Molybdänhalogenidcluster mit sechs terminalen Alkoholatliganden: (C18H36N2O6Na)2[Mo6Cl8(OCH3)6] · 6CH3OH und (C18H36N2O6Na2)2[Mo6Cl8(OC6H5)6]

Molybdenum(II) Halide Clusters with six Alcoholate Ligands: (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6CH₃OH and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] . The reaction of Na₂[Mo₆Cl₈(OCH₃)₆] and 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OCH₃)₆] · 6 CH₃OH ( 1 ), which is converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₈(OC₆H₅)₆] ( 2 ) by metathesis with phenol. According to single crystal structure determinations ( 1 : P3 1c, a=14.613(3) Å, c=21.036(8) Å; 2 : P3 1c, a=15.624(1) Å, c=19.671(2) Å) the compounds contain anionic clusters [Mo₆Cl₈ⁱ(OR^a)₆]^2? ( 1 : d(Mo—Mo) 2.608(1) Å to 2.611(1) Å, d(Mo—Cl) 2.489(1) Å to 2.503(1) Å, d(Mo—O) 2.046(4) Å; 2 : d(Mo—Mo) 2.602(3) Å to 2.608(3) Å, d(Mo—Cl) 2.471(5) Å to 2.4992(5) Å, d(Mo—O) 2.091(14) Å). Electronic interactions of the halide cluster and the phenolate ligands in [Mo₆Cl₈(OC₆H₅)₆]^2? is investigated by means of UV/VIS spectroscopy and EHMO calculations.     

New Perspectives in Polyoxometalate Chemistry by isolation of compounds containing very large moieties as transferable building blocks: (NMe4)5[As2Mo8V4AsO40] · 3H2O, (NH4)21[H3Mo57V6(NO)6O183(H2O)18] · 65 H2O, (NH2Me2)18(NH4)6[Mo57V6(NO)6O183(H2O)18] · 14 H2O,and (NH4)12[Mo36(NO)4O108(H2O)16] · 33 H2O

The compounds (NMe₄)₅[As₂Mo₈V₄AsO₄₀] · 3 H₂O 2a , (NH₄)₂₁[H₃Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 65 H₂O 3a , (NH₂Me₂)₁₈(NH₄)₆[Mo₅₇V₆(NO)₆O₁₈₃(H₂O)₁₈] · 14 H₂O 3b and (NH₄)₁₂[Mo₃₆(NO)₄O₁₀₈(H₂O)₁₆] · 33 H₂O 4a ( 3a and 4a were not correctly reported in the literature regarding to their composition, structures and the oxidation states of the metal centres) which contain large isolated anionic species, have been prepared (among them 3a, 3b , and 4a in rather high yield) and characterized by complete crystal structure analysis as well as IR/Raman, UV/VIS/NIR, ESR spectroscopy and magnetic susceptibility measurements, redox titrations, bond valence sum calculations, elemental analyses and thermogravimetric studies. Perspectives for polyoxometalate chemistry referring to the synthesis of “extremely” large nanoscaled species are discussed, together with the occurrence of a large transferable {Mo₁₇} building block in the compounds 3a, 3b and 4a which also exists in the corresponding iron compound Na₃(NH₄)₁₂[H₁₅Mo₅₇Fe₆(NO)₆O₁₈₃(H₂O)₁₈] · 76 H₂O 7a .     

Charakterisierung von Distorsionsisomeren der Anionen Pentacyano-oxo-molybdat(IV) sowie Tetracyano-oxo-aqua-molybdat(IV) im festen Zustand. Kristallstrukturen von [(C6H5)4P]3[MoO(CN)5] · 7 H2O(grün), [(C6H5)4As]2 [MoO(OH2)(CN)4] · 4 H2O (blau) und [(C6H5)4P]2[MoO(OH2)(CN)4] · 4 H2O (grün)

Characterization of Distortional Isomers of the Anions Pentacyano-oxo-molybdate(IV) and of Tetracyano-aqua-oxo-molybdate(IV) in the Solid State. Crystal Structures of [(C₆H₅)₄P]₃[MoO(CN)₅] · 7 H₂O (green), [(C₆H₅)₄As]₂[MoO(OH₂)(CN)₄] · 4 H₂O (blue), and [(C₆H₅)₄P]₂[MoO(OH₂) (CN)₄] · 4 H₂O (green) Preparation of a series of salts containing the new pentacyano-oxo-molybdate(IV) anion is described: Cs₂H[MoO(CN)₅] (blue), [(CH₃)₄N]₂H[MoO(CN)₅] · 2 H₂O (blue) and [Cr(en)₃] [MoO(CN)₅] · 4 H₂O (green). The green [(C₆H₅)₄P]₃[MoO(CN)₅] · 7 H₂O crystallizes triclinic in the space group P1 . The molybdenum(IV) center is in an pseudo-octahedral environment of a terminal oxo-group (d(Mo?O); 1.705(4) Å), a CN^? group in the trans-position (d(Mo? C): 2.373(6) Å), and four equatorial CN^? groups (averaged d(Mo? C): 2.178 (Å). The blue and green salts exhibit v(Mo?O) stretching frequencies at 948 cm^?1 and 920 cm^?1, respectively. Blue and green salts containing the [MoO(OH₂)(CN)₄]^2? anion and [(C₆H₅)₄P]⁺ or [(C₆H₅)₄As]⁺ cations have been prepared and characterized by single crystal crystallography. [(C₆H₅)₄P]₂[MoO(OH₂)(CN)₄] · 4 H₂O (green) and [(C₆H₅)₄As]₂[MoO(OH₂)(CN)₄] · 4 H₂O (blue) crystallize monoclinic in the space group C—P2₁/n. They are considered to be distortional isomers of the complex anion: the green species has a Mo?O bond distance of 1.72(2) Å whereas for the blue species d(Mo?O) = 1.60(2) Å is found; the corresponding v(Mo?O) frequencies are at 920 cm^?1 and 980 cm^?1.     

Alkalimolybdotellurate: Darstellung und Kristallstruktur von Rb6[TeMo6O24] · 10H2O und Rb6[TeMo6O24] · Te(OH)6 · 6H2O

Alkaline Molybdotellurates: Preparation and Crystal Structures of Rb₆[TeMo₆O₂₄] · 10H₂O and Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6H₂O Single crystals of Rb₆[TeMo₆O₂₄] · 10 H₂O and Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6 H₂O, respectively, were grown from aqueous solution. Rb₆[TeMo₆O₂₄] · 10 H₂O possesses the space group P1 . The lattice dimensions are a = 963.40(13), b = 972.56(12), c = 1 056.18(13) pm, α = 97.556(10), β = 113.445(9), γ = 102.075(10)°; Z = 1, 2 860 reflections, 215 parameters refined, R_g = 0.0257. The centrosymmetrical [TeMo₆O₂₄]^6? anions are stacked parallel to [010]. Rb(2) is coordinated with one exception by water molecules only. Folded chains consisting of [TeMo₆O₂₄]^6? anions and Rb(2) coordination polyhedra which are linked to pairs represent the prominent structural feature. Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6 H₂O crystallizes monoclinically in the space group C2/c with a = 1 886.4(3), b = 1 000.9(1), c = 2 126.5(3) pm, and β = 115.90(1)°; Z = 4, 3 206 reflections, 240 parameters refined, R_g = 0.0333. It is isostructural in high extent with (NH₄)₆[TeMo₆O₂₄] · Te(OH)₆ · 7 H₂O. Hydrogen bonds between Te(OH)₆ molecules and [TeMo₆O₂₄]^6? anions establish infinite strands. The [TeMo₆O₂₄]^6? anions gather around Te(OH)₆ providing channel-like voids extending parallel to [001].     

Molybdänhalogenidcluster mit zwei terminalen Alkoholatliganden: Synthese und Kristallstrukturen von (C18H36N2O6Na)2[Mo6Cl12(OCH3)2] und (C18H36N2O6Na)2[Mo6Cl12(OC15H11)2] · 2C4H6O3

Molybdenum(II) Halide Clusters with two Alcoholate Ligands: Syntheses and Crystal Structures of (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OCH₃)₂] and (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OC₁₅H₁₁)₂] · 2C₄H₆O₃ . Reaction of Mo₆Cl₁₂ with two equivalents of sodium methoxide in the presence of 2,2,2-crypt yields (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OCH₃)₂] ( 1 ), which can be converted to (C₁₈H₃₆N₂O₆Na)₂[Mo₆Cl₁₂(OC₁₅H₁₁)₂] · 2C₄H₆O₃ ( 2 ) by metathesis with 9-Anthracenemethanole in propylene carbonate. As confirmed by X-ray single crystal structure determination ( 1 : C2/m, a=25.513(8) Å, b=13.001(3) Å, c=10.128(3) Å, β=100.204(12)°; : C2/c, a=15.580(5) Å, b=22.337(5) Å, c=27.143(8) Å, β=98.756(10)°) the compounds contain anionic cluster units [Mo₆ClCl(OR^a)₂]^2? with two alcoholate ligands in terminal trans positions ( 1 : d(Mo—Mo) 2.597(2) Å to 2.610(2) Å, d(Mo—Clⁱ) 2.471(3) Å to 2.493(4) Å, d(Mo—Cl^a) 2.417(8) Å and 2.427(8) Å, d(Mo—O) 2.006(13) Å; 2 : d(Mo—Mo) 2.599(3) Å to 2.628(3), d(Mo—Clⁱ) 2.468(8) Å to 2.506(7) Å, d(Mo—Cl^a) 2.444(8) Å and 2.445(7) Å, d(Mo—O) 2.012(19) Å).     

Darstellung und Kristallstrukturen der ersten Alkalimetall‐hexacarbonatooxotetraberyllate: K6[Be4O(CO3)6] · 7 H2O und K6[Be4O(CO3)6]

Preparation and Crystal Structures of the first Alkalimetall‐hexacarbonato‐oxotetraberyllates: K₆[Be₄O(CO₃)₆] · 7 H₂O and K₆[Be₄O(CO₃)₆] K₆[Be₄O(CO₃)₆] · 7 H₂O has been prepared by dissolving freshly precipitated Be(OH)₂ in an aqueous KHCO₃ solution. After enriching the title compound by extraction with ethanol the heptahydrate crystallizes from the organic phase (triklin, P1¯ (No. 2) with a = 951, 01(11), b = 958, 45(12), c = 1601, 7(2) pm, α = 79, 253(13)°, β = 78, 943(12)°, γ = 65, 119(12)°, V_EZ = 1290, 6(3)·10⁶ pm³, Z = 2). Thermal decomposition forms rhombohedral crystals of the anhydrous compound (trigonal‐rhombohedric, R3¯ (No. 148) with a = 1416, 42(6), c = 1704, 5(1) pm, V_EZ = 2961, 4(3)·10⁶ pm³, Z = 6).     

Neue Oxonium-Bromochalkogenate(IV) — Darstellung,Struktur und Eigenschaften von [H3O][TeBr5] · 3C4H8O2 und [H3O]2[SeBr6]

New Oxonium Bromochalcogenates(IV) — Synthesis, Structure, and Properties of [H₃O][TeBr₅] · 3 C₄H₈O₂ and [H₃O]₂[SeBr₆] Dark red crystals of the composition [H₃O][TeBr₅] · 3 C₄H₈O₂ ( 1 ) were isolated from a saturated solution of TeBr₄ in 1,4-dioxane containing a small amount of water. In this compound (space group P2₁/m, a = 8.922(4) Å, b = 13.204(7) Å, c = 9.853(5) Å, β = 91.82(4)° at 150 K) a square pyramidal [TeBr₅]^? anion has been isolated for the first time. The coordination sphere of the anion is completed to a distorted octahedron by weak interaction with a dioxane molecule of the cationic system. The [H₃O]⁺ cations are connected to chains by dioxane molecules. At room temperature the compound is stable only in its mother liquor. Crystalline [H₃O]₂[SeBr₆] ( 2 ) (space group Fm3m, a = 10.421(1) Å at 170 K) is a bromoselenous acid of high symmetry. The [H₃O]⁺ ion is only weakly coordinated by Br atoms of the anion. The anions are isolated octahedral [SeBr₆]^2? units. The structure is isotypic to the K₂[PtCl₆] structure. Despite being a halogenochalcogen(IV) acid, 2 exhibits a remarkable thermal stability. Both oxonium compounds were characterized by single-crystal X-ray structure analyses. Vibrational spectra of 2 are reported.     

Synthesis and properties of Na6[Pb(S2O3)4] · 6H2O

Conditions for the synthesis of the water-soluble lead thiosulfate complex Na₆[Pb(S₂O₃)₄] · 6H₂O were determined. The complex synthesized was characterized by UV and IR spectroscopy and X-ray phase and thermal analyses. Thermolysis schemes were proposed on the basis of the IR and mass spectra of the thermal decomposition products.     

Hydrothermal Synthesis and Crystal Structures of Na2Be3(SeO3)4·H2O and Cs2[Mg(H2O)6]3(SeO3)4

The selenites, Na₂Be₃(SeO₃)₄ · H₂O and Cs₂[Mg(H₂O)₆]₃(SeO₃)₄, were synthesized under hydrothermal conditions. The crystal structures of Na₂Be₃(SeO₃)₄ · H₂O and Cs₂[Mg(H₂O)₆]₃(SeO₃)₄ were determined by single‐crystal X‐ray diffractions. Na₂Be₃(SeO₃)₄ · H₂O crystallizes in the triclinic space group P1 (no. 2) with unit cell parameters a = 4.8493(9), b = 12.013(2), c = 12.077(2) Å, and Z = 2, whereas Cs₂[Mg(H₂O)₆]₃(SeO₃)₄ crystallizes in the monoclinic space group C2/m (no. 12) with lattice cell parameters a = 12.596(6), b = 7.297(4), c = 16.914(8) Å, and Z = 2. Na₂Be₃(SeO₃)₄ · H₂O features a three‐dimensional open framework structure formed by BeO₄ tetrahedra and SeO₃ trigonal pyramids. Na cations and H₂O molecules are located in different tunnels. Cs₂[Mg(H₂O)₆]₃(SeO₃)₄ has a structure composed of isolated [Mg(H₂O)₆] octahedra and SeO₃ trigonal pyramids interacted by hydrogen bonds, and Cs cations are resided in‐between. Both compounds were characterized by thermogravimetric analysis and FT‐IR spectroscopy.     

Ein anionischer Oxohydroxo‐Komplex mit Bismut(III): Na6[Bi2O2(OH)6](OH)2 · 4H2O

An Anionic Oxohydroxo Complex with Bismuth(III): Na₆[Bi₂O₂(OH)₆](OH)₂ · 4H₂O Colourless, plate‐like, air sensitive crystals of Na₆[Bi₂O₂(OH)₆](OH)₂ · 4H₂O are obtained by reaction of Bi₂O₃ or Bi(NO₃)₃ · 5H₂O in conc. NaOH (58 wt %) at 200 °C followed by slow cooling to room temperature. The crystal structure (triclinic, P 1¯, a = 684.0(2), b = 759.8(2), c = 822.7(2) pm, α = 92.45(3)°, ß = 90.40(3)°, γ = 115.60(2)°, Z = 1, R1, wR2 (all data), 0, 042, 0, 076) contains dimeric, anionic complexes [Bi₂O₂(OH)₆]^4— with bismuth in an ψ¹‐octahedral coordination of two oxo‐ and three hydroxo‐ligands. The thermal decomposition was investigated by DSC/TG or DTA/TG and high temperature X‐ray powder diffraction measurements. In the final of three steps the decomposition product is Na₃BiO₃.     

The Crystal Structures of Two No–Metal Tricyanomelaminates: Diammonium Tricyanomelaminate Dihydrate [NH4]2[C6N9H] · 2 H2O and Dimelaminium Tricyanomelaminate Melamine Dihydrate [C3N6H7]2[C6N9H] · C3N6H6 · 2 H2O

Diammonium tricyanomelaminate dihydrate [NH₄]₂[C₆N₉H] · 2 H₂O ( 1 ) and dimelaminium tricyanomelaminate melamine dihydrate [C₃N₆H₇]₂[C₆N₉H] · C₃N₆H₆ · 2 H₂O ( 2 ) were obtained by metathesis reactions from Na₃[C₆N₉] in aqueous solution and characterized by single‐crystal X‐ray diffraction and ¹⁵N solid‐state NMR spectroscopy ( 1 ). Both salts contain mono‐protonated tricyanomelaminate (TCM) anions and crystallize as dihydrates. Considering charge balance requirements, the crystal structure of 1 (C2/c, a = 3181.8(6) pm, b = 360.01(7) pm, c = 2190.4(4) pm, β = 112.39(3)°, V = 2319.9(8) 10⁶ · pm³) can best be described by assuming a random distribution of an ammonium ion – crystal water pair over two energetically similar sites. Apart from two melaminium cations, 2 (P2₁/c, a = 674.7(5) pm, b = 1123.6(5) pm, c = 3400.2(5) pm, β = 95.398(5), V = 2566(2) 10⁶ · pm³) contains one neutral melamine per formula unit acting as an additional “solvent” molecule and yielding a donor‐acceptor type of π–stacking interaction.     

Bariumstannat‐Pulver durch hydrothermale Synthese und durch Thermolyse von Bariumzinn(IV)‐glykolaten. Synthese und Struktur von [Ba(C2H6O2)4][Sn(C2H4O2)3] und [Ba(C2H6O2)2][Sn(C2H4O2)3]·CH3OH

Barium Stannate Powders from Hydrothermal Synthesis and by Thermolysis of Barium‐Tin(IV)‐Glycolates. Synthesis and Structure of [Ba(C₂H₆O₂)₄][Sn(C₂H₄O₂)₃] and [Ba(C₂H₆O₂)₂][Sn(C₂H₄O₂)₃]·CH₃OH The hydrothermal reaction as well as the microwave assisted hydrothermal reaction of SnO₂·aq with barium hydroxide gives Ba[Sn(OH)₆] ( 1 ) as powder with bar like particles. Compound 1 of the same morphology can also be isolated from a hydrothermal reaction of [Ba(C₂H₆O₂)₄][Sn(C₂H₄O₂)₃] ( 3 ). The reaction of SnO₂·aq with Ba(OH)₂·8H₂O in ethylene glycol yields the glycolate [Ba(C₂H₆O₂)₄][Sn(C₂H₄O₂)₃] ( 3 ), which forms in methanol the solvate [Ba(C₂H₆O₂)₂][Sn(C₂H₄O₂)₃]·CH₃OH ( 4 ). Compounds 1 , 3 and 4 react at different temperatures to BaSnO₃ ( 2 ) consisting of powders with different morphologies; because of the grain size of the resulting powders compounds 3 and 4 are suitable as precursor for the fabrication of corresponding ceramics.     

[Mn(H2O)2]4[HNC5H4(COO)]2[C6H2(COO)4]2·4H2O — Ein dreidimensionales Koordinationspolymer mit Gastwassermolekülen in kanalartigen Hohlräumen

[Mn(H₂O)₂]₄[HNC₅H₄(COO)]₂[C₆H₂(COO)₄]₂·4H₂O — A Three‐dimensional Coordination Polymer with Guest Water Molecules in Channel‐like Voids Single crystals of [Mn(H₂O)₂]₄[HNC₅H₄(COO)]₂[C₆H₂(COO)₄]₂·4H₂O have been prepared in aqueous solution at 55 °C. Space group P1¯ (no. 2), a = 999.7(2), b = 1314.4(2), c = 1645.8(2) pm, α = 101.096(8)°, β = 92.796(14)°, γ = 96.03(2)°, V = 2.1053(5) nm³, Z = 2. There are four unique Mn²⁺ which are coordinated in a distorted, octahedral manner by two water molecules, three oxygen atoms of the pyromellitate anions and one oxygen atom of isonicotinic acid (Mn—O 208.6(2) — 227.3(3) pm). The connection of Mn²⁺ and [C₆H₂(COO)₄]^4— yields a three‐dimensional coordination polymer with two different, channel‐like voids extending parallel to [110]. The first channel accomodates water molecules, the second channel is filled by isonicotinic acid molecules. Thermogravimetric analysis in air revealed that the loss of water of crystallisation occurs in two steps between 97 and 200 °C. The dehydrated sample was stable between 200 and 340 °C. Further decomposition yielded Mn₃O₄.     

Nonanatrium-bis(hexahydroxoaluminat)-trihydroxid-hexahydrat (Na9[Al(OH)6]2(OH)3 · 6H2O) – Kristallstruktur,NMR-Spektroskopie und thermisches Verhalten

Nonasodium Bis(hexahydroxoaluminate) Trihydroxide Hexahydrate (Na₉[Al(OH)₆]₂(OH)₃ · 6H₂O) – Crystal Structure, NMR Spectroscopy and Thermal Behaviour The crystal structure of the nonasodium bis(hexahydroxoaluminate) trihydroxide hexahydrate Na₉[Al(OH)₆]₂(OH)₃ · 6H₂O (4.5 Na₂O Al₂O₃ · 13.5 H₂O) (up to now described as 3 Na₂O · Al₂O₃ · 6H₂O, 4Na₂O · Al₂O₃ · 13 H₂O and [3 Na₂O · Al₂O₃ · 6H₂O] [xNaOH · yH₂O], respectively) was solved. The X-ray single crystal diffraction analysis (triclinic, space group P1 , a = 8.694(1) Å, b = 11.344(2) Å, c = 11.636(3) Å, α = 74.29(2)°, β = 87.43(2)°, γ = 70.66(2)°, Z = 2) results in a structure, consisting of monomeric [Al(OH)₆]^3? aluminate anions, which are connected by NaO₆ octahedra groups. Furthermore the structure contains both, two hydroxide anions only surrounded by water of crystallization and OH groups of [Al(OH)₆]^3? aluminate anions and a hydroxide anion involved in three NaO₆ coordination octahedra directly and moreover connected with a water molecule by hydrogen bonding. The results of ²⁷Al and ²³Na-MAS-NMR investigations, the thermal behaviour of the compound and possible relations between the crystal structure and the conditions of coordination in the corresponding sodium aluminate solution are discussed as well.     

Molybdännitridtrichlorid-di-n-butylether, [MoNCl3 · O(C4H9)2]4; Darstellung,IR-Spektrum und Kristallstruktur

Molybdenum-nitride-trichloride-di-n -butylether [MoNCls₃ · 0 (C₄H₉)₂]₄; Preparation, I.R. Spectrum, and Crystal Structure Phenyldiazonium tetrachloronitridomolybdate, C₆H₅N₂[MoNCl₄], was obtained in the form of orange-red crystals from phenyldiazonium chloride and molybdenum nitride chloride in POCl₃ suspension. In boiling di-n-butylether it decomposes to chlorobenzene and the title compound which is obtained in the form of dark red crystals, sensitive to moisture. [MoNCl₃ · O(C₄H₉)₂]₄ can also be obtained directly from MoNCl₃ and dibutylether. It crystallizes in the monoclinic space group P2₁/c with two tetrameric molecules per unit cell. The lattice constants are at ?49°C a = 1 283, b = 1 170, c = 1 922 and β = 94.11°. The crystal structure was determined with the aid of X-ray diffraction data and was refined to a residual index of R = 0.047 for 1951 observed reflexions. In the [MoNCl₃ · O(C₄H₉)₂]₄ molecule the Mo atoms form a square; they are linked with one another via the N atoms with alternating Mo? N distances of 165 and 215 pm, which indicate triple and single bonds, respectively. In the position trans to the shorter Mo?N bond, the ether molecule is bonded by its oxygen atom. The I.R. spectra of C₆H₅N₂[MoNCl₄], C₆H₅N₂[MoCl₆], and [MoNCl₃ · O(C₄H₉)₂]₄ are recorded.     

Darstellung und Kristallstruktur von [Co(NH3)6]2P4O13 · 5 H2O

Preparation and Crystal Structure of [Co(NH₃)₆]₂P₄O₁₃ 7·5H₂O Single crystals of [Co(NH₃)₆]P₄O₁₃ · 5 H₂O were obtained by diffusion controlled growth. To this end sodium polytetraphosphate was prepared by column chromatography and allowed to react with [Co(NH₃)₆]Cl₃. The compound [Co(NH₃)₆]₂P₄O₁₃ · 5 H₂O contains the novel isolated polytetraphosphate anion. The expected systematic variation in bond length in the P? O? P bridges of the poly tetraphosphate anion was verified. The conformation of the anion is discussed.     

Die Kristallstruktur des Natriumoxohydroxoaluminathydrates Na2[Al2O3(OH)2] · 1,5 H2O

The Crystal Structure of the Sodium Oxohydroxoaluminate Hydrate Na₂[Al₂O₃(OH)₂] · 1.5 H₂O The crystal structure of the sodium oxohydroxoaluminate hydrate Na₂[Al₂O₃(OH)₂] ·s 1.5 H₂O (up to now described as Na₂O · Al₂O₃ · 2.5 H₂O and Na₂O · Al₂O₃ · 3 H₂O, respectively) was solved. The X-ray single crystal diffraction analysis (tetragonal, space group P-42₁m, a = 10.522(1) Å, c = 5.330(1) Å, Z = 4) results in a polymeric layered structure, consisting of AlO_3/2(OH) tetrahedral groups. Between these layers the Na⁺ ions are situated, which form tetrameric groups of face-linked NaO₆ octahedra. The involved O^2? ions are due to Al? O? Al bridges, Al? OH groups and water of crystallization. ²⁷Al and ²³Na MAS NMR investigations confirm the crystal structure analysis. The relations between the crystallization behaviour of the compound and the constitution of the aluminate anions in the corresponding sodium aluminate solution and in the solid, respectively, are discussed.     

Darstellung und Struktur der ersten gemischten Alkalimetallhydrogencarbonate NaA2[H(CO3)2] · 2H2O mit A = K,Rb

Preparation and Crystal Structure of the First Mixed Alkalimetal Hydrogencarbonates NaA₂[H(CO₃)₂] · 2H₂O with A = K, Rb The new hydrogencarbonates NaK₂[H(CO₃)₂] · 2H₂O (Pnma, a = 934.07(13) pm, b = 789.31(10) pm, c = 1142.1(5) pm, V_EZ = 842.0(4) · 10⁶ pm³, Z = 4, R1 (I ? 2σ(I)) = 0.023, wR2 = 0.066 for 989 reflections) and NaRb₂[H(CO₃)₂] · 2H₂O (Pnma, a = 948.24(11) pm, b = 811.37(9) pm, c = 1189.0(2) pm, V_EZ = 914.8(2) · 10⁶ pm³, Z = 4, R1 (I ≤ 2σ(I)) = 0.031, wR2 = 0.077 for 1063 reflections) were prepared from aqueous solutions. The crystal structures were determined. The isostructural compounds contain dimeric, non centrosymmetric [H(CO₃)₂]^3? anions. In NaK₂[H(CO₃)₂] · 2H₂O a short hydrogen bond (d(O … O) = 246.1(2) pm) with an asymmetric potential was detected. In NaRb₂[H(CO₃)₂] · 2H₂O a hydrogen bond with symmetric potential (d(O … O) = 247.8(5) pm) can be assumed. The IR-spectra of NaK₂[H(CO₃)₂] · 2H₂O and Na₃[H(CO₃)₂] · 2H₂O are compared.     

Kristallstruktur von Natrium‐Dihydrogencyamelurat‐Tetrahydrat Na[H2(C6N7)O3] · 4 H2O

Crystal Structure of Sodium Dihydrogencyamelurate Tetrahydrate Na[H₂(C₆N₇)O₃] · 4 H₂O Sodium dihydrogencyamelurate‐tetrahydrate Na[H₂(C₆N₇)O₃]·4 H₂O was obtained by neutralisation of an aqueous solution, previously prepared by hydrolysis of the polymer melon with sodium hydroxide. The crystal structure was solved by single‐crystal X‐ray diffraction ( a = 6.6345(13), b = 8.7107(17), c = 11.632(2) Å, α = 68.96(3), β = 87.57(3), γ = 68.24(3)°, V = 579.5(2) ų, Z = 2, R1 = 0.0535, 2095 observed reflections, 230 parameters). Both hydrogen atoms of the dihydrogencyamelurate anion are directly bound to nitrogen atoms of the cyameluric nucleus, thus proving the preference of the keto‐tautomere in salts of cyameluric acid in the solid‐state. The compound forms a layer‐like structure with an extensive hydrogen bonding network.     

X‐Ray Crystal Structures of Hexa‐oxotellurate Complexes of Ruthenium(VI) and Silver(III): Na6[RuO2{TeO4(OH)2}2]·16H2O and Na5[Ag{TeO4(OH)2}2]·16H2O

X‐ray crystal structures are reported for Na₆[RuO₂{TeO₄(OH)₂}₂]·16H₂O and Na₅[Ag{TeO₄(OH)₂}₂]·16H₂O which contain respectively Ru^VI and Ag^III coordinated to chelating bidentate tellurate ([TeO₄(OH)₂]⁴⁻) groups. Na₆[RuO₂{TeO₄(OH)₂}₂]·16H₂O: Space group P1¯, Z = 2, lattice dimensions at 120 K; a = 6.9865(1), b = 8.7196(2), c = 11.7395(2)Å, α = 74.008(1), β = 79.954(1), γ = 88.514(1)°; R1 = 0.025. Na₅[Ag{TeO₄(OH)₂}₂]·16H₂O: Space group P1¯, Z = 2, lattice dimensions at 120 K; a = 5.888(1), b = 8.932(1), c = 12.561(2)Å, α = 98.219(6), β = 97.964(9), γ = 93.238(14)°; R1 = 0.047.