The Triclinic Lanthanoid(III) Halide Oxidoarsenates(III) Sm3Cl2[As2O5][AsO3] and Tm3Br2[As2O5][AsO3]

Pale yellow single crystals of the composition Ln₃X₂[As₂O₅][AsO₃] (Ln = Tm for X = Br and Ln = Sm for X = Cl) were obtained via solid-state reactions in the systems Ln₂O₃/As₂O₃ from sealed silica ampoules using different halides as fluxing agents. Sm₃Cl₂[As₂O₅][AsO₃] and Tm₃Br₂[As₂O₅][AsO₃] crystallize isotypically in the triclinic space group P1 with Z = 2 and cell parameters of a = 543.51(4) pm, b = 837.24(6) pm, c = 1113.45(8) pm, α = 90.084(2)°, β = 94.532(2)°, γ = 90.487(2)° for the samarium and a = 534.96(4) pm, b = 869.26(6) pm, c = 1081.84(8) pm, α = 90.723(2)°, β = 94.792(2)° γ = 90.119(2)° for the thulium compound. The isotypic crystal structure of both representatives exhibits three crystallographically different Ln³⁺ cations, each with a coordination number of eight. (Ln1)³⁺ and (Ln2)³⁺ are only coordinated by three oxygen atoms, whereas (Ln3)³⁺ shows additional contacts to halide anions in forming square [LnO₄X₄]^9– antiprisms. All As³⁺ cations are surrounded by three oxygen atoms in the shape of isolated [AsO₃]^3– ψ¹-tetrahedra. They occur either isolated or condensed as pyroanionic [As₂O₅]^4– units with a bridging oxygen atom. In both anions, non-binding lone-pair electrons are present at the As³⁺ cations with a pronounced stereochemically active function.     

The Unique Crystal Structure of the Triclinic Samarium(III) Oxoselenate(IV) Sm2[SeO3]3

Pale yellow, needle‐shaped single crystals of Sm₂[SeO₃]₃ were obtained by heating stoichiometric mixtures of Sm₂O₃ and SeO₂ (molar ratio: 1:3) along with substantial amounts of CsCl as fluxing agent in evacuated sealed silica tubes at 830 °C for one week. According to X‐ray single‐crystal diffraction data, Sm₂[SeO₃]₃ crystallizes triclinic (space group: ) with two formula units per unit cell of the dimensions a = 698.62(7), b = 789.71(8), c = 910.34(9) pm, α = 96.693(5), β = 104.639(5), γ = 115.867(5)°. Its crystal structure contains two crystallographically distinct Sm³⁺ cations in eight‐ and ninefold coordination with oxygen atoms arranged as distorted uncapped or capped square antiprisms (d(Sm³⁺?O^2?) = 232?271 pm). These [(Sm1)O₈] and [(Sm2)O₉] polyhedra share opposite edges and faces to form zigzag chains along [100] with discrete pyramidal [SeO₃]^2? anions bridging units. Further linkage by [SeO₃]^2? anions in [010] direction leads to a three‐dimensional network, which exhibits almost rectangular channels along [111]. These tunnels offer width enough to incorporate the free non‐bonding electron pairs (?lone pairs”?) at the Se⁴⁺ cations, since all nine different Ψ¹‐tetrahedral [SeO₃]^2? groups (d(Se⁴⁺?O^2?) = 165?173 pm, ?(O–Se–O) = 94 – 108°) exhibit a pronounced stereochemical ?lone‐pair”? activity. For not being isotypic with neither triclinic Er₂[SeO₃]₃ (CN(Er³⁺) = 7 and 8) nor the remainder rare‐earth metal(III) oxoselenates(IV) of the composition M₂[SeO₃]₃ (≡ M₂Se₃O₉; M = Sc, Y, La, Ce – Lu), Sm₂[SeO₃]₃ claims a unique crystal structure among them.     

Einkristalle von La[AsO4] im Monazit‐ und Sm[AsO4] im Xenotim‐Typ

Single Crystals of La[AsO₄] with Monazite‐ and Sm[AsO₄] with Xenotime‐Type Structure Brick‐shaped, transparent single crystals of colourless monazite‐type La[AsO₄] (monoclinic, P2₁/n, a = 676.15(4), b = 721.03(4), c = 700.56(4) pm, β =104.507(4)°, Z = 4) and pale yellow xenotime‐type Sm[AsO₄] (tetragonal, I4₁/amd, a = 718.57(4), c = 639.06(4) pm, Z = 4) emerge as by‐products from alkali and rare‐earth metal chloride fluxes whenever the synthesis of lanthanide(III) oxoarsenate(III) derivatives from admixtures of the corresponding sesquioxides in sealed, evacuated silica ampoules is accompanied by air intrusion and subsequent oxidation. Nine oxygen atoms from seven discrete [AsO₄]^3? tetrahedra recruit the rather irregular coordination sphere of La³⁺ (d(La³⁺?O^2?) = 248 – 266 pm plus 291 pm) and even a tenth ligand could be considered at a distance of 332 pm. The trigonal dodecahedral figure of coordination consisting of eight oxygen atoms at distances of 236 and 248 pm (4× each) about Sm³⁺ is provided by only six isolated tetrahedral [AsO₄]^3? units. Alternating trans‐edge condensation of the latter with the [LaO₉₊₁] polyhedra of monazite‐type La[AsO₄] and the [SmO₈] polyhedra of xenotime‐type Sm[AsO₄] constitutes the main structural chain features along [100] or [001], respectively. The bond distances and angles of the complex [AsO₄]^3? anions range within common intervals (d(As⁵⁺?O^2?) = 167 – 169 pm, ?(O–As–O) = 100 – 116°) for both lanthanide(III) oxoarsenates(V) presented here.     

La3OCl[AsO3]2: Ein Lanthan‐Oxidchlorid‐Oxoarsenat(III) mit “lone‐pair”‐Kanalstruktur

La₃OCl[AsO₃]₂: A Lanthanum Oxide Chloride Oxoarsenate(III) with a “Lone‐Pair” Channel Structure La₃OCl[AsO₃]₂ was prepared by the solid‐state reaction between La₂O₃ and As₂O₃ using LaCl₃ and CsCl as fluxing agents in evacuated silica ampoules at 850 °C. The colourless crystals with pillar‐shaped habit crystallize tetragonally (a = 1299.96(9), c = 558.37(5) pm, c/a = 0.430) in the space group P4₂/mnm (no. 136) with four formula units per unit cell. The crystal structure contains two crystallographically different La³⁺ cations. (La1)³⁺ is coordinated by six oxygen atoms and two chloride anions in the shape of a bicapped trigonal prism (CN = 8), whereas (La2)³⁺ carries eight oxygen atoms and one Cl^? anion arranged in the shape of tricapped trigonal prism (CN = 9). The isolated pyramidal [AsO₃]^3? anions (d(As–O) = 175–179 pm) consist of three oxygen atoms (O2 and two O3), which surround the As³⁺ cations together with the free, non‐binding electron pair (lone pair) Ψ¹‐tetrahedrally (?(O–As–O) = 95°, 3×). One of the three crystallographically independent oxygen atoms (O1), however, is exclusively coordinated by four (La2)³⁺ cations in the shape of a real tetrahedron (d(O–La) = 236 pm, 4×). These [(O1)(La2)₄]¹⁰⁺ tetrahedra form endless chains in the direction of the c axis through trans‐edge condensation. Empty channels, constituted by the lone‐pair electrons of the Cl^? anions and the As³⁺ cations in the Ψ¹‐tetrahedral oxoarsenate(III) anions [AsO₃]^3?, run parallel to [001] as well.     

Die Chlorooxoarsenate(III) (PPh4)2[As4O2Cl10] · 2 CH3CN und (PPh4)2[As2OCl6] · 3 CH3CN

The Chlorooxoarsenates(III) (PPh₄)₂[As₄O₂Cl₁₀] · 2 CH₃CN and (PPh₄)₂[As₂OCl₆] · 3 CH₃CN (PPh₄)₂[As₂Cl₈] can be prepared from As₂O₃, SOCl₂ and PPh₄Cl in acetonitrile. Its oxidation with chlorine yields PPh₄[AsCl₆]. This was also obtained directly from arsenic, chlorine and PPh₄Cl, (PPh₄)₂[As₄O₂Cl₁₀] · 2 CH₃CN being a side product; the latter was obtained with high yield from AsCl₃, As₂O₃ and PPh₄Cl in acetonitrile. By addition of PPh₄Cl it was converted to (PPh₄)₂[As₂OCl₆] · 3 CH₃CN. According to their X-ray crystal structure analyses, both crystallize in the triclinic space group P 1. The [As₄O₂Cl₁₀]^2– ion can be regarded as a centrosymmetric association product of two Cl₂AsOAsCl₂ molecules and two Cl^– ions, each Cl^– ion being coordinated with all four As atoms. In the [As₂OCl₆]^2– ion the As atoms are linked via the O atom and two Cl atoms.     

Sm4S3[Si2O7] und NaSm9S2[SiO4]6: Zwei Sulfidsilicate mit dreiwertigem Samarium

Sm₄S₃[Si₂O₇] and NaSm₉S₂[SiO₄]₆: Two Sulfide Silicates with Trivalent Samarium The sulfide silicates Sm₄S₃[Si₂O₇] and NaSm₉S₂[SiO₄]₆ are obtained as light yellow transparent crystals by the reaction of Sm, Sm₂O₃, S, and SiO₂ with fluxing SmCl₃ or NaCl, respectively, in suitable molar ratios in fused evacuated silica tubes (850 °C, 7 d). Tetragonal crystals of Sm₄S₃[Si₂O₇] (I4₁/amd; Z = 8; a = 1186.4(1); c = 1387.0(2) pm) with ecliptically conformed [Si₂O₇]^6–‐groups of corner sharing [SiO₄]‐tetrahedra are formed. These double tetrahedra as well the sulfide anions (S^2–) coordinate two crystallographically independent metal cations. They provide coordination numbers of 8 + 1 (5 S^2– and 3 + 1 O^2–) for Sm1 and 9 (3 S^2– and 6 O^2–) for Sm2. NaSm₉S₂[SiO₄]₆ crystallizes hexagonally (P6₃/m; Z = 1; a = 975.32(9); c = 676.46(7) pm) in a modified bromapatite‐type structure. The coordination spheres about the two crystallographically different Sm³⁺ cations are built up by oxygen atoms of the orthosilicate units ([SiO₄]^4–) and sulfide anions (S^2–). As a result, Sm1 and Sm2 have coordination numbers of 9 and 8, respectively. Na⁺ and (Sm1)³⁺ occupy the position 4 f in a molar ratio of 1 : 3 whereas the lower coordinated (Sm2)³⁺ occupies the 6 h position.     

Neue Synthesewege für Thiohalogeno- und Cyclothioarsenate(III). Kristallstrukturen von PPh4[As2SBr6] · CH3CN und PPh4[SAsS5]

Novel Routes to the Synthesis of Thiohalogeno- and Cyclothioarsenates(III). Crystal Structures of PPh₄[As₂SBr₆] · CH₃CN and PPh₄[SAsS₅] By reactions of (PPh₄)₂[As₂Cl₈] and (PPh₄)₂[As₂Br₈] with Na₂S₄ in acetonitrile (PPh₄)₂[As₂SCl₆] · CH₃CN and (PPh₄)₂[As₂SBr₆] · CH₃CN were obtained, respectively. Using K₂S₅, PPh₄[As₂SCl₅] and PPh₄[SAsS₅] were the products. The latter can also be obtained from PPh₄[As₂SCl₅] and Na₂S₄, while PPh₄[As₃S₃Br₄] is formed from PPh₄[As₂SBr₅] with K₂S₅. Two X-ray crystal structure determinations were performed. PPh₄[As₂SBr₆] · CH₃CN: triclinic, P1 , Z = 2, a = 1200.4(7), b = 1507.3(6), c = 1594.4(8) pm, α = 81.59(2), β = 78.22(3), γ = 80.58(2)°, R = 0.096 for 2298 observed reflexions. The structure contains [As₂SBr₆]^2? -ions in which the two Sb atoms are joined via one S and two Br atoms. PPh₄[SAsS₅]: triclinic, P1 , Z = 2, a = 1133.9(4), b = 1142.5(4), c = 1186.9(5) pm, α = 102.77(4), β = 107.74(3), γ = 106.65(3)°, R = 0.043 für 2677 reflexions. In the [SAsS₅]^? -ion an AsS₅ ring in the chair conformation is present.     

Reaktionen von Oxiden der Elemente der V. Hauptgruppe mit Trithiazylchlorid Kristallstruktur von (S5N5)4[As8Cl28] · 2 S4N4

Reactions of Element Oxides of the Fifth Main Group with Trithiazyl Chloride. Crystal Structure of (S₅N₅)₄[As₈Cl₂₈] · 2 S₄N₄ Whereas P₄O₁₀ does not react with (NSCl)₃, the oxides As₂O₃, Sb₂O₃, and Bi₂O₃ react under formation of (S₅N₅)₄[As₈Cl₂₈] · 2 S₄N₄, S₅N₅[SbCl₆] and a mixture of S₄N₅[BiCl₄] and S₄N₄Cl[BiCl₄], respectively. The products were characterized by their IR spectra. The crystal structure of (S₅N₅)₄[As₈Cl₂₈] · 2 S₄N₄ was determined by means of X-ray diffraction (1168 independent observed reflexions, R = 0.059). Crystal data: tetragonal, space group P4 2₁c, Z = 2, a = 1596.6, c = 1520.1 pm. The compound consists of planar S₅N₅^⊕ cations, octameric anions [As₈Cl₂₈]^4? and S₄N₄ molecules. The S₅N₅^⊕ ions and the S₄N₄ molecules show positional disorder, which very probably is of dynamical type for the S₅N₅^⊕ ion. The [As₈Cl₂₈]^4? ions can be described as a (so far unknown) [As₄Cl₁₆]^4? ion with cubane-like structure (As? Cl bridging distances between 286 and 305 pm) to which four AsCl₃ molecules are attached via chloro bridges with As? Cl bond lengths between 314 and 328 pm.     

Topologisch und elektronisch bemerkenswerte „reduzierte”︁ Cluster des Typs [V18O42(X)]n− (X = SO4, VO4) mit Td-Symmetrie und davon abgeleitete Cluster [V(18–p)As2pO42(X)]m− (X = SO3, SO4, H2O; p = 3, 4)

Reduced Clusters with Remarkable Topological and Electronic Properties of the Type of [V₁₈O₄₂(X)]^n? (X = SO₄, VO₄) with T_d-Symmetry and Related Clusters [V_(18—p)As_2pO₄₂(X)]^m? (X = SO₃, SO₄, H₂O; p = 3, 4) The novel cluster-compounds Na₆[V₁₈O₄₂H₉(VO₄)] · 21 H₂O, (NH₄)₈[V₁₈O₄₂(SO₄)] · 25 H₂O, K₆[V₁₅As₆O₄₂(H₂O)] · 8 H₂O, (NH₄)₆[V₁₄As₈O₄₂(SO₃)], (NH₄)₆[V₁₄As₈O₄₂(SO₄)] and [N(CH3)₃]₄[₄V₁₄As₈0₄₂(H₂0)] were prepared and characterized by IR- and UV/Vis/NIR-spectroscopy, magnetic measurements and complete crystal structure analysis. For structural data see Inhaltsübersicht. Topological relations to the rhombicuboctahedron spanned by 24 0-atoms of the genuine hypothetical a-Keggin ion, at which the square planes are capped by V?O or As₂O groups, are discussed. Of particular interest are the ?extended”? Keggin ions [V₁₈O₄₂(X)]ⁿ- (X = SO₄ VO₄), (formaly derived from the hypothetical genuine a-Keggin ion by addition of six V?O groups) which have quite different electron populations in spite of the same structure of their cluster shells.     

Dinuclear Manganese(II) Complexes with Bridging Selenidodiarsenate Anions [As2Se4]4−, [As2Se5]4− and [As2Se6]2−

Solvothermal reaction of [MnCl₂(amine)] (amine = terpy and tren) with elemental As and Se at a 1:1:2 molar ratio in H₂O/tren (10:1) affords the dimanganese(II) complexes [{Mn(terpy)}₂(μ‐As₂Se₄)] ( 1 ) and [{Mn(tren)}₂(μ‐As₂Se₅)] ( 2 ) respectively. The tetradentate [As₂Se₄]^4? bridging ligands in 1 contain a central As–As bond and exhibit approximately C_2h symmetry. Pairs of gauche sited Se atoms participate in five‐membered As₂Se₂Mn chelate rings. In contrast, two AsSe₃ pyramids share a common corner in the [As₂Se₅]^4? ligands of 2 and each coordinates an [Mn(tren)]²⁺ fragment through a single terminal Se atom. Such dinuclear complexes are linked into tetranuclear moieties through weak Se···Mn interactions of length 3.026(3) Å involving one of these terminal Se atoms. At a 1:3:6 molar ratio, solvothermal reaction of [MnCl₂(tren)] with As and Se leads to formation of a second dinuclear complex [{Mn(tren)}₂(μ‐As₂Se₆)₂] ( 3 ), which contains two bridging bidentate [As₂Se₆]^2? ligands. These are cyclic with an As₂Se₄ ring and can be regarded as being derived from [As₂Se₅]^4? anions by formation of two Se‐Se bonds to an additional Se atom.     

A 3d‐4f Complex Constructed by the Assembly of a Cationic Template, [Cu(en)2]2+, and a 3D Anionic Coordination Polymer, [Sm2(C2O4)3(C5O5)(H2O)2]2–

A three‐dimensional (3D) 3d‐4f complex, [Cu(en)₂][Sm₂(C₅O₅)(C₂O₄)₃(H₂O)₂] · 8H₂O ( 1 ) (en = ethylenediamine, C₅O₅^2– = dianion of 4,5‐dihydroxycyclopent‐4‐ene‐1,2,3‐trione), were prepared via the in‐situ ring‐opening oxidation reaction of croconate in the presence of the template‐directed complex, [Cu(en)₂]²⁺ cation. The structural characterization determined by X‐ray diffraction determination reveals that the 3D anionic coordination polymer of [Sm₂(C₂O₄)₃(C₅O₅)(H₂O)₂]^2– in 1 can be describe in terms of in‐plane 2D honeycomb‐like [Sm₂(C₂O₄)₃] layered frameworks bridged by oxalate with bis‐chelating mode, being mutually interlinked via the bridge of μ_1,2,3,4‐croconate ligands with bis‐chelating coordination mode to complete the 3D open framework, which gives rise to 1D channels with pore size of 14.023 × 11.893 Å (longest atom–atom contact distances) along the b axis. The structure‐directing complex, [Cu(en)₂]²⁺, and solvated water molecules are resided into these honeycomb‐type hexagonal channels. The thermal stability of 1 was further studied by TGA and in‐situ powder X‐ray diffraction measurement.     

Thiochloroarsenate(III): Darstellung,Schwingungsspektren und Kristallstrukturen von PPh4[As2SCl5] und (PPh4)2[As2SCl6] · C2H4Cl2

Thiochloroarsenates (III): Preparation, Vibrational Spectra, and Crystal Structures of PPh₄[As₂SCl₅] and (PPh₄)₂[As₂SCl₆] · C₂H₄Cl₂ PPh₄[As₂SCl₅] can be obtained from As₂S₃ + PPh₄Cl with HCl in CH₂Cl₂ or 1,2-C₂H₄Cl₂. It reacts with a second mole of PPh₄Cl to yield (PPh₄)₂[As₂SCl₆]. The latter also is formed by the reaction of As₂S₅ + 2 PPh₄Cl with HCl, a second product being (PPh₄)₂[As₂Cl₈]. The i.r. and Raman spectra of the title compounds are reported. Their crystal structures were determined by X-ray diffraction. Crystal data: PPh₄[As₂SCl₅], monoclinic, space group P2₁/n, a = 1175.8, b = 1508.0, c = 1593.4 pm, β = 96.22°, Z = 4; (PPh₄)₂[As₂SCl₆] · C₂H₄Cl₂, triclinic, P1, a = 1166.3, b = 1188.2, c = 2044.6 pm, α = 95.47, β = 97.53, γ = 111.05°, Z = 2. Including the lone electron pairs, the coordination of the As atoms in the [As₂SCl₅]⁻ ion is distorted trigonal-bipyramidal with the S, one Cl atom, and an electron pair in equatorial positions; the two bipyramids around the two As atoms share a common edge. The As atoms in the [As₂SCl₆]²⁻ ion have a distorted octahedral coordination, the two octahedra share a common face; the lone electron pairs are in the trans positions to the S atom.     

[TMPA]4[Si8O20] · 34 H2O and [DDBO]4[Si8O20] · 32 H2O are heteronetwork clathrates with 1,1,4,4-tetramethylpiperazinium (TMPA) and 1,4-dimethyl-1,4-diazoniabicyclo[2.2.2]octane (DDBO) guest cations

[TMPA]₄[Si₈O₂₀] · 34 H₂O ( 1 ) and [DDBO]₄[Si₈O₂₀] · 32 H₂O ( 2 ) have been prepared by crystallization from aqueous solutions of the respective quaternary alkylammonium hydroxide and SiO₂. The crystal structures have been determined by single-crystal X-ray diffraction. 1 : Monoclinic, a = 16.056(2), b = 22.086(6), c = 22.701(2) Å, β = 90.57(1)° (T = 210 K), space group C2/c, Z = 4. 2 : Monoclinic, a = 14.828(9), b = 20.201(7), c = 15.519(5) Å, β = 124.13(4)° (T = 255 K), space group P2₁/c, Z = 2. The polyhydrates are structurally related host-guest compounds with three-dimensional host frameworks composed of oligomeric [Si₈O₂₀]^8? anions and H₂O molecules which are linked via hydrogen bonds. The silicate anions possess a cube-shaped double four-ring structure and a characteristic local environment formed by 24 H₂O molecules and six cations (TMPA, [C₈H₂₀N₂]²⁺, or DDBO, [C₈H₁₈N₂]²⁺). The cations themselves reside as guest species in large, irregular, cage-like voids. Studies employing ²⁹Si NMR spectroscopy and the trimethylsilylation method have revealed that the saturated aqueous solutions of 1 and 2 contain high proportions of double four-ring silicate anions. Such anions are also abundant species in the saturated solution of the heteronetwork clathrate [DMPI]₆[Si₈O₁₈(OH)₂] · 48.5 H₂O ( 3 ) with 1,1-dimethylpiperidinium (DMPI, [C₇H₁₆N]⁺) guest cations.     

Das gemischtvalente ternäre Oxoferrat(II,III) K3[Fe2O4] – eine aufgefüllte Variante des K2[Fe2O4]‐Typs

The Mixed‐Valent Oxoferrate(II,III) K₃[Fe₂O₄] – A Stuffed Variant of the K₂[Fe₂O₄] Type of Structure K₃[Fe₂O₄] has been obtained by tempering “Cs₃K₃CdO₄” in sealed Fe containers (36 d at 450–480 °C) as dark red transparent single crystals of rectangular shape. The structure determination (IPDS diffractometer data, MoKα, 1891 collected reflections, 234 symmetry independent, R1 = 0.033, wR2 = 0.088) confirms the space group Fddd; a = 596.11(9), b = 1140.3(1), c = 1717.9(3) pm; Z = 8. K₃[Fe₂O₄] exhibits a structure with [FeO₄] tetrahedra connected via corners leading to a three‐dimensional network closely related to the KFeO₂ type of structure. From the oxidation at 520 °C of iron metal with KO₂ in the presence of Na₂O black single crystal of K₂[Fe₂O₄] have been obtained. K₂[Fe₂O₄] crystallizes in the space group Pbca with Z = 8 and a = 559.18(7), b = 1122.1(1), c = 1592.8(2) pm (IPDS diffractometer data, MoKα, collected refelctions: 9543, 1213 symmetry independent, R1 = 0.043, wR2 = 0.102).     

Hydroxoverbindungen. 10. Über die Natriumoxohydroxostannate(II) Na4[Sn4O(OH)10] und Na2[Sn2O(OH)4]

Hydroxo Compounds. 10. The Sodium Oxohydroxostannates(II) Na₄[Sn₄O(OH)₁₀] and Na₂[Sn₂O(OH)₄] Na₄[Sn₄O(OH)₁₀] = Na₄[Sn(OH)₃]₂[Sn₂O(OH)₄] ( I ) and Na₂[Sn₂O(OH)₄] ( II ) have now been doubtlessly characterized as the first Na-hydroxostannates(II). I crystallizes monoclinic in P2₁/n (a = 1522.4(5) pm, b = 830.0(2) pm, c = 1276.0(3) pm, β = 104.8(2)°, Z = 4, R = 0.047, 1137 I_hkl); II crystallizes orthorhombic in P2₁2₁2₁ (a = 1450(2) pm, b = 1665(2) pm, c = 590.7(8) pm, Z = 8, R = 0.042, 1208 I_hkl). II is identical with the compound which was described up to now as “Na[Sn(OH)₃]”. The new compounds contain the complex anions [Sn(OH)₃]^? and [Sn₂O(OH)₄]^2?, whose structures are now proved. The oxotetrahydroxo-distannate(II) anion [Sn₂O(OH)₄]^2? exhibits a syn-conformation with respect to the projection along the (Sn? Sn) vector. The two compounds crystallize with pronounced layer structures, which show direct topotactical relations with one another as well as with SnO. This relates closely to the fast formation of SnO from crystals of I and II .     

Das erste oligomere Oxoindat(III): K14[In4O13]

The First Oligooxoindate(III): K₁₄[In₄O₁₃] For the first time K₁₄[In₄O₁₃] was obtained by heating intimate mixtures of K₂O, CdO and elementar In (molar ratio 3.1:1.0:1.0) in closed Ag-cylinders (30 days, 450°C) in form of yellow-brown single crystals. The structure determination by four circle diffractometer data MoKα, 3 689 out of 3 689 I_o(hkl), R = 4.22, R_w = 2.45) confirms the space group P2₁/c with lattice constants a = 687.7 pm; b = 3 118.5 pm; c = 686.4 pm; β = 119.3°; Z = 2. The characteristic feature of the structure is [In₄O₁₃]^14? groups, oligomers consisting of four corner-sharing InO₄ tetrahedra. These groups are connected by crystallographically distinct potassium atoms. The structure is isotypic with Na₁₄[Al₄O₁₃] [2] and K₁₄[Fe₃O₁₃] [3]. ECoN and MAPLE calculationes are discussed.     

[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.     

[Ho5(H2O)16(OH)2As6W64O220]25−, ein großes neuartiges Polyoxoanion aus trivakanten Keggin‐Fragmenten

[Ho₅(H₂O)₁₆(OH)₂As₆W₆₄O₂₂₀]^25?, a Large Novel Polyoxoanion from Trivacant Keggin Fragments The novel polyoxotungstate Na₇K₁₈[Ho₅(H₂O)₁₆(OH)₂As₆W₆₄O₂₂₀] · 56 H₂O ( 1 ) was synthesized in aqueous solution and characterized by X‐ray structure analysis, elemental analysis and IR spectroscopy. The anion in 1 represents one of the largest polyoxoanions known yet and exhibits an unusual arrangement of six Keggin units. It consists of six trivacant lacunary α‐B‐(AsW₉O₃₃)^9? Keggin fragments which are connected by a bridging [Ho₅W₁₀(H₂O)₁₆(OH)₂O₂₂]²⁹⁺ unit. The five Ho^III atoms are coordinated by eight oxygen atoms, forming a square‐antiprism.     

Neue Halogenochalkogen(IV)‐Säuren: [H3O(Benzo‐18‐Krone‐6)]2[Te2Br10] und [H5O2(Dibenzo‐24‐Krone‐8)]2[Te2Br10]

Novel Halogenochalcogeno(IV) Acids: [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] Systematic studies on halogenochalcogeno(IV) acids containing tellurium and bromine led to the new crystalline phases [H₃O(Benzo‐18‐Crown‐6)]₂[Te₂Br₁₀] ( 1 ) and [H₅O₂(Dibenzo‐24‐Crown‐8)]₂[Te₂Br₁₀] ( 2 ). The [Te₂Br₁₀]^2‐ anions consists of two edge‐sharing distorted TeBr₆ octahedra, the oxonium cations are stabilized by crownether. ( 1 ) crystallizes in the monoclinic space group P2₁/n with a = 14.520(5) Å, b = 22.259(6) Å, c = 16.053(5) Å, β = 97.76(3)° and Z = 4, whereas ( 2 ) crystallizes in the triclinic space group with a = 11.005(4) Å, b = 12.103(5) Å, c = 14.951(6) Å, α = 71.61(3)°, β = 69.17(3)°, γ = 68.40(3)° and Z = 1.     

High‐dimensional Polyoxoniobates Constructed from Lanthanide‐incorporated High‐nuclear {[Ln(H2O)4]3[Nb24O69(H2O)3]2} Secondary Building Units

In this work, two rare high‐dimensional polyoxoniobates with formulas of H₉[Cu(en)(H₂O)₂][Cu(en)₂]₈[Dy(H₂O)₄]₃[Nb₂₄‐O₆₉(H₂O)₃]₂ ? 36H₂O ( 1 ) and H₉K[Cu(en)₂(H₂O)]₅[Cu(en)₂]₄‐[Eu(H₂O)₄]₃[Nb₂₄O₆₉(H₂O)₃]₂ ? 2en ? 45H₂O ( 2 ) have been obtained under hydrothermal conditions. These extended materials are constructed from lanthanide‐incorporated triangular‐prism‐like polyoxoniobate secondary building units (SBUs) {[Ln(H₂O)₄]₃[Nb₂₄O₆₉(H₂O)₃]₂} (Ln=Dy, Eu). 1 and 2 represent the first examples of high‐dimensional polyoxometalate materials based on such lanthanide‐incorporated triangular‐prism‐like polyoxoniobate SBUs. Furthermore, the proton conduction property and the luminescent emission of these materials were evaluated.