Die gaschromatographische Trennung von langkettigen Fettaldehyden

Ohne Zusammenfassung     

Die Kristallstruktur von Ammonium-dioxodifluorovanadat

The Crystal Structure of NH₄VO₂F₂ Crystals of NH₄VO₂F₂ are monoclinic, space group Pc, a = 4.814(2), b = 11.434(3), c = 7.214(2) Å, β = 108.84(4)°. Z = 4. The VO₂F-ion is polymeric. The structure consists of endless chains of strongly distorted octahedra with common edges. Two adjacent polyhedra are linked by an asymmetrical oxygen bridge (bond lengths 1.74 and 2.21 Å) and an asymmetrical fluorine bridge (bond lengths 1.97 und 2.21 Å). The terminal V? O- and V? F-distances are 1.55 and 1.86 Å, respectively.     

Die Kristallstruktur von Kaliummonomethylcarbonat

Crystal Structure of Potassium Monomethylcarbonate Potassium monomethylcarbonate KCH₃CO₃ was obtained from reaction of dimethylcarbonate with potassium hydroxide in methanole. The crystal structure was determined (triclinic, P1 (no. 2), Z = 2, a = 380.9(2) pm, b = 558.9(3) pm, c = 985.3(3) pm, α = 100.71(2)°, β = 90.06(3)°, γ = 92.48(3)°, V = 205.9(2) · 10⁶ pm³, wR(F²) = 0.054, wR_obs(F) = 0.022). Structural relations between potassium monomethylcarbonate and potassium hydrogencarbonate are discussed.     

Die Kristallstruktur von Thalliumtrifluorid

The crystal structure of thallium trifluoride The crystal structure of TlF₃ has been determined form single crystal diffraction data. The unit cell is orthorhombic, space group Pnma≠D, with a = 5.825, b = 7.024, c = 4.851 Å, Z = 4. Each Tl has 8 nearest F-neighbours. The Tl–F distances range from 2.09 to 2.49 Å.     

Die Kristallstruktur von MoAlB

Zusammenfassung MoAlB kristallisiert orthorhombisch mit den Zellabmessungena=3,212,b=13,985,c=3,102 Å. In der Raumgruppe Cmem-D _2h ¹⁷ besetzen alle drei Atomarten die Punktlage 4 c) mity _Mo=0,0891,y _Al=0,304,y _B=0,465.

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MoAlB crystallizes with an orthorhombic unit cell having the lattice constantsa=3.212,b=13.985,c=3.102 Å. The three kinds of atoms all occupy the position 4 c) of space group Cmcm-D _2h ¹⁷ withy _Mo=0.0891,y _Al=0.304,y _B=0.465.

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Die Kristallstruktur von Zirkoniumtetrachlorid

Zirconium(IV) chloride crystallizes in the monoclinic space group P2/c with a = 6.361, b = 7.407, c = 6.256 Å β = 109.30°, Z = 2. The single crystal X-ray structure analysis shows the structure to consist of an arrangement of [ZrCl_4/2Cl₂] zig-zag chains. Within the chains each Zr atom has an octahedral environment; the octahedra are linked through sharing edges, the two terminal Cl ligands being mutually in cis-position. The structure is closely related to those of TcCl₄, PtI₄ and MoOCl₃. The Zr? Cl bond lengths are 2.655 (bridge), 2.498 (bridge) and 2.307 Å (terminal) ZrBr₄, HfCl₄, and HfBr₄ are isostructural with ZrCl₄     

Die Kristallstruktur von NaBiO2

The crystal structure of NaBiO₂ NaBiO₂ crystallizes monoclinic in C with a = 7.39₄, b = 7.26₂, c = 5.88₆ Å, β = 127.7°; Z = 4. Parameters were refined by least-squares (555 hkl with |h?l| = 0 to 4; R = 10.9%). Angular groups [BiO₂] are twisted by 180°, forming chains [BiO_2/2O_2/2] along [001]. The MADELUNG part of lattice energy (MAPLE) is calculated and discussed.     

Die Kristallstruktur von PrTe2

The Crystal Structure of PrTe₂ X‐ray diffraction single‐crystal structure analysis of PrTe₂ prepared by chemical vapour transport reactions starting with praseodymium and tellurium in the presence of trace amounts of iodine also revealed superstructure reflections indicating just as for CeTe₂ a (2 × 2 × 2)‐supercell of the basic anti‐Fe₂As‐type structure instead of a (2 × 2 × 1)‐supercell as for LaTe₂. In contrast to LaTe₂ with monoclinic symmetry (space group P1c1), PrTe₂ crystallizes tetragonal in the space group P4 with the lattice parameters a = 896.80(5) pm and c = 1811.9(1) pm (Z = 16). The doubling of the c‐lattice parameter compared to LaTe₂ is observed due to different polyanionic structural motifs in the heights z ≈ 0 and z ≈ ¹/₂. These are a herringbone pattern of [Te₂] dumbbell pairs (motif A; a topology which is also found in LaTe₂), isolated square four‐membered [Te₄] rings in z ≈ 0 (motif B) and additionally rectangular four‐membered [Te₄] rings in z ≈ ¹/₂ (motif C). Though CeTe₂ and PrTe₂ are crystallizing isotypically, there are distinct differences in the interatomic distances within the polyanionic Te layers and resulting from these also a different topology of the structural motif C. The individual structural elements are causing a diffraction pattern, which is all in all to be explained by a statistical superposition of the different elements in form of microdomains.     

Die Kristallstruktur von wasserfreiem Melaminiumchlorid

Crystal Structure of non‐aqueous Melaminium Chloride Melaminium chloride was obtained as colorless, needle‐shaped, single crystalline material from solid state reactions between melamin and ammonium chloride. The structure of [C₃N₆H₇]Cl was refined by single crystal X‐ray diffraction: I2/m, Z = 8, a = 852.87(4), b = 1704.4(1) c = 918.44(4) pm and β = 92.165(6)°. The crystal structure contains melaminium ions stacked to columns along [100] and linked via N‐H···N bridges to form bands along [001]. Both of the two distinct chloride ions are stabilized by six hydrogen bonds through distorted trigonal prismatic arrangements of hydrogen atoms to yield a supramolecular structure.     

Die Kristallstruktur von SrCaCrF7

The Crystal Structure of SrCaCrF₇ By solid state reaction of the component fluorides at elevated temperature single crystals of SrCaCrF₇ were obtained (a = 792.3(2), b = 724.7(2), c = 986.1(2) pm; space group Pnma, Z = 4). The X‐ray structure determination confirmed isotypism with the Ca₂AlF₇ type of structure: Isolated octahedra [CrF₆]^3— (mean Cr‐F: 189.7 pm) are opposed by infinitely netted planar cations [SrFCa_2/2]³⁺ which contain “independent” F atoms 3‐coordinated by alkaline earth atoms only. The Sr atoms prefer (at a level of 80%) the 8‐fold, the Ca atoms the 7‐fold coordinated positions between the octahedra.     

Die Kristallstruktur von RhHg2

Zusammenfassung RhHg₂ kristallisiert tetragonal mita=4,55₁ Å,c=2,99₈ Å,c/a=0.658₈ in der Raumgruppe P 4/mmm. Die Phase ist isotyp mit -PtHg₂.

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The structure of RhHg₂ was found to be tetragonal; the unit cell ofa=4,55₁ Å,c=2,99₈ Å,c/a=0,658₈ belongs to the space group P 4/mmm. RhHg₂ is isostructural with -PtHg₂.

     

Die Kristallstruktur von BaTeO3

Crystal Structure of BaTeO₃ Crystals of BaTeO₃ were prepared from melts. BaTeO₃ is isotropic with KClO₃ and crystallizes in the monoclinic system, space group P2₁/m. The lattice parameters are a = 4.63₃, b = 5.95₂, c = 7.30₈ Å, β = 111.2°. The formula unit is 2. The crystal structure was determined by Patterson synthesis, refined by least squares and confirmed by (F_o — F_c) synthesis. Using isotropic temperature corrections the R-value of 1072 observed reflections calculated as 0.748, and anisotropic the R-value as 0.702. In BaTeO₃ tellurium forms with three oxygen atoms pyramidal TeO₃-groups, barium has to oxygen atoms the coordination 7+2. The TeO₃ groups are not linked one with another, but with the BaO₉ polyhedrons by common corners and edges, the latter are linked one with another only by common edges.     

Die Kristallstruktur von TaNi2

Zusammenfassung TaNi₂ kristallisiert im MoSi₂-Typ.     

Die Kristallstruktur von 1,2-Diferrocenylethanen

X-ray crystal structure analyses of stereoisomeric 1,2-dimethyl and diphenyl 1,2-diferrocenyl ethanes (1,2) as well as of 1,1,2,2-tetraferrocenyl ethane (3) showed that racemic (threo) and meso (erythro)2 adopt conformations with antiperiplanar arrangement of the ethane H-atoms (andC ₂ andC _i symmetry, resp.), whereas1 and3 prefer the synclinal (skew) conformations. In3 the torsional angle between the ethane H-atoms is increased to appr. 90°;3 represents a chiral structure withC ₂ symmetry.For the conformation of tetraferrocenyl ethane (3) in solutionC ₂ symmetry could be deduced from the¹³C-nmr. spectra.The conformations of the diferrocenyl ethanes are discussed and compared with those of corresponding alkyl and aryl ethanes.

Herrn Prof. Dr.E. Ziegler (Graz) mit den besten Wünschen zum 70. Geburtstag gewidmet.     

Die Kristallstruktur von LiInSe2

The Crystal Structure of LiInSe₂ The crystal structure of LiInSe₂ has been determined from single crystal data (β-NaFeO₂ type, space group Pna2₁ (No. 33), a = 718.3(2), b = 839,8(3), c = 678.1(2) pm; 375 hkl, R = 0.032; R(w) = 0.029). The mean values 253.6 pm of the bond distances Li? Se are larger than calculated, the distances In? Se (256.8 pm) are equal with the calculated values. The structure is discussed in relation to the analogous LiB^IIIC₂^VI compounds.     

Die Synthese von radioaktiv markierten langkettigen Alkyl-Cholesterinäthern

Ohne Zusammenfassung     

Die Kristallstruktur von Mn11Si19 und deren Zusammenhang mit Disilicid-Typen

Zusammenfassung Die Kristallstruktur von Mn₁₁Si₁₉ wird mit Hilfe vonFourier-und Differenz-Fourier-Synthesen bestimmt (RaumgruppeD _2d ⁸ ). Die Struktur ist gekennzeichnet durch eine einfache Unterzelle der Manganatome, die eine diamantoide Anordnung ähnlich wie die Ti-Atome im TiSi₂-Typ bilden. Die Elementarzelle von Mn₁₁Si₁₉ besitzt gegenüber der Unterzelle die 11fachec-Achse.

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The crystal structure of Mn₁₁Si₁₉ has been determined by means of Fouriersynthesis (space group D _2d ⁸ ). The structure type is characterized by a simple subcell for the manganese atoms, forming a diamond-like arrangement similar to that of the titanium atoms in TiSi₂. With respect to thec-axis the unit cell of Mn₁₁Si₁₉ corresponds to eleven (11) subcells.

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Die Kristallstruktur von V3Al und sein Mischungsverhalten mit isotypen Phasen

Zusammenfassung Im Bereich der homogenen Mischphase V_1,00–0,47Al_0,00–0,53 wird die metastabile Kristallart V₃Al erfaßt. V₃Al besitzt Cr₃O-Struktur (-Wolfram-Typ). Lückenlose Mischreihen von V₃Al mit V₃Sb und Nb₃Sn werden nachgewiesen. Unter gleichen Bedingungen, Homogenisierung bei 1000 und 1100°C, treten dagegen mit V₃Si, V₃Ge und Nb₃Al Mischungslücken auf.Mit 1 Abbildung