Na2B2S5 and Li2B2S5: Two Novel Perthioborates with Planar 1,2,4-Trithia-3,5-Diborolane Rings

For the first time perthioborates with trigonal planar coordination of boron were prepared. Na₂B₂S₅ (Pnma, a = 12.545(2) Å, b = 7.441(1) Å, c = 8.271(1) Å, Z = 4) and Li₂B₂S₅ (Cmcm, a = 15.864(1) Å, b = 6.433(1) Å, c = 6.862(1) Å, Z = 4) were obtained by reaction of the metal sulfides with stoichiometric amounts of boron and an excess of sulfur (effective molar ratio M:B:S = 1:1:4) at 600°C (650°C) and subsequent annealing. The non-isotypic structures contain exactly planar [B₂S₅]^2? groups consisting of five-membered B₂S₃ rings with one additional exocyclic sulfur on each of the boron atoms. The alkaline metal cations are four-coordinate (lithium) and (four + four)-coordinate (sodium) respectively.     

LiBaBS3 und LiBaB3S6: Zwei neue quaternäre Thioborate mit trigonal-planar koordiniertem Bor

LiBaBS₃ and LiBaB₃S₆: Two New Quaternary Thioborates with Trigonally Coordinated Boron LiBaBS₃ (P2₁/c; a = 7.577(2) Å, b = 8.713(2) Å, c = 8.687(2) Å, β = 116.22(2)°; Z = 4) und LiBaB₃S₆ (Cc; a = 15.116(3) Å, b = 8.824(2) Å, c = 8.179(2) Å, β = 117.46(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of the metal sulfides, boron, and sulfur at 750°C. The anionic part of the structure of the orthothioborate LiBaBS₃ consists of isolated planar [BS₃]^3? anions. The crystal structure of the metathioborate LiBaB₃S₆ contains [B₃S₆]^3? anions formed by six-membered B₃S₃ rings with three exocyclic sulfur atoms. The metal cations are situated between the anion units leading to a ninefold sulfur coordination of the barium atoms and to a fivefold (LiBaBS₃) and fourfold (LiBaB₃S₆) coordination of the lithium atoms.     

Na2B2Se7, K2B2S7 und K2B2Se7: Drei Perchalkogenoborate mit neuem polymeren Anionengerüst

Na₂B₂Se₇, K₂B₂S₇, and K₂B₂Se₇: Three Perchalcogenoborates with a Novel Polymeric Anion Network Na₂B₂Se₇ (I 2/a; a = 11.863(4) Å, b = 6.703(2) Å, c = 13.811(6) Å, β = 109.41(2)°; Z = 4), K₂B₂S₇ (I 2/a; a = 11.660(2) Å, β = 6.827(1) Å, c = 12.992(3) Å, β = 106.78(3)°; Z = 4), and K₂B₂Se₇ (I 2/a; a = 12.092(4) Å, b = 7.054(2) Å, c = 13.991(5) Å, β = 107.79(3)°; Z = 4) were prepared by reaction of stoichiometric amounts of sodium selenide (potassium sulfide) with boron and sulfur or of potassium selenide and boron diselenide, respectively, at 600°C with subsequent annealing. The crystal structures consist of polymeric anion chains of composition ([B₂S₇]^2?)_n or ([B₂Se₇]^2?)_n formed by spirocyclically connected five-membered B₂S₃ (B₂Se₃) rings and six-membered B₂S₄ (B₂Se₄) rings. The nine-coordinate alkaline metal cations are situated in between.     

Syntheses and Crystal Structures of Rb2B2Se7, Tl2B2Se7, Cs3B3Se10, and Tl3B3Se10: New Perseleno‐selenoborates with Polymeric Anionic Chains

The perseleno‐selenoborates Rb₂B₂Se₇ and Cs₃B₃Se₁₀ were prepared from the metal selenides, amorphous boron and selenium, the thallium perseleno‐selenoborates Tl₂B₂Se₇ and Tl₃B₃Se₁₀ directly from the elements in evacuated carbon coated silica tubes by solid state reactions at temperatures between 920 K and 950 K. All structures were refined from single crystal X‐ray diffraction data. The isotypic perseleno‐selenoborates Rb₂B₂Se₇ and Tl₂B₂Se₇ crystallize in the monoclinic space group I 2/a (No. 15) with lattice parameters a = 12.414(3) Å, b = 7.314(2) Å, c = 14.092(3) Å, β = 107.30(3)°, and Z = 4 for Rb₂B₂Se₇ and a = 11.878(2) Å, b = 7.091(2) Å, c = 13.998(3) Å, β = 108.37(3)° with Z = 4 for Tl₂B₂Se₇. The isotypic perseleno‐selenoborates Cs₃B₃Se₁₀ and Tl₃B₃Se₁₀ crystallize in the triclinic space group P1 (Cs₃B₃Se₁₀: a = 7.583(2) Å, b = 8.464(2) Å, c = 15.276(3) Å, α = 107.03(3)°, β = 89.29(3)°, γ = 101.19(3)°, Z = 2, (non‐conventional setting); Tl₃B₃Se₁₀: a = 7.099(2) Å, b = 8.072(2) Å, c = 14.545(3) Å, α = 105.24(3)°, β = 95.82(3)°, γ = 92.79(3)°, and Z = 2). All crystal structures contain polymeric anionic chains of composition ([B₂Se₇]^2–)_n or ([B₃Se₁₀]^3–)_n formed by spirocyclically fused non‐planar five‐membered B₂Se₃ rings and six‐membered B₂Se₄ rings in a molar ratio of 1 : 1 or 2 : 1, respectively. All boron atoms have tetrahedral coordination with corner‐sharing BSe₄ tetrahedra additionally connected via Se–Se bridges. The cations are situated between three polymeric anionic chains leading to a nine‐fold coordination of the rubidium and thallium cations by selenium in M₂B₂Se₇ (M = Rb, Tl). Coordination numbers of Cs⁺ (Tl⁺) in Cs₃B₃Se₁₀ (Tl₃B₃Se₁₀) are 12(11) and 11(9).     

BaB2S4: Das erste nicht‐oxidische Chalkogenoborat mit trigonal‐planar und tetraedrisch koordiniertem Bor

BaB₂S₄: The first non‐oxidic Chalcogenoborate with Boron in a trigonal‐planar and tetrahedral Coordination Hitherto we know boron in a trigonal‐planar and a tetrahedral coordination within one crystal structure from boron oxides in various compounds. With the novel bariummetathioborate BaB₂S₄ we now report a crystal structure containing BS₃ and BS₄ units in the ratio 1 : 1 forming infinite chains along [001]. BaB₂S₄ was synthesized in a solid state reaction at a temperature of 800 °C from barium sulfide, amorphous boron and sulfur and crystallizes in the monoclinic space group Cc (no. 9) with the following lattice parameters: a = 6.6465(5) Å, b = 15.699(1) Å, c = 6.0306(5) Å, β = 110.96(1)°, Z = 4.     

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.     

Li5B7S13 und Li9B19S33: Zwei Lithiumthioborate mit neuen hochpolymeren Anionengerüsten

Li₅B₇S₁₃ and Li₉B₁₉S₃₃: Two Lithium Thioborates with Novel Highly Polymeric Anion Networks Li₅B₇S₁₃ (C2/c; a = 17.304(2) Å, b = 21.922(3) Å, c = 12.233(2) Å, β = 134.91(1)°; Z = 8) and Li₉B₁₉S₃₃ (C2/c; a = 23.669(9) Å, b = 14.361(3) Å, c = 12.237(3) Å, β = 103.77(2)°; Z = 4) were prepared by reaction of stoichiometric amounts of lithium sulfide, boron, and sulfur at 750°C (Li₅B₇S₁₃) and 700°C (Li₉B₁₉S₃₃) with subsequent annealing. The crystal structures consist of interpenetrating, polymeric boron sulfur anion networks which are formed by corner-sharing of B₄S₁₀ and B₁₀S₂₀ units (Li₅B₇S₁₃), or B₁₉S₃₆ units (Li₉B₁₉S₃₃). The lithium cations are situated in between with a strong disorder in Li₉B₁₉S₃₃.     

Sr3(BS3)2 und Sr3(B3S6)2: Zwei neue nicht‐oxidische Chalkogenoborate mit trigonal‐planar koordiniertem Bor

Sr₃(BS₃)₂ and Sr₃(B₃S₆)₂: Two Novel Non‐oxidic Chalcogenoborates with Boron in a Trigonal‐Planar Coordination The thioborates Sr₃(BS₃)₂ and Sr₃(B₃S₆)₂ were prepared from strontium sulfide, amorphous boron and sulfur in solid state reactions at a temperature of 1123 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. Sr₃(BS₃)₂ crystallizes in the monoclinic spacegroup C2/c (No. 15) with a = 10.187(4) Å, b = 6.610(2) Å, c = 15.411(7) Å, β = 102.24(3)° and Z = 4. The crystal structure of Sr₃(B₃S₆)₂ is trigonal, spacegroup R3¯ (Nr. 148), with a = 8.605(1) Å, c = 21.542(4) Å and Z = 3. Sr₃(BS₃)₂ contains isolated [BS₃]^3— anions with boron in a trigonal‐planar coordination. The strontium cations are found between the layers of orthothioborate anions. Sr₃(B₃S₆)₂ consists of cyclic [B₃S₆]^3— anions and strontium cations, respectively.     

Syntheses of Halogenated Polyhedral Phosphaboranes: Crystal Structure of conjuncto‐3,3′‐(closo‐1,2‐P2B4Br3)2

Co‐pyrolysis of B₂Br₄ with PBr₃ at 480 °C gave, in addition to the main product closo‐1,2‐P₂B₄Br₄, conjuncto‐3,3′‐(1,2‐P₂B₄Br₃)₂ ( 1 ) and the twelve‐vertex closo‐1,7‐P₂B₁₀Br₁₀ ( 2 ), both in low yields. X‐ray structure determination for 1 [triclinic, space‐group P1 with a = 7.220(2) Å, b = 7.232(2) Å, c = 8.5839(15) Å, α = 97.213(15)°, β = 96.81(2)°, γ = 94.07(2)° and Z = 1] confirmed that 1 adopts a structure consisting of two symmetrically boron–boron linked distorted octahedra with the bridging boron atoms in the 3,3′‐positions and the phosphorus atoms in the 1,2‐positions. The intercluster 2e/2c B–B bond length is 1.61(3) Å. The shortest boron–boron bond within the cluster framework is 1.68(2) Å located between the boron atoms antipodal to the phosphorus atoms. The icosahedral phosphaborane 2 was characterized by ¹¹B‐¹¹B COSY NMR spectroscopy showing cross peaks indicative for the isomer with the phosphorus atoms in 1,7‐positions. Both the X‐ray data of 1 and the NMR spectroscopic data of 1 and 2 give further evidence for the influence of an antipodal effect of heteroatoms to cross‐cage boron atoms and, vice versa, of an additional shielding of the phosphorus atoms caused by B‐Hal substitution at the boron positions trans to phosphorus.     

Die Perthioborate RbBS3, TIBS3 und TI3B3S10

The Perthioborates RbBS₃, TIBS₃, and Tl₃B₃S₁₀ . RbBS₃ (P2₁/c, a=7.082(2) Å, b=11.863(4) Å, c=5.794(2) Å, β=106.54(2)°) was prepared as colourless, plate-shaped crystals by reaction of stoichiometric amounts of rubidium sulfide, boron, and sulfur at 600°C and subsequent annealing. TlBS₃ (P2₁/c, a=6.874(3) Å, b=11.739(3) Å, c=5.775(2) Å, β=113.08(2)°) which is isotypic with RbBS₃ was synthesized from a sample of the composition Tl₂S · 2 B₂S₃. The glassy product which was obtained after 7 h at 850°C was annealed in a two zone furnace for 400 h at 400→350°C. Yellow crystals of TlBS₃ formed at the warmer side of the furnace. Tl₃B₃S₁₀ (P1 , a=6.828(2) Å, b=7.713(2) Å, c=13.769(5) Å, α=104.32(2)°, β=94.03(3)°, γ=94.69(2)°) was prepared as yellow plates from stoichiometric amounts of thallium sulfide, boron, and sulfur at 850°C and subsequent annealing. All compounds contain tetrahedrally coordinated boron. The crystal structures consist of polymeric anion chains. In the case of RbBS₃ and TlBS₃ nonplanar five-membered B₂S₃ rings are spirocyclically connected via the boron atoms. To obtain the anionic structure of Tl₃B₃S₁₀ every third B₂S₃ ring of the polymeric chains of MBS₃ is to be substituted by a six-membered B(S₂)₂B ring.     

Drei neue Selenoborato-closo-dodekaborate: Synthesen und Kristallstrukturen von Rb8[B12(BSe3)6], Rb4Hg2[B12(BSe3)6] und Cs4Hg2[B12(BSe3)6]

Three Novel Selenoborato- closo -dodecaborates: Syntheses and Crystal Structures of Rb₈[B₁₂(BSe₃)₆], Rb₄Hg₂[B₁₂(BSe₃)₆], and Cs₄Hg₂[B₁₂(BSe₃)₆] The three selenoborates Rb₈[B₁₂(BSe₃)₆] (P1, a = 10.512(5) Å, b = 10.450(3) Å, c = 10.946(4) Å, α = 104.53(3)°, β = 91.16(3)°, γ = 109.11(3)°, Z = 1), Cs₄Hg₂[B₁₂(BSe₃)₆] (P1, a = 9.860(2) Å, b = 10.740(2) Å, c = 11.078(2) Å, α = 99.94(3)°, β = 90.81(3)°, γ = 115.97(3)°, Z = 1), and Rb₄Hg₂[B₁₂(BSe₃)₆] (P1, a = 9.593(2) Å, b = 10.458(2) Å, c = 11.131(2) Å, α = 99.25(3)°, β = 91.16(3)°, γ = 116.30(3)°, Z = 1) were prepared from the metal selenides, amorphous boron and selenium by solid state reactions at 700 °C. These new chalcogenoborates contain B₁₂ icosahedra completely saturated with six trigonal-planar BSe₃ entities functioning as bidentate ligands to form a persubstituted closo-dodecaborate anion. The two isotypic compounds Rb₄Hg₂[B₁₂(BSe₃)₆] and Cs₄Hg₂[B₁₂(BSe₃)₆] are the first selenoborate structures containing a transition metal which are characterized by single crystal diffraction.     

Phosphanimin- und Phosphaniminato-Komplexe von Bor. Synthese und Kristallstrukturen von [BF3(Me3SiNPEt3)], [BCl2(NPPh3)]2, [BCl2(NPEt3)]2, [B2Cl3(NPEt3)2]+BCl4− und [B2Cl2(NPiPr3)3]+BCl4−

Phosphaneimine and Phosphoraneiminato Complexes of Boron. Synthesis and Crystal Structures of [BF₃(Me₃SiNPEt₃)], [BCl₂(NPPh₃)]₂, [BCl₂(NPEt₃)]₂, [B₂Cl₃(NPEt₃)₂]⁺BCl₄^?, and [B₂Cl₂(NPⁱPr₃)₃]⁺BCl₄^? The title compounds have been prepared from the corresponding silylated phosphaneimines and boron trifluoride etherate and boron trichloride, respectively. The compounds form white moisture sensitive crystals, which were characterized by ¹¹B-nmr-spectroscopy, IR-spectroscopy and by crystal structure determinations. [BF₃(Me₃SiNPEt₃)] : Space group P2₁/c, Z = 4, R = 0.032 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1361.0, b = 819.56, c = 1422.5 pm, β = 109.86°. The donor acceptor complex forms monomeric molecules with a B? N bond length of 157.8 pm. [BCl₂(NPPh₃)]₂ · 2 CH₂Cl₂ : Space group P2₁/c, Z = 2, R = 0.049 for reflections with I > 2σ(I). Lattice dimensions at ?50°C: a = 1184.6, b = 2086.4, c = 843.0 pm, β = 96.86°. The compound forms centrosymmetric dimeric molecules in which the boron atoms are linked to B₂N₂ four-membered rings with B? N distances of 152.7 pm via μ₂-N bridges of the NPPh₃ groups. [BCl₂(NPEt₃)]₂ : Space group Pbca, Z = 4, R = 0.029 for reflections with I > 2σ(I). Lattice dimensions at ?90°C: a = 1269.5, b = 1138.7, c = 1470.3 pm. The compound has a molecular structure corresponding to the phenyl compound with B? N ring distances of 151.0 pm. [B₂Cl₃(NPEt₃)₂]⁺BCl₄^? : Space group Pbca, Z = 8, R = 0.034 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1309.3, b = 1619.8, c = 2410.7 pm. Within the cations the boron atoms are linked to planar, asymmetrical B₂N₂ four-membered rings with B? N distances of 155.1 and 143.1 pm via the μ₂-N atoms of the NPEt₃ groups. [B₂Cl₂(NPⁱPr₃)₃]⁺BCl₄^? · CH₂Cl₂: Space group Pna2, Z = 4, R = 0.033 for reflections with I > 2σ(I). Lattice dimensions at ?70°C: a = 1976.5, b = 860.2, c = 2612.7 pm. Within the cations the boron atoms are linked to planar, asymmetrical B₂N₂ four-membered rings with B? N distances of 153.7 and 150.5 pm via the μ₂-N atoms of two of the NPⁱPr₃ groups. The third NPⁱPr₃ group is terminally connected to the sp²-hybridized boron atom with a B? N distance of 133.5 pm and with a B? N? P bond angle of 165.3°.     

Synthese und Struktur von Cs11[(WN2,5O1,5)2](N3)2, ein Caesiumoxonitridomonowolframat(VI)-azid

Synthesis and Structure of Cs₁₁[(WN_2,5O_1,5)₂](N₃)₂, a Cesium Oxo Nitrido Monotungstate(VI) Azide Cs₁₁[(WN_2,5O_1,5)₂](N₃)₂ results from the reaction of a mixture of CsNH₂, W and WO₃ at 620 °C in autoclaves. It crystallizes monoclinic in the space group C2/m with the lattice parameters a = 12.421(4) Å, b = 11.568(6) Å, c = 10.516(4) Å, β = 118.71(3)° and Z = 4. The crystal structure is built up by isolated tetrahedra [WX₄] with X = N, O, which are connected by cesium cations. Between the cesium ions lie azide ions separated from the anions [WX₄]. The tungsten atoms and azide ions together build up the motif of a distorted arrangement of the CsCl structure type.     

Die Kristall- und MolekülStruktur von S4N4·2C7H8

Crystal and Molecular Structure, of S₄N₄ · 2C₇H₈ The structure of the title compound has been determined from threedimensional X-ray data. Crystals are monoclinic, with unit cell dimenions a = 16.532 Å, b = 8.563 Å, c = 10.880 Å, β = 103.2°, space group C? C2/c and Z = 4. Least squares refinement, by use of 1132 independent reflections measured on a diffractometer has reached 3.9%. In the S₄N₄·2C₇H₈ molecules the organic components are linked to two sulfur atoms of the S₄N₄, ring each.     

Halogenide der Seltenerdmetalle Ln4X5Z. Teil 3: Das Chlorid La4Cl5B4 – Präparation,Struktur und Verwandtschaft zu La4Br5B4, La4I5B4

Rare Earth Halides Ln₄X₅Z. Part 3: The Chloride La₄Cl₅B₄ – Preparation, Structure, and Relation to La₄Br₅B₄, La₄I₅B₄ La₄Cl₅B₄ is synthesized by reaction of LaCl₃, La metal and boron in sealed Ta containers at 1050 °C < T < 1350 °C. It crystallizes in the monoclinic space group C2/m with a = 16.484(3) Å, b = 4.263(1) Å, c = 9.276(2) Å and β = 120.06(3)°. Ce₄Cl₅B₄ is isotypic, a = 16.391(3) Å, b = 4.251(1) Å, c = 9.180(2) Å and β = 120.20(3)°. The La atoms form strings of trans-edge shared La octahedra, and the B atoms inside the strings form B₄-rhomboids, which are condensed to chains via opposite corners. The Cl atoms interconnect the channels according to La₂La_4/2Clⁱ⁻ⁱ_6/2Cl^i−a_2/2Cl^a−i_2/2. The crystal structures of the bromide and the iodide are comparabel, however, the interconnection of the strings is different in the three structure types, as 14 Cl, 13 Br and 12 I atoms surround the La₆ octahedra.     

Cs2Ba(O3)4 · 2 NH3, das erste ionische Erdalkaliozonid

Cs₂Ba(O₃)₄ · 2 NH₃, the First Ionic Alkaline Earth Metal Ozonide Cs₂Ba(O₃)₄ · 2 NH₃ is the first ionic ozonide containing an alkaline earth metal cation. Its synthesis has been achieved via partial cation exchange of CsO₃ dissolved in liquid ammonia. According to a single crystal X‐ray structure determination (Pnnm; a = 6.312(2) Å, b = 12.975(3) Å, c = 8.045(2) Å; Z = 2; R₁ = 4.6%; 848 independent reflections) ozonide anions, cesium cations and ammonia molecules form a CsCl‐type arrangement, where Cs⁺ and NH₃ occupy one half of the cation sites, each. Ba²⁺ is coordinated by four ozonide groups and two ammonia molecules. Because of a short hydrogen bond to one of the terminal oxygen atoms, the respective O–O‐distance in the ozonide ion is longer than the other. The shortest intermolecular O–O‐distance ever observed in ionic ozonides has been found in this compound, which can be taken as a first clue for the radical ozonide anion to dimerize like the isoelectronic SO₂^– does.     

Syntheses and Crystal Structures of a New Niobium Polysulfide K6Nb4S22 and two New Dimorphic Tantalum Polysulfides K6Ta4S22

The new compounds K₆Nb₄S₂₂ and K₆Ta₄S₂₂ ( I ) have been synthesised by the reaction of NbS₂ or Ta metal in a K₂S₃ flux. Using TaS₂ as educt a second modification of K₆Ta₄S₂₂ ( II ) is obtained. K₆Nb₄S₂₂ and K₆Ta₄S₂₂ (form I ) crystallise in the monoclinic space group C2/c with a = 35.634 (2)Å, b = 7.8448 (4)Å, c = 12.1505 (5)Å, β = 100.853 (5)°, V = 3335.8 (3)ų, and Z = 4 for K₆Nb₄S₂₂ and a = 35.563 (7) Å, b = 7.836 (2)Å, c = 12.139 (2)Å, β = 100.56 (3)°, V = 3325.5 (2)ų, and Z = 4 for K₆Ta₄S₂₂ ( I ). The second modification K₆Ta₄S₂₂ (form II ) crystallises in the monoclinic space group P2₁/c with a = 7.5835 (6)Å, b = 8.7115 (5)Å, c = 24.421 (2)Å, β = 98.733 (9)°, V = 1594.6 (2)ų, and Z = 2. The structures consist of [M₄S₂₂]^6— anions composed of two M₂S₁₁ sub‐units which are linked into M₄S₂₂ units via terminal sulfur ligands. The anions are well separated by the K⁺ cations. Differences between the structures of the title compounds and those with the heavier alkali cations Rb⁺ and Cs⁺ are caused by the different arrangement of the [M₄S₂₂]^6— anions around the cations and the different S^2—/S₂^2— binding modes. The thermal behaviour of both modifications was investigated using differential scanning calorimetry (DSC). From these investigations there is no hint for a polymorphic transition between the two forms. After heating crystals of form II above the melting point and cooling the melt to room temperature a crystalline powder of form I can be isolated.     

Über Chalkogenolate. 98 [1]. Kristall- und Molekülstruktur von Wolfram(IV)-äthylthioxanthat

On Chalcogenolates. 98. Crystal and Molecular Structure of Tungsten(IV) Ethylthioxanthate W[S₂C? SC₂H₅]₄ crystallizes with Z = 2 in the tetragonal space group P4₂/n with cell dimensions a = 11.108(5) Å and c = 9.489(5) Å. The crystal and molecular structure has been determined from single crystal X-ray data at ?160°C and refined to a conventional R of 0.058. The structure consists of isolated molecules. The tungsten atom is bonded to eight sulfur atoms from four chelating thioxanthate ligands. The coordination geometry approximates very closely to triangularly dodecahedral.     

Die Kristallstruktur des Tetracäsium-μ-oxo-decachlorodiosmat(IV), Cs4[Os2O Cl10]

Crystal Structure of Tetracäsium-μ-oxo-decachlordiosmate(IV), Cs₄[Os₂OCl₁₀] The anhydrous binuclear complex Cs₄[Os₂OCl₁₀] crystallizes with an orthorhombic unit cell, Pcab, a = 12.521, b = 13.994, c = 11.798 Å and Z = 4 formula units. The complex anion forms corner sharing octahedrons tetragonally deformed. The interatomic distances are Os ? O = 1.778 Å and Os ? Cl = 2.370 (4×) and 2.433 Å (1×) respectively. The Cs atoms are coordinated differently. The interatomic distances Cs ? Cl range from 3.46 to 3.87 Å. The structure is discussed in connection with analogous complexes. Details of other polynuclear complexes of Os are added.     

Metall-Schwefelstickstoff-Verbindungen. 16. Reaktionsprodukte von Blei- und Zinnsalzen mit S4N4 Die Strukturen von PbN2S2 · NH3, PbN2S2 und SnCl4 · 2S4N4

Metal Sulfur Nitrogen Compounds. 16. Products of the Reaction of Lead- and Tin Salts with S₄N₄. Structures of PbN₂S₂ · NH₃, PbN₂S₂, and SnCl₄ · 2S₄N₄ PbN₂S₂ · NH₃ is monoclinic, P2₁/a, a = 5.671, b = 16.123, c = 6.102 Å, β = 95.12°, Z = 4, PbN₂S₂, however, orthorhombic, P2₁2₁2₁, a = 4.375, b = 7.654, c = 12.274 Å, Z = 4. The planar five-membered PbN₂S₂ rings in both compounds show no remarkable differences. In PbN₂S₂ · NH₃, the NH₃ molecule is bound to Pb perpendicularly to the plane of the ring. The structure of the long known addition compound SnCl₄ · 2S₄N₄ was determined. It is orthorhombic, Pc2₁b, a = 11.467, b = 11.995, c = 12.374 Å, Z = 4. Sn shows sixfold coordination, the two S₄N₄ rings are attached to Sn trans to each other via a N atom.