Synthese und Kristallstrukturen der Calcium‐Iridiumsilicide Ca3Ir4Si4 und Ca2Ir2Si

Synthesis and Crystal Structures of the Calcium Iridium Silicides Ca₃Ir₄Si₄ and Ca₂Ir₂Si The new compounds Ca₃Ir₄Si₄ und Ca₂Ir₂Si were prepared by reaction of the elemental components in sealed tantalum ampoules at 1200 °C. Their structures were determined from X‐ray single crystal data. Ca₃Ir₄Si₄(cubic, space group I4¯3m, a = 7.4171(2)Å, Z = 2) crystallizes with the Na₃Pt₄Ge₄ type structure. For Ca₂Ir₂Si (monoclinic, space group C2/c, a = 9.6567(5)Å, b = 5.8252(2)Å, c = 7.3019(4)Å, β = 100.212(2)°, Z = 4) a new structure was found. Chains of edge sharing, heavily distorted SiIr₄‐tetrahedra (Ir‐Si: 2.381 and 2.414Å) are connected via short Ir—Ir‐contacts (2.640Å) to form an open Ir/Si‐framework accommodating a three‐dimensional arrangement of calcium atoms (Ca—Ca: 3.413 ‐ 3.948Å).     

Synthese und Kristallstrukturen von α‐ und β‐Ba3(PS4)2 sowie von Ba3(PSe4)2

Synthesis and Crystal Structures of α‐, β‐Ba₃(PS₄)₂ and Ba₃(PSe₄)₂ Ba₃(PS₄)₂ and Ba₃(PSe₄)₂ were prepared by heating mixtures of the elements at 800 °C for 25 h. Both compounds were investigated by single crystal X‐ray methods. The thiophosphate is dimorphic and undergoes a displacive phase transition at about 75 °C. Both modifications crystallize in new structure types. In the room temperature phase (α‐Ba₃(PS₄)₂: P2₁/a; a = 11.649(3), b = 6.610(1), c = 17.299(2) Å, β = 90.26(3)°; Z = 4) three crystallographically independent Ba atoms are surrounded by ten sulfur atoms forming distorted polyhedra. The arrangement of the PS₄ tetrahedra, isolated from each other, is comparable with the formation of the SO₄^2? ions of β‐K₂SO₄. In β‐Ba₃(PS₄)₂ (C2/m; a = 11.597(2), b = 6.727(1), c = 8.704(2) Å; β = 90.00(3)°; Z = 2) the PS₄ tetrahedra are no more tilted along [001], but oriented parallel to each other inducing less distorted tetrahedra and polyhedra around the Ba atoms, respectively. Ba₃(PSe₄)₂ (P2₁/a; a = 12.282(2), b = 6.906(1), c = 18.061(4) Å; β = 90.23(3)°; Z = 4) is isotypic to α‐Ba₃(PS₄)₂ and no phase transition could be detected up to about 550 °C.     

Zur Kenntnis von BaTiVO4 und SrTiVO4

On BaTiVO₄ and SrTiVO₄ BaTiVO₄ and SrTiVO₄ were prepared in closed systems by solid state reactions. They crystallize with orthorhombic symmetry (BaTiVO₄: space group D-Pmnb; a = 5.889; b = 7.889; c ?10.397 Å; Z = 4; SrTiVO₄: space group D-P2¹,2¹,2¹,2¹; a = 5.855; b = 7.572; c = 10.012 Å; Z = 4) and belong to β-K₂SO₄-type. The ordered occupation of point positions by Ba²⁺ and Tl⁺ as well as the decrease in symmetry of SrTiVO₄ are discussed.     

Synthese und Kristallstruktur von Sr2Rh7P6

Synthesis and Crystal Structure of Sr₂Rh₇P₆ Single crystals of Sr₂Rh₇P₆ were obtained by reaction of the elements in molten lead at 1100 °C and investigated by X-ray methods. The compound crystallizes tetragonally (a = 11.080(2), c = 4.098(1) Å) and forms a crystal structure (P 4 2₁m; Z = 2) with ThCr₂Si₂ analogous units, which are linked with each other in a new way. Therefore the RhP₄ tetrahedra form bands of edge sharing chains parallel to [001] anstead of layers as in the ThCr₂Si₂ type structure. The arrangement enables a part of the P atoms to form short P–P distances of 2,26 Å and space for additional Rh atoms with a likewise distorted tetrahedral coordination of P atoms is obtained.     

Synthese und Kristallstrukturen neuer phosphorverbrückter bimetallischer Cluster der Elemente Quecksilber und Eisen

Synthesis and Crystal Structures of New Phosphorus‐bridged Bimetallic Clusters of the Elements Mercury and Iron The reaction of [Fe(CO)₄(HgX)₂] (X = Cl, Br) with P(SiMe₃)₂^tBu in the presence of tertiary phosphines and phosphinium salts leads to the ionic compounds [PPh₄]₂[Hg₁₂{Fe(CO)₄}₈(P^tBu)₄X₂] (X = Cl, Br) ( 1 , 2 ). If [Fe(CO)₄(HgX)₂] reacts with P(SiMe₃)₂^tBu the polymeric polynuclear complex [Hg₁₅{Fe(CO)₄}₃(P^tBu)₈Br₈]n ( 3 ) as well as the twenty mercury‐ and eight iron‐atoms containing [Hg₂₀{Fe(CO)₄}₈(P^tBu)₁₀X₄]‐clusters (X = Br, Cl) ( 4 , 5 ) are formed. The reaction of [Fe(CO)₄(HgX)₂] with LiPPh₂ yields to the phosphanido‐bridged [Hg₄{Fe(CO)₄}₂(PPh₂)₂Cl₂] ( 6 ), where as the use of LiP(SiMe₃)Ph leads to the diphosphinidene‐bridged cluster [Li(thf)₄]₂[Hg₁₀{Fe(CO)₄}₆(P₂Ph₂)₂Br₆] ( 7 ). The structures of the compounds 1–7 were characterized by X‐ray single crystal structure analysis.     

Synthese und Strukturaufklärung von SrBeLa2O5

A new compound of the formula SrBeLa₂O₅ was prepared by high temperature technique. Single crystal X-ray investigations led to orthorhombic symmetry (a=9.730,b=7.377,c=6.687 Å, space group: D _2h ¹⁶ -Pnma,Z=4). SrBeLa₂O₅ shows a typical tunnel structure of a three-dimensional connection of Sr, La/O-prisms, related to a distortedKgomé-network. The tunnels are occupied by La³⁺- and Be²⁺-ions. A detailed discussion of the polyhedra, their connection, and the statistical distribution of Sr²⁺ and La³⁺ within the trigonal O^2–-prisms are given.

     

Synthese und Kristallstruktur des ersten Oxonitridoborates — Sr3[B3O3N3]

Synthesis and Crystal Structure of the First Oxonitridoborate — Sr₃[B₃O₃N₃] The cyclotri(oxonitridoborate) Sr₃[B₃O₃N₃] was synthesized at 1450 °C as coarsely crystalline colourless crystals by the reaction of SrCO₃ with poly(boron amide imide) using a radiofrequency furnace. The structure was solved by single‐crystal X‐ray diffractometry (Sr₃[B₃O₃N₃], Z = 4, P2₁/n, a = 663.16(2), b = 786.06(2), c = 1175.90(3) pm, η = 92.393(1)°, R1= 0.0441, wR2 = 0.1075, 1081 independent reflections, 110 refined parameters). Besides Sr²⁺ there are hitherto unknown cyclic [B₃O₃N₃]^6— ions (B—N 143.7(10) — 149.1(9) pm, B—O 140.5(8) — 141.4(8) pm).     

Synthese und Kristallstrukturen ternärer Phosphide und Arsenide des Rhodiums und Iridiums

Ternary Phosphides and Arsenides of Rhodium and Iridium: Synthesis and Crystal Structures Single crystals of eight new compounds were prepared by heating mixtures of the elements in a lead flux. They were investigated by X‐ray methods. Ca₂Ir₁₂P₇ (a = 9.512(1), c = 3.923(1) Å)is an additional representative of the Zr₂Rh₁₂P₇ type structure, micro domains required refinements of the structural parameters in space group P6₃/m. Ca₅Rh₁₉P₁₂ (a = 12.592(1), c = 3.882(1) Å) and Ca₅Ir₁₉P₁₂ (a = 12.577(2), c = 3.954(1) Å) crystallize with the Ho₅Ni₁₉P₁₂ type structure (P6¯2m; Z = 1), whereas the compounds A₆Rh₃₀X₁₉ form a slightly modified structure of the Yb₆Co₃₀P₁₉ type. The lattice constants are: Ca₆Rh₃₀P₁₉: a = 15.532(1) Å, c = 3.784(1) Å Sr₆Rh₃₀As₁₉: a = 16.135(2) Å, c = 3.916(1) Å Eu₆Rh₃₀P₁₉: a = 15.566(1) Å, c = 3.821(1) Å Eu₆Rh₃₀As₁₉: a = 16.124(1) Å, c =5 3.903(3) Å Yb₆Rh₃₀P₁₉: a = 5 15.508(1) Å, c =5 3.770(1) Å Because one of the four non‐metal atoms, located on different crystallographic sites, is disordered along [001] micro domains are formed. Therefore the parameters were not refined in space group P6¯ (Yb₆Rh₃₀P₁₉ type), but in space group P6₃/m. The metal:non‐metal ratio of all compounds is in the range of 2:1. Accordingly most of the non‐metal atoms are coordinated by nine metal atoms, which form tricapped trigonal prisms. These polyhedra are combined with each other in a different way.     

Synthese und Kristallstrukturen von IMalnBr4 und NaInI4

Inhaltsübersicht. Einkristalle von NaInBr₄ und NaInI₄ erhält man aus Gemengen der binären Komponenten durch langsames Abkühlen der Schmelze. NaInBr₄ gehört zum NaAlCl₄-Typ: Orthorhombisch, P2₁2₁2₁, Z = 4; a = 1108,1(1); b = 1050,7(1); c = 676,1(1) pm. NaInI₄ ist isotyp mit LiAlCl₄: Monoklin, P2₁/c, Z = 4; a = 852,1(2); b = 766,1(2); c = 1558,3(3) pm; β = 92,65(2)°. In beiden Strukturen treten annähernd tetraedrische Baugruppen [InX₄]^– (X = Br, I) auf. Die Koordinationszahl von Na⁺ ist C.N. = 6 (NaInI₄; leicht verzerrt oktaedrisch) bzw. C.N. = 6+1+1 (NaInBr₄; verzerrtes, doppelt bekapptes Prisma). Synthesis and Crystal Structures of NaInBr₄ and NaInI₄ Single crystals of NaInBr₄ and NaInI₄ are obtained from mixtures of the binary components by slow cooling of the melts. NaInBr₄ belongs to the NaAlCl₄ type of structure: Ortho-rhombic, P2₁2₁2₁, Z = 4, a = 1108.1(1), b = 1050.7(1), c = 676.1(1) pm. NaInI₄ is isotypic with LiAlCl₄: Monoclmic, P2₁/c, Z = 4, a = 852.1(2), b = 766.1(2), c = 1558.3(3) pm, β = 92.65(2)°. Almost tetrahedral polyhedra [InX₄]^– (X = Br, I) are characteristic for both structures. The coordination number of Na⁺ is C.N. = 6 (NaInI₄; slightly distorted octahedron) and C.N. = 6+1+1 (NaInBr₄; distorted bicapped trigonal prism), respectively.     

Synthese und Kristallstruktur von Ba6ZnIn2Cl20

Synthesis and Crystal Structure of Ba₆ZnIn₂Cl₂₀ Colourless single crystals of Ba₆ZnIn₂Cl₂₀ are obtained from a 6 : 3 : 2 molar mixture of BaCl₂, ZnCl₂ and InCl₃ at 420 °C in a Pyrex ampoule. It crystallizes with the monoclinic space group P2₁/c (Z = 4) with a = 1957.8(2), b = 1014.69(8), c = 1778.7(2) pm, β = 110.94(1)°, in a new structure. Zn²⁺ is surrounded tetrahedrally and In³⁺ octahedrally by chloride ions. Half of the [InCl₆] octahedra are isolated from each other, the other half shares common edges to form [In₂Cl₁₀] double octahedra. Ba²⁺ has coordination numbers of eight and nine. There are chloride ions that do not belong to Zn²⁺ or In³⁺ so that the formula may be written as Ba₁₂Cl₁₀[ZnCl₄]₂[InCl₆]₂[In₂Cl₁₀].     

Verfeinerung der Kristallstruktur des Dicaesium-Tetraazido-Zinkates Cs2Zn(N3)4 und die Kristallstrukturen komplexer Zinkazide

Summary The crystal structure of dicesium-tetraazido-zincate, Cs₂Zn(N₃)₄, has been refined from single crystal X-ray-diffractometer data. The previously reported orthorhombic structure, consisting of isolated Zn(N₃)₄-tetrahedra was confirmed and improved lattice parameters and atomic distances were determined. The azide groups are asymmetric and the coordination of central nitrogen atoms to cesium was observed. A table of structure data and mean atomic distances for fourteen zinc-azide compounds is added and the structures are discussed.

Herrn Prof. Dr. Karl Torkar zum 70. Geburtstag gewidmet     

Synthese und Kristallstruktur von Sr3Ga2O5Cl2 und Sr3Fe1.18Al0.82O5Cl2

Solid state reactions, by using a flux, lead to the new compounds Sr₃Ga₂O₅Cl₂ (A) and Sr₃Fe_1.18Al_0.82O₅Cl₂ (B). By means of single crystal X-Ray determinations a monoclinic symmetry (space group C ₂ ² -P2₁, (A):a=9.569 (2) Å; (B):a=9.550 (2) Å,Z=4) was found. Both compounds are not isotypic to Sr₃Fe₂O₅Cl₂ but crystallize like Ba₃Fe₂O₅Cl₂.

     

Synthese,Charakterisierung und Kristallstrukturen von Tetraiodoferraten(III)

Preparation, Characterization, and Crystal Structures of Tetraiodoferrates(III) The extremely air and moisture sensitive tetraiodoferrates MFeI₄ with M = K, Rb and Cs have been synthesized by reaction of Fe, MI and I₂ at 300°C in closed quartz ampoules. The essentially more stable alkylammonium tetraiodoferrates NR₄FeI₄ with R = H, C₂H₅, n-C₃H₇, n-C₄H₉ and n-C₅H₁₁ can be obtained by reaction of Fe, NR₄I and I₂ in nitromethane. The Raman and UV/Vis-spectra of the black compounds show the existence of tetrahedral [FeI₄]^? ions in the structures. The crystal structure of the monoclinic CsFeI₄ (CsTlI₄ type, spgr P2₁/c; a = 7.281(1) Å; b = 17.960(3) Å; c = 8.248(2) Å; β = 107.35(15)°) is built up by tetrahedral [FeI₄]^? ions and CsI₁₁ polyhedra. The crystal structure of the orthorhombic (n-C₅H₁₁)₄NFeI₄ (spgr Pnna; a = 20.143(4) Å; b = 12.683(3) Å; c = 12.577(3) Å) contains tetrahedral [(n-C₅H₁₁)₄N]⁺ ions and [FeI₄]^? ions, respectively.     

Präparation und Strukturanalyse der Verbindungen Ba2Pb4F10Br2–xIx (x = 0–2) mit verwandten kristallchemischen Motiven aus der Fluoritund Matlockitstruktur

Preparation and Structure of the Compounds Ba₂Pb₄F₁₀Br_2–xI_x (x = 0–2) with Related Structure Motifs of the Fluorites and Matlockites Colourless single crystals of Ba₂Pb₄F₁₀Br_2–xI_x (x = 0–2) have been obtained under hydrothermal conditions (T = 250 °C, 10 d), starting from stoichiometric amounts of BaF₂, PbF₂, PbBr₂ and PbI₂. The compounds crystallize in the tetragonal space group P4/nmm (No. 129). A complete miscibility in the region x = 0–2 has been observed. The mixed crystals follow Vegard's rule. For the compounds with the composition Ba₂Pb₄F₁₀Br₂ (a = 5.9501(2) Å, c = 9.6768(10) Å, R[F² > 2σ(F²)] = 0.022, wR(F² all reflections) = 0.059), Ba₂Pb₄F₁₀Br_1.1I_0,9 (a = 5.9899(3) Å, c = 9.7848(5) Å, R[F² > 2σ(F²)] = 0.014, wR(F² all reflections) = 0.035) and Ba₂Pb₄F₁₀I₂ (a = 6.6417(3) Å, c = 9.9216(10) Å, R[F² > 2σ(F²)] = 0.023, wR(F² all reflections) = 0.049) complete structure analyses have been performed on the basis of single crystal diffractometer data. Microcrystalline single phase compounds Ba₂Pb₄F₁₀Br_2–xI_x (x = 0–2) have been obtained by coprecipitation from aqueous solutions of KF, KBr (KI) and Ba(CH₃COO)₂, Pb(NO₃)₂ in acetic acid medium. For Ba₂Pb₄F₁₀Br_1.5I_0.5 and Ba₂Pb₄F₁₀Br_0.5I_1.5 powder data of microcrystalline samples were used for the Rietveld analyses (R_Bragg = 0.077 for Ba₂Pb₄F₁₀Br_1,5I_0,5 and R_Bragg = 0.065 for Ba₂Pb₄F₁₀Br_0.5I_1.5). The crystal structure comprises alternating structural features of fluorite related type (CaF₂) around Ba and matlockite related type (PbFCl) around Pb1 and Pb2 along the c axis. Barium shows a {8 + 4} cuboctahedral coordination of fluorine. The coordination polyhedron around the two crystallographically independent lead atoms is a monocapped quadratic antiprism built of {4 + 1} fluorine and {4} bromine or iodine atoms, respectively.     

Solvothermale Synthese und Bestimmung der Kristallstrukturen von AgBiI4 und Ag3BiI6

Solvothermal Synthesis and Crystal Structure Determination of AgBiI₄ and Ag₃BiI₆ AgBiI₄ and Ag₃BiI₆ were synthesized by solvothermal reaction from AgI and BiI₃ in diluted HI‐solution (20 %) at a temperature of 160 °C. The greyish‐black crystals grow as octahedra (AgBiI₄) or hexagonal/trigonal platelets (Ag₃BiI₆). AgBiI₄ crystallizes in space group Fd3¯m with a = 1222.3(1) pm (300 K) and Z = 8 whereas Ag₃BiI₆ shows the space group R3¯m with a = 435.37(6) pm, c = 2081.0(4) pm (300 K) and Z = 1. Both crystal structures show stacking sequence abcabc… of hexagonal layers containing Iodine. Bismuth and silver are sharing octahedral sites with different mass ratio in both structures. The part of silver which could be localized varies with temperature. This behaviour indicates mobility of silver within the crystal structure. The ionic conductivity of AgBiI₄ is explored. AgBiI₄ and Ag₃BiI₆ show close structural relationship, with AgBiI₄ as a variant with a higher degree of order.     

Synthese,Eigenschaften und Kristallstrukturen von Magnesium-Diazadien-Komplexen

Synthesis, Properties and Crystal Structures of Magnesium Diazadiene Complexes Reactions of phenyl-substituted 1,4-diaza-1,3-butadienes (DAD) RN?CPh? CPh?NR (R = C₆H₅) 1a , C₆H₄-4-CH₃ 1b , C₆H₄-4-OCH₃ ( 1c ) with magnesium in dimethoxyethan lead to complexes of the type [Mg(DAD)₂(DME)] 2a–c , with DAD ligands in form of radical anions. Furthermore, highly reactiv complexes of the composition [Mg(DAD)(DME)₂] 3a–c could be obtained. The crystal structures of 2a, 3a and 3c were determined.     

Synthese und Kristallstrukturen der Phosphaniminato-Komplexe [SnI(NPPh3)]2 und [SnI3(NPPh3)]2

Synthesis and Crystal Structures of the Phosphoraneiminato Complexes [SnI(NPPh₃)]₂ and [SnI₃(NPPh₃)]₂ The phosphoraneiminato complex of the divalent tin, [SnI(NPPh₃)]₂ ( 1 ), originates from the reaction of metallic tin with N-iodine triphenylphosphaneimine, INPPh₃, in dichloromethane suspension. 1 forms yellow, moisture sensitive crystals, which can be converted into the red phosphoraneiminato complex of the tetravalent tin, [SnI₃(NPPh₃)]₂ ( 2 ), by oxidation with iodine. According to the crystal structure analyses 1 and 2 have centrosymmetric dimeric molecular structures in which the tin atoms are linked via the N atoms of the NPPh₃^– groups. The tin atoms in 1 have a ψ-tetrahedral coordination, those in 2 a trigonal-bipyramidal one. 1 : Space group P 1, Z = 1, lattice dimensions at –80 °C: a = 779.0(1), b = 1080.1(1), c = 1170.4(1) pm, α = 64.49(1)°, β = 88.42(1)°, γ = 79.13(1)°, R = 0.0293. 2 : Space group P2₁/n, Z = 2, lattice dimensions at –80 °C: a = 1252.4(1), b = 1421.3(3), c = 1260.1(1) pm, β = 108.50(1)°, R = 0.0518.     

Synthese und Kristallstruktur von K2Mn3S4

Synthesis and Crystal Structure of K₂Mn₃S₄ Single crystals of K₂Mn₃S₄ have been prepared by a fusion reaction of potassium carbonate with manganese in a stream of hydrogen sulfide at 900 °C. K₂Mn₃S₄ crystallizes in a new monoclinic layered structure type (P2/c, a = 7.244(2) Å, b = 5.822(1) Å, c = 11.018(5) Å, β = 112.33(3)°, Z = 2) which can be described as a stacking variant of the orthorhombic Cs₂Mn₃S₄ structure type. Measurements of the magnetic susceptibilities show antiferro‐magnetic interactions.     

Die Kristallstrukturen der Phosphanimin‐Komplexe [NaI(HNPPh3)3] und [SrI2(HNPPh3)2(THF)2] sowie des Natrium‐triphenylphosphaniminats [NaNPPh3]6

Crystal Structures of the Phosphaneimine Complexes [NaI(HNPPh₃)₃] and [SrI₂(HNPPh₃)₂(THF)₂], as well as of Sodium Triphenylphosphoraneiminate [NaNPPh₃]₆ [NaI(HNPPh₃)₃] ( 1 ) has been obtained as yellow, moisture sensitive crystals as an intermediate product of the synthesis of sodium triphenylphosphoraneiminate, [NaNPPh₃]₆ ( 2 ) from Ph₃PI₂ and sodium amide in liquid ammonia. Correspondingly, colourless crystals of [SrI₂(HNPPh₃)₂(THF)₂] ( 3 ) are formed from strontium amide and Ph₃PI₂ in liquid ammonia and subsequent recrystallisation of the primary product [SrI₂(HNPPh₃)₄] from thf solution. The complexes 1 – 3 are mainly characterized by crystal structure determinations. 1 · 0,5 thf: space group P3c1, Z = 4, lattice dimensions at 193 K: a = b = 1533.2(1); c = 2545.6(1) pm, R = 0.0417. 1 has a molecular structure in which the sodium atom is tetrahedrally coordinated by the iodine atom with a distance of 315.9 pm and by the nitrogen atoms of the three HNPPh₃ molecules with a distance of 238.9 pm. 2 · C₇H₈: space group P1, Z = 1, lattice dimensions at 213 K: a = 1457.1(1), b = 1484.9(1), c = 1502.7(1) pm; α = 116.32(1)°, β = 115.358(10)°, γ = 93.585(14)°; R = 0.0520. 2 has a molecular structure in which the six sodium atoms and the six nitrogen atoms of the (NPPh₃^–) groups form a hexagonal prism with approximate D_3d symmetry. 3 · 2 thf: space group P1, Z = 2, lattice dimensions at 193 K: a = 1042.9(1), b = 1337.4(1), c = 2095.1(1) pm; α = 90.130(8)°, β = 96.310(8)°, γ = 111.985(8)°; R = 0.0310. 3 has a molecular structure in which the strontium atom is octahedrally coordinated by the iodine atoms, by the nitrogen atoms of the HNPPh₃ molecules and by the oxygen atoms of the thf molecules, all ligands being in trans‐position to one another.     

Das Zintl-Konzept als Syntheseprinzip: Darstellung und Kristallstrukturen von K2Ba3Sb4 und KBa4Sb3O

Starting from the Zintl-Concept: Syntheses and Crystal Structures of K₂Ba₃Sb₄ and KBa₄Sb₃O The black, metallic lustrous, air sensitive compounds K₂Ba₃Sb₄ and KBa₄Sb₃O were prepared from melts of mixtures of the elements, in case of KBa₄Sb₃O with a stoichiometric amount of Sb₂O₃. K₂Ba₃Sb₄ crystallizes in the orthorhombic system, space group Pnma (a = 870.5(1) pm, b = 1770.2(2) pm, c = 923.6(1) pm, Z = 4) and is the first Sb compound with only [Sb₂]^4– dumbbells in the anionic partial structure. The compound KBa₄Sb₃O crystallizes in the tetragonal system, space group I4/mcm (a = 882.4(1) pm, c = 1659.4(2) pm, Z = 4). In this structure antimony forms [Sb₂]^4–-dumbbells and isolated ions Sb^3–. Each antimony ion of the dumbbells – in K₂Ba₃Sb₄ as well as in KBa₄Sb₃O – is coordinated in form of a bicapped skew trigonal prism. The isolated Sb^3– ions in KBa₄Sb₃O center bicapped tetragonal antiprisms, the O^2– ions occupy tetrahedral voids.