Zur Kristallchemie der Ytterbium(II)-Halogenide YbCl2 und YbBr2

Crystal data and the structure types of the ytterbium dihalides YbCl₂ and YbBr₂ have been determined by the usual X-ray methods using single crystals. YbCl₂ crystallizes with the orthorhombic space group Pbca and the lattice dimensions a = 13.18 Å, b = 6.96 Å, c = 6.70 Å. It is proved to be isostructural with SrI_2. the structure of which has recently been determined. DyCl₂ and TmCl₂, of which only powder diagrams exist for the present, are most likely to have the same crystal structure. YbBr₂ (orthorhombic space group Pnnm, a = 6.63 Å, b = 6.93 Å. c = 4.37 Å) crystallizes with the CaCl₂ arrangement which may be described as a slight distortion of the rutile structure. Some aspects of the crystal chemistry of all four ytterbium dihalides are summarized in a short discussion.     

Die Trennung der homologen Phenole und Kresole

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Darstellung und Kristallstruktur der bekannten Zintl‐Phasen Cs3Sb7 und Cs4Sb2

Synthesis and Crystal Structure of the known Zintl Phases Cs₃Sb₇ and Cs₄Sb₂ Cs₃Sb₇ and Cs₄Sb₂ were synthesized from the elements and their crystal structures were determined on the basis of single crystal x‐ray data. Cs₃Sb₇ crystallizes in the monoclinic system with space group P2₁/c (a = 1605.7(1) pm, b = 1571.1(1) pm, c = 2793.9(2) pm, β = 96.300(2)°, Z = 16) and contains anions Sb₇^3–. In the structure of Cs₄Sb₂ (orthorhombic, space group Pnma, a = 1598.5(3) pm, b = 631.9(2) pm, c = 1099.5(2) pm, Z = 4) dumbbells Sb₂^4– are present.     

Synthese eines homologen steroidischen 17β-Pyrrolinons Partialsynthetische Versuche in der Reihe der Herzgifte, 9. Mitteilung

Synthesis of a homologous steroidal 17β-pyrrolinone. We describe the synthesis of 4′-[(3β-Hydroxy-androst-5-en-17β-yl)methyl]-3′-pyrrolin-2′-one ( 15 ) starting from 3β-acetoxy-23-diazo-21,24-dinorchol-6-en-22-one ( 1 ).     

Kinetik der Bromierung von Phenolen und phenolischen Mehrkernverbindungen. 3. Mitt. Die Reaktionsf?higkeit isomerer Dreikernverbindungen und einer homologen Reihe von Mehrkernverbindungen

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Kinetik der Bromierung von Phenolen und phenolischen Mehrkernverbindungen. 3. Mitt. Die Reaktionsfähigkeit isomerer Dreikernverbindungen und einer homologen Reihe von Mehrkernverbindungen

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Struktur und magnetische Eigenschaften von Cs2Mn3S4 und Cs2Co3S4

Structure and Magnetic Properties of Cs₂Mn₃S₄ and Cs₂Co₃S₄ The atomic arrangements of the isotypic compounds Cs₂Mn₃S₄ and Cs₂Co₃S₄ were determined by X-ray investigations on single crystals (space group Ibam, Z = 4). To interprete the magnetic properties of Cs₂Mn₃S₄ mixed crystals of the series Cs₂(Mn_xZn_1-x)₃S₄ have been examined. Additionally neutron diffraction experiments were carried out and yielded the spin structures of Cs₂Mn₃S₄ and Cs₂Co₃S₄ (Shubnikov space group Ibam'). The deviations of the magnetic moments from those expected for high-spin d⁵ ions are explained by means of crystal field calculations.     

Einkristallstrukturbestimmungen der kubischen Hochdruckelpasolithe Rb2LiFeF6 und Cs2NaFeF6: Druck-Abstands-Paradoxon ohne Änderung der Koordinationszahl

Single Crystal Structure Determinations of the Cubic High Pressure Elpasolites Rb₂LiFeF₆ and Cs₂NaFeF₆: Pressure-Distance Paradox without Change of Coordination Number At single crystals of metastable high pressure phases of Rb₂LiFeF₆ (a = 824.4 pm) and Cs₂NaFeF₆ (a = 873,9 pm) the parameters of the cubic elpasolite structure (Fm3 m, Z = 4) were determined by X-ray methods. Compared to the 12L-structures of the normal pressure phases (R3 m, hex. Z = 6) only the distances within the 12-coordination, Rb? F = 291.7 resp. Cs? F = 309.9 pm, are compressed by 2–3%. However, the octahedral distances Fe? F = 194.6 pm and Li? F = 217.6 pm resp. Fe? F = 194.9 pm and Na? F = 242.0 pm, are enlarged by 1–4%, though there was no increase in coordination number. This paradoxical behaviour is discussed. Difference Fourier syntheses reveal disorder only for the lithium positions in Rb₂LiFeF₆, which are 30 pm off-center, corresponding to a splitting of distances Li? F into 188, 247 and 4 × 220 pm.     

Darstellung,Struktur und Schwingungsspektren der Oxofluorowolframate(VI) Cs2[WO3F2] und Cs3[W2O4F7]

Synthesis, Structure, and Vibrational Spectra of the Oxofluorotungstates(VI) Cs₂[WO₃F₂] and Cs₃[W₂O₄F₇] Cs₂[WO₃F₂] crystallizes from a melt with the same composition. The orthorhombic unit cell with a = 6.779(2), b = 7.668(1) and c = 11.626(3) Å, space group Pn2₁a, contains 4 formula units. The WO₃F₂^2? anion is polymer, W octahedrally coordinated according to the results of the X-ray crystal structure determination. Planar dioxodifluoro groups are linked into chains by oxygen atoms. The lengths of the W? O bonds are alternating. Cs₃[W₂O₄F₇] crystallizes trigonal, space group P3 m1, with a = 21.118(4) and c = 8.434(2) Å, Z = 9. The structure consists of two sets of crystallographically non equivalent dimeric anions with the formula [O₂F₃W? F? WO₂F₃]^3?. Part of the ligand atoms are disordered. The vibrational spectra of both compounds show the presence of cis-dioxo groups of the terminal ligands.     

Darstellung und Kristallstruktur der Dialkalimetalltrichalkogenide Rb2S3, Rb2Se3, Cs2S3 und Cs2Se3

Preparation and Crystal Structure of the Dialkali Metal Trichalcogenides Rb₂S₃, Rb₂Se₃, Cs₂S₃, and Cs₂Se₃ Crystalline products were obtained by the reaction of the pure alkali metals with the chalcogens in the molar ratio 2:3 in liquid ammonia at pressures up to 3000 bar and temperatures around 600 K. The substances crystallize in the K₂S₃ type structure (space group Cmc2₁(NO. 36)). Unit cell constants see ?Inhaltsübersicht”?. The characteristic feature of this structure are bent polyanions X₃^2?:(X = S,Se). The new described compounds are compared with the other known alkali metal trichalcogenides.     

Chloroberyllate mit Stickstoff‐Donorliganden. Die Kristallstrukturen von (Ph4P)[BeCl3(Py)], (Ph4P)2[(BeCl3)2(TMEDA)], (Ph4P)[BeCl2{(Me3SiN)2CPh}] und (Ph4P)2[BeCl4] · 2CH2Cl2

Chloroberyllates with Nitrogen Donor Ligands. Crystal Structures of (Ph₄P)[BeCl₃(py)], (Ph₄P)₂[(BeCl₃)₂(tmeda)], (Ph₄P)[BeCl₂{(Me₃SiN)₂CPh}], and (Ph₄P)₂[BeCl₄] · 2CH₂Cl₂ The title compounds were obtained as colourless, moisture sensitive crystals by reactions of (Ph₄P)₂[Be₂Cl₆] with pyridine, tmeda (N, N′‐tetramethylethylendiamine), or with the silylated benzamidine PhC—[N(SiMe₃)₂(NSiMe₃)], whereas the tetrachloro beryllate was isolated as a by‐product from a solution in dichloromethane in the presence of the silylated phosphaneimine Me₃SiNP(tol)₃. All compounds were characterized by crystal structure determinations and by IR spectroscopy. (Ph₄P)[BeCl₃(Py)] ( 1 ): Space group Pbcm, Z = 4, lattice dimensions at 193 K: a = 756.2(1), b = 1739.2(2), c = 2016.3(2) pm, R₁ = 0.0626. The complex anion contains tetrahedrally coordinated beryllium atom with a Be—N distance of 176.5 pm. (Ph₄P)₂[(BeCl₃)₂(tmeda)]·2CH₂Cl₂ ( 2 ·2CH₂Cl₂). Space group P1¯, Z = 1, lattice dimensions at 193 K: a = 1072.7(1), b = 1132.6(1), c = 1248.9(1) pm, α = 95.34(1)°, β = 92.80(1)°, γ = 90.81(1)°, R₁ = 0.0344. Both nitrogen atoms of the tmeda molecule coordinate with BeCl₃^— units forming the centrosymmetric complex anion with Be—N distances of 181.3 pm. (PPh₄)[BeCl₂{(Me₃SiN)₂CPh}] ( 3 ). Space group C2, Z = 2, lattice dimensions at 193 K: a = 1255.4(2), b = 1401.9(2), c = 1085.2(2) pm, R₁ = 0.0288. In the complex anion the benzamidinato ligand {(Me₃SiN)₂CPh}^— acts as chelate with Be—N distances of 174.9 pm. (Ph₄P)₂[BeCl₄]·2CH₂Cl₂ ( 4 ·2CH₂Cl₂). Space group P2/c, Z = 4, lattice dimensions at 193 K: a = 2295.4(1), b = 982.5(1), c = 2197.2(2) pm, β = 99.19(1)°, R₁ = 0.0586. 4 ·2CH₂Cl₂ contains nearly ideal tetrahedral [BeCl₄]^2— ions, like the previously described 4 ·2, 5CH₂Cl₂, which crystallizes in the space group P1¯, with Be—Cl distances of 203.4 pm on average.     

Polymorphie von Cs2NaMnF6. Die Kristallstrukturen der Hochdruck- und der Hochtemperaturmodifikation

Polymorphism of Cs₂NaMnF₆. Crystal Structures of the High Pressure and the High Temperature Phase Cs₂NaMnF₆ has been prepared in three polymorphous forms and investigated by X-ray diffraction. Under high pressure (> 5 kbar) a cubic α-phase was formed with elpasolite structure (space group Fm3m, a = 876.2 pm, Z ? 4, R ? 0.045 for 12 powder reflections). By quenching from 700°C a high temperature γ-form could be trapped with 12L-Cs₂NaCrF₆ structure (space group R¯3m, Z = 6, R_w ? 0.041 for 419 independent single crystal reflections). The “normal” β-phase is a low symmetric variant of this 12L-type. The influence of the Jahn-Teller effect on the structures and the polymorphism is discussed.     

Kristallstruktur und Schwingungsspektren der Caesium- und Kalium-Hexathiometadiphosphate Cs2P2S6 und K2P2S6

Crystal Structure and Vibration Spectra of Cs₂P₂S₆ and K₂P₂S₆ . Cs₂P₂S₆ and K₂P₂S₆ crystallize in the orthorhombic system, space group Immm, Z = 2 with the lattice constants . The compounds are isotypic to Tl₂P₂S₆. In the structure there are discrete P₂S₆^2? anions. Two PS₄ tetrahedra are connected by a common edge to hexathiometadiphosphate groups. The far infrared, infrared, and Raman spectra of these compounds are assigned on the basis of P₂S₆^2? units with D_2h symmetry in analogy to the isoelectronic Al₂Cl₆. The melting points are 440 ± 10°C for Cs₂P₂S₆ and 508 ± 10°C for K₂P₂S₆.     

Struktur und Rheologie von pharmazeutischen und kosmetischen Cremes. Cetrimid-Cremes. Der Einflu? der Alkoholkettenl?nge und der homologen Zusammensetzung

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Darstellung und Kristallstruktur von Cs2Sb4S7

Preparation and Crystal Structure of Cs₂Sb₄S₇ The first thioantimonite of Cesium has been synthesized and its crystal structure determined. The substance crystallizes monoclinic with spacegroup P2₁/_c. The lattice constants are a = 1111.2(5) pm, b = 1227.1(5) pm, c = 1163.7(5) pm and ß = 97.60(5)°. There are four formula units in the unit cell. Sb–S chains are formed by trigonal SbS₃ pyramids and ψ-trigonal SbS₄ bipyramids.