K3ReH6 – Synthese,Struktur und magnetische Eigenschaften

K₃ReH₆ – Synthesis, Structure, and Magnetic Properties K₃ReH₆ and K₃ReD₆ were synthesized by the reaction of potassium hydride (deuteride) with rhenium powder under a hydrogen pressure between 3000–3500 bar at 850 K. X-ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compound at the triple axis spectrometer TAS 1 in the temperature range 5–600 K led to the atomic arrangement, which corresponds to that of the cryolite with [ReH₆]^3–-octahedra as characteristic units. Magnetic susceptibility measurements in the temperature range from 3.5 K and room temperature revealed a weak temperature independent paramagnetism. Quantum mechanical calculations confirm these facts and show in detail that the large value of the spin-orbit coupling parameter is essential for the magnetic behaviour.     

Na3RuD7 – Synthese und Struktur

Na₃RuD₇ – Synthesis and Structure Na₃RuD₇ was synthesized by the reaction of sodium deuteride with ruthenium powder under a hydrogen pressure of 6000 bar at 900 K. X‐ray investigations on powdered samples and elastic neutron diffraction experiments led to the atomic arrangement (space group: P4₂/mnm), which is characterized by isolated [RuD₇]‐anions. The coordination polyhedron formed by the seven deuterium ligands can be described as a distorted pentagonal bipyramide.     

Synthese und Struktur von Li3RhH6, einem ternären Hydrid mit isolierten [RhH6]3−-Oktaedern

Synthesis and Structure of Li₃RhH₆ — a Ternary Hydride with Isolated [RhH₆]^3? Octahedra The ternary rhodium hydride Li₃RhH₆ was synthesized by the reaction of lithium hydride with rhodium under a hydrogen pressure of 80 bar. X-ray investigations on powdered samples and an elastic neutron diffraction experiment on the deuterated compound led to the complete structure determination (space group: Pnma, Z = 4). The atomic arrangement is isotypic to the Na₃RhH₆ structure type. The crystal structure contains isolated [RhH₆]^3? octahedra, which are separated by the lithium ions.     

Li2PtH2, Darstellung und Struktur

Li₂PtH₂, Synthesis and Structure The synthesis of Li₂PtH₂ succeeded in decomposing Li₅Pt₂H₉ at 220°C in an argon atmosphere. X-ray investigations on a powdered sample and elastic neutron diffraction experiments on the deuterated compound led to the complete structure. Li₂PtH₂ crystallizes in the space group Immm with Z = 2. The structure is characterized by [PtH₂]^2? -dumb-bells which are hitherto unknown in platinum compounds. The arrangement of the [PtH₂]^2? -anions and of the lithium cations shows a close relationship to the hydride Li₂PdH₂ which crystallizes tetragonal I-centred.     

Hochdrucksynthese und Struktur von Rb2PtH6 und Cs2PtH6, ternären Hydriden mit K2PtCl6-Struktur

High-pressure Synthesis and Structure of Rb₂PtH₆ and Cs₂PtH₆, Ternary Hydrides with K₂PtCl₆-Structure The ternary platinum hydrides Rb₂PtH₆ and Cs₂PtH₆ were synthesized by the reaction of rubidium hydride and cesium hydride, respectively, with platinum sponge under a hydrogen pressure above 1 500 bar at 500°C. X-ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compounds at the time-of-flight spectrometer POLARIS led to their complete structure determination. Their atomic arrangements are isotypic with that of K₂PtCl₆ containing isolated [PtH₆]^2?-octahedra (space group: Fm3 m, Z = 4).     

Na3OsH7 – Synthese,Struktur und magnetische Eigenschaften,sowie Untersuchungen zur Existenz einer analogen Rutheniumverbindung

Na₃OsH₇ – Synthesis, Structure, and Magnetic Properties as well as Investigations on the Existence of the Analogous Ruthenium Compound Na₃OsH₇ was synthesized by the reaction of sodium hydride with osmium powder under a hydrogen pressure of more than 1500 bar at 870 K. X‐ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compound led to the atomic arrangement (space group: P4₂/mnm), which is characterized by isolated [OsD₇]‐anions. The coordination polyhedron formed by the seven deuterium ligands can be described as a distorted pentagonal bipyramide. Magnetic susceptibility measurements in the temperature range between 3.5 K and room temperature revealed a weak temperature independent paramagnetism. Quantum mechanical calculations confirm these facts and show in detail that the large value of the spin‐orbit coupling constant is responsible for the magnetic behaviour of the osmium (IV) compound. To synthesize the analogous ruthenium hydride it was necessary to increase the hydrogen pressure during the reaction up to 5000 bar. X‐ray investigations showed that Na₃RuH₇ crystallizes in an atomic arrangement isotypic to that of the osmium compound.     

Ca2RhD5.4 – Strukturbestimmung über Neutronenbeugungsexperimente

Ca₂RhH_5.4 – Structure Determination via Neutron Diffraction Experiments The structure of Ca₂RhH₅ described by Moyer et al. is only known respective to the arrangement of the metal atoms. Elastic neutron diffraction experiments on the deuterated compound led to the complete structure, which corresponds to that of the K₂PtCl₆ type structure with the chloride sites statistically occupied in accordance with the formula of the mixed valent compound Ca₂RhD_5.4. A neutron diffraction diagram of a high resolution T–O–F spectrometer led to the up to now unknown compound Ca₈Rh₅D₂₃ which crystallises isotypic to the analogous strontium compound in an atomic arrangement representing a transition from the K₂PtCl₆ type to the perovskite type structure.     

BiGaIn2S6 – Synthese,Struktur und Eigenschaften

BiGaIn₂S₆ – Synthesis, Structure, and Properties The novel compound BiGaIn₂S₆ was obtained in the quaternary system Bi–Ga–In–S. BiGaIn₂S₆ forms red transparent platelets and exhibits a range of homogeneity between BiGa₁In₂S₆ and BiGa_0.8In_2.2S₆. The compound is a semiconductor with E_g(opt.) = 1.9 eV. – BiGaIn₂S₆ crystallizes monoclinically forming a new structure type (a = 1112.0 pm, b = 380.6 pm, c = 1228.0 pm, β = 116.30°, Z = 2, space group P2₁/m, no. 11). The S atoms form strongly corrugated 2 D fragments of the (hc)₂ sphere packing type. The In atoms occupy octahedral holes (d(In–S) = 262 pm) and the Ga atoms tetrahedral holes (d(Ga–S) = 234 pm) inside the 2 D-layers. The Bi atoms on the top of trigonal BiS₃ pyramids (d(Bi–S) = 265 pm) are at the periphery of the layers and have four additional S ligands from the neigbouring layer at much larger distances (d(Bi–S) = 319 pm). – The bonding of a Bi^III sulfide is analyzed for the first time by the Electron Localization Function (ELF).     

Bisaminophosphane – Synthese,Struktur und Reaktivität

Bisaminophosphanes – Synthesis, Structure, and Reactivity Different pathways for the synthesis of bis(alkylamino)phosphanes RP(N(H)R′)₂ are described. t‐BuP(N(H)‐ Dipp)₂ (Dipp = 2,6‐i‐Pr₂–C₆H₃) was structurally characterized by single crystal X‐ray diffraction. The reactivity of the compounds was examplarily investigated using t‐BuP(N(H)t‐Bu)₂. Its reaction with Me₃Al and R₂AlH (R = Me, Et, i‐Bu) in 1 : 1 and 1 : 2 stoichiometrie yield monosubstituted compounds of the type t‐BuP(N(H)t‐Bu)(N(AlR₂)t‐Bu).     

LaSr3NiRuO4H4: A 4d Transition‐Metal Oxide–Hydride Containing Metal Hydride Sheets

The synthesis of the first 4d transition metal oxide–hydride, LaSr₃NiRuO₄H₄, is prepared via topochemical anion exchange. Neutron diffraction data show that the hydride ions occupy the equatorial anion sites in the host lattice and as a result the Ru and Ni cations are located in a plane containing only hydride ligands, a unique structural feature with obvious parallels to the CuO₂ sheets present in the superconducting cuprates. DFT calculations confirm the presence of S= Ni⁺ and S=0, Ru²⁺ centers, but neutron diffraction and μSR data show no evidence for long‐range magnetic order between the Ni centers down to 1.8 K. The observed weak inter‐cation magnetic coupling can be attributed to poor overlap between Ni 3d and H 1s in the super‐exchange pathways.     

DySBr und DySI – Synthese,Kristallstruktur und Magnetismus

DySBr and DySI – Synthesis, Crystal Structure, and Magnetism By reaction of Dy₂S₃ with Dy metal and Br₂ (I₂) at 750°C (900°C), single phase crystalline DySBr (DySI) has been synthesized. Crystal structure refinement of DySBr confirms the FeOCl-type structure (R = 0.049; space group Pmmn, Z = 2, lattice parameters (in Å): a = 5.349(2), b = 4.079(2), c = 8.066(2)) which is also ascertained for DySI (R = 0.059; lattice parameters (in Å): a = 5.320(2), b = 4.168(1), c = 9.224(5)). The magnetic susceptibilities (temperature range 3.4 K – 295 K) can be described on the basis of simple models (cubic crystal field, molecular field approximation) above 5 K and 15 K respectively. The deviations at low temperature are assumed to be related essentially to Dy—Dy exchange interactions which are not adequately described with the molecular field approach.     

CsC2H: Synthese,Kristallstruktur und spektroskopische Eigenschaften

CsC₂H: Synthesis, Crystal Structure, and Spectroscopic Properties CsC₂H was synthesised by the reaction of caesium solved in liquid ammonia with acetylene. The crystal structure could be solved and refined from X‐ray and neutron powder diffraction data (space group: R3c, Z = 18). The structure is characterised by C₂H^– trimers which are surrounded by caesium ions. Spectroscopic investigations (IR and Raman) of the stable monoalkalimetal acetylides mainly confirm the data given in the literature and show that the alkalimetal cation has a marked influence on the vibrational properties of the C₂H^– anion.     

K3MnH5, das erste salzartige Manganhydrid

K₃MnH₅, the First Salt-like Manganese Hydride K₃MnH₅ and K₃MnD₅ were synthesized by the reaction of potassium hydride (deuteride) with manganese powder under a hydrogen pressure above 3000 bar at 875 K. X-ray investigations on powdered samples and elastic neutron diffraction experiments on the deuterated compound at the time-of-flight spectrometer LAD in the temperature range 5–600 K led to the complete structure determination. The atomic arrangement is isotypic with that of Cs₃[CoCl₄]Cl (space group: 14/mcm, Z = 4). The structure of K₃MnH₅ contains isolated [MnH₄]^2?-tetrahedra and additional hydrogen ions which are exclusively coordinated by potassium cations. The magnetic susceptibilities show Curie-Weiss behaviour. At temperatures below 50 K there are obviously antiferromagnetic interactions.     

β-SrNH und β-SrND – Synthese und Kristallstrukturbestimmung mittels Röntgen- und Neutronenbeugung an Pulvern

β-SrNH and β-SrND – Synthesis and Crystal Structure Determination by X-Ray and Neutron Powder Diffraction By reaction of strontium with NH₃ in a flow tube at 750 °C a novel modification of strontium imide, β-SrNH, was obtained as a dark yellow powder. According to X-ray powder diffractometry und crystal structure determination by direct methods β-SrNH and β-SrND adopt a highly distorted variant of the NaCl type of structure (Pnma, a = 757.70(1), b = 392.260(4), c = 569.652(9) pm, Z = 4, wR_p = 0.098, R_p = 0.075, R_F = 0.044). Temperature dependent neutron powder diffraction of β-SrND revealed the position of the D atoms which in contrast to α-SrND are crystallographically ordered. At higher temperatures β-SrNH transforms to α-SrNH.     

Synthese,Struktur und Eigenschaften von drei Tetranatrium-tetrametaphosphimat-Hydraten

Synthesis, Structure, and Properties of Three Tetrasodium Tetrametaphosphimate Hydrates Single crystals of three tetrasodium tetrametaphosphimate hydrates Na₄(PO₂NH)₄ · x H₂O with x = 2 and 3, respectively, have been obtained and characterized by single crystal X-ray diffraction. Dimorphous Na₄(PO₂NH)₄ · 3 H₂O is formed at RT. It crystallizes monoclinic ( 1 ) or triclinic ( 2 ) (α-Na₄(PO₂NH)₄ · 3 H₂O ( 1 ): P2₁, a = 1002.7(2), b = 1189.7(2), c=1193.1(2)pm, β=104.93(1)°, Z=4; β-Na₄(PO₂NH)₄ · 3 H₂O ( 2 ): P 1¯, a = 843.64(9), b = 848.54(10), c = 994.7(2) pm, α = 83.07(1), β = 76.31(1), γ = 87.46(1)°, Z = 2). Compound 2 is formed in the presence of NaCl during the crystallization from aqueous solution. Tetrasodium tetrametaphosphimate dihydrate ( 3 ) is formed at 60 °C (Na₄(PO₂NH)₄ · 2 H₂O ( 3 ): C2/c, a = 2225.6(3), b = 513.0(1), c = 1566.7(2) pm, β = 134.21(1)°, Z = 4). In 1 and 2 the P₄N₄ ring of the tetrametaphosphimate ions attains a saddle and in 3 a twistboat conformation. The conformations of the anions have been analysed using torsion angles, displacement asymmetry parameters, and puckering parameters. The (PO₂NH)₄^4– rings of the compounds 1 , 2 , and 3 are linked by N–H · · &mid     

Dihydroxytrimethylstiboran – einige Eigenschaften und Struktur

Dihydroxytrimethylstiborane – Properties and Structure (CH₃)₃Sb(OH)₂ · H₂O ( 1 ) is prepared by reaction of (CH₃)₃SbCl₂ and NaOH. 1 reacts with CO₂ to yield [(CH₃)₃SbOH]₂CO₃ · 2 H₂O ( 2 ). Thermogravimetric investigations and mass spectra show that 1 and 2 decompose at low temperature and low pressure to H₂O, CO₂ and (CH₃)₃SbO. The crystal and molecular structures of 1 and 2 are determined. 1 crystallizes orthorhombic (Pbca) with a = 1185.2, b = 1069.6, c = 1207.6 pm and Z = 8. 2 crystallizes in the acentric monoclinic space group Cc with a = 657.3, b = 1168.5, c = 2048.2 pm, β = 95,33° and Z = 4. The infrared spectra are discussed with regard to the hydrogen bonding.