇S₄, TlTaS₃, TlIn₃S₅, TlIn₅S₈, and TlCr₂V₃S₈. In them the Tl⁺ cation is included in anion sublattices and stabilizes their regularity. The cation sublattices are substantially distorted and have additional conjugation to the anionic positions of the thallium cations. The monoclinic structures (the last three) have geometrically similar anionic and cationic “forced skeletons,” while in tetragonal (the first two) and orthorhombic symmetries they are modified by symmetry restrictions.     

New thallium iodates—Synthesis, characterization, and calculations of Tl(IO3)3 and Tl4(IO3)6, [Tl3Tl(IO3)6]

Two new thallium iodates have been synthesized, Tl(IO₃)₃ and Tl₄(IO₃)₆ [Tl⁺₃Tl³⁺(IO₃)₆], and characterized by single-crystal X-ray diffraction. Both materials were synthesized as phase-pure compounds through hydrothermal techniques using Tl₂CO₃ and HIO₃ as reagents. The materials crystallize in space groups R-3 (Tl(IO₃)₃) and P-1 (Tl₄(IO₃)₆). Although lone-pairs are observed for both I⁵⁺ and Tl⁺, electronic structure calculations indicate the lone-pair on I⁵⁺ is stereo-active, whereas the lone-pair on Tl⁺ is inert.     

Darstellung,Eigenschaften, röntgenographische und spektroskopische Untersuchung von Tl4Nb2S11 und Tl4Ta2S11

On Polychalcogenides of Thallium with M₂Q₁₁ Groups as a Structural Building Block. I Preparation, Properties, X‐ray Diffractometry, and Spectroscopic Investigations of Tl₄Nb₂S₁₁ and Tl₄Ta₂S₁₁ The new ternary compounds Tl₄Nb₂S₁₁ and Tl₄Ta₂S₁₁ were prepared using Thallium polysulfide melts. Tl₄M₂S₁₁ crystallises isotypically to K₄Nb₂S_8.9Se_2.1 in the triclinic space group P 1 with a = 7.806(2) Å, b = 8.866(2) Å, c = 13.121(3) Å, α = 72.72(2)°, β = 88.80(3)°, and γ = 85.86(2)° for M = Nb and a = 7.837(1) Å, b = 8.902(1) Å, c = 13.176(1) Å, α = 72.69(1)°, β = 88.74(1)°, and γ = 85.67(1)° for M = Ta. The interatomic distances as well as angles within the [M₂S₁₁]^4– anions are similar to those of the previously reported data for analogous alkali metal polysulfides. Significant differences between Tl₄M₂S₁₁ and A₄M₂S₁₁ (A = K, Rb, Cs) are obvious for the shape of the polyhedra around the electropositive elements. The two title compounds melt congruently at 732 K (M = Nb) and 729 K (M = Ta). The optical band gaps were estimated as 1.26 eV for Tl₄Nb₂S₁₁ and as 1.80 eV for the Tantalum compound.     

Das Indiumsesquichlorid,In2Cl3: ein pseudobinäres,gemischtvalentes Indium(I)-hexachloroindat(III)

Indium Sesquichloride, In₂Cl₃: a Pseudobinary, Mixed-valence Indium(I) Hexachloroindate(III) Colorless In₂Cl₃, obtained by reduction of InCl₃ with metallic In, according to In[In^IIICl₆] a pseudobinary, mixed-valence indium(I) hexachloroindate(III), crystallizes orthorhombic (Pnma, Z = 32) with a = 1261.4(3), b = 2523.8(5), c = 1456.2(2) pm (Guinier-Simon data), V_m(In₂Cl₃) = 87.3 cm³ × mol^?1. In^III occupies octahedral holes separated from each other (d?(In^III? Cl) = 251 pm). Coordination numbers of 7 to 11 are observed for In^I (d?(In^I? Cl) = 329–359 pm). In₂Cl₃ is isotypic with α-Tl₂Cl₃.     

Phase diagram of the Tl-TlI-S system and thermodynamic properties of the compound Tl<Subscript>6</Subscript>SI<Subscript>4</Subscript>

Phase equilibria in the Tl-TlI-S composition region of the Tl-S-I system were studied by differential thermal analysis, x-ray powder diffraction, and measurements of the microhardness and the emf of concentration circuits relative to a thallium electrode. A series of polythermal sections, an isothermal section at 300 K, and a projection of the liquidus surface were constructed. Primary crystallization regions of six phases, including the ternary compounds Tl₆SI₄ and Tl₃SI, were outlined, and the types and coordinates of non- and monovariant equilibria were determined. It was shown that the ternary compound Tl₆SI₄ forms tie lines with Tl, TlI, Tl₂S, Tl₄S₃, and TlS in the subsolidus region and that the homogeneity region of Tl₆SI₄ below 400 K does not exceed 1 mol %. From the emf measurement data, the standard thermodynamic functions of formation and standard entropy of the compound Tl₆SI₄ were calculated: G _f,298⁰ = −601.7 ± 2.5 kJ/mol, ΔH _f,298⁰= −595.1 ± 4.0 kJ/mol, and S ₂₉₈⁰ = 672 ± 10 J/(mol K).     

Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten. XXXIII [1] In2P2O7, ein Indium(I)‐diphosphato‐indat(III) und In4(P2O7)3 — Darstellung,Kristallisation und Kristallstrukturen

Contributions on Crystal Chemistry and Thermal Behaviour of Anhydrous Phosphates. XXXIII [1] In₂P₂O₇ an Indium(I)‐diphosphatoindate(III), and In₄(P₂O₇)₃ — Synthesis, Crystallization, and Crystal Structure Solid state reactions via the gas phase lead to the new mixed‐valence indium(I, III)‐diphosphate In₂P₂O₇. Colourless single crystals of In₂P₂O₇ have been grown by isothermal heating of stoichiometric amounts of InPO₄ and InP (800 °C; 7d) using iodine as mineralizer. The structure of In₂P₂O₇ [P2₁/c, a = 7.550(1) Å, b = 10.412(1) Å, c = 8.461(2) Å, b = 105.82(1)°, 2813 independent reflections, 101 parameter, R1 = 0.031, wR2 = 0.078] is the first example for an In⁺ cation in pure oxygen coordination. Observed distances d(In^I‐O) are exceptionally long (d_min(In^I‐O) = 2.82 Å) and support assumption of mainly s‐character for the lone‐pair at the In⁺ ion. Single crystals of In₄(P₂O₇)₃ were grown by chemical vapour transport experiments in a temperature gradient (1000 → 900 °C) using P/I mixtures as transport agent. In contrast to the isostructural diphosphates M₄(P₂O₇)₃ (M = V, Cr, Fe) monoclinic instead of orthorhombic symmetry has been found for In₄(P₂O₇)₃ [P2₁/a, a = 13.248(3) Å, b = 9.758(1) Å, c = 13.442(2) Å, b = 108.94(1)°, 7221 independent reflexes, 281 parameter, R1 = 0.027, wR2 = 0.067].     

Preparation of Thallium Hexacyanoferrate Film and Mixed‐Film Modified Electrodes with Cobalt(II) Hexacyanoferrate

Thallium hexacyanoferrate films have been prepared from various aqueous electrolyte solutions using consecutive cyclic voltammetry. The cyclic voltammograms recorded the direct deposition of thallium hexacyanoferrate films from the mixing of Tl³⁺ and [Fe(CN)₆]^3? ions from solutions of seven cations: Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, H⁺, and Tl⁺. An electrochemical quartz crystal microbalance (EQCM) and cyclic voltammetry were used to study the in situ growth of the thallium hexacyanoferrate films. The thallium hexacyanoferrate film shows a single redox couple with a formal potential between +0.6 V and +1.2 V, and shows a cation effect (H⁺, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, and Tl⁺). A mixed film and a two‐layered modified electrodes composed of a thallium hexacyanoferrate film with cobalt(II) hexacyanoferrate film were prepared.     

Darstellung von μ-Schwefeldisulfoniumsalzen [(CH3)2S?Sx?S(CH3)2]2+2A− (x = 1–3, A− = AsF6−, SbF6−, SbCl6−). Über die Analogie im Reaktionsverhalten zwischen Sulfanen und Sulfoniumsalzen

Preparation of μ-Sulfurdisulfonium Salts [(CH₃)₂S? S_x? S(CH₃)₂]²⁺2A^? (x = 1–3, A^? = AsF₆^?, SbF₆^?, SbCl₆^?). On the Analogy of the Reactivity of Sulfanes and Sulfonium Salts The preparation of the μ-sulfurdisulfonium salts [(CH₃)₂S? S_x? S(CH₃)₂]²⁺(A^?)₂ with x = 1–3 and A^? = AsF₆^?, SbF₆^?, SbCl₆^? is reported. The salts are formed by reaction of (CH₃)₂SH⁺A^? and (CH₃)₂SSH⁺A^? with SCl₂ and S₂Cl₂, resp. They are characterized by vibrational spectroscopic measurements. [(CH₃)₂S? S₂? S(CH₃)₂]²⁺(SbF₆^?)₂ crystallizes in the space group C2/c with a = 1 884.5(7) pm, b = 1 302.8(5) pm, c = 1 477.2(5) pm, β = 98.62(3)° und Z = 8.     

A6Nb4S22 (A = Rb and Cs), compounds with the tetrameric complex anion [Nb4S22]6−: Preparation via the molten flux method and crystal structure determination

The new ternary niobium polysulfides A₆Nb₄S₂₂ were prepared at a low temperature of 350°C via the molten flux method by reacting A₂S₃ (A = Rb, Cs) with niobium metal and additional sulfur. The crystal structure is characterized by [Nb₄S₂₂]^6? anions. Two Nb₂S₁₀ subunits are joined by a S₂^2?. Nb⁵⁺ is coordinated by S₂^2? and S^2? ligands according to [Nb₂(μ-η², η¹-S₂)(η²-S₂)₃(S)₂]₂(μ-η¹-S₂)^6?. Every Nb is in a sixfold coordination, and the polyhedra can be regarded as strongly distorted pentagonal pyramids. Within the unit cell the anions are stacked in “rods” parallel to the crystallographic b-axis. These stacks are arranged in “layers” and the A⁺ ions are located between the layers.     

Preparation,Crystal Structure,Physical Properties,and Electronic Band Structure of TlTaS3

TlTaS₃ was prepared by applying a sequence of two melting processes with mixtures of Tl₂S, Ta, and S having different molar metal to sulphur ratios. TlTaS₃ crystallises in space group Pnma with a = 9.228(3)Å, b = 3.5030(6)Å, c = 14.209(3)Å, V = 459.3(2)ų, Z = 4. The structure is closely related to the NH₄CdCl₃‐type. Characteristic features of the structure are chains of edge‐sharing [Ta(+5)S₄S_2/2]₂ double octahedra running along [010]. These columns are linked by Tl⁺ ions. The Tl⁺ ion is surrounded by eight S^2— anions to form a distorted bi‐capped trigonal prism. The Tl⁺ ions are shifted from the centre of the trigonal prism toward one of the rectangular faces. This is discussed in context with other isostructural compounds. TlTaS₃ is a semiconductor. The electronic structure is discussed on the base of band structure calculations performed within the framework of density functional theory.     

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.     

Extraction of indium(III) from chloride medium with 1-phenyl-3-methyl-4-acylpyrazol-5-ones. Synergic effect with high molecular weight ammonium salts.

The extraction of In(III) from 1M (Na,H)(Cl,ClO₄) media with 4-acylpyrazol-5-ones (HL) in toluene at 25°C is described by equilibria In ³⁺ + 3 $\text{HL}$ ? $\text{InL}{}_3$ + 3 H⁺ (log K = 1.48, 1.03, 0.87 with acyl = benzoyl, lauroyl, 2-thenoyl), InCl ²⁺ + 2 $\text{HL}$ ? $\text{InClL}{}_2$ + 2 H⁺ (log K = 0.26, ?0.45, ?0.35 respectively) and In³⁺ + m Cl^? ? InCl_m^(3-m)+ (log β_m available from literature). The extraction from 1M (Na,H)(Cl,NO₃) medium is enhanced by addition of aliquat (TOMA⁺,Cl^?) and the following synergic equilibrium takes place : $\text{InCl}{}_2$ + $\text{(TOMA}{}^{\mathrm{+}}$,Cl^?) ? $\text{(TOMA}{}^{\mathrm{+}}$, InCl₂L₂^? (log K = 5.49, 5.25, 5.21 respectively). Cl^? of (TOMA⁺,Cl^?) is exchanged by NO₃^? with the equilibrium constant log K = 1.50. If (TOMA⁺,Cl^?) is replaced by tri-n-octylammonium chloride, the synergic effect is largely reduced (log K = 4.17 with acyl = benzoyl). The extraction from chloride solutions containing ClO₄^? remains unchanged by addition of ammonium salts.     

Mise en évidence d'une solution solide de type spinelle dans le diagramme de phase du systeme InS

Evidence is presented for normal-spinel domain of homogeneity between the compositions InS_1.50?ε and InS_1.35. Structural study of a single crystal of composition InS_1.44 indicates indium vacancies on the tetrahedral sites. The compound In₂S₃, regardless of conditions of formation, is a tetragonal superstructure of the spinel lattice (a₀) with $\text{a = a}{}_0\text{2}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$ and c = 3a₀. The spinel-type domain shows peritectic decomposition at 850°C for the composition InS_1.40.     

Interaction in the Yb2S3-In2S3 system

A T-x diagram is designed for the Yb₂S₃-In₂S₃ system using physicochemical methods. A complex chemical reaction occurs in the system to yield ternary compounds Yb₃InS₆ (S₁), YbInS₃ (S₂), Yb₃In₅S₁₂ (S₃), and YbIn₃S₆ (S₄). In₂S₃-based limited solid solutions are found. Phases S₁, S₃, and S₄ are formed by peritectic reactions at 1260, 1200, and 1100 K, respectively. Compound S₂ melts congruently at 1390 K. Compound S₃ crystallizes in monoclinic system (a = 10.90 Å, b = 21.01 Å, c = 3.846 Å, β = 96.2°). Compounds S₁ and S₄ crystallize in orthorhombic system (for S₁, a = 16.76 Å, b = 13.70 Å, c = 3.88 Å; for S₄, a = 3.86 Å, b = 11.64 Å, c = 20.98 Å, d _exp = 4.62 g/cm³). Compound S₂ crystallizes in cubic system (a = 10.68 Å).     

Indiumwolframat,In2(WO4)3 – ein In3+ leitender Festkörperelektrolyt

Indium Tungstate, In₂(WO₄)₃ – an In³⁺ Conducting Solid Electrolyte Polycrystalline In₂(WO₄)₃ has been electrochemically characterized and unambiguously identified as an In³⁺ conducting solid electrolyte. By heating, indium tungstate undergoes a phase transition between 250 °C and 260 °C transforming from a monoclinic to an orthorhombic phase for which the conduction properties have been determined. The adopted crystal structure in this high temperature region corresponds to the Sc₂(WO₄)₃ type structure. The electrical conductivity was investigated by impedance spectroscopy in the temperature range 300–700 °C and amounts to about 3.7 · 10^–5 Scm^–1 at 600 °C with a corresponding activation energy of 59.5 kJ/mol. Polarization measurements indicated an exclusive current transport by ionic charge carriers with a transference number of about 0.99. In dc electrolysis experiments, the trivalent In³⁺ cations were undoubtedly identified as mobile species. A current transport by oxide anions was not observed.     

Synthesis,Crystal Structure,and Optical Property of the Quaternary Semiconductor La4Cd4In2S13

The sulfide La₄Cd₄In₂S₁₃ in the quaternary RE/M/N/Q (RE = rare‐earth metal; M = Zn, Cd; N = Ga, In; Q = chalcogenides) system was prepared from stoichiometric mixtures of the elements by solid‐state reactions at 1223 K in an evacuated silica tube. The La₄Cd₄In₂S₁₃, crystallizing in the Pbam space group, is isostructural with Pb₄Bi₄In₂S₁₃. The structure of La₄Cd₄In₂S₁₃ consists of double chains of CdS₆ octahedra extending along [001] direction that are interconnected by single chains of InS₆ octahedra by edge‐sharing into 1D ribbons. These ribbons are further fused by the infinite one‐dimensional chains of InS₄ tetrahedra by corner‐sharing into Z‐shaped [Cd₄In₂S₁₃]^12– layers perpendicular to the b direction separated by the La³⁺ ions. UV/Vis/NIR diffuse reflectance spectroscopy study shows its optical gap of around 2.27 eV.     

Zur Kenntnis der Phasen A2−2xSn5+xCl12 (A = K,In)

On the A_2?2xSn_5+xCl₁₂ (A = K, In) Phases The refinement of the structure of A_2-2xSn_5+xCl₁₂ compounds (A = K⁺, In⁺) with single crystal data is reported. They crystallize with the Th₇S₁₂ type arrangement (a = 1192(2) pm, c = 428.9(8) pm (K-compound); a = 1189.8(6) pm, c = 431.2(3) pm (In-compound)) for which we propose the space group P6 . The possibility of meroedric twinning is discussed. Due to the composition of these compounds the structure is necessarily disordered and this leads to a wide range of homogeneity which can be influenced by the size and the polarity of the A type cation.     

Synthesis and Crystal Structure of Rb6Ta4S22: The First Tantalum Polysulfide Composed of the Dimeric Complex Anion [Ta4S22]6–

The reaction of Rb₂S₃, Ta and S in a 1.3 : 1 : 5.6 molar ratio at 400 °C yields red‐orange crystals of the new ternary compound Rb₆Ta₄S₂₂ being the first tantalum polysulfide containing the dimeric complex anion [Ta₄S₂₂]^6–. The polysulfide anions are composed of two Ta₂S₁₁ subunits which are linked to Ta₄S₂₂ units via terminal sulfur ligands. The Ta⁵⁺ centers are coordinated by S₂^2– and S^2– ligands according to [(Ta₂(μ₂‐η²,η¹‐S₂)₃(η²‐S₂)(S)₂)₂(μ₂‐η¹,η¹‐S₂)]^6–. Every Ta⁵⁺ ion is surrounded by seven sulfur ions forming a strongly distorted pentagonal bipyramid. In the crystal structure the discrete [Ta₄S₂₂]^6– anions are stacked parallel to the crystallographic b‐axis. The Rb⁺ cations are located between these stacks. Rb₆Ta₄S₂₂ crystallizes in the monoclinic space group P2₁/c (No. 14) with a = 11.8253(9) Å, b = 7.9665(4) Å, c = 19.174(2) Å, β = 104.215(9)°, V = 1751.0(2) ų, Z = 2.