Wasserfreie Selenite des Lanthans: Synthese und Kristallstruktur von La2(SeO3)3 und LaFSeO3

Anhydrous Selenites of Lanthanum: Syntheses and Crystal Structures of La₂(SeO₃)₃ and LaFSeO₃ Colorless single crystals of La₂(SeO₃)₃ were obtained via the decomposition of La₂(SeO₄)₃ in the presence of NaCl in sealed gold ampoules. The compound crystallizes in the orthorhombic system (Pnma, Z = 4, a = 846.7(1), b = 1428.6(1), c = 710.3(2) pm, R_all = 0.0223) and contains La³⁺ in tenfold coordination of oxygen atoms which belong to seven SeO₃^2– groups. Hence, three of the latter act as bidentate ligands. The reaction of LiF with La₂(SeO₄)₃ in sealed gold ampoules yielded colorless single crystals of LaFSeO₃ (monoclinic, P2₁/c, Z = 12, a = 1819.8(3), b = 715.75(8), c = 846.4(1) pm, β = 96.89(2)°, R_all = 0.0352). The crystal structure contains three crystallographically different La³⁺ ions. La1 is surrounded by six oxygen atoms from five SeO₃^2– groups and four fluoride ions, La2 is coordinated by two bidentate SeO₃^2– ions and seven fluoride ligands. La3 is surrounded by oxygen atoms only with the coordination number and polyhedron being almost the same as found for La³⁺ in La₂(SeO₃)₃. Furthermore, the crystal structures of both compounds are strongly influenced by the lone pairs of the SeO₃^2– groups.     

Pr4(SeO3)2(SeO4)F6 und NaSm(SeO3)(SeO4): Selenit‐Selenate der Selten‐Erd‐Elemente

Pr₄(SeO₃)₂(SeO₄)F₆ and NaSm(SeO₃)(SeO₄): Selenite‐Selenates of Rare Earth Elements Light green single crystals of Pr₄(SeO₃)₂(SeO₄)F₆ have been obtained from the decomposition of Pr₂(SeO₄)₃ in the presence of LiF in a gold ampoule. The monoclinic compound (C2/c, Z = 4, a = 2230.5(3), b = 710.54(9), c = 835.6(1) pm, β = 98.05(2)°, R_all = 0.0341) contains two crystallographically different Pr³⁺ ions. Pr(1)³⁺ is attached by six fluoride ions and two chelating SeO₃^2– groups (CN = 10), Pr(2)³⁺ is surrounded by four fluoride ions, three monodentate SeO₃^2– and two SeO₄^2– groups. One of the latter acts as a chelating ligand, so the CN of Pr(2)³⁺ is 10. The selenite ions are themselves coordinated by five and the selenate ions by four Pr³⁺ ions. The coordination number of the F^– ions is three and four, respectively. The linkage of the coordination polyhedra leads to cavities in the crystal structure which incorporate the lone pairs of the selenite ions. The reaction of Sm₂(SeO₄)₃ and NaCl in gold ampoules yielded light yellow single crystals of NaSm(SeO₃)(SeO₄). The monoclinic compound (P2₁/c, Z = 4, a = 1066.9(2), b = 691.66(8), c = 825.88(9) pm, β = 91.00(2)°, R_all = 0.0530) contains tenfold oxygen coordinated Sm³⁺ ions. The oxygen atoms belong to five SeO₃^2– and two SeO₄^2– ions. Two of the SeO₃^2– groups as well as one of the SeO₄^2– groups act as a chelating ligand. The sodium ions are surrounded by five SeO₄^2– ions and one SeO₃^2– group. One of the selenate ions is attached chelating leading to a coordination number of seven. Each selenite group is coordinated by six (5 × Sm³⁺ and 1 × Na⁺), each selenate ion by seven cations (5 × Na⁺ and 2 × Sm³⁺).     

Gd3(SeO3)4F: Ein Fluoridselenit mit μ3‐SeO32–und μ3‐F–‐überkappten Gd3‐Ringen

Gd₃(SeO₃)₄F: A Fluoride Selenite with μ₃‐SeO₃^2– and μ₃‐F^– Capped Gd₃ Rings The decomposition of Gd₂(SeO₄)₃ in the presence of LiF in sealed gold ampoules yields single crystals of Gd₃(SeO₃)₄F (hexagonal, P6₃mc, Z = 2, a = 1044.3(1), b = 694.32(7) pm, R_all = 0.0286). In the crystal structure one SeO₃^2– group and one F^– ion cap a ring of three Gd atoms. Furthermore, the crystal structure is strongly influenced by the lone pairs of the SeO₃^2– ions.     

CoSm(SeO3)2Cl,CuGd(SeO3)2Cl,MnSm(SeO3)2Cl,CuGd2(SeO3)4 und CuSm2(SeO3)4: Übergangsmetallhaltige Selenite von Samarium und Gadolinum

CoSm(SeO₃)₂Cl, CuGd(SeO₃)₂Cl, MnSm(SeO₃)₂Cl, CuGd₂(SeO₃)₄ and CuSm₂(SeO₃)₄: Transition Metal containing Selenites of Samarium and Gadolinum The reaction of CoCl₂, Sm₂O₃, and SeO₂ in evacuated silica ampoules lead to blue single crystals of CoSm(SeO₃)₂Cl (triclinic, , Z = 4, a = 712.3(1), b = 889.5(2), c = 1216.2(2) pm, α = 72.25(1)°, β = 71.27(1)°, γ = 72.08(1)°, R_all = 0.0586). If MnCl₂ is used in the reaction light pink single crystals of MnSm(SeO₃)₂Cl (triclinic, , Z = 2, a = 700.8(2), b = 724.1(2), c = 803.4(2) pm, α = 86.90(3)°, β = 71.57(3)°, γ = 64.33(3)°, R_all = 0.0875) are obtained. Green single crystals of CuGd₂(SeO₃)₂Cl (triclinic, , Z = 4, a = 704.3(4), b = 909.6(4), c = 1201.0(7) pm, α = 70.84(4)°, β = 73.01(4)°, γ = 70.69(4)°, R_all = 0.0450) form analogously in the reaction of CuCl₂ and Gd₂O₃ with SeO₂. CoSm(SeO₃)₂Cl contains [CoO₄Cl₂] octahedra, which are connected via one edge and one vertex to infinite chains. The Mn²⁺ ions in MnSm(SeO₃)₂Cl are also octahedrally coordinated by four oxygen and two chlorine ligands. The linkage of the polyhedra to chains occurs exclusively via edges. Both, the cobalt and the manganese compound show the Sm³⁺ ions in eight and ninefold coordination of oxygen atoms and chloride ions. In CuGd(SeO₃)₂Cl the Cu²⁺ ions are coordinated by three oxygen atoms and one Cl^— ion in a distorted square planar manner. One further Cl^— and one further oxygen ligand complete the [CuO₃Cl] units yielding significantly elongated octahedra. The latter are again connected to chains via two common edges. For the Gd³⁺ ions coordination numbers of ?8 + 1”? and nine were found. Single crystals of the deep blue selenites CuM₂(SeO₃)₄ (M = Sm/Gd, monoclinic, P2₁/c, a = 1050.4(3)/1051.0(2), b = 696.6(2)/693.5(1), c = 822.5(2)/818.5(2) pm, β = 110.48(2)°/110.53(2)°, R_all = 0.0341/0.0531) can be obtained from reactions of the oxides Sm₂O₃ and Gd₂O₃, respectively, with CuO and SeO₂. The crystal structure contains square planar [CuO₄] groups and irregular [MO₉] polyhedra.     

Halogenidsulfate des Gadoliniums: Synthese und Kristallstruktur von GdClSO4 und GdFSO4

Halide Sulfates of Gadolinium: Synthesis and Crystal Structure of GdClSO₄ and GdFSO₄ Single crystals of GdClSO₄ are obtained from the reaction of Gd₂(SO₄)₃ and GdCl₃ in silica ampoules. In the monoclinic compound (P2₁/c, Z = 4, a = 943.7(1), 657.59(8), 680.05(9) pm, β = 104.87(2)?, R_all = 0.0352) Gd³⁺ is surrounded by five sulfate groups and three chloride ligands. One of the sulfate groups acts as a bidentate ligand so that the coordination number of Gd³⁺ is nine. The reaction of Gd₂(SO₄)₃ with LiF in sealed gold ampoules yields colorless transparent single crystals of GdFSO₄. The compound crystallizes orthorhombic (Pnma, Z = 4, a = 843.6(1), b = 701.76(8), c = 643.38(7) pm, R_all = 0.0207) and contains eight‐coordinate Gd³⁺ ions. The ligands are six oxygen atoms of five sulfate groups and two fluoride ions.     

LiLa2F3(SO4)2 und LiEr2F3(SO4)2: Fluoridsulfate der Selten‐Erd‐Elemente mit Lithium

LiLa₂F₃(SO₄)₂ and LiEr₂F₃(SO₄)₂: Fluoride‐Sulfates of the Rare‐Earth Elements with Lithium The reaction of LiF with the anhydrous sulfates M₂(SO₄)₃ (M = La, Er) in sealed gold ampoules yields single crystals of the pseudo quaternary compounds LiLa₂F₃(SO₄)₂ and LiEr₂F₃(SO₄)₂. According to X‐ray single crystal investigations, LiLa₂F₃(SO₄)₂ crystallizes with the monoclinic (I2/a, Z = 4, a = 828.3(2), b = 694.7(1), c = 1420.9(3) pm, β = 95.30(2)°, R_all = 0.0214) and LiEr₂F₃(SO₄)₂ with the orthorhombic crystal system (Pbcn, a = 1479.1(2), b = 633.6(1), c = 813.7(1) pm, R_all = 0.0229). A common feature of both structures is a dimeric unit of metal atoms connected via three fluoride ions. This leads to relatively short metal‐metal distances (La³⁺–La³⁺: 389 pm, Er³⁺–Er³⁺: 355 pm). In LiLa₂F₃(SO₄)₂, Li⁺ is surrounded by four oxygen atoms of four sulfate groups and one fluoride ion in form of a trigonal bipyramid, in LiEr₂F₃(SO₄)₂ two further fluoride ligands are attached.     

Zur Kenntnis der Hydrate M(HSeO3)2 · 4H2O (M = Mg,Co, Ni,Zn). Röntgenstrukturanalytische,schwingungsspektroskopische und thermoanalytische Untersuchungen

On the Hydrates M(HSeO₃)₂ · 4H₂O (M = Mg, Co, Ni, Zn) – Crystal Structures, IR, Raman, and Thermoanalytical Investigations From aqueous solutions of M(HSeO₃)₂ single crystals of Mg(HSeO₃)₂ · 4H₂O and of the hitherto unknown compounds Co(HSeO₃)₂ · 4H₂O, Ni(HSeO₃)₂ · 4H₂O and Zn(HSeO₃)₂ · 4H₂O could be obtained. The crystal structures, X-ray powder, IR, Raman and thermoanalytical (DTA, TG, Raman heating) data are presented and discussed. The crystal data of the isotypic compounds are: monoclinic, space group C2/c, Z = 4, Mg: a = 1 464.6(2), b = 755.3(1), c = 1 099.9(1) pm, β = 126.59(1)°, V = 0.9769(1) nm³, Co: a = 1 462.5(2), b = 756.5(2), c = 1 102.2(2) pm, β = 126.53(1)°, V = 0.9798(2) nm³, Ni: a = 1 452.2(2), b = 751.0(1), c = 1 091.5(1) pm, β = 126.28(1)°, V = 0.9595(1) nm³, Zn: a = 1 468.3(2), b = 755.8(1), c = 1 103.1(1) pm, β = 126.79(1)°, V = 0.9804(2) nm³. The crystal structures consist of hexagonal packed [M(HSeO₃)₂ · 2H₂O]_n chains of [MO₄(H₂O)₂] octahedra linked by Se atoms. They contain trigonal pyramidal SeO₂OH^?ions with “free” hydroxyl groups and also “free” molecules of water of crystallization. The hydroxyl groups build strong H-bonds (O? H …? O distances: 265–268 pm). The IR spectra show AB doublett bands in the OH stretching mode region of the hydroxyl groups. The water molecules of crystallization are linked to planar (H₂O)₄ tetramers by H-bonds with unusually short O? H …? O bond distances of 271–273 pm. DTA and TG measurements indicate that thermal decomposition results in the direct formation of the respective diselenite MSe₂O₅. Raman heating measurements show under quasi static conditions the intermediate formation of the anhydrous hydrogen selenites.     

RbAu(SeO4)2: First Structure Determination of a Ternary Gold Selenate

Yellow single crystals of RbAu(SeO₄)₂ were obtained upon evaporation of a solution prepared from the reaction of elemental gold and Rb₂CO₃ with conc. selenic acid. In the crystal structure (monoclinic, C2/m, Z = 2, a = 1078.7(4), b = 522.7(1), c = 739.3(2) pm, β = 116.45(2)°) Au³⁺ is in square planar coordination of oxygen atoms which belong to four SeO₄^2- ions. According to [Au(SeO₄)_4/2]^- anionic chains are formed which are connected by the Rb⁺ ions. The latter are surrounded by two chelating and six monodentate selenate groups leading to a CN of 10.     

Saure Sulfate des Neodyms: Synthese und Kristallstruktur von (H5O2)(H3O)2Nd(SO4)3 und (H3O)2Nd(HSO4)3SO4

Acidic Sulfates of Neodymium: Synthesis and Crystal Structure of (H₅O₂)(H₃O)₂Nd(SO₄)₃ and (H₃O)₂Nd(HSO₄)₃SO₄ Light violett single crystals of (H₅O₂)(H₃O)₂ · Nd(SO₄)₃ are obtained by cooling of a solution prepared by dissolving neodymium oxalate in sulfuric acid (80%). According to X‐ray single crystal investigations there are H₃O⁺ ions and H₅O₂⁺ ions present in the monoclinic structure (P2₁/n, Z = 4, a = 1159.9(4), b = 710.9(3), c = 1594.7(6) pm, β = 96.75(4)°, R_all = 0.0260). Nd³⁺ is nine‐coordinate by oxygen atoms. The same coordination number is found for Nd³⁺ in the crystal structure of (H₃O)₂Nd(HSO₄)₃SO₄ (triclinic, P1, Z = 2, a = 910.0(1), b = 940.3(1), c = 952.6(1) pm, α = 100.14(1)°, β = 112.35(1)°, γ = 105.01(1)°, R_all = 0.0283). The compound has been prepared by the reaction of Nd₂O₃ with chlorosulfonic acid in the presence of air. In the crystal structure both sulfate and hydrogensulfate groups occur. In both compounds pronounced hydrogen bonding is observed.     

Das erste Hexaoxoselenat (VI) – Synthese und Charakterisierung von Na12(SeO6)(SeO4)3

The First Hexaoxoselenate(VI) – Synthesis and Characterization of Na₁₂(SeO₆)(SeO₄)₃ Pure Na₁₂(SeO₆)(SeO₄)₃ has been prepared by solid state reaction at 500 °C from a mixture of Na₂O and Na₂SeO₄ in silver crucibles. The crystal structure has been determined from single crystal data (Pnma, a = 1577.2(7), b = 781.7(3), c = 1475.5(7) pm, Z = 4, R1 = 0.030, wR2 = 0.058, 2480 observed reflections [I_o ≥ 2σ(I_o)]). Na₁₂(SeO₆)(SeO₄)₃ contains novel SeO₆^6– anions. There exists an unexpected topological relationship between the SeO₆Naⁱ₈Na^a₂Na^a_4/2 part of the structure and the MoCl₂ structure type (Mo₆Clⁱ₈Cl^a₂Cl^a_4/2). The crystal structure as determined is consistent with spectroscopic data (IR, Raman, ⁷⁷Se‐MAS‐NMR).     

Synthesis and Characterization of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2

Red single crystals of Gd₂[Pt₂(SO₄)₄(HSO₄)₂](HSO₄)₂ (triclinic, , Z = 1, a = 844.02(9), b = 908.50(9), c = 939.49(8) pm, α = 107.73(1)°, β = 112.10(1)°, γ = 103.53(1)°) were obtained by the reaction of [Gd(NO₃)(H₂O)₇][PtCl₆]·4H₂O with sulfuric acid at 320 °C in a sealed glass ampoule. In the crystal structure, Pt₂ dumbbells are coordinated by four chelating sulfate groups and two monodentate hydrogensulfate ions. Two further HSO₄^? ions are not bonded to the Pt₂ dumbbell. The Gd³⁺ ions are eightfold coordinated by oxygen atoms. The IR data of Gd₂[Pt₂(SO₄)₄(HSO₄)₂](HSO₄)₂ are typical for these type of compounds. The thermal decomposition of the compound leads to elemental platinum and Gd₂O₃.     

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.     

Synthese und Struktur der Nitridoborat‐Nitride Ln4(B2N4)N (Ln = La,Ce) des Formeltyps Ln3+x(B2N4)Nx (x = 0, 1, 2)

Synthesis and Structure of Nitridoborate Nitrides Ln₄(B₂N₄)N (Ln = La, Ce) of the Formula Type Ln_3+x(B₂N₄)N_x (x = 0, 1, 2) The missing member of the formula type Ln_3+x(B₂N₄)N_x with x = 1 was synthesized and characterized for Ln = La and Ce. According to the single‐crystal X‐ray structure solution Ce₄(B₂N₄)N crystallizes in the space group C2/m (Z = 2) with the lattice parameters a = 1238.2(1) pm, b = 357.32(3) pm, c = 905.21(7) pm and β = 129.700(1)°. The anisotropic structure refinement converged at R1 = 0.039 and wR2 = 0.099 for all independent reflections. A powder pattern of La₄(B₂N₄)N was indexed isotypically with a = 1260.4(1) pm, b = 366.15(3) pm, c = 919.8(1) pm and β = 129.727(6)°. A structure rational for nitridoborates and nitridoborate nitrides containing B₂N₄ ions with the general formula Ln_3+x(B₂N₄)N_x with x = 0, 1, 2 is presented.     

Wasserfreie Sulfate der Selten‐Erd‐Elemente: Synthese und Kristallstruktur von Y2(SO4)3 und Sc2(SO4)3

Anhydrous Sulfates of Rare Earth Elements: Syntheses and Crystal Structures of Y₂(SO₄)₃ and Sc₂(SO₄)₃ The reaction of YCl₃ and Li₂SO₄ in sealed gold ampoules yields colorless single crystals of Y₂(SO₄)₃. According to the X‐ray single crystal determination the compound crystallizes with orthorhombic symmetry (Pbcn, Z = 4, a = 1273.97(13), b = 916.76(9), c = 926.08(7) pm, R_all = 0.0274). The crystal structure is buildt up from [YO₆] octahedra and sulfate tetrahedra connected via all vertices. In the same way [ScO₆] octahedra and sulfate groups are connected in the crystal structure of Sc₂(SO₄)₃ (trigonal, R‐3, Z = 6, a = 870.7(1), c = 2247.0(4) pm, R_all = 0.0255). Single crystals of Sc₂(SO₄)₃ were obtained via crystallisation of powder samples from a NaCl melt. The crystal structures of both compounds are closely related to each other and to the binary sulfides Rh₂S₃ and Lu₂S₃; the structures are the same with the complex SO₄^2– ions replacing the S^2– ions of the sulfides.     

Hexachloroplatinates of the Lanthanides: Syntheses and Thermal Decomposition of [M(NO3)2(H2O)6]2[PtCl6]·2H2O (M = La,Pr) and [M(NO3)(H2O)7][PtCl6]·4H2O (M = Gd,Dy)

The reaction of the nitrates M(NO₃)₃·6H₂O (M = La, Pr) and (H₃O)₂PtCl₆ led to yellow single crystals of [M(NO₃)₂(H₂O)₆]₂[PtCl₆]·2H₂O (M = La, Pr) (monoclinic, P2₁/c, Z = 2, La/Pr: a = 697.4(3)/695.5(1), b = 1654.5(1)/1652.5(2), c = 1317.7(6)/1318.5(3) pm, β = 93.97°(7)/93.93°(2), R_all = 0.0169/0.0659) while the reaction of M(NO₃)₃·5H₂O (M = Gd, Dy) and (H₃O)₂PtCl₆ yielded yellow single crystals of [M(NO₃)(H₂O)₇][PtCl₆]·4H₂O (monoclinic, P2₁/n, Z = 4, Gd/Dy: a = 838.72(3)/838.40(2), b = 2131.98(6)/2139.50(7), c = 1142.63(3)/1143.10(3) pm, β = 95.670(4)/95.698(3), R_all = 0.0475/0.0337). The crystal structures consist of octahedral [PtCl₆]^2? anions and complex [M(NO₃)₂(H₂O)₆]₂⁺ and [M(NO₃)(H₂O)₇]²⁺ cations, respectively. The thermal decomposition of both types of compounds leads via various steps to elemental platinum and the oxide chlorides MOCl (M = La, Pr, Gd, Dy).     

Das wasserfreie Lanthanacetat,La(CH3COO)3, und sein Precursor,NH4)3[La(CH3COO)6] · 1/2 H2O: Synthese,Strukturen, thermisches Verhalten

Anhydrous Lanthanum Acetate, La(CH₃COO)₃, and its Precursor, ·NH₄)₃[La(CH₃COO)₆] · 1/2 H₂O: Synthesis, Structures, Thermal Behaviour Single crystals of (NH₄)₃[La(CH₃COO)₆] · ½ H₂O are obtained by refluxing La₂O₃in (CH₃COO)₃ · 1.5 H₂O with an excess of NH₄CH₃COO in methanol. The crystal structure (trigonal, R3 , Z = 6, a = 1 365.0(3) pm, c = 2 360(1) pm, R = 0.088, R_w = 0.061 exhibits the coordination number of nine for La³⁺, which is surrounded by three chelating-type bidentate and three unidentate acetate groups. Characteristic are monomeric units of [La(CH₃COO)₆]^3? which are connected to a three-dimensional network by hydrogen bonds with the NH ions. Thermal decomposition consists of four steps with La(CH₃COO)₃, La₂(CO₃)₃ and La₂O₂CO₃ as intermediates and La₂O₃ as the final Product. Single crystals of La(CH₃COO)₃ are obtained from La₂O₃ in a melt of NH₄CH₃COO (molar ratio 1:12) in a sealed glass ampoule. The crystal structure (trigonal, R3 , Z = 18, a = 2 203.0(5) pm; c = 987.1(3) pm, R = 0.027, R_w = 0.023) shows the coordination number of ten for La³⁺. These are three-dimensionally connected by oxygen atoms of the acetate groups with two tetradentate double-bridging and one Z,Z-type-bridging bidentate acetate group.     

Synthese und Kristallstruktur von Hydrogenselenaten zweiwertiger Metalle – M(HSeO4)2 (M = Mg,Mn, Zn) und M(HSeO4)2 · H2O (M = Mn,Cd)

Synthesis and Crystal Structure of Hydrogen Selenates of Divalent Metals – M(HSeO₄)₂ (M = Mg, Mn, Zn) and M(HSeO₄)₂ · H₂O (M = Mn, Cd) New hydrogen selenates M(HSeO₄)₂ (M = Mg, Mn, Zn) and M(HSeO₄)₂ · H₂O (M = Mn, Cd) have been synthesized using MSeO₄ (M = Mg, Mn, Zn, Cd) and 90% selenic acid as starting materials. The crystal structures have been determined by X-ray single crystal crystallography. The compounds M(HSeO₄)₂ (M = Mg, Zn) belong to the structure type of Mg(HSO₄)₂, whereas Mn(HSeO₄)₂ forms a new structure type. Both hydrogen selenate monohydrates are isotypic to Mg(HSO₄)₂ · H₂O. In all compounds the metal atoms are octahedrally coordinated by oxygen atoms of different HSeO₄-tetrahedra. In the HSeO₄-tetrahedra the Se–OH-distances (mean value 1.70 Å) are about 0.1 Å longer than Se–O-distances (mean value 1.62 Å). In the structure of M(HSeO₄)₂ (M = Mg, Zn) there are zigzag chains of hydrogen bonded HSeO₄-tetrahedra. The structure of Mn(HSeO₄)₂ is characterized by chains of HSeO₄-tetrahedra in form of screws. Hydrogen bonds from and to water molecules connect double layers of MO₆-octahedra and HSeO₄-tetrahedra in the structures of M(HSeO₄)₂ · H₂O.     

Synthese und Kristallstruktur von Y(HSO4)3-I und Y(HSO4)3 · H2O

Syntheses and Crystal Structures of Y(HSO₄)₃-I and Y(HSO₄)₃ · H₂O Lath shaped crystals of Y(HSO₄)-I are obtained by treatment of Y₂O₃ with conc. sulfuric acid at 200 °C. Y(HSO₄)₃-I crystallizes orthorhombic (Pbca, Z = 8, a = 1201.5(1), b = 953.76(8), c = 1650.4(1) pm, R_all = 0.0388). In the crystal structure Y³⁺ is coordinated by eight monodentate HSO₄^– groups. Colorless, plate like single crystals of Y(HSO₄)₃ · H₂O grew from a solution of Y₂O₃ in 85% sulfuric acid upon cooling. In the crystal structure of the triclinic compound (P1, Z = 2, a = 679.8(1), b = 802.8(2), c = 965.9(2) pm, α = 79.99(2)°, β = 77.32(2)°, γ = 77.50(2)°, R_all = 0.0264) Y³⁺ is surrounded by seven HSO₄^– groups and one molecule of water.     

Einfach und doppelt deprotonierte Maleinsäure in Praseodym‐hydrogenmaleat‐octahydrat,Pr(C4O4H3)3 · 8 H2O,und Praseodym‐maleatchlorid‐tetrahydrat,Pr(C4O4H2)Cl · 4 H2O

Single and Double Deprotonated Maleic Acid in Praseodymium Hydrogenmaleate Octahydrate, Pr(C₄O₄H₃)₃ · 8 H₂O, and Praseodymiummaleatechloride Tetrahydrate, Pr(C₄O₄H₂)Cl · 4 H₂O Single crystals of Pr(C₄O₄H₃)₃ · 8 H₂O grew by slow evaporation of a solution which had been obtained by dissolving Pr(OH)₃ in aqueous maleic acid. The triclinic compound (P1, Z = 2, a = 728.63(3), b = 1040.23(3), c = 1676.05(8) pm, α = 72.108(2)°, β = 87.774(2)°, γ = 70.851(2)°, R_all = 0.0261) contains Pr³⁺ ions in ninefold coordination of oxygen atoms which belong to two monodentate maleate ions and seven H₂O molecules. There is one further non‐coordinating maleate ion and one crystal water molecule in the unit cell. Thermal treatment of Pr(C₄O₄H₃)₃ · 8 H₂O leads first to the anhydrous compound which then decomposes to the respective oxide in two steps upon further heating. Evaporation of a solution of Pr(C₄O₄H₃)₃ · 8 H₂O which contained additional Cl^– ions yielded single crystals of Pr(C₄O₄H₂)Cl · 4 H₂O. In the crystal structure (monoclinic, P2₁/c, Z = 4, a = 866.0(1), b = 1344.3(1), c = 896.9(1) pm, β = 94.48(2)°, R_all = 0.0227), the Pr³⁺ ions are surrounded by nine oxygen atoms. The latter belong to four H₂O molecules and three maleate ions. Two of the latter act as bidentate ligands.     

Synthese und Kristallstrukturen von Bromid—Thiosilicaten Ln3Br[SiS4]2 der Lanthanide (Ln = La,Ce, Pr,Nd, Sm,Gd)

Synthesis and Crystal Structures of Lanthanide Bromide Thiosilicates Ln₃Br[SiS₄]₂ (Ln = La, Ce, Pr, Nd, Sm, Gd) Single crystals of the bromide—thiosilicates Ln₃Br[SiS₄]₂ were prepared by reaction of lanthanide metal (Ln = La, Ce, Pr, Nd, Sm, Gd), sulfur, silicon and bromine in quartz glass tubes. The thiosilicates crystallize in the monoclinic spacegroup C2/c (Z = 4) isotypically to the iodide analogues Ln₃I(SiS₄)₂ and the A—type chloride—oxosilicates Ln₃Cl[SiO₄]₂ with the following lattice constants: La₃Br[SiS₄]₂: a = 1583.3(4) pm, b = 783.0(1) pm, c = 1098.2(3) pm, β = 97.33(3)° Ce₃Br[SiS₄]₂: a = 1570.4(3) pm, b = 776.5(2) pm, c = 1092.2(2) pm, β = 97.28(2)° Pr₃Br[SiS₄]₂: a = 1562.6(3) pm, b = 770.1(2) pm, c = 1088.9(2) pm, β = 97.50(2)° Nd₃Br[SiS₄]₂: a = 1561.4(4) pm, b = 766.0(1) pm, c = 1085.3(2) pm, β = 97.66(3)° Sm₃Br[SiS₄]₂: a = 1555.4(3) pm, b = 758.5(2) pm, c = 1079.9(2) pm, β = 98.28(2)° Gd₃Br[SiS₄]₂: a = 1556.5(3) pm, b = 750.8(1) pm, c = 1074.5(2) pm, β = 99.26(2)° In the crystal structures the bromide ions form chains along [001] with trigonal planar coordination by lanthanide cations, while the [SiS₄]^4‐—building units display isolated distorted tetrahedra.