Na4[PbO4] — Darstellung neuer Plumbate(IV) durch Oxydation intermetallischer Phasen

Na₄[PbO₄] — Preparation of new Plumbates(IV) by Oxidizing Intermetallic Phases By oxidizing NaPb with Na₂O₂ (molar ratio Na₂O₂:NaPb = 2.04:1; Ag-tubes; 600°C/50d) we obtained for the first time small orange coloured single crystals of Na₄[PbO₄]: Na₄[SiO₄]-type [2], P? 1 (I.T. No. 2) with a = 898.5(3); b = 675.6(3); c = 592.2(2) pm; α = 124.75(1)°; β = 96.75(1)°; γ = 100.18(2)°; Z = 2; (four circle diffractometer data (MoK; 3 251 I_o(hkl); R = 3.4%; R_w = 3.0%), parameters see text. Furthermore the Madelung part of lattice energy (MAPLE), effective coordination numbers (ECoN), mean fictive ionic radii (MEFIR) and the charge distribution (CHARDI) are being calculated.     

Zur Kristallstruktur von KGaO2 und NaGaO2(II) [1]

The Crystal Structure of KGaO₂ and NaGaO₂(II) By annealing intimate mixtures of K₂O, Na₂O and β-Ga₂O₃ (K : Na : Ga = 2.2 : 1.1 : 1) we obtained single crystals of K₂Na₄[(GaO₃)₂] and KGaO₂ (Ag-cylinder; 600°C, 26 d). Structure refinement for KGaO₂ (four-circle diffractometer data, Mo-Kα , 1 390 or 1 390 I_o(hkl); R = 5.55%, R_w = 3.05%) confirms the space group Pbca; a = 552.1 pm, b = 1 107.5 pm, c = 1 580.7 pm, Z = 16. According to K[GaO_4/2] we have a stuffed cristobalite-related structure. Single crystals of NaGaO₂(II) were grown by annealing intimate mixtures of Na₂O₂ and GaAs (Na₂O₂ : GaAs 4.1 : 1) in Ag-cylinders that were not completely closed (570°C, 6 weeks). Structure refinement for NaGaO₂(II) (four-circle diffractometer data, Mo-Kα , 588 of 616 I_o(hkl); R = 4.54%, R_w = 4.06%) confirms the spacegroup Pna2₁; a = 549.8(1) pm, b = 720.6(1) pm, c = 529.8(1) pm, Z = 4. In NaGaO₂(II) we have a wurtzite-related structure.     

Neue Silicate mit „Stuffed Pyrgoms”︁: CsKNaLi9{Li[SiO4]}4, CsKNa2Li8{Li[SiO4]}4, RbNa3Li8{Li[SiO4]}4 [1] und RbNaLi4{Li[SiO4]}2 [2]

More Silicates with ?Stuffed Pyrgoms”?: CsKNaLi₉{Li[SiO₄]}₄, CsKNa₂Li₈{Li[SiO₄]}₄, RbNa₃Li₈{Li[SiO₄]}₄ [1] and RbNaLi₄{Li[SiO₄]}₂ [2] Single crystals of the new silicates CsKNaLi₉{Li[SiO₄]}₄, CsKNa₂Li₈{Li[SiO₄]}₄, RbNa₃Li₈{Li[SiO₄]}₄ and RbNaLi₄{Li[SiO₄]}₂ as well as powder (Rb-containing compounds only) were obtained for the first time. The samples were prepared by heating well ground mixtures of the binary oxides in Ni and Ag tubes, respectively. The structure determination was carried out by four-circle diffractometer data (MoKα radiation; Siemens AED 2): CsKNaLi₉{Li[SiO₄]}₄: tetragonally prismatic crystals, light yellow; 726 I₀(hkl), R = 4.4%, R_w = 2.8%; a = 1 102.0(6), c = 637.9(5) pm; Z = 2; space group I4/m; 2 CsO_0.55 + Li₄TlO₄ + glas (560°C, 15 d). CsKNa₂Li₈{Li[SiO₄]}₄: tetragonally prismatic crystals, light yellow; 727 I₀(hkl), R = 4.4%, R_w = 2.6%; a = 1 103.5(7), c = 637.7(4) pm; Z = 2; space group I4/m; 1.1 CsO_0.61 + 1.1 KO_0.55 + 1.4 NaO_0.52 + 6.5 Li₂O + 4 SiO₂ (600°C, 60 d). RbNa₃Li₈{Li[SiO₄]}₄: tetragonally prismatic crystals, colourless; 600 I₀(hkl), R = 2.3%, R_w = 2.0%; a = 1 092.08(6), c = 632.76(4) pm; Z = 2; space group I4/m; 4 RbO_0.57 + 3 NaO_0.52 + 6.5 Li₂O + 4 SiO₂ (650°C, 63 d). RbNaLi₄{Li[SiO₄]}₂: monoclinic, ball-shaped, colourless; 1 224 I₀(hkl), R = 3.1%, R_w = 3.1%; a = 1 573.10(13), b = 630.48(5), c = 781.25(8) pm, b = 90.566(8)°; Z = 4; space group C2/m; 1.1 RbO_0.52 + 1.2 NaO_0.45 + 5 Li₂O + 4 SiO₂ (700°C, 40 d).     

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.     

Preparation and Crystal Structure of Potassium Iron Hydrogen Phosphate,KFe3(HPO4)2(H2PO4)6 · 4 H2O

Single crystals of potassium iron hydrogen phosphate, KFe₃(HPO₄)₂(H₂PO₄)₆ · 4 H₂O, were prepared hydrothermally by heating a mixture of Fe₂O₃, H₃PO₄ and K₂CO₃ with a small amount of water. It crystallizes monoclinic, space group C2/c (N° 15 Int. Tab.) with Z = 4 and a = 1701(2), b = 960.4(5), c = 1750(1) pm, β = 90.88(7)°. The crystal structure was solved by using 1716 unique reflections F₀ > 4σ(F₀) with a final wR2 value of 0.126 (SHELXL-93). The main feature of the crystal structure are layers formed by PO₄-tetrahedra around the FeO₆-octahedra parallel to (001). K⁺ and H₂O molecules connect these layers. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), Charge Distribution (CHARDI) and the Madelung Part of Lattice Energy (MAPLE) are calculated for the title compound. The existence of hydrogen bonds is confirmed by these calculations.     

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.     

Darstellung und Kristallstruktur von K6[Al2O6] und Rb6[Al2O6]

Preparation of Crystal Structure of K₆[Al₂O₆] and Rb₆[Al₂O₆] Colourless single crystals of K₆[Al₂O₆] have been prepared from intimate mixtures of KAlO₂ and K₂O (550°C, 90 d). The structure determination from four-circle diffractometer data (MoKα , 742 I_o(hkl), R = 2.2%, R_w = 2.1%) confirms the space group C2/m with Z = 2; a = 698.25 pm, b = 1 103.54 pm, c = 646.49 pm, β = 102.49°. Colourless single crystals of hitherto unknown Rb₆[Al₂O₆] have been prepared from intimate mixtures of RbAlO₂ and Rb₂O (520°C, 120 d). The structure determination from four-circle diffractometer data (MoKα , 1 240 I_o(hkl)) results in the residual values R = 7.2%, R_w = 4.9%; space group C2/m; a = 725.92 pm, b = 1 143.33 pm, c = 678.06 pm, β = 104.05°; Z = 2. K₆[Al₂O₆] and Rb₆[Al₂O₆] are isostructural with K₆[Fe₂O₆]. A characteristic structure unit is the anion [Al₂O₆]^6? consisting of two edge-sharing [AlO₄] tetrahedra. Effective Coordination Numbers (ECoN), Mean Fictive Ionic Radii (MEFIR), the Madelung Part of Lattice Energy (MAPLE) and the Charge Distribution (CHARDI) are calculated and discussed.     

Das erste gemischt-valente Oxocobaltat(I,II): Rb5Co2O4 [1]

A New Mixed-Valent Oxide of Cobalt(I, II): Rb₅Co₂O₄ For the first time we obtained a new mixed-valent oxide of mono- and divalent Cobalt. Black-red single-crystals of Rb₅Co₂O₄ were prepared by heating powders of “Rb₆CdO₄” in closed Co-cylinders at 500° during 48 days. Structure solution and refinement are covered by two measurements with four-circle diffractometers. MoKα : 2 145 I_o(hkl), out of 2 818 I_o(hkl), R = 9.85%, R_w = 5.93% AgKα : 1 813 I_o(hkl) out of 4 007 I_o(hkl), R = 9.46%, R_w = 6.51%) and confirm the space-group P1 . The lattice constants are a = 696.4(1) pm, b = 922.2(3) pm, c = 958.9(3) pm , α = 117.99(2)°, β = 89.96(2)°, γ h= 108.12(2)°, Z = 2 According to its composition Rb₁₀[OCoO]₂[OCoO₂CoO] the structure is built up by two Co atoms of chemically and crystallographically different nature. We find isolated dumb-bell-like anions [O? Co? O]^3? being already known with monovalent Co (e. g. K₃CoO₂) together with units [OCoO₂CoO]^4? of two connected triangles CoO₃ being well-known from K₂BeO₂ ? K₄[Be₂O₄]. ECoN/mEFIR calculations are made starting with values obtained by a new procedure called “MEFIR-FIT”.     

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].     

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.     

Das erste Oxoferrat(I): Zur Konstitution von K3[FeO2] und K3[NiO2]

The First Oxoferrate(I): On the Constitution of K₃[FeO₂] and K₃[NiO₂] Garnet-red single crystals of K₃[FeO₂] were obtained for the first time by heating intimate mixtures of K₆[CdO₄] and CdO (molar ratio 1:1.16) in closed Fe-cylinders at 450°C during 40 d. The same way of preparation via “reaction with the cylinder surface” was applied to prepare similarly coloured single crystals of K₃[NiO₂] (K₆CdO₄ in closed Ni-cylinders at 500°C during 49 d). The structure determination by four circle diffractometer data (MoKα , K₃[FeO₂]: 731 out of 731 I_o(hkl), R = 5.76%, R_w = 5.33%, K₃[NiO₂]: 755 out of 755 I_o(hkl), R = 8.70%, R_w = 4.25%) confirms the space groups P 4₁2₁2 and P 4₃2₁2, respectively. K₃[FeO₂]: a = 604.2(2) pm, c = 1 402.7(3) pm, Z = 4 K₃[NiO₂]: a = 603.6(1) pm, c = 1 405.2(2) pm, Z = 4. (powder data, standard deviations in parentheses) Essential feature of the structure are the dumb-bell-like anions [O? M? O]^3? (M = Fe, Ni). Their arrangement corresponds to a stuffed derivative of the KrF₂-type. Magnetic properties of K₃[FeO₂] were determined and cover the monovalence of Fe. MAPLE-calculations reveal the strong coincidence of monovalent VIIIb-cations.     

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.     

K10[Co4O9], ein neues Oxocobaltat(II) mit oligomerem Anion

K₁₀[Co₄O₉], a New Oligooxocobaltate(II) For the first time dark-red single crystals of K₁₀[Co₄O₉] were obtained by heating mixtures of KO_0.48 and CdO (molar ratio 2.7:1) in closed Co-cylinders at 450°C during 73 d. Structure solution and refinement (four-circle diffractometer data, Mo Kα , 2 996 out of 2 996 I_o(hkl), R = 5.20%, R_w = 3.03%) confirm the space-group P1 and show structural relationship with Na₁₀[Co₄O₉] [2]. The lattice constants are a = 667.84(5) pm, b = 917.91(9) pm, c = 908.49(7) pm, α = 119.400(7)°, β = 90.851(7)°, γ = 110.260(6)°, Z = 1 . (powder data (Guinier-Simon), standard deviations in parentheses) MAPLE calculations are made and a comparative survey of MAPLE values of oxocobaltates(II) is given.     

Oxydation intermetallischer Phasen: Na3[AuO2] aus NaAu und Na2O2

Oxidation of Intermetallic Phases: Na₃[AuO₂] from NaAu and Na₂O₂ The hitherto unknown Na₃[AuO₂] was prepared in transparent, colourless single crystals from NaAu and Na₂O₂[1:1; sealed Ag-cylinder, 430°C, 6 d]. The crystal structure (P4₂/mnm); a = 970.5(1), c = 457.8(1) pm; Z = 4; four-circle diffractometer PW 1100, 333 out of 380 I₀(hkl), R = 7.0% and [R_w = 6.5%] was solved. Like KAgO-Type there are planar rings [Na₂Au₂O₄]^4?. Na(1) has the uncommon coordinations number 2 . The Effective Coordination Numbers, ECoN, the Mean Fictive Ionic Radii, MEFIR, and the Madelung Part of Lattice Energy, MAPLE, are calculated.     

Oxydation intermetallischer Phasen: Na5InO4 aus Naln und Na2O2

Oxidation of Intermetallic Phases: Na₅InO₄ from NaIn and Na₂O₂ By oxidation of NaIn with Na₂O₂ [sealed Ag-cylinder 430°C, 1 d] Na₅InO₄ is formed as light yellow, coarse single crystals. The lattice constants of the orthorhombic cell are: According single crystal data [Pbca; four-circle diffractometer PW 1100, 1 748 out of 1 769 I₀(hkl); R = 6.3% and R_w = 4.5%] Na₅InO₄ is isotypic with α-Li₅GaO₄. The Madelung Part of Lattice Energie, MAPLE, the Mean Fictiv Ionic Radii, MEFIR, and the Effectiv Coordination Numbers, ECoN, are calculated.     

Oxydation intermetallischer Phasen: CsK2[AuO2] aus CsAu + K2O2

Oxidation of Intermetallic Phases CsK₂[AuO₂] from CsAu+K₂O₂ We prepared the hitherto unknown CsK₂[AuO₂] [Heating mixtures of CsAu and K₂O_2,2; 1:1; gives single crystals (Ag-cylinder, 430°C, 6d)]. The single crystals are light blue, nearly colourless, and transparent. A new type of structure is found. The single crystal data are: Pnma; a = 1256.5(5), b = 727.3(2), c = 627.9(2)pm, Z = 4; four-circle diffractometer PW 1100, MoKα;849 out of 871 I₀(hkl), R = 7.3% and R_w = 6.3%. The Madelung Part of Lattice Energy, MAPLE, is calculated.     

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.     

Die Antimonid–Triantimonidometallate(III) Cs6K3Sb[AlSb3] und Cs6K3Sb[GaSb3]

The Antimonide Triantimonidometallates(III) Cs₆K₃Sb[AlSb₃] and Cs₆K₃Sb[GaSb₃] The novel compounds Cs₆K₃Sb[AlSb₃] and Cs₆K₃Sb[GaSb₃] are formed from stoichiometric mixtures of Cs, AlSb (GaSb) and KSb in sealed niobium ampoules at 950 K. The hexagonal structures are especially characterized by one-dimensional rod packings ¹∞[Cs₆K₃Sb] which are formed from columns of condensed (Cs₆K_6/2) icosahedra. The icosahedra are centered by Sb^3-? anions. The trigonal planar anions [AlSb₃]^6-? and [GaSb₃]^6-? are embedded between the icosahedra columns, and they are coordinated by alkali metal atoms. The FIR spectra were assigned to the vibrations of the [MSb₃]^6-? anions, with respect to the 6 m2-D_3h symmetry. (P6₃/mmc, No. 194; a = 1101.7 and 1097.2 pm; c = 1158.9 and 1150.1 pm; Z = 2; Single crystal data: 574 and 546 reflections; R = 0.073 and 0.029. Distances:d(Al? Sb) = 265.4 pm; d(Ga? Sb) = 265.1 pm; d(Sb? Cs) = 401.6–423.0 pm; d(Sb? K) = 358.6–367.3 pm).     

Das erste Oxocobaltat des Typs A2CoIIO2: K2CoO2 = K4[OCoO2CoO]

The First Oxocobaltate of the Type A₂Co^IIO₂: K₂CoO₂ = K₄[OCoO₂CoO] By “reaction with the cylinder surface” of intimate mixtures of K₂O and CdO (molar ratio 1:1) in closed Co-Cylinders at 450°C during 73 d dark-red single-crystals of K₂CoO₂ were obtained. Structure solution and refinement (four-circle diffractometer-data, MoKα , 1 567 independent I_o(hkl), none was omitted, R = 3.25%, R_w = 2.67%) result in a monoclinic unit cell containing anions [Co₂O₄]^4? of two connected triangles similar to those of Rb₁₀[Co^IO₂]₂[CoO₄]. MAPLE-values and Charge-distributions are given and discussed.     

Zur Konstitution von Alkaliperoxotantalaten(V): Über den Aufbau von K3[Ta(O2)4]

On the Constitution of Peroxotantalates(V) with Alkali Metals: On the Structure of K₃[Ta(O₂)₄] [1] By solving of recently precipitated Ta₂O₅ · aq in a 1.5-molar solution of KOH in 3% H₂O₂ and subsequently cooling at 0°C we obtained colourless single-crystals of K₃[Ta(O₂)₄]. The compound crystallizes tetragonal (spacegroup 142m) with a = 679.5(1) pm, c = 791.2(1) pm, Z = 2 (Guinier-de-Wolff powder data). The determinated crystal structure (four-circle diffractometer, 444 out of 444 I₀(hkl); R = 1.51%, R_w = 1.48%, parameters see text) proves that K₃[Ta(O₂)₄] is isotypic with K₃[Cr(O₂)₄] [2]. 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.