Das erste „Lithovanadat”︁: K2{LiVO4}.

The First ?Lithovanadate”?: K₂{LiVO₄} By heating of well ground mixtures of the binary oxides [K₂O, Li₂O, V₂O₅, K:Li: V = 2.2:1.1:1.0; Ni-tube, 900°C, 46 d] colourless monoclinic single crystals of K₂[LiVO₄] have been prepared for the first time: space group C2/m; a = 835.7(1) pm, b = 774.5(1) pm, c = 753,3(1) pm, β = 90.23(1)°. The structure was determined by four-circle diffractometer data [MoKα, 1018 form 1262 I₀ (hkl), R = 8.65%, R_w = 5.67%], parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, have been calculated.     

Das erste Diniobat mit ‚isolierten’︁ Anionen: KLi4[NbO5]=K2Li8[Nb2O10]

The First Diniobate with ‘Isolated’ Anions: KLi₄[NbO₅]=K₂Li₈[Nb₂O₁₀] [1] . By heating of well ground mixtures of the binary oxides [K₂O, Li₂O, Nb₂O₅, K:Li:Nb=1.1:4.4:1, Pt-tube, 1100°C, 3d] colourless, triclinic single crystals of KLi₄NbO₅ have been prepared for the first time: space group P1 (Nr. 2) with a=816.9(2) pm, b=592.2(2) pm, c=589.7(2) pm, α=121.00(2)º, β=91.78(2)°, γ=99.23(2)°, Z=2. The crystal structure was solved by four-cycle diffractometer data [Mo-Kα , 1386 from 1386 I_o(hkl), R=3.4%, R_w=2.6%], parameters see text. Characteristic for this structure are “isolated” groups of [Nb₂O₁₀] and the tetrahedral coordination of Li(1), Li(2), and Li(3). Li(4) has a tetragonal-pyramidal coordination. The structural relations are deduced by Schlegel Diagrams. The Madelung Part of Lattice Energy, MAPLE, the Effective Coordination Numbers, ECoN and the charge distribution have been calculated and discussed.     

Zur Konstitution von ‚KPbO2’︁

On the Constitution of ‘KPbO₂’ Transparent, orangered single crystals of K₂Pb₂O₄ have been obtained by heating mixtures of K₂O₂ and PbO (K:Pb = 1:1) [Ag-cylinders, 560°C, 40 d, after cooling (15°C/h)]. The space group is P1 , a = 1295.94(9), b = 753.35(7), c = 697.12(8) pm, α = 118.00(1)°, β = 106.15(1)°, γ = 93.44(1)°, Z = 4, d_x = 6.573 und d_pyk = 6.54 g · cm³. The structure is characterized by rutilanalogous chains of edge-connected [PbO₆] octahedra along [001] according to [PbO_4/2O_2/1] = PbO₄. On both sides of such a chain there are respectively three O^2?, which belong to two octahedra, alternating capped with Pb²⁺ or not capped, corresponding to [PbO₄]Pb₂[PbO₄]□₂… = Pb₂O₄. Those capped chains are held together by K(1)…K(4), each of them with C.N. 6. The order of the chains corresponds to the motive of a closest packing. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated and discussed.     

Zur kenntnis ‚Kationen-reicher’︁ Tantalate und Niobate Über Na5TaO5 und Na5NbO5

On Tantalates and Niobates ‘rich in Cations’. On Na₅TaO₅ and Na₅NbO₅ Colourless, transparent single crystals of Na₅TaO₅ [annealed mixtures of Na₂O, Li₂O, and Ta₂O₅, Na : Li : Ta = 6.6 : 1.1 : 1, Ni-cylinder, 1000°C, 75 d] as well as Na₅NbO₅ [annealed mixtures of Na₂O, Li₂O, and Nb₂O₅, Na : Li : Nb = 6.6 : 1.1 : 1, Ni-cylinder, 1000°C, 75 d] have been prepared. Single crystal data show that both isotypic oxides represent a deformed variant of the NaCl-type of structure [Na₅TaO₅: 1154 from 1250 I₀ (hkl), four-cycle diffractometer Philips PW 1100, ω2-θ scan, Ag? Kα , R = 4.88%, space group c2/c with a = 629.3(1) pm, b = 1025.4(2) pm, c = 1004.6(2) pm, b? 106.80(2)°, z = 4 and Na₅NbO₅: 998 from 1247 I₀(hkl), four-cycle diffractometer Philips PW 1100, ω-2θ scan, Ag? Kα , R = 8.58% and R_w = 7.67%, space group C2/2 with a = 629.1(1) pm, b = 1024.4(2) pm, c = 1004.2(2) pm, b? = 106.80(2)°, Z = 4]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from Mean Effective Fictive Ionic Radii, MEFIR, as well as Charge Distribution, CHARDI, are calculated.     

Das erste „Litho-Manganat(V)”︁ mit Schichtstruktur: Cs2{Li[MnO4]}

The First “Litho-Manganate(V)” with Layer-Structure: Cs₂{Li[MnO₄]} By heating intimate mixtures of the oxides [CsO_1,2, Li₂MnO₃; Cs: Mn = 2,3 : 1; Ag-Zylinder, 580°C, 62 d] blue-green single crystals of Cs₂{Li[VO₄]} were obtained for the first time. The new “Litho-Manganate(V)” crystallices orthorhombic (SG: Cmc2₁) with a = 596.08(7), b = 1202.6(1), c = 816.8(1) pm (Guinier-Simon data), Z = 4. It is isotypic with Cs₂{Li[VO₄]} [1]. The structure was determined by four-circle-diffractometer data [Mo? Kα , for 496I_o(hkl) R = 3.1%, R, = 2.4%], parameters see text. The Madelung Part of Lattice Energie, MAPLE and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, MEFIR, are calculated and disscussed.     

Ein „Lithosilicat”︁ mit Kolumnareinheiten: RbLi5{Li[SiO4]}2

A “Lithosilicate” with Columnar Units: RbLi₅{Li[SiO₄]}₂ In order to prepare RbLi₃[SiO₄] single crystals of RbLi₅{Li[SiO₄]}₂ have been obtained for the first time by heating of a well ground mixture of the binary oxides RbO_0.68, LiO_0.5 and SiO₂ [Rb:Li:Si = 1.1:3.0:1.0; 600°C; 21 d] in tightly closed Ni tubes. The new “lithosilicate” crystallizes monoclinic (space group C2/m with a = 1563.1(2) pm, b = 635.4(1) pm, c = 776.3(1) pm, β = 90.53(1)°, Guinier-Simon powder data). The crystal structure was determined by four-cycle diffractometer data [Philips PW 1100, 1237 from 1609 I_o(hkl), Z = 4, R = 9.2%, R_w = 8.3%], parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, have been calculated.     

Zur Kenntnis ‘Kationen-reicher’ Tantalate Über Li7[TaO6]

On Tantalates ‘rich in Cations’ On Li₇[TaO₆] For the first time, colourless single crystals of Li₇[TaO₆] were grown by annealing intimate mixtures of Li₂O and Ta₂O₅ (Li:Ta = 7,7:1) in closed Ni-cylinders (1 000°C, 156 d). [Trigonal-rhomboedral with a = 535.8(1) pm, c = 1 507.3(3) pm, c/a = 2.81/Guinier-Simon-powder data; Z = 3. Space group R3 for the part Li(1)₆TaO₆ and presumably P3 for Li₇TaO₆, including Li(2)]. The crystal structure was solved by four-cycle-diffractometer data [Mo? Kα , 331 from 331 I_o(hkl), R = 1.99%, R_w = 1.96%], parameters see text. The positions of anions correspond to the motif of a hexagonal closest packing of spheres, obviously deformed (with MEFIR of O^2? space filling corresponds to 69.8% instead of expected 73.2%. 1/3 of the octahedron holes are ordered occupied by Ta and Li(2), 1/2 of the tetrahedral holes likewise ordered by Li(1). All polyhedra of coordination of the anions are trigonal prisms. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, as well as charge distribution ‘CHARDI’ are calculated and discussed.     

Ein Oxomanganat(V) neuen Typs: K11{Li[OMnO3]4}

An Oxomanganate(V) of New Type: K₁₁{Li[OMnO₃]}₄ By heating of well ground mixtures of the oxides [K₂O₂, LiMnO₄, K:Mn = 2.2:1, Ag-tube, 580°C, 30 d] blue-green tetragonal single crystals of K₁₁{Li[OMnO₃]₄} have been prepared for the first time: space group I4 2m; a = 787,18(7) pm, c = 1750.9(3) pm. The structure was determined by four-circle-diffractometer data [MoKα , 1236 from 1303 I_o(h kl), R = 3.9%, R_w = 3.1%], parameters see text. The Madelung Part of Lattice Energy, MAPLE, and the Effective Coordination Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, have been calculated.     

Über „Orthoindate”︁ der Alkalimetalle: Zur Kenntnis von K5[InO4]

A New ?Orthoindate”? of an Alkali Metal: K₅[InO₄] Hitherto unknown K₅[InO₄] was prepared by heating intimate mixtures of K₂O, In₂O₃ and elementar In (molar ratio 10.0 : 1.0 : 4.0) in closed Ni-cylinders (30 days, 500°C) in form of pale red, nearly colourless, transparent, single crystals. Same crystals were obtained by heating mixtures of K₂O, CdO and elementar In (molar ratio 3.1 : 1.0 : 1.0) in closed Ag-cylinders (30 days, 450°C), too. In this case we also found yellow-brown crystals of K₁₄[In₄O₁₃] [1]. Structure determination by four circle diffractometer data (MoKα, 15279 out 17454 I_o(hkl), R = 5.60%, R_w = 5.25%). Space group P1 with a = 1827.9 pm; b = 1694.4 pm; c = 1329.4 pm; α = 113.3°; β = 111.4°; γ = 105.2°; Z = 16. Characteristic feature of the structure are isolated [InO₄]^5?-tetraeder. The Madelung Part of Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and Charge Distribution, VADI, are calculated.     

“Fragmentierung” und “Aggregation” bei Bleioxiden Über das Oligooxoplumbat(IV) K2Li6[Pb2O8]

“Fragmentation” and “Aggregation” on Lead Oxides. On the Oligooxoplumbate(IV) K₂Li₆[Pb₂O₈] For the first time, the dinuclear Oxoplumbate(IV) K₂Li₆[Pb₂O₈] has been prepared as transparent colourless single crystals by heating mixtures of K₂PbO₃, Li₂O, and “PbO₂” with K:Li:Pb = 1:3:1 e. g. [Ag-cylinders, sealed under vacuum in Supremax-glass ampoule, 660°C, 120 d]. The structure determination verifies the space group P1 with a = 6.9720(9), b = 5.9252(6), c = 5.9312(7) Å, α = 88.05(1)°, β = 107.94(1)°, γ = 107.30(1)°; d_x = 4.95 g · cm^?3, d_pyk = 4.91 g · cm^?3; Z = 1, [2107 symmetry independent hkl, fourcircle-diffractometer Philips PW 1100, ω—2Θ—scan, MoKα, R = 5.07%, R_w = 4.59%, absorption not considered]. The structure is characterized by the group [Pb₂O₈] — two edge connected (equatorial/apical) trigonal bipyramids — that is observed for the first time. Several ways of synthesis are given. The Madelung Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these via Mean Effective Ionic Radii, MEFIR, are calculated.     

Über Oxide mit dem “Butterfly-Motiv”: Rb6[Fe2O5] und K6[Fe2O5]

New Oxides with the “Butterfly-Motive”: Rb₆[Fe₂O₅] and K₆[Fe₂O₅] Rb₆[Fe₂O₅] and K₆[Fe₂O₅] were obtained for the first time by annealing intimate mixtures of “Rb₆CdO₄” with CdO (molar ratio 1 : 1.1) and KO_0.48 with CdO (molar ratio 5.9 : 1) respectively in closed Fe-cylinders. Determination and refinement of the crystalstructure confirms the space group C2/m (four-circle-diffractometer data). Rb₆[Fe₂O₅]: Ag Kα , 720 out of 1220 Io(hkl), R = 9.68%, R_w = 6.09%; a = 718.9pm, b = 1183.1 pm, c = 695.4pm, β = 95.05°, Z = 2; K₆[Fe₂O₅]: MoKα , 1214 Out of 12141_o(hkl), R = 3.20070, R_w = 2.48%, a = 691.21 pm, b = 1142.78pm, c = 665.50pm, β = 93.82°, Z = 2. The binuclear unit [O₂FeOFeO₂]^6? already known to be planar with oxoferrates(II) now was observed to be angular here and closely related to Na₆[Be₂O₅].     

Synthese und Kristallstrukturen der Nitrido‐Chloro‐Molybdate [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 und [Li(12‐Krone‐4)(NMoCl4)]2 · 2 CH2Cl2

Syntheses and Crystal Structures of the Nitrido‐chloro‐molybdates [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ and [Li(12‐Crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ Both the title compounds as well as [Li(12‐crown‐4)₂]⁺MoNCl₄^– were made from MoNCl₃ and the chlorides MgCl₂ and LiCl, respectively, in dichloromethane suspensions in the presence of tetrahydrofuran and 12‐crown‐4, respectively. They form orange‐red moisture‐sensitive crystals, which were characterized by their IR spectra and partly by crystal structure analyses. [Mg(THF)₄{NMoCl₄(THF)}₂] · 4 CH₂Cl₂ ( 1 ): space group C2/m, Z = 2, lattice dimensions at –50 °C: a = 1736.6(1), b = 1194.8(1), c = 1293.5(2) pm; β = 90.87(1)°; R₁ = 0.037. In 1 the magnesium ion is coordinated octahedrally by the oxygen atoms of the four THF molecules and in trans‐position by the nitrogen atoms of the two [N≡MoCl₄(THF)]^– ions. [Li(12‐crown‐4)(NMoCl₄)]₂ · 2 CH₂Cl₂ ( 2 ): space group P 1, Z = 1, lattice dimensions at –70 °C: a = 930.4(1), b = 957.9(1), c = 1264.6(1) pm; α = 68.91(1)°, β = 81.38(1)°, γ = 63.84(1)°; R₁ = 0.0643. 2 forms a centrosymmetric ion ensemble in the dimeric cation of which, i. e. [Li(12‐crown‐4)]₂²⁺, the lithium ions on the one hand are connected to the four oxygen atoms each of the crown ether molecules in a way not yet known; and in addition, each of the lithium ions enters into a intermolecular Li–O bond with neighboring crown ether molecules under formation of a Li₂O₂ four‐membered ring. The two N≡MoCl₄^– counterions are loosely coordinated to one oxygen atom each of the crown ether molecules with Mo–O distances of 320.2 pm.     

Synthese,Kristallstrukturen und Absorptionsspektren der neuen „Cupriosilicate”︁: K6[CuSi2O8] und Rb4[CuSi2O7]

Synthesis, Crystal Structures, and Absorption Spectra of the New “Cupriosilicates”: K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] were obtained by annealing intimate mixtures of K₂O and Rb₂O, respectively, CuO and SiO₂ in sealed Ag cylinders at 500°C as transparent greenish-blue single crystals. The structure solution (IPDS-data Mo Kα; K₆[CuSi₂O₈]: 1292 F²(hkl), R1 = 0.059; wR2 = 0.103 and Rb₄[CuSi₂O₇]: 763 F²(hkl), R1 = 0.049; wR2 = 0.114) confirms the space group P1 for both compounds. K₆[CuSi₂O₈]: a = 619.4(2); b = 665.5(2); c = 753.0(2) pm; α = 83.66(3); β = 87.71(3); γ = 70.19(3)°; Z = 1. Rb₄[CuSi₂O₇]: a = 631.9(9); b = 707.5(10); c = 715.2(6) pm; α = 114.2(1); β = 100.7(1); γ = 107.9(1)°; Z = 1. The Madelung Part of the Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, these calculated via Mean Effective Ionic Radii, MEFIR, are given. The absorption spectra of K₆[CuSi₂O₈] and Rb₄[CuSi₂O₇] are discussed in terms of the Angular Overlap Model, AOM.     

Das erste zweikernige Oxoferrat(II): „Cs2K4[O2FeOFeO2]”︁

The First Binuclear Oxoferrate(II): ?Cs₂K₄[O₂FeOFeO₂]”? For the first time ?Cs₂K₄[Fe₂O₅]”? was obtained by annealing intimate mixtures of Cs₂O, K₂O, and CsFeO₂ (molar ratio Cs : K : CsFeO₂ 1.3 : 2.1 : 1) in a closed Fe-cylinder (74 d; 470°C) in the form of red single crystals. The structure determination (four-circle diffractometer, MoKα , 760 out of 857 I_o(h kl); R = 5.8%, R_w = 4.6%) confirms the space group C2/m; a = 707.4, b = 1138.5, c = 699.7 pm, β = 91.76°, Z = 2. Essential part of the structure is the binuclear, planar [O(1)₂Fe? O(2)? FeO(1)₂]^6? group which is for the first time observed with oxoferrates(II). Despite different space groups the crystal structure is related to that of Rb₂Na₄[Co₂O₅].     

Das erste Oxogermanat mit „Stuffed Pyrgoms”︁: CsNa3Li8{Li[GeO4]}4

The First Oxogermanate with “Stuffed Pyrgoms”: CsNa₃Li₈{Li[GeO₄]}₄ By heating the binary oxides CsO_0.52, NaO_0.45, LiO_0.5 and GeO₂ in the mol. ratio 1.24:1.4:6.7:3.9 (Ni tubes; 600°C/89 resp. 65 d) we obtained for the first time CsNa₃Li₈{Li[GeO₄]}₄ in form of pale yellow prisms as well as powder: space group I4/m (I. T. No. 87) with a = 1 120.73(5); c = 651.64(5) pm; Z = 2; (four circle diffractometer data; MoKα; 5 152 I_o(hkl); R = 1.7%; R_w = 1.6%), parameters see text. The structure determination confirmes its being isotypic with CsKNaLi₉{Li[SiO₄]}₄, CsKNa₂Li₈{Li[SiO₄]}₄ and RbNa₃Li₈{Li[SiO₄]}₄. The Madelung part of lattice energy (MAPLE), effective coordination numbers (ECoN), mean fictive ionic radii (MEFIR) and the charge distribution (CHARDI) are calculated.     

Das erste Titanat mit „Stuffed Pyrgoms”︁: RbNa3Li12[TiO4]4 = RbNa3Li8{Li[TiO4]}4

The First Titanate with ?Stuffed Pyrgoms”?: RbNa₃Li₁₂[TiO₄]₄ = RbNa₃Li₈{Li[TiO₄]}₄ By heating a well grounded mixture of the binary oxides Rb₂O, Na₂O, Li₂O, and TiO₂ [Rb:Na:Li:Ti = 1.1:3.1:12.5:4.0; 780°C, 41 d] we obtained RbNa₃Li₈{Li[TiO₄]}₄ as colourless platelike crystals. This first titanate with ?stuffed pyrgoms”? is isostructural with RbNa₃Li₈{Li[SiO₄]}₄, CsKNa₂Li₈{Li[SiO₄]}₄ and CsKNaLi₉{Li[SiO₄]}₄ [2]. The compound crystallizes tetragonal I4/m with a = 1 125.8(1) pm and c = 652.4(1) pm (Guinier-Simon-Data, Z = 2). The structure was determined by four-cyrcle-data (Siemens AED2, MoK) and leds to the residual values R = 3.7% and R_w = 3.1% (additional data see text). The Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN), Mean Fictive Ionic Raddii (MEFIR) and the Charge Distribution in Solids (CHARDI) are calculated and discussed.     

Alkalimetall‐Oxoantimonate: Synthesen,Kristallstrukturen und Schwingungsspektren von ASbO2 (A = K,Rb), A4Sb2O5 (A = K,Rb, Cs) und Cs3SbO4

Alkaline Metal Oxoantimonates: Synthesis, Crystal Structures, and Vibrational Spectroscopy of ASbO₂ (A = K, Rb), A₄Sb₂O₅ (A = K, Rb, Cs), and Cs₃SbO₄ The compounds ASbO₂ (A = K/Rb; monoclinic, C2/c, a = 785.4(3)/799.6(1) pm, b = 822.1(4)/886.32(7) pm, c = 558.7(3)/559.32(5) pm, β = 124.9(1)/123.37(6)°, Z = 4) are isotypic with CsSbO₂ and the corresponding bismutates. The structures of the antimonates A₄Sb₂O₅ (A = K/Rb: orthorhombic, Cmcm, a = 394.9(1)/407.34(7) pm, b = 1807.4(1)/1893.5(1) pm, c = 636.34(9)/655.60(8) pm, Z = 2) and Cs₄Sb₂O₅ (monoclinic, Cm, a = 1059.81(7) pm, b = 692.68(8) pm, c = 811.5(1) pm, β = 98.7(1)°, Z = 2) both contain the anion [O₂SbOSbO₂]^4–. Cs₃SbO₄ (orthorhombic, Pnma, a = 1296.1(1) pm, b = 919.24(8) pm, c = 679.95(6) pm, Z = 4) crystallizes with the K₃NO₄ structure type.     

Oxydation intermetallischer Phasen: K4{Na2[Tl2O6]} aus NaTl und K2O2

Oxidation of Intermetallic Phases: K₄{Na₂[Tl₂O₆]} from NaTl and K₂O₂ The hitherto unknown K₄{Na₂[Tl₂O₆]} was prepared in form of transparent, yellow single crystals from NaTl and KO_1,08 (molar ratio 1:1.3; sealed Ag-cylinder; 450°C, 30 d). The structure determination (four-circle diffractometer, MoKα, 1 280 out of 1 523 I_o(hkl), R = 5.75%, R_w = 4.58%) confirms the space group P2₁/c with a = 641.3 pm, b = 691.1 pm, c = 1188.5 pm, β = 95.69° and Z = 2. As characteristic building units of the structure there are doubles of tetrahedra of [Tl₂O₆] and [Na₂O₆]. The compound is isotypic with Cs₆[In₂O₆] and Rb₆[Tl₂O₆]. The Madelung Part of Lattice Energy, MAPLE, the Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and Charge Distribution, CHARDI, are calculated.     

Die Kristallstruktur von Ag2Ge2O5: Eine neuartige Gerüststruktur von Ge2O52−

Crystal Structure of Ag₂Ge₂O₅: A New Ge₂O₅^2? Network Structure Ag₂Ge₂O₅ was prepared from the binary oxides at high O₂ pressures. Single crystal X-ray diffraction work indicated monoclinic symmetry (P2₁/c; a = 1101.3(2); b = 1006.3(1); c = 1221.9(3) pm; ß = 94.6(1)°). The structure was determined by direct methods (3372 independent structure factors) and refined to a conventional R value of 0.084. A new Ge₂O₅^2? network structure was found with germanium coordinated octahedrally (­d(Ge—O) = 188,7 pm) and tetrahedrally (­d(Ge—O) = 175,9 pm), in equal proportions, by oxygen. The polyhedra share vertices and edges, thus forming a three dimensional channel system, which is occupied by Ag⁺ ions. The shortest Ag—Ag distance of 284 pm, like the pale yellow colour of the compound, indicates Ag⁺—Ag⁺ interaction.     

Die Oxoantimonate(III) Rb2Sb8O13 und Cs8Sb22O37: Neue Schicht‐ und Gerüststrukturen mit ‘Lone‐Pair’ ‐Kationen

The Oxoantimonates(III) Rb₂Sb₈O₁₃ and Cs₈Sb₂₂O₃₇: New Framework and Layer Structures with ‘Lone‐Pair’ Cations The oxoantimonates(III) Rb₂Sb₈O₁₃ and Cs₈Sb₂₂O₃₇ were synthezised from Sb₂O₃, the elemental alkali metals (A) and the hyperoxides (AO₂) at 500 °C. The crystal structures of Rb₂Sb₈O₁₃ (monoclinic, P2₁/m, a=743.7(12)pm, b=1724(3)pm, c=1380(2)pm, β=90.44(4) °, Z=4) and Cs₈Sb₂₂O₃₇ (monoclinic, Cc, a=1299.93(11)pm, b=719.87(6)pm, c=3089.9(3)pm, β=96.00(2) °, Z=2) exhibit complex layer (Rb) and framework oxoantimonate ions (Cs), with the Sb^III cation, due to its stereochemically active ‘lone‐pair’, in ψ‐tetrahedral (CN=3) to ψ‐trigonal‐bipyramidal (CN=4) coordination by O.