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.     

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.     

Ketten aus Ringen: K5{Li[Ge2O7]} — das erste „Litho-Digermanat”︁

Chains consisting of Rings: K₅{Li[Ge₂O₇]} — the First ‘Litho-Digermanate’ By heating of a well-ground mixture of the binary oxides KO_0.55, Li₂O and GeO₂ (K: Li: Ge = 6.1 : 2.2 : 2; Ni-tube; 600°C; 49 d) we obtained for the first time single crystals of K₅{Li[Ge₂O₇]}. This ‘lithodigermanate’ represents a completely new type of structure: monoclinic, space group P2₁/c, a = 624.9(2) pm, b = 1586.6(8) pm; c = 1058.3(6) pm and β = 109.38(4)°; Guinier-Simon data, Z = 4. The structure was solved by four-circle diffractometer data [Siemens AED II, Mo? Kα ; 2872 I_o(hkl); R = 4.5%, R_w = 3.3%], parameters see text. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, MEFIR, as well as charge distribution CHARDI, are calculated and discussed.     

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.     

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.     

Li10Si2PbIIO10 = Li20[(SiO4)4(OPbO2PbO)] — Das erste „gemischte”︁ Silicat-Plumbat(II)

Li₁₀Si₂Pb^IIO₁₀ = Li₂₀[(SiO₄)₄(OPbO₂PbO)] — The first ?mixed”? Silicate-Plumbate(II) Colourless crystals of Li₁₀Si₂PbO₁₀ were obtained by heating a well-ground mixture of LiPb, Li₂O₂ and ?SiO₂”? (deriving from Duran glas) in Ag-tubes (650°C; 60 d). The crystal structure was determined (four-circle diffractometer data, Mo? K, 1 474 I_o(hkl), R = 4.2%, R_w = 2.8%, parameters see text). The silicate-plumbate crystallizes monoclinic (space group C2/m; I. T. No. 12) with a = 2985.1(4); b = 610.6(6); c = 512.8(1) pm, β = 99.70(9)° (four-circle data), Z = 4. Further the Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN), the Mean Fictive Ionic Radii (MEFIR) and the Charge Distribution (CHARDI) are being calculated.     

Ein neues Oxogermanat: Li8GeO6 = Li8O2[GeO4]. (Mit einer Bemerkung über Li8SiO6 und Li4GeO4)

A New Oxogermanate: Li₈GeO₆ ? Li₈O[GeO₄] Transparent colourless single crystals of Li₈GeO₆(P6₃cm, a = 550.09(8), c = 1072.2(3) pm, Z = 2; 4-circle-diffractometer Siemens AED 2, MoKα; 326 I_o(hkl), R = 2.4%, R_w = 2.0%), have been prepared. As by-product we always got colourless isometric single crystals of Li₄GeO₄. For the first time we could grow single crystals of Li₈SiO₆ of suitable size and quality. Our structure refinement confirms the assumed structure model [2]: Li₈GeO₆ and Li₈SiO₆ are isotypic with Li₈CoO₆[3] (Li₈SiO₆: a = 542.43(8), c = 1062.6(2) pm, Z = 2; 4-circle-diffractometer Siemens AED 2, MoK_α; 306 I_o(hkl), R = 3.6%, R_w= 3.0%). The known crystal structure of Li₄GeO₄ [4] is confirmed and refined (Cmcm, a = 776.6(2), b = 735.7(3), c = 604.9(2) pm, Z = 4; 4-circle-diffractometer Siemens AED 2, MoKα, 298 I_o(hkl), R = 1.9%, R_w = 1.4%). The Madelung Part of Lattice Energy, MAPLE, and Effective coordination-Numbers, ECoN, these via Mean Fictive Ionic Radii, MEFIR, are calculated.     

Über Cs2Li2[GeO4]

About Cs₂Li₂[GeO₄] By heating of a well-ground mixture of the binary oxides CsO_0.55, Li₂O and GeO₂ (Cs:Li:Ge=2,6:2,2:1; Ni-tube; 600 °C; 49d) we got single crystals of Cs₂Li₂[GeO₄] for the first time. Cs₂Li₂[GeO₄] is isotypic to Rb₂Li₂[MO₄] [M = Si, Ti, Ge] [2] and Cs₂Li₂[MO₄] (M = Si, Ti) [3]: according to this Cs₂Li₂[GeO₄] crystallizes triclinic, in the spacegroup P1 with a = 968.7(4) pm, b = 586.0(2) pm, c = 571.4(2) pm, α = 92.71(4)°, β = 110.95(3)° and γ = 94.34(4)° (Guinier-Simon data), Z = 2. The structure was determined by four-circle diffractometer data (Ag? K_α ; 2381 I_o(hkl); R = 8,4%; R_w = 5.0%), parameters see text. Further the Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN) and the Mean Fictive Ionic Radii (MEFIR), have been calculated.     

Zwei neue Silicat-Chloride mit zweiwertigem Europium: LiEu3[SiO4]Cl3 und Li7Eu8[SiO4]4Cl7

Two New Silicate-Chlorides with Divalent Europium: LiEu₃[SiO₄]Cl₃ and Li₇Eu₈[SiO₄]₄Cl₇ LiEu₃[SiO₄]Cl₃ was prepared by reaction of LiCl with Eu₂SiO₄ and Li₇Eu₈[SiO₄]₄Cl₇ from Li with Eu₂O₃, SiO₂ and LiCl. The crystal structures of LiEu₃[SiO₄]Cl₃ (Pmna, a = 946.95(13); b = 699.52(8); c = 1 368.0(2) pm; Z = 4; R1 = 0.0325, R2_w = 0.0642) and Li₇Eu₈[SiO₄]₄Cl₇ (P2₁/c; a = 851.85(5); b = 948.62(7); c = 1 679.0(2) pm; β = 96.221(8)°; Z = 2; R1 = 0.0352, R2_w = 0.0744) were determined from four-circle diffractometer data. LiEu₃[SiO₄]Cl₃ contains [Li(SiO₄)₂] units and LiCl₆ octahedra while in Li₇Eu₈[SiO₄]₄Cl₇ larger ?lithosilicate”? groups are found. In both structures, the Eu²⁺ ions are coordinated mostly eightfold by O^2? and Cl^? ligands.     

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.     

Zwei Formen (A- und B-Typ) von Pr2Te[SiO4]

Two Types (A and B) of Pr₂Te[SiO₄] Two forms of praseodymium(III) telluride ortho-silicate (Pr₂Te[SiO₄]) are obtained as light green, transparent single crystals (A type: bricks, B type: needles, both unsensitive to hydrolysis) from a CsCl melt by reacting Pr, TeO₂ and SiO₂ in stoichiometric ratios (950 °C, 10 d) in evacuated silica tubes. A-Pr₂Te[SiO₄] crystallizes orthorhombically (Pbcm; a = 633.70(3), b = 724.42(4), c = 1125.13(8) pm; Z = 4) with alternatingly arranged monolayers {(Pr2)Te}⁺ and {(Pr1)[SiO₄]}^– parallel (001). Pr1 exhibits a coordination number of nine (6 O and 3 Te) while Pr2 has ten next neighbours (6 O and 4 Te), in which all the oxygen atoms are components of discrete ortho-silicate tetrahedra ([SiO₄]^4–), as also is the case in the B-type structure. The telluride anions show coordination numbers of seven (3 Pr1 and 4 Pr2). B-Pr₂Te[SiO₄] crystallizes monoclinically (P2₁/c; a = 989.90(7), b = 648.03(4), c = 870.68(6) pm, β = 94.307(8)°; Z = 4) with along [100] alternatingly sheethed double layers [{(Pr1)Te}₂]²⁺ and [{(Pr2)[SiO₄]}₂]^2–. This results in coordination numbers of eight (4 O and 4 Te) for Pr1, nine plus one (8 O and 1 + 1 Te) for Pr2, and five plus one (4 Pr1 and 1 + 1 Pr2) for Te. The almost 8% higher density of Pr₂Te[SiO₄] in the A-type structure (D_x = 6.45 g/cm³) compared to that of B-type Pr₂Te[SiO₄] (D_x = 5.98 g/cm³) is quite remarkable.     

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.     

Neue Alkalioxoarsenate (V) Zur Kenntnis von Rb2Li[AsO4] und Cs2Li[AsO4]

New Alkalioxoarsenates (V). On Rb₂Li[AsO₄] and Cs₂Li[AsO₄] By heating of well-grounded mixtures of the binary oxides (A₂O, Li₂O₂, and As₂O₃; A : Li : As = 2 : 1 : 1; Ni-tube, 550°C, 21 d; A = Rb, Cs) colourless single crystals of Rb₂Li[AsO₄] and Cs₂Li[AsO₄] were obtained for the first time. These new orthoarsenates(V) crystalize orthorhombic (space group C mc2₁? C, No. 36) with Z = 4. As expected they are isotypic with the according orthovanadates(V) [2] A₂Li[VO₄], A = Rb, Cs. The lattice constants of Rb₂Li[AsO₄]: a = 582.1(4) pm, b = 1171.1(7) pm, c = 792.4(5) pm and Cs₂Li[AsO₄]: a = 596.4(2) pm, b = 1223.4(2) pm, c = 819.7(3) pm were taken from Guinier-Simon powder data. The structure was determined by four-circle-diffractometer data [Siemens AED II, MoKα , 6290 I₀ (hkl), R = 3.5%, R_w = 3.2% to Rb₂Li[AsO₄]; 3518 I₀ (hkl), R = 2.8%, R_w = 2.6% to Cs₂Li[AsO₄]; parameters see text]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, these calculated via Mean Fictive Ionic Radii, MEFIR, as well as charge distribution CHARDI are calculated and discussed.     

Neue Vertreter des K2Li14[Pb3O14]-Typs Cs2Li14[Tb3O14] und K2Li14[Zr3O14] [1, 2]

Inhaltsübersicht. Erstmals wurden klar durchscheinende, orange-farbene Einkristalle von Cs₂Li₁₄[Tb₃O₁₄] aus Cs₂TbO₃ und Li₂O (Tb: Li = 1:5) dargestellt [550°C, 21 d, verschlossenes AuRohr]. Es liegt der K₂Li₁₄[Pb₃O₁₄]-Typ vor [Vierkreisdiffraktometerdaten, PW 1100, MoKä-Strahlung, 660 I_o(hkl), R = 4,8%, R_w = 3,4%, Immm, a = 1293,5(8), b = 792,6(3), c = 740,4(3) pm, Z = 2, d_rö = 4,65]. Ebenfalls neu wurde K₂Li₁₄[Zr₃O₁₄] in Form farbloser Einkristalle durch Tempern inniger Gemenge von K₂O, Li₂O und ZrO₂ (K: Li: Zr = 1:4:1,5) dargestellt [900°C, 14 d, geschlossene Ni-Bombe] und röntgenographisch untersucht. Die Strukturverfeinerung [612 I_o(hkl), Vierkreisdiffraktometerdaten, PW 1100, MoKα-Strahlung, R = 5,9%, R_w = 5,3%, Immm, a = 1244,6, b = 776,4, c = 724,3 pm, Z = 2] bestätigt die Isotypie mit K₂Li₁₄[Pb₃O₁₄]. Der Madelunganteil der Gitterenergie, MAPLE, Effektive Koordinationszahlen, ECoN, diese über Mittlere Effektive Ionenradien, MEFIR, wurden berechnet. Für die nun bekannten Vertreter dieses Typs wurde ein Isotypievergleich vorgenommen. New Compounds of the K₂Li₁₄[Pb₃O₁₄] Type: Cs₂Li₁₄[Tb₈O₁₄] and K₂Li₁₄[Zr₃O₁₄] For the first time Cs₂Li₁₄[Tb₃O₁₄] has been prepared as orange single crystals from Cs₂TbO₃ and Li₂O (Tb: Li = 1:5) [550°C, 21 d, sealed Au-Tube]. Structure Refinement [four-circle diffractometer data, PW 1100, MoKα radiation, 660 I_o(hkl), R = 4.8%, R_w = 3.4%, Immm, a = 1293.5(8), b = 792.6(3), c = 740.4(3) pm, Z = 2, d_rö = 4.65] confirms isotypy with K₂Li₁₄[Pb₃O₁₄]. K₂Li₁₄[Zr₃O₁₄] has also been prepared as colorless single crystals from K₂O, Li₂O, and ZrO₂ (K: Li: Zr = 1:4:1.5), [900°C, 14 d, closed Ni-cylinder] and investigated by x-ray [612 I_o(hkl), four-circle diffractometer data, PW 1100, MoKα radiation, R = 5.9%, R_w = 5.3%, Immm, a = 1244.6, b = 776.4, c = 724.3 pm, Z = 2]. The Madelung Part of Lattice Energy, MAPLE, and Effective Coordination Numbers, ECoN, the latter derived from Mean Effective Fictive Ionic Radii, MEFIR, are calculated. A detailed comparison of the structures is carried out.     

Neue Oxoferrate(III). Na2Li3[FeO4] und K2Li3[FeO4]

New Oxoferrates (III). Na₂Li₃[FeO₄] and K₂Li₃[FeO₄] . Na₂Li₃[FeO₄] and K₂Li₃[FeO₄] (transparent, pink or light yellow single crystals) have been prepared by heating mixtures of the oxides (Na:Li:Fe = 2.2:3.3:1; Ag-tube, 720°C, 27 d or K:Li:Fe = 2.2:3.3:1; analogous, 700°C, 40 d). Na₂Li₃[FeO₄] is isotypic with Na₂Li₃[GaO₄] (a = 832.2(1), b = 796.0(1), c = 656.3(1)pm, Pnnm) and K₂Li₃[FeO₄] with K₂Li₃[GaO₄] (a = 557.7(1), b = 880.6(1), c = 1101.8(2)pm, β = 111.51(2)°, P2₁/c). Four cycle diffractometer data: MoK_α, 525 out of 686 I₀(hkl), R = 9.36%, R_w = 5.97% or 1424 out of 1424 I₀(hkl), R = 8.45%, R_w = 5.66%. Parameters see text. The structures are characterized by calculations of the Madelung Part of Lattice Energy, MAPLE. The Effective Coordination Numbers, ECoN, which are calculated by means of Mean Fictive Ionic Radii, MEFIR, are compared with the analogous gallates.     

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 Oxydation intermetallischer Phasen: Die Oxoplumbate(II) K6[Pb2O5] [1] und K4[PbO3] [2]

On the Oxidation of Intermetallic Phases: The Oxoplumbates(II) K₆[Pb₂O₅] [1] and K₄[PbO₃] [2] Very pale yellow crystals of K₆[Pb₂O₅] were obtained by heating a wellground mixture of LiPb und K₂O₂ (K₂O₂: LiPb = 2.5:1) in Ag-tubes (550°C; 40 d). The crystal structure, triclinic, space group P1 , a = 1 326.7(6); b = 758.8(4); c = 637.0(3) pm; α = 92.17(3)°; β = 94.41(3)°; γ = 112.85(4)°; Z = 2 was determined (four-circle diffractometer data, Mo? K, 3 270 I_o(hkl), R = 8.0%, R_w = 3.5%, parameters see text). The pale yellow crystals of K₄[PbO3] were received by heating KPb and K₂O₂ (K₂O₂: KPb = 3.3:2) in Ni-tubes (450°C; 17 d). The crystal structure (orthorhombic, space group Pbca with a = 658.2(1); b = 1 131.8(4); c = 1 872.2(6) pm; Z = 8) was refined (four-circle diffractometer data, Mo? K, 2 003 I_o(hkl), R = 4.9%, R_w = 2.8%). The Madelung Part of Lattice Energy (MAPLE), Effective Coordination Numbers (ECoN), the Mean Fictive Ionic Radii (MEFIR) and the Charge Distribution (CHARDI) are being calculated for both oxides.     

Das erste quaternäre Oxostannat mit „Inselstruktur”︁: RbNa3[SnO4]

The First Quaternary Oxostannate with Isolated Anion Structure: RbNa₃[SnO₄] For the first time colourless single crystals of RbNa₃SnO₄ which are isotypic with NaLi₃SiO₄ and NaLi₃GeO₄ [2] have been prepared by heating e.g. a well ground mixture of RbSn and Na₂O₂ [Rb : Na = 1 : 4.0; 750°C; 21 d; Ni-tube]. The crystal structure was solved by four-cycle-diffractometer data [Siemens AED2; 1801 I₀(hkl); space group I4₁/a; Z = 16; a = 1279.57, c = 1510.85 pm; R = 5.7%; R_w = 4.4%]. Mean Fictive Ionic Radii, MEFIR, Effective Coordination Numbers, ECoN, and the Madelung Part of Lattice Energy, MAPLE, are calculated. The isotypism of the compounds mentioned above is compared graphically.     

Zur Existenz polynärer Oxide der Alkalimetalle mit einwertigen Cobalt bzw. Nickel [1, 2]

On the Existence of Polynary Oxides of the Alkali Metals with Monovalent Cobalt and Nickel For the first time we obtained RbNa₂NiO₂, KNa₂NiO₂, Na₃CoO₂ and K₃CoO₂ [RbNa₂NiO₂: Na₂NiO₂ + Rb₂O, Rb:Ni = 1.8:1, 600°C, 28 d, Ni-tube; KNa₂NiO₂: Na₂NiO₂ + K₂O, K:Ni = 1.8:1, 600°C, 20 d, Ni-tube; Na₃CoO₂: Na₂O + CoO: Na:Co = 8.8:1, 500°C, 20 d, Co-tube; K₃CoO₂: K₂O + CoO: K:Co = 4.4:1, 550°C, 20 d, Co-tube]. According to X-ray structure analysis of single crystals monovalent Co and Ni is present [always four-circle-diffractometer data, MoKα -radiation; RbNa₂NiO₂: AED 2, all 163 I_o(hkl), R = 3.4%, R_w = 1.9%, I4/mmm, a = 461.7(1), c = 973.6(3) pm, Z = 2; KNa₂NiO₂: AED 2, all 341 I_o(hkl), R = 5.6%, R_w = 3.5%, Cmma, a = 1 048.5(3), b = 626.8(1), c = 621.9(1) pm, Z = 4; Na₃CoO₂: PW 1 100, 517 of 568 I_o(hkl), R = 2.9%, R_w = 1.8%, P4₂/mnm, a = 940.0, c = 464.5 pm, Z = 4; K₃CoO₂: PW 1 100, all 940 I_o(hkl), R = 5.0%, R_w = 3.9%, Pnma, a = 1 190.0, b = 730.4, c = 604.1 pm, Z = 4]. All samples are red, the single crystals transparent. Two O^2? coordinate Ni¹⁺ and Co¹⁺, respectively, like a dumb-bell. Mean Fictive Ionic Radii, MEFIR, and Effective Coordination Numbers, ECoN, and Madelung part of lattice energy, MAPLE, are given.