Tetraammin-Lithium-Kationen zur Stabilisierung phenylsubstituierter Zintl-Anionen: Die Verbindung [Li(NH3)4]2[Sn2Ph4]

Tetraammine Lithium Cations Stabilizing Phenylsubstituted Zintl-Anions: The Compound [Li(NH₃)₄]₂[Sn₂Ph₄] Ruby-red, brittle single crystals of [Li(NH₃)₄]₂[Sn₂Ph₄] were synthesized by the reaction of diphenyltin dichloride and metallic lithium in liquid ammonia at ?35°C. The structure was determined from X-ray singlecrystal diffractometer data: Space group, P1 , Z = 1, a = 9.462(2) Å, b = 9.727(2) Å, c = 11.232(2) Å, α = 66.22(3)°, β = 85.78(3)°, γ = 61.83(3)°, R₁ (F ? 4σF) = 5.13%, wR₂ (F₀² ? 4σF) = 10.5%, N(F ? 4σF) = 779, N(Var.) = 163. The compound contains to Sb₂Ph₄ isosteric centres [Sn₂Ph₄]^2? as anions which are connected to rods by lithium cations in distorted tetrahedral coordination by ammonia. These rods are arranged parallel to one another in the b,c-plane, but stacked along [100].     

Zur Kenntnis der Oxocobaltate(II) Na4[CoO3], ein Nesocobaltat(II)

On the Knowledge of Oxocobaltates(II). Na₄[CoO₃], the First Nesocobaltate(II) Newly prepared transparent, blood red single crystals of Na₄[CoO₃] (Na₂O/?CoO’? Na:Co = 4.4:1, cobalt tube, 550°C, 20d, dry argon), crystallize triclinically, P1, a = 8.14₄, b = 6.22₀, c = 5.75₈ Å; α = 117.5, β = 89.9, γ = 111.2 (diffractometer data), Z = 2. There are carbonate-like, isolated [CoO₃] groups, respectively parameters and distances see text. 2358 symmetry independent reflections (automatical four cycle diffractometer PW 1100, Mo–Kα, graphite monochromator, 4° ? Θ ? 36°), R = 0.0597. The Madelung Part of the Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN and Mean Fictive Ionic Radii, MEFIR are calculated and discussed.     

Synthesis and Structure of [Sn4Se11]6–, [Sn2Se52–], and [Sn3Se72–] – Model Anions for the Solventothermal Reaction Pathway to Lamellar Selenidostannates(IV)

Reaction of A₂CO₃ (A = K, Rb) with Sn and Se in an H₂O/CH₃OH mixture at 115–130°C affords the isotypic selenidostannates(IV) A₆Sn₄Se₁₁ _. xH₂O (A = K, x = 8) 1 and 2 whose discrete [Sn₄Se₁₁]^6– anions each contain two corner‐bridged ditetrahedral [Sn₂Se₆]^4– species. Similar reaction conditions with A = Cs afford Cs₂Sn₂Se₅ _. H₂O ( 3a ) and Cs₂Sn₂Se₅ ( 3b ) in which such [Sn₂Se₆]^4– building blocks are connected through common Se atoms into infinite [Sn₂Se₅^2–] chains. The [Sn₃Se₇^2–] ribbons of (Et₄N)₂Sn₃Se₇ ( 4 ), formed by treating (Et₄N)I with Sn and Se in methanol at 130°C, can be regarded as resulting from the condensation of [Sn₂Se₅^2–] chains with molecular [SnSe₄]^4– anions. The anions [Sn₄Se₁₁]^6–, [Sn₂Se₅^2–], and [Sn₃Se₇^2–] represent the products of individual reaction steps on the potential condensation pathway of [Sn₂Se₆]^4– to the lamellar selenidostannates(IV) [Sn₄Se₉^2–] or [Sn₃Se₇^2–].     

K3Au5Pb: eine Schichtstruktur mit [AuAu3/2]-Gold-Tetraedern und [Pb2/2]-Blei-Ketten

K₃Au₅Pb: Layers of [AuAu_3/2] Gold Tetrahedra and [Pb_2/2] Lead Chains Silver coloured, brittle single crystals of K₃Au₅Pb were synthesized by reaction of potassium azide with gold sponge and lead powder at T = 920 K. The structure of the compound (space group Imma, Z = 4, a = 5.646(1) Å, b = 19.500(4) Å, c = 8.412(1) Å) was determined from X-ray single-crystal diffractometry data. The gold lead partial structure consists of layers of [AuAu_3/2] tetrahedra and [Pb_2/2] zigzag chains with four-bonded lead atoms which are connected to a framework structure via Au–Pb contacts. The potassium atoms occupy channels within the gold lead partial structure.     

Darstellung und Struktur der Tetrafluoroaurate(III) MI[AuF4] mit MI = Li,Rb

Synthesis and Structure of Tetrafluoroaurates(III) M^I[AuF₄] with M^I = Li, Rb Single crystal investigations on Rb[AuF₄], light yellow, confirm the tetragonal unit cell (K[BrF₄]-type) with a = 618.2(1) and c = 1191(1) pm, Z = 4, space group I 4/mcm-D (No. 140). Li[AuF₄], light yellow too, crystallizes monoclinic with a = 485.32(7), b = 634.29(8), c = 1004.43(13) pm, β = 92.759(12), Z = 4; space group P 2/c-C (No. 13). The structure of Li[AuF₄] is related to the Rb[AuF₄]-type of structure.     

K11[HSn(PWO34)2] · 27 H2O – Synthese und Struktur

K₁₁[HSn (PW O₃₄)₂] · 27 H₂O – Synthesis and Structure K₁₁[HSn (PWO₃₄)₂] · 27 H₂O 1 can be synthesized in an “one-pot reaction” from commercially obtainable educts (SnCl₂; Na₂HPO₄ · 7 H₂O, Na₂WO₄ · 2 H₂O) in high yields and has been characterized by elemental analysis, IR/Raman-, UV/Vis-spectroscopy as well as by X-ray crystal structure analysis. The example of 1 again demonstrates the validity of our working hypothesis, that polyoxometalates can be obtained by linking highly charged, transferable building blocks by cationic centres within the scope of an optimal charge control. For structural details see “Inhaltsübersicht”.     

Kristallstruktur und Eigenschaften von Calcium- und Strontiumhexathiodiphosphat(IV), Ca2P2S6 und Sr2P2S6, mit einem Beitrag zu Ca5P8 und Pb2P2S6

Crystal Structure and Properties of Calcium and Strontium Hexathiodiphosphate(IV), Ca₂P₂S₆ and Sr₂P₂S₆, with a Contribution on Ca₅P₈ and Pb₂P₂S₆ Ca₂P₂S₆ and Sr₂P₂S₆ were prepared from metal and a mixture of red phosphorus and sulfur (molar ratio M:P:S = 1:1:3) in 2 corundum crucibles inserted in quartz ampullae under vacuum (20 d 900°C). The compounds were obtained as colourless, crystalline powders containing single crystals. They crystallize in the Sn₂P₂S₆ (high temperature form) type structure (P2₁/c, Z = 2): Ca₂P₂S₆ a = 653.2(2)pm, b = 728.1(2)pm, c = 1110.1(4)pm, β = 124.00(4)°, d = 2.50(2); Sr₂P₂S₆ a = 664.3(2)pm, b = 755.7(3)pm, c = 1139.7(3)pm, β = 124.07(2)°, d = 2.97(2). The anions P₂S have staggered confirmation and are arranged with the motif of a cubic close-packing. Sr²⁺ is coordinated by 8S which form a twofold face-capped trigonal prism and belong to 4P₂S. Structure calculations clearly show that Pb₂P₂S₆ also crystallizes in P2₁/c and not in Pc [1]. Also, Raman- and IR-spectra of Ca₅P₈ were recorded at 20°C. The stretching vibrations of P were assigned in analogy to those of P₂S in alkaline earth hexathiodiphosphates(IV). The range of their frequencies (480 to 340 cm^?1) is essentially smaller and shifted to smaller values compared with P₂S in Ca₂P₂S₆ and Sr₂P₂S₆ (620 to 390 cm^?1). The symmetry of P is not D_3d but C_2h as in the case of P₂S.     

Rapid and Simple Isolation of the Crystalline Molybdenum-Blue Compounds with Discrete and Linked Nanosized Ring-Shaped Anions: Na15[MoMoO462H14(H2O)70]0.5 [MoMoO457H14(H2O)68]0.5 · ca. 400 H2O and Na22[MoMoO442H14(H2O)58] · ca. 250 H2O

The blue mixed-crystal title compound Na₁₅[MoMoO₄₆₂H₁₄ (H₂O)₇₀]_0.5[MoMoO₄₅₇H₁₄ · (H₂O)₆₈]_0.5 · ca. 400 H₂O ≡ Na₁₅[ 1 a ]_0.5[ 1 b ]_0.5 · ca. 400 H₂O 1 , which crystallizes in the triclinic space group P 1 (a = 30.785(2), b = 32.958(2), c = 47.318(3) Å, α = 90.53(1), β = 89.86(1), γ = 96.85(1)°, V = 47665(6) ų, Z = 2, D_calc = 2.149 g cm^–3), precipitates within one day when an acidic (pH ≈ 1) aqueous solution of sodium molybdate (because of the extremely high solubility of the reaction product used in relatively high concentration) is reduced by sodium dithionite. 1 contains hitherto unknown pure molybdenum-oxide based, nanosized, ring-shaped, crystallographically independent cluster anions of the type {Mo₁₅₄} 1 a and {Mo₁₅₂} 1 b , the lacunary-type analogue of 1 a . Using the same reducing agent but in the presence of a reagent with a high affinity to the specific {Mo₂}-type building unit (also a leaving group) of 1 a , such as formic acid, the compound Na₂₂[MoMoO₄₄₂H₁₄(H₂O)₅₈] · ca. 250 H₂O 2 (space group P 1, a = 24.724(1), b = 35.726(2), c = 44.608(3) Å, α = 93.25(1), β = 93.51(1), γ = 106.72(1)°, V = 37552(4) ų, Z = 2, D_calc = 2.401 g cm^–3) is obtained in which the giant rings, having four missing {Mo₂} units compared to 1 a , are linked to chains. Until now, similar chain-type compounds could only be obtained using a non-well-defined synthetic method.     

Trigonal kristallisierende Metall(II)-hexacyanoferrate(II)M2II[Fe(CN)6]

Trigonal Crystallizing Metal(II) Hexacyanoferrates(II) M₂^II[Fe(CN)₆] According to X-ray powder diagrams, Ca₂[Fe(CN)₆], Cd₂[Fe(CN)₆], Zn₂[Fe(CN)₆] · 2 H₂O, Pb₂[Fe(CN)₆] and the firstly described compounds Zn₂[Fe(CN)₆] · 2 NH₃ and Sn₂[Fe(CN)₆] crystallize trigonal containing one formula unit in the unit cell. Ca₂[Fe(CN)₆] and Cd₂[Fe(CN)₆] are belonging to the space group D—P3 1m, the other compounds to D—P3 m1. The latters are described as coordination polymers with a coordination number 4 for Zn and 3 for Sn and Pb, respectively.     

Dibrommethylsulfoniumsalze – Darstellung und Kristallstruktur [1]

Dibromomethylsulfoniumsalts — Preparation and Crystal Structure The salts CH₃SBrA^? (A^? = SbCl, AsF) were prepared by various routes and characterized by their Ramanspectra. CH₃SBrAsF crystallized in the monoclinic space group P2₁/c with a = 770,5(4) pm, b = 942,4(12) pm, c = 1329,3(14) pm, β = 100,28(6)°, Z = 4. Distances and bond angles in the cation are as expected.     

Cs4[Sc6C]Cl13 und Cs4[Pr6(C2)]I13 — zwei Beispiele für das fehlende Bindeglied bei der Verknüpfung der Baueinheiten [M6Z]XX

Cs₄[Sc₆C]Cl₁₃ and Cs₄[Pr₆(C₂)]I₁₃ — Two Examples for the Missing Link in the Connectivity of [M₆Z]X X Building Units Cs₄[Sc₆C]Cl₁₃ (tetragonal, I4₁/amd, a = 1 540.5(4), c = 1 017.9(7) pm, c/a = 0.661, Z = 4, R = 0.038, R_w = 0.026) and Cs₄[Pr₆(C₂)]I₁₃ (a = 1 804.9(3), c = 1 259.5(3) pm, c/a = 0.698, R = 0.106, R_w = 0.068) are obtained as green-black and blue-black single crystals with brass-like metallic lustre through metallothermic reduction of ScCl₃ and PrI₃, respectively, with cesium in the presence of carbon in sealed tantalum containers. The, overall, isotypic compounds contain isolated [Sc₆C] and [Pr₆(C₂)] clusters, respectively, that are surrounded by 18 halide (X) ligands (12 Xⁱ and 6 X^a; X = Cl or I). The connection is carried out via the motif [M₆Z]XXXX (M = Sc and Pr; Z = C and C₂, respectively) and is thereby the missing link of the motifs of connection for the composition A_x[M₆Z]X₁₃. Analogous interconnection of [TiO₆] octahedra is found in the anatase-type of structure of TiO₂.     

19F-NMR-spektroskopischer Nachweis und statistische Untersuchung zur Bildung der gemischten Clusteranionen [(Mo6ICl)F]2−, n = 0–7, und Darstellung von (TBA)2[(Mo6I)F]

¹⁹F NMR Spectroscopic Evidence and Calculation of the Statistical Formation of Mixed Cluster Anions [(Mo₆I Cl )F ]^2?, n = 0–7, and Preparation of (TBA)₂[(Mo₆I )F ] The octa-μ₃-iodo-hexafluoro-hexamolybdate(2?)ion [(Mo₆I)F]^2? is prepared for the first time. The system of the 21 innersphere mixed clusters (Mo₆ICl)⁴⁺, n = 0–7 is formed by exchange of innersphere bound Clⁱ against outersphere bound I^a on tempering solid [(Mo₆Cl)I] at 400°C. Prolonged tempering leads to increasing average n values of the mixture, which is converted into the tetrabutylammonium salt (TBA)₂[(Mo₆ICl)F]. Using increments of chemical shifts and integral peak intensities the 54 ¹⁹F-nmr signals of the 21 species (compound n = 8 is absent) are assigned and confirmed by the 2 D-¹⁹F/¹⁹F-COSY spectrum. From the measured intensities the distribution of the different compounds is determined and proves significant deviation from statistical occupation, revealing the preference of isomers with iodine atoms occupying edges of the innersphere cube and discrimination of those sharing diagonals of the faces. Moreover all compounds with n = 3 and 4 are present overaverage in comparison to the others.     

Darstellung,Schwingungsspektrum und Kristallstruktur von (n‐Bu4N)2[(W6Cl)F] · 2 CH2Cl2 und 19F‐NMR‐spektroskopischer Nachweis der gemischten Clusteranionen [(W6Cl)FCl]2–, n = 1–6

Synthesis, Vibrational Spectra, and Crystal Structure of ( n ‐Bu₄N)₂[(W₆Cl )F ] · 2 CH₂Cl₂ and ¹⁹F NMR Spectroscopic Evidence of the Mixed Cluster Anions [(W₆Cl )F Cl ]^2–, n = 1–6 The reaction of (n‐Bu₄N)₂[(W₆Cl)Cl] with CF₃COOH in dichloromethane gives intermediately a mixture of the cluster anions [(W₆Cl)(CF₃COO)Cl]^2–, n = 1–6. By treatment with NH₄F the outer sphere coordinated trifluoracetato ligands are easily substituted and the components of the series [(W₆Cl)FCl], n = 1–6 are formed and characterized by their distinct ¹⁹F NMR chemical shifts. An X‐ray structure determination has been performed on a single crystal of (n‐Bu₄N)₂[(W₆Cl)F] · 2 CH₂Cl₂ (orthorhombic, space group Pbca, a = 15.628(4), b = 17.656(3), c = 20.687(4) Å, Z = 4). The low temperatur IR (60 K) and Raman (20 K) spectra are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are f_d(WW) = 1.89, f_d(WF) = 2.43 and f_d(WCl) = 0.93 mdyn/Å.     

Die Kristallstruktur von Perowskiten ANiIIMVIO6. II. Das Sr2NiWO6

The Crystal Structure of Perovskites A Ni^IIM^VIO₆. II. Sr₂NiWO₆ The results of an X-ray single crystal study of the perovskite Sr[Ni^IIW^VI]⁽⁶⁾O₆, ordered in the octahedral sites, are given. While Sr[Ni^IITe^VI]⁽⁶⁾O₆ crystallizes in a monoclinically deformed structure of the perovskite (elpasolite) type, showing a phase transition to a tetragonal lattice at 675 °K, Sr[Ni^IIW^VI]⁽⁶⁾O₆ is tetragonal already at 298°K (space group: C; a = b = 5.559 Å; c = 7.918 Å; Z = 2). The Ni? O distances found for the tungsten compound are nearly identical with those of the tellurium perovskite. In contradiction to crystal field theory very different values of the ligand field parameter Δ (ca. 25%) are observed for these two compounds however. Obviously this effect is caused by the rather different kind of bonding within the NiO₆ polyhedra in the two compounds. On the basis of the structural results the Ni? O-bonding in the two perovskites is discussed in dependence of the next nearest cationic environment.     

Metallorganische Verbindungen der Lanthanoide. 111. Synthese und Charakterisierung kationischer Metallocen-Komplexe der Lanthanoide. Röntgenstrukturanalyse von [CpYb(THF)2][BPh4]

Organometallic Compounds of the Lanthanoids. 111. Synthesis and Characterization of Cationic Metallocene Complexes of the Lanthanoides. X-Ray Crystal Structure of [Cp Yb(THF)₂][BPh₄] Cationic organolanthanoide compounds [(C₅H₄R)₂Sm(THF)₂][BPh₄] (R = ^tBu ( 1 ), SiMe₃ ( 2 )), [PyrSm(THF)][BPh₄] ( 3 ) (Pyr* = NC₄H₂^tBu₂-2,5), [CpLn(THF)₂][BPh₄] (Cp* = C₅Me₅; Ln = Y ( 4 ), Yb ( 5 )), and [(C₅Me₄Et)₂ Ln(THF)₂][BPh₄] (Ln = Y ( 6 ), Sm ( 7 )) have been synthesized by oxidation of the divalent metallocenes [(C₅H₄R)₂Sm(THF)₂] (R = ^tBu, SiMe₃), [PyrSm(THF)], [CpYb(THF), and [(C₅Me₄Et)₂Sm(THF)] with Ag[BPh₄] and by protolysis of the lanthanoide alkyls [CpYMe(THF)], [CpYbCH(SiMe₃)₂], and [(C₅Me₄Et)₂LnCH(SiMe₃)₂] (Ln = Y, Sm) by [NEt₃H][BPh₄]. The ¹H- and ¹³C-NMR spectra of the new compounds are discussed. 5 crystallizes in the space group P2₁/c with a = 10.604(7), b = 21.749(3), c = 19.124(4) Å, β = 96.47(4)°, Z = 4 and V = 4383(3) ų (R = 0.0291 for 8517 observed reflections with F_o ≥ 4σ (F_o).     

Darstellung und Kristallstruktur von trans-(Ph4As)2[OsCl2(NCS)(SCN)], Schwingungsspektren und Normalkoordinatenanalyse

Preparation and Crystal Structure of trans-(Ph₄As)₂[OsCl₂(NCS) (SCN) ], Vibrational Spectra and Normal Coordinate Analysis By treatment of trans-[OsCl₂I₄]^2? with (SCN)₂ in dichloromethane a mixture of different linkage isomers is formed, from which trans-[OsCl₂(NCS)(SCN)]^2? has been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X-Ray structure determination on a single crystal of trans-(Ph₄As)₂[OsCl₂(NCS)(SCN)] (triclinic, space group P 1 , a = 12.505(5), b = 12.056(5), c = 19.833(5) Å, α = 108.047(5)°, β = 91.964(5)°, γ = 117.048(5)°, Z = 2) reveals that two cis-positioned Thiocyanate(N) groups are coordinated with Os? N? C angles of 172.1° and 173.0° and two cis-positioned Thiocyanate(S) groups are coordinated with Os? S? C angles of 106.9° and 108.7°. Using the molecular parameters of the X-Ray determination the low temperature (10 K) IR and Raman spectra of the (n-Bu₄N) salt of the linkage isomer are assigned by a normal coordinate analysis based on a modified valence force field. The valence force constants are f_d(OsN) = 1.63 and f_d(OsS) = 1.30 mdyn/Å. Taking into account the trans influence a good agreement between observed and calculated frequencies is achieved.     

Synthese und Kristallstruktur von [N(Hex)4][Cu2(CN)3]

Synthesis and Crystal Structure of [N(Hex)₄] [Cu₂(CN)₃] [N(Hex)₄][Cu₂(CN)₃] has been prepared by solvothermal reaction of CuCN with Tetra‐n‐hexylammoniumiodide in acetone. The crystal structure is built up by condensed (CuCN)₆ and (CuCN)₇ rings, forming a zeolith type cyanocuprate(I) framework [Cu₂(CN)₃^—]. Space group R3; α = 44.482(6), c = 21.283(4) Å, V = 36471(9) ų; Z = 9.     

Iodostannate mit polymeren Anionen: (Me3PhN)4 [Sn3I10], [Me2HN–(CH2)2–NMe2H]2 [Sn3I10] und [Me2HN–(CH2)2–NMe2H][Sn3I8]

Iodostannates with Polymeric Anions: (Me₃PhN)₄ [Sn₃I₁₀], [Me₂HN–(CH₂)₂–NMe₂H]₂ [Sn₃I₁₀], and [Me₂HN–(CH₂)₂–NMe₂H] [Sn₃I₈] The polymeric iodostannate anions in (Me₃PhN)₄ [Sn₃I₁₀] ( 1 ) and [Me₂HN–(CH₂)₂–NMe₂H]₂ [Sn₃I₁₀] ( 2 ) consist of Sn₃I₁₂‐trioctahedra, which share four common iodine atoms with adjacent units to form infinite layers in 1 and polymeric chains in 2 . In the anion of [Me₂HN–(CH₂)₂–NMe₂H] [Sn₃I₈] ( 3 ) distorted SnI₆ octahedra sharing common edges and vertices form a two‐dimensional network. (Me₃PhN)₄ [Sn₃I₁₀] ( 1 ): Space group C2/c (No. 15), a = 2406.9(2), b = 968.26(7), c = 2651.7(2) pm, β = 111.775(9), V = 5738.9(8) · 10⁶ pm³; [Me₂HN–(CH₂)₂–NMe₂H]₂ [Sn₃I₁₀] ( 2 ): Space group P2₁/n (No. 14), a = 1187.2(1), b = 1554.4(1), c = 1188.9(1) pm, β = 116.620(8), V = 1961.4(3) · 10⁶ pm³; [Me₂HN–(CH₂)₂–NMe₂H] [Sn₃I₈] ( 3 ): Space group P2₁/c (No. 14), a = 1098.9(2), b = 803.93(7), c = 1571.5(2) pm, β = 102.96(1), V = 1352.9(2) · 10⁶ pm³.     

NaAuIn2, ein ternäres Aurid mit ethananalogen In2Au6-Baueinheiten und [In2/2]-Ketten

NaAuIn₂, a Ternary Auride with Ethane Analogous In₂Au₆ Building Units and [In_2/2] Chains Silver coloured, brittle single crystals of NaAuIn₂ were synthesized by the reaction of NaN₃, gold-sponge and indium at 500°C. The structure was determined from X-ray single-crystal diffractometry data: space group Cmcm, Z = 4, a = 4.482(1) Å, b = 10.366(2) Å, c = 7.869(2) Å, R/R_w(w = 1) = 0.017/0.020, Z(F) ≥ 3σ(F) = 547 and N(var.) = 16. NaAuIn₂ crystallizes in the MgCuAl₂-structure type. Gold and indium form a framework structure. [AuIn_6/3] layers with trigonal prismatically coordinated gold are connected via In—In contacts along [010] which consist of ethane analogous In₂Au₆-building units. The In-partial structure consists of saw tooth like [In_2/2] chains along [001]. The sodium atoms occupy channel-like cavities within the Au—In framework structure.     

Cs5[Na{W4N10}]: The first framework nitridotungstate(VI)

Cs₅[Na{W₄N₁₀}] was prepared from a mixture of NaNH₂, CsNH₂ and tungsten powder (molar ration 1 : 10 : 4) at 700°C in autoclaves. After the reaction is finished the nitride is embedded in an alkali metal matrix. Dark red crystals were isolated by washing out the alkali metal with liquid ammonia at room temperature. The structure of Cs₅[Na{W₄N₁₀}] was solved by X-ray single crystal data: I4₁ (No. 80), Z = 4, a = 13.926(3) Å, c = 8.723(3) Å, Z(F) ≥ 3σ(F) = 1535, Z(Variables) = 63, R/R_w = 0.040/0.052. The compound is highly sensitive against moisture giving oxotungstates and ammonia. It contains a framework of tetrahedra [WNN_3/2^1.5?]. Sodium shares four terminal nitrogen ligands. Including sodium a distorted, β-cristobalite type arrangement [Na{W₄N₁₀}^5?] results. It contains caesium in all interstices formed by twelve nitrogen ligands in so-called Friauf polyhedra.