Preparation and ionic conductivity of (100−x)(0.8Li2S·0.2P2S5)·xLiI glass–ceramic electrolytes

The glass–ceramic electrolytes of (100?x)(0.8Li₂S·0.2P₂S₅)·xLiI (in mole percent; x?=?0, 2, 5, 10, 15, 20, and 30) were prepared by mechanical milling and subsequent heat treatment. Crystalline phases analogous to the thio-LISICON region II or III in the Li₂S–GeS₂–P₂S₅ system were precipitated. The thio-LISICON III analog phase was mainly precipitated at the composition x?=?0, and the thio-LISICON II analog phase was precipitated in the composition range from x?=?2 to 15. The X-ray diffraction peaks of the thio-LISICON II analog phase shifted to the lower diffraction angle side with increasing the LiI content. High conductivities above 2?×?10^?3?S?cm^?1 at room temperature were observed in the glass–ceramics at the wide composition range from x?=?2 to 15. The glass–ceramic electrolyte at x?=?5 with the highest conductivity of 2.7?×?10^?3?S?cm^?1 showed a wide electrochemical window of about 10 V. The addition of LiI to the 80Li₂S·20P₂S₅ (in mole percent) glass was effective in crystallizing the thio-LISICON II analog phase with high conductivity from the glass.     

Über Glasbildung und Eigenschaften von Chalkogenidsystemen. XXXIII. [1] Kondensierte Thio- und Selenohypodigermanate und -silicate Na8M4X10 (MSi,Ge) und Na4Ge4X8 (XS,Se)

About Glass Formation and Properties of Chalcogenide Systems. XXXIII. Condensed Thio- and Selenohypodigermanates and -silicates Na₈M₄X₁₀ (M?Si, Ge) and Na₄Ge₄X₈ (X?S, Se) The formation of the compounds Na₈Si₄X₁₀ and Na₈Ge₄X₁₀ (X?S, Se) is reported prepared by reaction of Ge₂S₃ or Ge₂Se₃ with Na₂S or Na₂Se, respectively, in CH₃OH utilizing a mole ratio of 1 to 2 or in the case of the Si compounds by synthesis from the elements. Applying the mole ratio Ge₂X₃:Na₂X = 1 the compounds Na₄Ge₄X₈ (X?S, Se) are obtained. The anion constitution is discussed in relation with cryoscopic mole weight measurements in Glauber-salt melts.     

Über Glasbildung und Eigenschaften von Chalkogenidsystemen. XIII. Über die Verbindungen Na6Ge2S6 · 4 CH3OH und Na6Ge2Se6 · 4 CH3OH

Glass Formation and Properties of Chalcogenide Systems. XIII. On the Compounds Na₆Ge₂S₆ · 4 CH₃OH and Na₆Ge₂Se₆ · 4 CH₃OH The glasses Ge₂S₃ and Ge₂Se₃ are soluble in solutions of Na₂S or Na₂Se in CH₃OH forming Na₆Ge₂S₆ · 4 CH₃OH and Na₆Ge₂Se₆ · 4 CH₃OH. On heating the CH₃OH-free substances are formed. From the i.r. and Raman spectra can de seen that the structure of the ions Ge₂S, Ge₂Se, P₂S₆^4?, and of Si₂Cl₆ is of the same type. The formation of the compounds can be regarded as a chemical proof for the existence of [Ge₂S₆] and [Ge₂Se₆] units as structural groups in the glasses Ge₂S₃ and Ge₂Se₃.     

Non‐hydrogenated amorphous germanium carbide with adjustable microstructure and properties: a potential anti‐reflection and protective coating for infrared windows

Amorphous non‐hydrogenated germanium carbide (a‐Ge_1?xC_x) films have been deposited using magnetron co‐sputtering technique by varying the sputtering power of germanium target (P_Ge). The effects of P_Ge on composition and structure of the a‐Ge_1?xC_x films have been analyzed. The FTIR spectrum shows that the C–Ge bonds were formed in the a‐Ge_1?xC_x films according to the absorption peak at ~610 cm^?1. The Raman results indicate that the amorphous films also contain both Ge and C clusters. The XPS results reveal that the carbon concentration decreased as P_Ge increased from 40 to 160 W. The fraction of sp³ C–C bonds remains almost constant when increasing P_Ge from 40 to 160 W. The sp² C–C content of a‐Ge_1?xC_x film decreases gradually to 35.9% with P_Ge up to 160 W. Nevertheless, sp³ C–Ge sites rose with increasing P_Ge. Furthermore, the hardness and the refractive index gradually increased with increasing P_Ge. The excellent optical transmission of annealed a‐Ge_1–xC_x double‐layer coating at 400 °C suggests that a‐Ge_1?xC_x films can be used as an effective anti‐reflection coating for the ZnS IR window in the wavelength region of 8–12 µm, and can endure higher temperature than hydrogenated amorphous germanium carbide do. Copyright © 2012 John Wiley & Sons, Ltd.     

Über Chalkogenolate. 198. Untersuchungen über Polythiocuprate (I) [Cu(Sx)]− 2. Hydrazinium- und Ethylendiammoniumpolythiocuprate(I)

On Chalcogenolates. 198. Studies on Polythiocuprates(I) [Cu(S_x)]^?. 2. Hydrazinium and Ethylenediammonium Polythiocuprates(I) The red polythiocuprates(I) 1–5 (formulae see ?Inhaltsübersicht”?) have been prepared by reaction of hydrazinium or ethylenediammonium polysulfides with copper(II) salts, dissolved in water, under variable conditions. Their properties are described. In aqueous alkaline media 1–5 decompose into CuS and S; in the presence of carbon disulfide CuS, S_x^2?, and CS₃^2? besides CS₄^2? and S₂CO^2? are formed. The existence of the discreet ion [Cu₂CS₇]^2?, described in literature, was not confirmed. The polythiocuprates(I) 1–5 , dissolved im dimethylformamide, decompose via the radical anion S₃^?. The decomposition of S₃^? has been studied kinetically by means of compound 5 . The half-life of decay of S₃^? is τ_1/2 = 71.5 h at 20°C. The pentathiocuprate(I) 3 reacts with n-butyl chloride to produce the substituted sulfanes (C₄H₉)₂S_x′ where x = 1, 2 and 3.     

Darstellung und Kristallstrukturen von Li4−2xSr2+xB10S19 (x ≈ 0,27) und Na6B10S18. Zwei neue Thioborate mit hochpolymeren Makrotetraeder-Netzwerken

Synthesis and Crystal Structures of Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27) and Na₆B₁₀S₁₈. Two Novel Thioborates with Highly Polymeric Macro-tetrahedral Networks Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27) and Na₆B₁₀S₁₈ were prepared from the reaction of strontium sulfide and lithium sulfide (sodium sulfide) with boron and sulfur at 700°C in graphitized silica tubes. Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27) crystallizes in the monoclinic space group P2₁/c with a = 10.919(2) Å, b = 13.590(3) Å, c = 16.423(4) Å, and β = 90.48(2)°, Na₆B₁₀S₁₈ in the tetragonal space group I4₁/acd with a = 14.415(3) Å, c = 26.137(4) Å. Both structures contain supertetrahedral B₁₀S₂₀ units which are linked through tetrahedral corners to form a three-dimensional polymeric network in the case of Na₆B₁₀S₁₈ and one-dimensional chains in the case of Li_4?2xSr_2+xB₁₀S₁₉ (x ≈ 0.27). All boron atoms are in tetrahedral BS₄ coordination (B? S bond lengths vary from 1.879(5) to 1.951(5) Å (1.875(10) to 1.987(9) Å)). The strontium and lithium (sodium) cations are located within large channels formed by the anions.     

A Series of Novel Organically Templated Germanium Antimony Sulfides

A series of novel organically templated germanium antimony sulfides have been solvothermally synthesized and structurally, thermally, and optically characterized. The compound [Me₂NH₂]₆[(Ge₂Sb₂S₇)(Ge₄S₁₀)] ( 1 ) features two distinct tetranuclear [Ge₂Sb₂S₇]^2? and [Ge₄S₁₀]^4? isolated clusters. The compound [(Me)₂NH₂][DabcoH]₂[Ge₂Sb₃S₁₀] ( 2 ) (Dabco=triethylenediamine) features a 1D‐[Ge₂Sb₃S₁₀]_n^3n? ribbon constructed with two [GeSbS₅]_n^3n? chains bridged by Sb³⁺ ion in ψ‐SbS₄ configuration. Compounds [M(en)₃][GeSb₂S₆] (M=Ni ( 3 ), Co ( 4 ) en=ethylenediamine) feature the unique 2D grid layer structures of [GeSb₂S₆]_n^2n?. The compound [(Me)₂NH₂]₂[GeSb₂S₆] ( 5 ) previously reported by us features a 3D chiral microporous structure with the chiral channels. The optical absorption spectra indicate that all the compounds are wide bandgap semiconductors. Thermal stabilities of these compounds have been investigated by thermogravimetric analyses (TGA).     

Über Chalkogenolate. 180. Methoxythiocarbonyl-methylsulfane CH3O?CS?Sx?CH3 mit x = 1, 2 und Methylthiothiocarbonyl-methylsufane CH3S?CS?Sx?CH3 mit x = 1, 2

On Chalcogenolates. 180. Methoxythiocarbonyl Methyl Sulfanes CH₃O? CS? S_x? CH₃ with x = 1, 2 and Methylthiothiocarbonyl Methyl Sulfanes CH₃S? CS? S_x? CH₃ with x = 1, 2 The monosulfanes have been prepared by known procedures. For the first time the disulfanes have been synthesized by reaction of K[S₂C? OCH₃] and K[S₂C? SCH₃] with the S-methyl ester of methanethiosulfonic acid CH₃? SO₂? SCH₃. The sulfanes CH₃O? CS? S_x? CH₃ and CH₃S? CS? S_x? CH₃, where x = 1 and 2, have been characterized by means of electron absorption, infrared, nuclear magnetic resonance, and mass spectra.     

Electroconductivity and transport numbers of solid electrolytes La10−x CaxA6O27−δ and La9.33+δA6−x AlxO26 (A = Si, Ge) with apatite-like structure

The ion-oxygen conductivity of apatite-like compounds based on lanthanum silicates and germanates La₁₀A₆O₂₇ (A = Si, Ge), La_10?x Ca_xSi₆O_27?δ (x = 0.25, 0.5, 1.0), La_9.75Ca_0.25Ge₆O_27?δ and La_9.33+δSi_6?x Al_xO₂₆(x=0.4, 0.8, 1.5) is studied in the interval of partial oxygen pressures pO₂ extending from 10^?16 to 10⁵ Pa, at temperatures of 500–1000°C. The electroconductivity of undoped compounds La₁₀A₆O₂₇ (A = Si, Ge) exceeds that of yttria-stabilized zirconia. The electroconductivity of lanthanum germanate (1.7 × 10^?2 and 8.5 × 10^?2S cm^?1 at 700 and 900°C, respectively) is substantially higher than that of lanthanum silicate (9.8 × 10^?3 and 3.5 × 10^?2 S cm^?1 at 700 and 900°C). Doping lanthanum germanate with calcium raises its electroconductivity (2.7 × 10^?2 and 1.3 × 10^?1 S cm^?1 for La_9.75Ca_0.25Ge₆O_27?δ at 700 and 900°C). Conversely, doping lanthanum silicate with ions of calcium or aluminum reduces the conductivity. In the pO₂ interval studied, the above compounds are ionic conductors and represent a class of solid electrolytes of promise for various electrochemical devices.     

Selenogermanate aus wäßriger Lösung: Darstellung und Struktur von Na4Ge2Se6 · 16 H2O

Selenogermanates from Aqueous Solution: Preparation and Structure of Na₄Ge₂Se₆ · 16 H₂O Selenogermanates(IV) are prepared from aqueous solutions by reaction of alkali selenides with GeSe₂. Na₄Ge₂Se₆ · 16 H₂O, being obtained from stoichiometric 1:1 quantities, is characterized by a complete X-ray structure analysis and by vibrational spectra. The compound is monoclinic (P2₁/c) with a = 9.894(4), b = 11.781(5), c = 12.225(6) Å, β = 92.90(4)°, Z = 2. It contains isolated Ge₂Se₆^4? anions consisting of two edge-sharing tetrahedra [Ge? Se 2.303(2)–2.419(2) Å] which are in contact to the hydrated octahedral [Na(H₂O)₆]⁺ ions through Se ? H? O bridges within an extensive hydrogen bridge system. Raman-active vibrations are observed at 306, 294, 207, 139, and 121 cm^?1. Adamantane-like Ge₄Se₁₀^4? can be prepared in a similar way as Ge₂Se₆^4? if a 1:2 molar ratio of alkali selenide to GeSe₂ is employed.     

Über Chalkogenolate. 197. Untersuchungen über Polythiocuprate(I) [Cu(Sx)]− 1. Eigenschaften und Reaktionen von Ammoniumtetrathiocuprat(I)

On Chalcogenolates. 197. Studies on Polythiocuprates(I) [Cu(S_x)]^?. 1. Properties and Reactions of Ammonium Tetrathiocuprate(I) The properties of NH₄[Cu(S₄)] have been studied. In watery alkaline media it decomposes into CuS and S; in the presence of carbon disulfide CuS, S_x^2?, and CS₃^2? besides CS₄^2? and S₂CO^2? are formed. The compound (NH₄)₂[Cu₂CS₇], described in literature, does not exist. In dimethylformamide dissolved NH₄[Cu(S₄)] decomposes via the radical anion S₃^?. NH₄[Cu(S₄)] reacts with n-butyl chloride to yield the substituted sulfanes (C₄H₉)₂S_x with x = 1, 2, and 3.     

General Formation of MxCo3−xS4 (M=Ni,Mn, Zn) Hollow Tubular Structures for Hybrid Supercapacitors

A simple and versatile method for general synthesis of uniform one‐dimensional (1D) M_xCo_3?xS₄ (M=Ni, Mn, Zn) hollow tubular structures (HTSs), using soft polymeric nanofibers as a template, is described. Fibrous core–shell polymer@M‐Co acetate hydroxide precursors with a controllable molar ratio of M/Co are first prepared, followed by a sulfidation process to obtain core–shell polymer@M_xCo_3?xS₄ composite nanofibers. The as‐made M_xCo_3?xS₄ HTSs have a high surface area and exhibit exceptional electrochemical performance as electrode materials for hybrid supercapacitors. For example, the MnCo₂S₄ HTS electrode can deliver specific capacitance of 1094 F g^?1 at 10 A g^?1, and the cycling stability is remarkable, with only about 6 % loss over 20 000 cycles.     

Cobalt‐Doped FeS2 Nanospheres with Complete Solid Solubility as a High‐Performance Anode Material for Sodium‐Ion Batteries

Considering that the high capacity, long‐term cycle life, and high‐rate capability of anode materials for sodium‐ion batteries (SIBs) is a bottleneck currently, a series of Co‐doped FeS₂ solid solutions with different Co contents were prepared by a facile solvothermal method, and for the first time their Na‐storage properties were investigated. The optimized Co_0.5Fe_0.5S₂ (Fe0.5) has discharge capacities of 0.220 Ah g^?1 after 5000 cycles at 2 A g^?1 and 0.172 Ah g^?1 even at 20 A g^?1 with compatible ether‐based electrolyte in a voltage window of 0.8–2.9 V. The Fe0.5 sample transforms to layered Na_xCo_0.5Fe_0.5S₂ by initial activation, and the layered structure is maintained during following cycles. The redox reactions of Na_xCo_0.5Fe_0.5S₂ are dominated by pseudocapacitive behavior, leading to fast Na⁺ insertion/extraction and durable cycle life. A Na₃V₂(PO₄)₃/Fe0.5 full cell was assembled, delivering an initial capacity of 0.340 Ah g^?1.     

The electrochemical performance of sodium-ion-modified spinel LiMn2O4 used for lithium-ion batteries

The spinel LiMn₂O₄ cathode material has been considered as one of the most potential cathode active materials for rechargeable lithium ion batteries. The sodium-doped LiMn₂O₄ is synthesized by solid-state reaction. The X-ray diffraction analysis reveals that the Li_1?x Na _x Mn₂O₄ (0?≤?x?≤?0.01) exhibits a single phase with cubic spinel structure. The particles of the doped samples exhibit better crystallinity and uniform distribution. The diffusion coefficient of the Li_0.99Na_0.01Mn₂O₄ sample is 2.45?×?10^?10 cm^?2 s^?1 and 3.74?×?10^?10 cm^?2 s^?1, which is much higher than that of the undoped spinel LiMn₂O₄ sample, indicating the Na⁺-ion doping is favorable to lithium ion migration in the spinel structure. The galvanostatic charge–discharge results show that the Na⁺-ion doping could improve cycling performance and rate capability, which is mainly due to the higher ion diffusion coefficient and more stable spinel structure.     

Control of Luminescence by Tuning of Crystal Symmetry and Local Structure in Mn4+‐Activated Narrow Band Fluoride Phosphors

Mn⁴⁺‐doped fluoride phosphors have been widely used in wide‐gamut backlighting devices because of their extremely narrow emission band. Solid solutions of Na₂(Si_xGe_1?x)F₆:Mn⁴⁺ and Na₂(Ge_yTi_1?y)F₆:Mn⁴⁺ were successfully synthesized to elucidate the behavior of the zero‐phonon line (ZPL) in different structures. The ratio between ZPL and the highest emission intensity υ₆ phonon sideband exhibits a strong relationship with luminescent decay rate. First‐principles calculations are conducted to model the variation in the structural and electronic properties of the prepared solid solutions as a function of the composition. To compensate for the limitations of the Rietveld refinement, electron paramagnetic resonance and high‐resolution steady‐state emission spectra are used to confirm the diverse local environment for Mn⁴⁺ in the structure. Finally, the spectral luminous efficacy of radiation (LER) is used to reveal the important role of ZPL in practical applications.     

Ag6B10S18: Ein neues Thioborat mit tetraedrischer Koordination des Bors

Ag₆B₁₀S₁₈: A Novel Thioborate with Tetrahedral Coordination of Boron Ag₆B₁₀S₁₈ was prepared as a novel thioborate from the reaction of stoichiometric amounts of Ag₂S, B, and S at 700°C with successive annealing at 580–460°C. The orange-yellow compound crystallizes in the monoclinic space group C2/c with a = 21.663(8), b = 21.639(8), c = 16.572(5) Å, ß = 129.40(4)°, Z = 8, d_x = 2.948 g · cm^?3. According to the complete X-ray crystal structure analysis the anionic part of the Ag₆B₁₀S₁₈ structure contains B₁₀S₂₀ “supertetrahedra” consisting of ten parallel corner-sharing BS₄ tetrahedra; the B₁₀S₂₀ groups are linked through corners to form a layer-like arrangement of (B₁₀S₁₆S_4/2^6?)_n = (B₁₀S₁₈^6?)_n polyantions. The mean B? S bond length is 1.915 Å. The electron densities in the regions of the Ag⁺ ions show a dynamically disordered arrangement which can be described by a distribution of the 6 Ag⁺ ions of the asymmetric unit over 18 partially occupied sites, these structural characteristics making Ag₆B₁₀S₁₈ an Ag⁺ ionic conductor. The i.r. spectrum of the compound shows B? S stretching vibrations at 610, 640, 685, 735, and 760 cm^?1.     

Highly selective transport of lead cation through bulk liquid membrane by macrocyclic ligand of decyl-18-crown-6 as carrier

The liquid membrane transport of Pb²⁺ cation using decyl-18-crown-6 as selective ion carrier was studied. The transport of lead ion across the liquid membrane in the presence of S₂O ₃ ^2? , P₂O ₇ ^4? , CN^?, SCN^?, and DDC^? as stripping agents in the receiving phase shows that the nature and the concentration of the stripping agents affect on Pb²⁺ cation transport and the maximum transport occurs when the sodium thiosulfate (Na₂S₂O₃) was used. The effects of various parameters influencing the transport efficiency such as the pH of the source and receiving phases, the concentration of picrate ion as counter ion in the source phase were also studied. Five replicated experiments show that a value 82.12 ± 2.09% of the initial concentration of the Pb²⁺ cation in the source phase is extracted into the receiving phase after 4 hours. Also the selectivity and efficiency of lead ion transport from the source phase containing equimolar mixtures of Na⁺, K⁺, Ca²⁺, Ni²⁺, Cu²⁺, Cd²⁺ and Ag⁺ metal cations were investigated.     

Na12Ge17: A Compound with the Zintl Anions [Ge4]4— and [Ge9]4— — Synthesis,Crystal Structure,and Raman Spectrum

Na₁₂Ge₁₇ is prepared from the elements at 1025 K in sealed niobium ampoules. The crystal structure reinvestigation reveals a doubling of the unit cell (space group:P2₁/c; a = 22.117(3)Å, b = 12.803(3)Å, c = 41.557(6)Å, β = 91.31(2)°, Z = 16; Pearson code: mP464), furthermore, weak superstructure reflections indicate an even larger C‐centred monoclinic cell. The characteristic structural units are the isolated cluster anions [Ge₉]^4— and [Ge₄]^4— in ratio 1:2, respectively. The crystal structure represents a hierarchical cluster replacement structure of the hexagonal Laves phase MgZn₂ in which the Mg and Zn atoms are replaced by the Ge₉ and Ge₄ units, respectively. The Raman spectrum of Na₁₂Ge₁₇ exhibits the characteristic breathing modes of the constituent cluster anions at ν = 274 cm^—1 ([Ge₉]^4—) and ν = 222 cm^—1 ([Ge₄]^4—) which may be used for identification of these clusters in solid phases and in solutions. Raman spectra further prove that Na₁₂Ge₁₇ is partial soluble both in ethylenediamine and liquid ammonia. The solution and the solid extract contain solely [Ge₉]^4—. The remaining insoluble residue is Na₄Ge₄. By heating the solvate Na₄Ge₉(NH₃)_n releases NH₃ and decomposes irreversibly at 742 K, yielding Na₁₂Ge₁₇ and Ge.     

Über Chalkogenolate. 181 [1]. Thiocarbamoyl-methylsulfane

On Chalcogenolates. 181. Thiocarbamoyl Methyl Sulfanes The thiocarbamoyl methyl sulfanes H₂N? CS? S_x? CH₃? NH? CS? S_x? CH₃, and (CH₃)₂N? CS? S_x? CH₃ with x = 1 and 2 have been prepared by known procedures (for x = 1) and by reaction of the corresponding dithiocarbamate with the S-methylester of methanethiosulfonic acid CH₃? SO₂? SCH₃ (for x = 2). The compounds have been studied by means of diverse spectroscopic methods.     

Atom Exchange Versus Reconstruction: (GexAs4−x)x− (x=2, 3) as Building Blocks for the Supertetrahedral Zintl Cluster [Au6(Ge3As)(Ge2As2)3]3−

The Zintl anion (Ge₂As₂)^2? represents an isostructural and isoelectronic binary counterpart of yellow arsenic, yet without being studied with the same intensity so far. Upon introducing [(PPh₃)AuMe] into the 1,2‐diaminoethane (en) solution of (Ge₂As₂)^2?, the heterometallic cluster anion [Au₆(Ge₃As)(Ge₂As₂)₃]^3? is obtained as its salt [K(crypt‐222)]₃[Au₆(Ge₃As)(Ge₂As₂)₃]?en?2 tol ( 1 ). The anion represents a rare example of a superpolyhedral Zintl cluster, and it comprises the largest number of Au atoms relative to main group (semi)metal atoms in such clusters. The overall supertetrahedral structure is based on a (non‐bonding) octahedron of six Au atoms that is face‐capped by four (Ge_xAs_4?x)^x? (x=2, 3) units. The Au atoms bind to four main group atoms in a rectangular manner, and this way hold the four units together to form this unprecedented architecture. The presence of one (Ge₃As)^3? unit besides three (Ge₂As₂)^2? units as a consequence of an exchange reaction in solution was verified by detailed quantum chemical (DFT) calculations, which ruled out all other compositions besides [Au₆(Ge₃As)(Ge₂As₂)₃]^3?. Reactions of the heavier homologues (Tt₂Pn₂)^2? (Tt=Sn, Pb; Pn=Sb, Bi) did not yield clusters corresponding to that in 1 , but dimers of ternary nine‐vertex clusters, {[AuTt₅Pn₃]₂}^4? (in 2 – 4 ; Tt/Pn=Sn/Sb, Sn/Bi, Pb/Sb), since the underlying pseudo‐tetrahedral units comprising heavier atoms do not tend to undergo the said exchange reactions as readily as (Ge₂As₂)^2?, according to the DFT calculations.