Four New Thioantimonates(III) with the General Formula [TM(tren)]Sb4S7 (TM = Mn,Fe, Co,Zn) with the Transition Metal as Part of a Thioantimonate(III) Network Synthesized under Solvothermal Conditions and Tuning of the Optical Band Gap by the Transition Metal Cation

Four new thioantimonate(III) compounds with the general formula [TM(tren)]Sb₄S₇, TM = Mn 1 , Fe 2 , Co 3 and Zn 4 , were synthesized under solvothermal conditions by reacting elemental TM, Sb and S in an aqueous solution of tren (tren = tris(2‐aminoethyl)amine). All compounds crystallize in the monoclinic space group P2₁/n with four formula units in the unit cell. Single crystal X‐ray analyses of 1 [a = 8.008(2), b = 10.626(2), c = 25.991(5) Å, β = 90.71(3)°, V = 2211.4(8) ų], 2 [a = 8.0030(2), b = 10.5619(2), c = 25.955(5) Å, β = 90.809(3)°, V = 2193.69(8) ų], 3 [a = 7.962(2), b = 10.541(2), c = 25.897(5) Å, β = 90.90(3)°, V = 2173.0(8) ų] and 4 [a = 7.978(2), b = 10.625(2), c = 25.901(5) Å, β = 90.75(3)°, V = 2195.2(8) ų] reveal that the compounds are isostructural. The [Sb₄S₇]^2‐ anions are composed of three SbS₃ trigonal pyramids and one SbS₄ unit as primary building units (PBU). The PBUs share common edges and corners to form semicubes (Sb₃S₄) which may be regarded as secondary building units (SBU). The SBUs and SbS₃ pyramids are joined in an alternating fashion yielding the equation/tex2gif-stack-1.gif[Sb₄S₇^‐] anionic chain which is directed along [100]. Weaker Sb‐S bonding interactions between neighbored chains lead to the formation of layers within the (001) plane which contain pockets that are occupied by the cations. The TM²⁺ ions are in a trigonal bipyramidal environment of four N atoms of the tren ligand and one S atom of the thioantimonate(III) anion. The optical band gaps depend on the TM²⁺ ion and amount to 3.11 eV for 1 , 2.04 eV for 2 , 2.45 eV for 3 , and 2.60 eV for 4 .     

Li17Sb13S28: A New Lithium Ion Conductor and addition to the Phase Diagram Li2S–Sb2S3

Li₁₇Sb₁₃S₂₈ was synthesized by solid‐state reaction of stoichiometric amounts of anhydrous Li₂S and Sb₂S₃. The crystal structure of Li₁₇Sb₁₃S₂₈ was determined from dark‐red single crystals at room temperature. The title compound crystallizes in the monoclinic space group C2/m (no. 12) with a=12.765(2) Å, b=11.6195(8) Å, c=9.2564(9) Å, β=119.665(6)°, V=1193.0(2) ų, and Z=4 (data at 20 °C, lattice constants from powder diffraction). The crystal structure contains one cation site with a mixed occupation by Li and Sb, and one with an antimony split position. Antimony and sulfur form slightly distorted tetragonal bipyramidal [SbS₅E] units (E=free electron pair). Six of these units are arranged around a vacancy in the anion substructure. The lone electron pairs E of the antimony(III) cations are arranged around these vacancies. Thus, a variant of the rock salt structure type with ordered vacancies in the anionic substructure results. Impedance spectroscopic measurements of Li₁₇Sb₁₃S₂₈ show a specific conductivity of 2.9×10^?9 Ω^?1 cm^?1 at 323 K and of 7.9×10^?6 Ω^?1 cm^?1 at 563 K, the corresponding activation energy is E_A=0.4 eV below 403 K and E_A=0.6 eV above. Raman spectra are dominated by the Sb?S stretching modes of the [SbS₅] units at 315 and 341 cm^?1 at room temperature. Differential thermal analysis (DTA) measurements of Li₁₇Sb₁₃S₂₈ indicate peritectic melting at 854 K.     

Solvothermal Synthesis and Crystal Structures of Two Thioantimonate(V) Compounds with the [SbS4]3— Anion Acting as a Monodentate Ligand: [Mn(C6H18N4)(C6H19N4)]SbS4 and [Mn(C6H14N2)3]2[Mn(C6H14N2)2(SbS4)2]·6H2O

The two novel thioantimonate(V) compounds [Mn(C₆H₁₈N₄)(C₆H₁₉N₄)]SbS₄ ( I ) and [Mn(C₆H₁₄N₂)₃][Mn(C₆H₁₄N₂)₂(SbS₄)₂]·6H₂O ( II ) were synthesized under solvothermal conditions by reacting elemental Mn, Sb and S in the stoichiometric ratio in 5 ml tris(2‐aminoethyl)amine (tren) at 140 °C or chxn (trans‐1, 2‐diaminocyclohexane, aqueous solution 50 %) at 130 °C. Compound I crystallises in the triclinic space group P1¯, a = 9.578(2), b = 11.541(2), c = 12.297(2)Å, α = 62.55(1), β = 85.75(1), γ = 89.44(1)°, V = 1202.6(4)ų, Z = 2, and II in the monoclinic space group C2/c, a = 32.611(2), b = 13.680(1), c = 19.997(1)Å, β = 117.237(5)°, V = 7931.7(8)ų, Z = 4. In I the Mn²⁺ cation is surrounded by one tetradentate tren molecule, one protonated tren acting as a monodentate ligand and a monodentate [SbS₄]^3— anion yielding a distorted octahedral environment. In II one unique Mn²⁺ ion is in an octahedral environment of three bidentate chxn molecules and the second independent Mn²⁺ ion is coordinated by two chxn ligands and two monodentate [SbS₄]^3— units leading to a distorted octahedral surrounding. The compounds were investigated and characterized with thermal and spectroscopic methods.     

Solvothermal Synthesis and Crystal Structure of the New Layered Thioantimonate(III) [Ni(C4H13N3)2]9Sb22S42 · 0.5H2O: Interconnection of the SbS3, SbS4, and SbS5 Primary Building Units Yielding the Very Large Sb30S30 Heteroring

The novel thioantimonate(III) [Ni(dien)₂]₉Sb₂₂S₄₂ · 0.5H₂O was synthesised under solvothermal conditions by reacting elemental Ni, Sb and S in an aqueous solution of diethylenetriamine (dien) (80%). The compound crystallises in the triclinic space group P1¯, a = 8.997(2) Å, b = 15.293(3) Å, c = 34.434(7) Å, α = 85.51(3)°, β = 84.16(3)°, γ = 83.54(3)°, V = 4672.7 (16) ų, Z = 1. The layered [Sb₂₂S₄₂^18—] anion in [Ni(dien)₂]₉Sb₂₂S₄₂ · 0.5H₂O is composed of nine SbS₃ trigonal pyramids, one SbS₄ and one SbS₅ unit. The interconnection of these units by sharing common S atoms yields Sb‐S heterorings of different sizes. Besides the smaller Sb₂S₂ and Sb₃S₃ rings a very large Sb₃₀S₃₀ heteroring is observed. The structure directing effect of the [Ni(dien)₂]²⁺ cations is obvious as they are located above and below the pores of the anion. The nine [Ni(dien)₂]²⁺ cations exhibit different conformations. All Ni²⁺ cations are in an octahedral environment of six N atoms of two dien ligands. The anions and cations are stacked perpendicular to [100] in an alternating fashion.     

Low‐Temperature Synthesis of Diamminesodium(1+) Triamminesodium(1+) Trithioantimonate(3−) Ammoniate (1 : 2 : 1 : 2) ([Na(NH3)3]2[Na(NH3)2]SbS3⋅2 NH3), A Solvated Neutral Sodium Trithioantimonate(3−) (3 : 1) Na3SbS3) Ion Complex

A solution of sodium in liquid ammonia reacts with Sb₂S₃ to form large colorless crystals of the composition Na₃SbS₃⋅10 NH₃. The trigonal‐pyramidal SbS₃³⁻ anion is ion‐paired with three Na⁺ counter ions, the coordination spheres of which are completed by eight ammine ligands. The resulting neutral [Na(NH₃)₃]₂[Na(NH₃)₂]SbS₃ molecules crystallize together with two ammonia molecules of solvation in the space group P2₁/c (a=9.828(2), b=6.0702(4), c=33.4377(6) Å, β=91.362(7)°, V=1994.2(5) ų, Z=4).     

Another Example for the Ability of the $\rm SbS^{3-}_{3}$ Anion to act as a Bidentate Ligand: Solvothermal Synthesis,Crystal Structure,Calculated and Experimental Raman Spectra of [Cr(tren)SbS3]·H2O

The new charge neutral complex [Cr(tren)SbS₃]·H₂O was synthesized under solvothermal conditions applying CrCl₃·6H₂O, Sb₂S₃, and S as starting material in an aqueous tren solution (tren = tris(2‐aminoethyl)amine)). The compound crystallizes in the non‐centrosymmetric space group P2₁2₁2₁ with a = 8.7779(15), b = 10.7122(17), c = 15.4286(18) Å, V = 1450.8(4) ų. In the structure the Cr³⁺ ion is surrounded by four N atoms of the amine molecules and by two S atoms of a trigonal pyramidal [SbS₃]^3? group, i.e., the latter acts as a bidentate ligand. A three‐dimensional network is formed via hydrogen bonds between the complexes and water molecules. The main resonances in the Raman spectrum can be explained on the basis of calculated data. The most intense band is due to the Sb‐S stretching vibration. The thermal properties were investigated by DTA‐TG measurements. On heating [Cr(tren)SbS₃]·H₂O decomposes in two distinct steps. The first step corresponds to the removal of the water molecules and the second step to the loss of the tren ligand.     

Cu3SbS3: Zur Kristallstruktur und Polymorphie

Cu₃SbS₃: Crystal Structure and Polymorphism The hitherto unknown crystal structure of β-Cu₃SbS₃ at room temperature could be determined from a twinned crystal. The compound crystallizes in the monoclinic system, space group P2₁/c (No. 14), with a = 7.808(1), b = 10.233(2) and c = 13.268(2) Å, β = 90.31(1)°, V = 1 060.1(2) ų, Z = 8. An Extended-Hückel-Calculation shows weak bonding interactions between copper atoms which are coordinated trigonal planar. At ?9°C a first order phase transition occurs and the crystals disintegrate. The low-temperature modification (γ) crystallizes in the orthorhombic system with a = 7.884(2), b = 10.219(2) and c = 6.623(2) Å, V = 533.6(2) ų (?100°C). At 121°C a phase transition of higher order is observed. The high-temperature polymorph (α) of Cu₃SbS₃ is orthorhombic again. From high-temperature precession photographs the space groups Pnma (No. 62) or Pna2₁ (No. 33) can be derived. The lattice constants at 200°C are a = 7.828(3), b = 10.276(4) and c = 6.604(3) Å, V = 531.2(2) ų.     

Supertetrahedral Networks and Lithium‐Ion Mobility in Li2SiP2 and LiSi2P3

The new phosphidosilicates Li₂SiP₂ and LiSi₂P₃ were synthesized by heating the elements at 1123 K and characterized by single‐crystal X‐ray diffraction. Li₂SiP₂ (I4₁/acd, Z=32, a=12.111(1) Å, c=18.658(2) Å) contains two interpenetrating diamond‐like tetrahedral networks consisting of corner‐sharing T2 supertetrahedra [(SiP_4/2)₄]. Sphalerite‐like interpenetrating networks of uniquely bridged T4 and T5 supertetrahedra make up the complex structure of LiSi₂P₃ (I4₁/a, Z=100, a=18.4757(3) Å, c=35.0982(6) Å). The lithium ions are located in the open spaces between the supertetrahedra and coordinated by four to six phosphorus atoms. Temperature‐dependent ⁷Li solid‐state MAS NMR spectroscopic data indicate high mobility of the Li⁺ ions with low activation energies of 0.10 eV in Li₂SiP₂ and 0.07 eV in LiSi₂P₃.     

Novel Copper(I)‐Thioantimonates(III): Solvothermal Synthesis,Crystal Structures,Thermal Stability and Magnetic Properties of (C2N2H10)0.5Cu2SbS3, (C3N2H12)0.5Cu2SbS3, and (C4N2H14)0.5Cu2SbS3

The novel copper(I)‐thioantimonates(III) (enH₂²⁺)_0.5Cu₂SbS₃ ( I ) (en = ethylendiamine), (1, 3‐DAPH₂²⁺)_0.5Cu₂SbS₃ ( II ) (1, 3‐DAP = 1, 3 diaminopropane) and (1, 4‐DABH₂²⁺)_0.5Cu₂SbS₃ ( III ) (1, 4‐DAB = 1, 4‐diaminobutane) were synthesized under solvothermal conditions reacting Sb₂S₃, CuCl₂·2H₂O, S with the amines. The compounds crystallize in the monoclinic space group P2₁/n. The primary building units are a SbS₃ trigonal pyramid and two distorted CuS₃ units. In the structures the SbS₃ pyramid is connected to six CuS₃ moieties and every S atom has bonds to one Sb atom and to two Cu atoms. Further interconnection leads to the formation of ten‐membered (10 MR) Cu₃Sb₂S₅ and six‐membered (6 MR) Cu₂SbS₃ rings. Every 10 MR is condensed to four 10 MR and four 6 MR to form a single layer within the (010) plane. Two such single layers are connected to a double layer thus forming the final [Cu₂SbS₃]^— layered anion. The [CuSbS₃]^— protonated amines are located between the layers and the interlayer spacing depends on the size and orientation of these amines. Between the Sb atom and one Cu atom a remarkable short distance of about 2.7Å is observed. At elevated temperatures the compounds decompose into CuSbS₂ and Cu₃SbS₄ suggesting a complex redox reaction. Diamagnetic susceptibilities indicate the copper(I) in the metal sulfide frameworks. All three compounds are semiconductors with intermediate band gaps of about 2 eV.     

New Thioantimonates(III) with Different Sb:S Ratios: Solvothermal Syntheses and Crystal Structures of [(C3H10NO)(C3H10N)][Sb8S13], [(C2H8NO)(C2H8N)(CH5N)][Sb8S13], [(C6H16N2)(C6H14N2)][Sb6S10], and [C8H22N2][Sb4S7]

Four new thioantimonates(III) with compositions [(C₃H₁₀NO)(C₃H₁₀N)][Sb₈S₁₃] ( 1 ) (C₃H₉NO = 1‐amino‐3‐propanol, C₃H₉N = propylamine), [(C₂H₈NO)(C₂H₈N)(CH₅N)][Sb₈S₁₃] ( 2 ) (C₂H₇NO = ethanolamine, C₂H₇N = ethylamine, CH₅N = methylamine), [(C₆H₁₆N₂)(C₆H₁₄N₂)][Sb₆S₁₀] ( 3 ) (C₆H₁₄N₂ = 1,2‐diaminocyclohexane) and [C₈H₂₂N₂][Sb₄S₇] ( 4 ) (C₈H₂₀N₂ = 1,8‐diaminooctane) were synthesized under solvothermal conditions. Compound 1 : triclinic space group P$\bar{1}$ , a = 6.9695(6) Å, b = 13.8095(12) Å, c = 18.0354(17) Å, α = 98.367(11), β = 96.097(11) and γ = 101.281(11)°; compound 2 : monoclinic space group P2₁/m, a = 7.1668(5), b = 25.8986(14), c = 16.0436(11) Å, β = 96.847(8)°; compound 3 : monoclinic space group P2₁/n, a = 11.6194(9), b = 10.2445(5) Å, c = 27.3590(18) Å, β = 91.909(6)°; compound 4 : triclinic space group P$\bar{1}$ , a = 7.0743(6), b = 12.0846(11), c = 13.9933(14) Å, α = 114.723(10), β = 97.595(11), γ = 93.272(11)°. The main structural feature of the two atoms thick layered [Sb₈S₁₃]^2– anion in 1 are large nearly rectangular pores with dimensions 11.2 × 11.7 Å. The layers are stacked perpendicular to [100] to form tunnels being directed along [100]. In contrast to 1 the structure of 2 contains a [Sb₈S₁₃]^2– chain anion with Sb₁₂S₁₂ pores measuring about 8.9 × 11.5 Å. Only if longer Sb–S distances are considered as bonding interactions a layered anion is formed. The chain anion [Sb₆S₁₀]^2– in compound 3 is unique and is constructed by corner‐sharing SbS₃ pyramids. Two symmetry‐related single chains consisting of alternating SbS₃ units and Sb₃S₃ rings are bound to Sb₄S₄ rings in chair conformation. Finally, in the structure of 4 the SbS₃ and SbS₄ moieties are joined corner‐linked to form a chain of alternating SbS₄ units and (SbS₃)₃ blocks. Neighboring chains are connected into sheets that contain relatively large Sb₁₀S₁₀ heterorings. The sheets are further connected by sulfur atoms generating four atoms thick double sheets.     

Vergleich der Kristallstrukturen der Tetraammoniakate von Lithiumhalogeniden,LiBr·4NH3 und LiI·4NH3, mit der Struktur von Tetramethylammoniumiodid,N(CH3)4I

A Comparison of the Crystal Structures of the Tetraammoniates of Lithium Halides, LiBr·4NH₃ and LiI·4NH₃, with the Structure of Tetramethylammonium Iodide, N(CH₃)₄I Crystals of the tetraammoniates of LiBr and LiI sufficient in size for X‐ray structure determinations were obtained by slow evaporation of NH₃ at room temperature from a clear solution of the halides in liquid ammonia. The compounds crystallize in the space group Pnma (No. 62) with four formula units in the unit cell: LiBr·4NH₃: a = 11.947(5)Å, b = 7.047(4)Å, c = 9.472(3)Å LiI·4NH₃: a = 12.646(3)Å, b = 7.302 (1)Å, c = 9.790(2)Å For N(CH₃)₄I the structure was now successfully solved including the hydrogen positions of the methyl groups. N(CH₃)₄I: P4/nmm (No. 129), Z = 2, a = 7.948(1)Å, c = 5.738(1)Å The ammoniates of LiBr and LiI crystallize isotypic in a strongly distorted arrangement of the CsCl motif. Even N(CH₃)₄I has an CsCl‐like structure. Both structure types differ mainly in their orientation of the [Li(NH₃)₄]⁺ — resp. [N(CH₃)₄]⁺ — cations with respect to the surrounding “cube” of anions.     

Cu3SbSe3: Synthese und Kristallstruktur

The Crystal Structure of Cu₃SbSe₃ The hitherto unknown crystal structure of Cu₃SbSe₃ has been determined from single crystals. The compound crystallizes in the orthorhombic system, space group Pnma (No. 62), with a = 7.9865(8), b = 10.6138(9) and c = 6.8372(7) Å, V = 579.6(1) ų, Z = 4. Most remarkable feature of the structure are groups of three cis-edge-sharing tetrahedra [Cu₃Se₈] which are interlinked to a threedimensional arrangement by SbSe₃-units. In contrast to Cu₃SbS₃ in the temperature range from ?180 to 25°C no hints for a phase transition could be detected by means of X-ray- and thermoanalytical methods.     

Synthesis,Structure Characterization,and Optical Properties of the Aluminosilicate Li2Na3AlSi2O8

The aluminosilicate Li₂Na₃AlSi₂O₈ was crystallized from the Li₂CO₃–H₃BO₃ flux system. It crystallizes in the orthorhombic space group Cmca, with cell dimensions a = 14.1045 (19) Å, b = 14.7054 (19) Å, c = 7.0635 (9) Å, and Z = 8. The crystal structure consists of a two‐dimensional infinite layer, which is composed of [Al₂Si₂O₁₂] groups and [SiO₄] tetrahedra. The lithium and sodium atoms filling in the interlayer and intralayer link the layers together and balance the charge. IR spectroscopy and BVS calculations were used to verify the validity of the structure. The calculated band structures and the density of states of Li₂Na₃AlSi₂O₈ suggest that its direct gap is 4.28 eV.     

New SbS2 strings in the BaSb2S4 structure

The new compound BaSb₂S₄ crystallizes in the monoclinic system (space group: $\text{P2}{}_1\text{c}$, No. 14) with a = 8.985(2) Å, b = 8.203(3) Å, c = 20.602(5) Å, β = 101.36(3)°. SbS₃ ψ tetrahedra and ψ-trigonal SbS₄ bipyramids are connected by common corners and edgers to infinite strings. These are arraged cross-wise in sheets perpendicular to the c axis.     

Synthese und Kristallstruktur der Monoammoniakate von Lithiumhalogeniden: LiBr·NH3 und LiI·NH3

Syntheses and Crystal Structures of the Monoammoniates of Lithium Halides: LiBr·NH₃ and LiI·NH₃ Crystals of LiBr·NH₃ and LiI·NH₃ sufficient in size and quality for X‐ray structure determinations were obtained in autoclaves by the reaction of Li with NH₄Br and LiH with NH₄I at 523 K and 423 K respectively. Lattice constants obtained from X‐ray single crystal data are: LiBr·NH₃: P2₁/n, a = 7, 077(2)Å, b = 7, 026(2)Å, c = 7, 490(2)Å β = 114, 84(3)°, Z = 4 LiI·NH₃: P2₁, a = 4, 493(1)Å, b = 6, 077(1)Å, c = 7, 512(2)Å β = 107, 15(3)°, Z = 2 The ammoniates contain different structural building units. Both of them contain layers of connected tetrahedra Li(NH₃)X_3/3 with X = Br, I. Tetrahedra‐double units with a common Br‐Br edge occur, whilst for the iodide all tetrahedra are exclusively vertex connected to puckered layers. IR‐ and Raman‐spectroscopic measurements show, that only weak H‐bridges N‐H···X are present and that the NH₃‐ligands are in fixed positions at room temperature.     

Complex Topology of Uranyl Polyphosphate Frameworks: Crystal Structures of α‐, β‐K[(UO2)(P3O9)] and K[(UO2)2(P3O10)]

Three new uranyl polyphosphates, α‐K[(UO₂)(P₃O₉)] ( 1 ), β‐K[(UO₂)(P₃O₉)] ( 2 ), and K[(UO₂)₂(P₃O₁₀)] ( 3 ), were prepared by high‐temperature solid‐state reactions. The crystal structures of the compounds have been solved by direct methods: 1 – monoclinic, P2₁/m, a = 8.497(1), b = 15.1150(1), c = 14.7890(1) Å, β = 91.911(5)°, V = 1898.3(3) ų, Z = 4, R₁ = 0.0734 for 4181 unique reflections with |F₀| ≥ 4σ_F; 2 – monoclinic, P2₁/n, a = 8.607(1), b = 14.842(2), c = 14.951(1) Å, β = 95.829(5)°, V = 1900.0(4) ų, Z = 4, R₁ = 0.0787 for 3185 unique reflections with |F₀| ≥ 4σ_F; 3 – Pbcn, a = 10.632(1), b = 10.325(1), c = 11.209(1) Å, V = 1230.5(2) ų, Z = 4, R₁ = 0.0364 for 1338 unique reflections with |F₀| ≥ 4σ_F. In the structures of 1 and 2 , phosphate tetrahedra share corners to form infinite [PO₃]^? chains, whereas, in the structure of 3 , tetrahedra form linear [P₃O₁₀]^5? trimers. The structures are based upon 3‐D frameworks of U and P polyhedra linked by sharing common O corners. The infinite [PO₃]^? chains in the structures of 1 and 2 are parallel to [100] and [–101], respectively. The uranyl polyphosphate frameworks are occupied by host K⁺ cations.     

Kristallstrukturen und chemische Bindung von AM2GeSe4 (A = Sr,Ba; M = Cu,Ag)

New Noncentrosymmetric Selenogermanates. I. Crystal Structures and Chemical Bonding of AM ₂GeSe₄ ( A = Sr, Ba; M = Cu, Ag) Three new quaternary selenogermanates were synthesized by heating the elements at 983–1073 K. Their crystal structures were determined by single crystal X‐ray methods. The dark red semiconductors crystallize in noncentrosymmetric space groups. SrCu₂GeSe₄ (Ama2, a = 10.807(4) Å, b = 10.735(4) Å, c = 6.541(2) Å, Z = 4) forms a new structure type, whereas BaCu₂GeSe₄ (P3₁, a = 6.490(1) Å, c = 16.355(3) Å, Z = 3) and BaAg₂GeSe₄ (I222, a = 7.058(1) Å, b = 7.263(1) Å, c = 8.253(2) Å, Z = 2) crystallize in structures known from thiostannates. Main structural features are almost regular GeSe₄‐, but distorted CuSe₄‐ or AgSe₄‐tetrahedra sharing corners or edges. Eight selenium atoms coordinate the alkaline earth atoms in the voids of these three dimensional tetrahedral networks. Chemical bonding and the electronic structure are elucidated by self‐consistent band structure calculations and the COHP method. The electron density and the electron localization function ELF of SrCu₂GeSe₄ reveal a significant stronger covalent character for the Ge–Se bonds compared with the Cu–Se bonds. For this reason the GeSe₄ tetrahedra appear as quasi molecular entities, arranged spatially according to the motifs of closest packing. The metal atoms occupy the tetrahedral and octahedral voids of these “tetrahedra packing”. This concept allows to derive the structures of AM₂GeSe₄‐compounds from simple binary structure types as Li₃Bi or Ni₂In.     

Synthesis,Magnetism, and Crystal Structure of Li2Fe[(PO4)(HPO4)] and its Hydrogen Position Refinement

Lithium iron(III) monophosphate-monohydrogen-monophosphate, Li₂Fe[(PO₄)(HPO₄)], was synthesized under mild hydrothermal conditions and its crystal structure was determined by single crystal X-ray diffraction methods. Crystallographic data: monoclinic, P12₁/n1 (no. 14), a = 4.8142(2) Å, b = 7.9898(4) Å, c = 7.4868(4) Å, β = 104.398(3)°, V = 278.93(2) ų, Z = 2, D_x = 3.104 g · cm^-3. The structure is characterized by FeO₆ octahedra sharing common O-corners with six neighbouring PO₄ tetrahedra to form a three-dimensional framework. Lithium cations are located within channels running along [100]. The channels are formed by eight-membered rings resulting from the connection of alternating FeO₆ octahedra (4×) and phosphate tetrahedra (4×). High-resolution diffraction data allowed to refine a split model for the position of the hydrogen atom. Magnetization data confirm the valence state 3+ for iron and detect an antiferromagnetic ordering of the iron moments below 23.6 K. Thermal decomposition of the compound was investigated by DTA/TG methods.     

Li2I(OH): Eine Verbindung mit eindimensional unendlich kantenverknüpften [Li4/2(OH)]+-Pyramiden

Li₂I(OH): A Compound with Onedimensional Infinite Edge Sharing [Li_4/2(OH)⁺] Pyramids The pseudobinary system LiOH/LiI was investigated by X-ray methods. Two compounds, Li₂I(OH) and Li₅I(OH)₄ exist. The structure of Li₂I(OH) was solved by single-crystal data. For Li₅I(OH)₄ lattice constants and space group symmetry are given: Li₂I(OH): Pnma, Z = 4, a = 10.339(4) Å, b = 5.567(1) Å, c = 6.643(2) Å, Z(F_o) mit (F_o)² ≧ 3σ(F_o)² = 439, Z (parameter) = 23, R/R_w = 0.030/0.040 Li₅I(OH)₄: Pmmn or P2₁mn(= Pmn2₁), Z = 2, a = 10.42 Å, b = 5.30 Å, c = 5.81 Å Li₂I(OH) crystallizes in a new type of structure. The motif of a distorted hexagonal close-packed arrangement of iodide ions is penetrated by chains of [Li_4/2(OH)⁺].     

Lithium Ion Motion in Lithium Nitridoborate Chalcogenides Li5(BN2)Ch (Ch = Se,Te)

The compounds Li₅(BN₂)Se and Li₅(BN₂)Te were synthesized at 900 °C in a closed system utilizing weld shut niobium ampoules and obtained as white microcrystalline powders. Their crystal structures were solved and refined on the basis of single‐crystal X‐ray diffraction data with the space group I4₁md [a = 6.3983(4) Å, c = 11.1072(9) Å for Li₅(BN₂)Se and a = 6.5878(3) Å, c = 11.4382(7) Å for Li₅(BN₂)Te]. The temperature dependent Li⁺ motion was investigated by ⁷Li MAS NMR spectroscopy.