Li3BS3 und LiSrBS3: Neue Orthothioborate mit trigonal-planar koordiniertem Bor

Li₃BS₃ and LiSrBS₃: New Orthothioborates with Trigonal Planar Boron Coordination We report on the two new orthothioborates Li₃BS₃ (Pnma; a = 8.144(1) Å, b = 10.063(2) Å, 6.161(1) Å; Z = 4) and LiSrBS₃ (Pnma; a = 7.557(1) Å, b = 9.083(2) Å, c = 7.049(1) Å: Z = 4). The two new phases were prepared by reaction of the metal sulfides, amorphous boron, and sulfur at 700°C. Both compounds contain isolated, planar [BS₃]^3?-anions. The lithium ions have fourfold (Li₃BS₃) and sixfold (LiSrBS₃) sulfur coordination, the strontium ion shows an eightfold sulfur coordination. The two compounds represent new A₃BX₃ resp. AA′BX₃ structure types.     

Syntheses and Crystal Structures of the Novel Ternary Thioborates Na3BS3, K3BS3, and Rb3BS3

The orthothioborates Na₃BS₃, K₃BS₃ and Rb₃BS₃ were prepared from the metal sulfides, amorphous boron and sulfur in solid state reactions at temperatures between 923 and 973 K. In a systematic study on the structural cation influence on this type of ternary compounds, the crystal structures were determined by single crystal X‐ray diffraction experiments. Na₃BS₃ crystallizes in the monoclinic space group C2/c (No. 15) with a = 11.853(14) Å, b = 6.664(10) Å, c = 8.406(10) Å, β = 118.18(2)° and Z = 4. K₃BS₃ and Rb₃BS₃ are monoclinic, space group P2₁/c (No. 14) with a = 10.061(3) Å, b = 6.210(2) Å, c = 12.538(3) Å, β = 112.97(2) and a = 10.215(3) Å, b = 6.407(1) Å, c = 13.069(6) Å, β = 103.64(5)°, Z = 4. The potassium and rubidium compounds are not isotypic. All three compounds contain isolated [BS₃]^3– anions with boron in a trigonal‐planar coordination. The sodium cations in Na₃BS₃ are located between layers of orthothioborate anions, in the case of K₃BS₃ and Rb₃BS₃ stacks of [BS₃]^3– entities are connected via the corresponding cations. X‐ray powder patterns were measured and compared to calculated ones obtained from single crystal X‐ray structure determinations.     

Syntheses,Crystal Structures,and Properties of the Novel Thioborates KBa4(BS3)3 and K4Ba11(BS3)8S

Our systematic studies on quaternary thioborates containing both a comparably small alkali metal ion and a large alkaline earth cation lead to the two new crystalline phases KBa₄(BS₃)₃ and K₄Ba₁₁(BS₃)₈S. The former consists of isolated BS₃ units and the corresponding counter‐ions while in the latter BS₃^3– and S^2– anions coexist. In both compounds boron is found in a trigonal‐planar coordination, in the case of K₄Ba₁₁(BS₃)₈S the additional sulfide anions are located inside an octahedron built of six barium cations. The two compounds were prepared in solid state reactions from the metal sulfides, amorphous boron and sulfur. Evacuated carbon coated silica tubes were used as reaction vessels since temperatures up to 870 K were applied. KBa₄(BS₃)₃ crystallizes in the monoclinic space group C 2/c (no. 15) with a = 14.299(6) Å, b = 8.808(3) Å, c = 13.656(5) Å, β = 98.72(4)°, and Z = 4, while for K₄Ba₁₁(BS₃)₈S the trigonal space group R 3 c (no. 167) was found with a = 18.146(3) Å, c = 25.980(7) Å, and Z = 6. X‐ray powder patterns are compared to calculated diffraction data obtained from single crystal X‐ray structure determination, in the case of K₄Ba₁₁(BS₃)₈S vibrational spectra were recorded.     

Isomers of SiCl3Li

An ab initio study on the title compound was performed in this work. The structures at MP2(FULL)/6‐311G* level of theory and their energies at the CCSD(T)/6‐311G* level of theory were provided. Their vibrational frequencies and ²⁹Si nuclear magnetic resonance (NMR) chemical shift had been carried out too. The thermodynamic data were calculated in order to help judge the relative stability of the isomers of SiCl₃Li at experimental temperatures. © 2000 John Wiley & Sons, Inc. Int J Quant Chem 79: 17–24, 2000     

Calculated ro-vibrational spectrum of 7Li+3 and 7Li2 6Li+

Calculated ro-vibrational energy levels (J ⩽ 4) and transition intensities are presented for the two most abundant isotopomers of Li⁺₃. The calculations use the recent ab initio potential energy surface of Searles et al. (Spectrochim. Acta 43A, 699 (1987); 44A, 505 (1988); 44A, 985 (1988)). The rotational levels of the ground state and vibrational fundamentals are given in terms of parameterised Hamiltonians due to Watson retaining terms to fourth-order. The small splitting of the degenerate ν₂ mode in the mixed isotopomer leads to strong Coriolis coupling between the ν₂ and ν₃ in ⁷Li₂ ⁶Li⁺.     

Interpretation of the photoelectron spectra of superalkali species: Li3O and Li3O-

The present paper deals with the interpretation of the photoelectron spectrum of the Li(3)O(-). After several failed attempts to attribute all of the observed peaks in the experimental spectrum to anionic species, neutral species were considered assuming a sequential two-photon absorption mechanism. We find that only two of the six observed peaks can be attributed to photodetachments and that all other observed features can be assigned to ionizations from the ground and excited states of the neutral. Nuclear distributions other than three lithium atoms surrounding the oxygen are not likely to be stable. The interpretation of the experimental peak located at about 1.2 eV remains challenging. It can either be attributed to the second electron detachment (involving the HOMO -1 orbital) energy from the anion's triplet C(2v) state or to higher excited states (involving HOMO +10, 11, 12... orbitals) of the neutral species. Furthermore, we have examined the influence of vibrational displacements on the location of the observed peaks. We find that this effect is smaller than 0.05 eV and, therefore, must be considered as negligible.     

Supertetrahedral polyanionic network in the first lithium phosphidoindate Li3InP2 – structural similarity to Li2SiP2 and Li2GeP2 and dissimilarity to Li3AlP2 and Li3GaP2

Phosphide-based materials have been investigated as promising candidates for solid electrolytes, among which the recently reported Li₉AlP₄ displays an ionic conductivity of 3 mS cm⁻¹. While the phases Li–Al–P and Li–Ga–P have already been investigated, no ternary indium-based phosphide has been reported up to now. Here, we describe the synthesis and characterization of the first lithium phosphidoindate Li₃InP₂, which is easily accessible via ball milling of the elements and subsequent annealing. Li₃InP₂ crystallizes in the tetragonal space group I4₁/acd with lattice parameters of a = 12.0007(2) and c = 23.917(5) Å, featuring a supertetrahedral polyanionic framework of interconnected InP₄ tetrahedra. All lithium atoms occupy tetrahedral voids with no partial occupation. Remarkably, Li₃InP₂ is not isotypic to the previously reported homologues Li₃AlP₂ and Li₃GaP₂, which both crystallize in the space group Cmce and feature 2D layers of connected tetrahedra but no supertetrahedral framework. DFT computations support the observed stability of Li₃InP₂. A detailed geometrical analysis leads to a more general insight into the structural factors governing lithium ion mobility in phosphide-based materials: in the non-ionic conducting Li₃InP₂ the Li ions exclusively occupy tetrahedral voids in the distorted close packing of P atoms, whereas partially filled octahedral voids are present in the moderate ionic conductors Li₂SiP₂ and Li₂GeP₂.

Li₃InP₂ exhibits a polyanionic framework of corner-sharing InP₄ tetrahedra and DFT computations reveal the stability trend for indium in the tetragonal structure compared to the orthorhombic structure of the lighter homologues.     

Lithium-ion Mobility in Li6B18(Li3N) and Li Vacancy Tuning in the Solid Solution Li6B18(Li3N)1−x(Li2O)x

All-solid-state batteries are promising candidates for safe energy-storage systems due to non-flammable solid electrolytes and the possibility to use metallic lithium as an anode. Thus, there is a challenge to design new solid electrolytes and to understand the principles of ion conduction on an atomic scale. We report on a new concept for compounds with high lithium ion mobility based on a rigid open-framework boron structure. The host–guest structure Li₆B₁₈(Li₃N) comprises large hexagonal pores filled with Li₇N] strands that represent a perfect cutout from the structure of α-Li₃N. Variable-temperature ⁷Li NMR spectroscopy reveals a very high Li mobility in the template phase with a remarkably low activation energy below 19 kJ mol⁻¹ and thus much lower than pristine Li₃N. The formation of the solid solution of Li₆B₁₈(Li₃N) and Li₆B₁₈(Li₂O) over the complete compositional range allows the tuning of lithium defects in the template structure that is not possible for pristine Li₃N and Li₂O.     

Li+ cation coordination in [Li2(CF3SO3)2(diglyme)] and [Li3(C2F3O2)3(diglyme)]

The title compounds, poly­[[[bis(2‐methoxy­ethyl) ether]­lithium(I)]‐di‐μ₃‐tri­fluoro­methanesulfonato‐lithium(I)], [Li₂(CF₃SO₃)₂(C₆H₁₄O₃)]_n, and poly­[[[bis(2‐methoxy­ethyl) ether]­lithium(I)]‐di‐μ₃‐tri­fluoro­acetato‐dilithium(I)‐μ₃‐tri­fluoro­acetato], [Li₃(C₂F₃O₂)₃(C₆H₁₄O₃)]_n, consist of one‐dimensional polymer chains. Both structures contain five‐coordinate Li⁺ cations coordinated by a tridentate diglyme [bis(2‐methoxy­ethyl) ether] mol­ecule and two O atoms, each from separate anions. In both structures, the [Li(diglyme)X₂]^? (X is CF₃SO₃ or CF₃CO₂) fragments are further connected by other Li⁺ cations and anions, creating one‐dimensional chains. These connecting Li⁺ cations are coordinated by four separate anions in both compounds. The CF₃SO₃^? and CF₃CO₂^? anions, however, adopt different forms of cation coordination, resulting in differences in the connectivity of the structures and solvate stoichiometries.     

Low temperature synthesis of highly ion conductive Li7La3Zr2O12–Li3BO3 composites

Highly lithium ion conductive composites with Al-doped Li₇La₃Zr₂O₁₂ (LLZ) and amorphous Li₃BO₃ were prepared from sol–gel derived precursor powders of LLZ and Li₃BO₃. Precursor LLZ powders with cubic phase were obtained by a heat treatment of the precursor dried gel at 600 °C. Pellets of the mixture of the obtained LLZ and Li₃BO₃ were first held at 700 °C, and then successively sintered at 900 °C. Density of the sintered pellet with Li₃BO₃ was larger than that of the pellet without Li₃BO₃. From the TEM observation, the pellets were found to consist of cubic LLZ and amorphous Li₃BO₃. Total electrical conductivity of the obtained LLZ–Li₃BO₃ composite was 1 × 10^− 4 Scm^− 1 at 30 °C.     

Die Kristallstruktur von Li2SnO3

Li₂SnO₃ crystallises monoclinic, C, with a = 5.295, b = 9.184, c = 10.032 Å and β = 100.13°; Z = 8. The positions of Sn were obtained from PATTERSON maps and the positions of O and Li by FOURIER difference method. Parameters were refined by least squares-method [1462 reflexes (h 01)–(h 71); R = 10.5%]. The average distances of Li? O are 2.07 Å, and 2.20 Å for Sn? O. The Li₂SnO₃ structure can be derived from the NaCl type: in a cubic closest packing of oxygen 2/3 of the octahedral holes are occupied by lithium and 1/3 by tin.     

Zur Kristallstruktur von Li3InCl6

Ternary Halides of the A₃MX₆ Type. VIII On the Crystal Structure of Li₃InCl₆ Colorless single crystals of Li₃InCl₆ are obtained from a 3 : 1 molar mixture of LiCl and InCl₃ via Bridgman‐type crystal growth. The crystal structure (monoclinic, C2/m, Z = 2, a = 643.2(3), b = 1109.3(3), c = 639.8(3) pm, β = 109.8(1)° R₁ = 0.0549, wR₂ = 0.1364 (all data) may be derived from the AlCl₃‐type of structure as was previously also found for the bromides Li₃MBr₆ (M = Sm–Lu, Y) and iodides Li₃MI₆ (M = Er–Yb, Y).     

Die Kristallstruktur von Li2TeO3

Crystal Structure of Li₂TeO₃ Crystals of Li₂TeO₃ were prepared from melts. Li₂TeO₃ crystallizes in the monoclinic system, space group C2/c. The lattice parameters are a = 5.06₉, b = 9.56₆, c = 13.72₇ Å, β = 95.4°. The formular unit is 8. The crystal structure has been determined by Patterson and threedimensional differential Fourier synthesis refined by least squares using isotropic temperature corrections. The final R-value of 772 observed reflections is 0.101. Li₂TeO₃ forms a layer lattice consisting of trigonal TeO₃ pyramids and deformed LiO₄ tetrahedrons. The TeO₃ pyramids are only connected with the corners of LiO₄ groups, which are linked one with another by common corners and edges.