Na5FeS4 – das erste Thioferrat(III) mit diskreten tetraedrischen Anionen

Na₅FeS₄ — the First Thioferrate(III) with Discrete Tetrahedral Anions Ruby red crystals of Na₅FeS₄ were obtained by reacting a stoichiometric mixture of Na₂S, Fe, and S at 970 K. The compound is orthorhombic, space group Pbca, with a = 11.947(5), b = 7.091(3), c = 21.54(1) Å, Z = 8. The crystal structure was determined from single crystal diffractometer data. The atomic arrangement – which corresponds to that of Na₅GaO₄ [1] – is characterized by discrete tetrahedral [FeS₄] groups, separated from each other by Na⁺ cations. Measurements of the magnetic susceptibilities show coupling effects between Fe³⁺ ions below 28 K. At higher temperatures a Curie-Weiss behaviour indicates a high-spin-state of the Fe³⁺ ions. Relationships between the interatomic distances and the magnetic moments in alkali thioferrates are discussed.     

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.     

Cs4Re6S13 und Cs4Re6S13,5 – zwei Verbindungen mit [Re6S8]-Baueinheiten in geringfügig variierten Gerüststrukturen

Cs₄Re₆S₁₃ and Cs₄Re₆S_13.5 — Two Compounds with [Re₆S₈] Clusters Slightly Differing as to their Framework Structures Cs₄Re₆S₁₃ was synthesized by the reaction of cesium carbonate with rhenium at 800°C in an argon atmosphere charged with sulphur. The preparation of Cs₄Re₆S_13.5 succeeded by an analogous procedure using a stream of H₂S. Structural investigations on single crystals revealed atomic arrangements in which [Re₆S₈] clusters are linked threedimensionally by S_n^2? bridges. In the compound Cs₄Re₆S₁₃ $\buildrel \wedge \over =$ Cs₄[Re₆S₈]S_2/2(S₂)_4/2 the rhenium atoms of adjacent Re₆-octahedra are connected by sulphide and disulphide bridges in a ratio of 1:2. In the compound Cs₄Re₆S_13.5 $\buildrel \wedge \over =$ Cs₄[Re₆S₈]S_2/2(S₂)_3/2(S₃)_1/2 one disulphide bridge is replaced by one trisulphide bridge. The nearly regular Re₆-octahedra correspond with a diamagnetic 24-electron configuration.     

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.     

Darstellung,Struktur und magnetische Eigenschaften der Natriumeisenchalkogenide Na6FeS4 und Na6FeSe4

Synthesis, Structure, and Magnetic Properties of the Sodium Iron Chalcogenides Na₆FeS₄ and Na₆FeSe₄ The compounds Na₆FeS₄ and Na₆FeSe₄ have been synthesized by fusion reactions of sodium carbonate with iron and chalcogen in a stream of hydrogen. Structural investigations on single crystals show that both compounds crystallize in an atomic arrangement isotypic with Na₆ZnO₄ (space group P6₃mc). The structure is characterized by isolated [FeX₄]-tetrahedra. The magnetic susceptibilities show Curie-Weiss behaviour. The deviations at low temperatures are obviously caused by antiferromagnetic interactions.     

Inelastic neutron scattering and Raman spectroscopies and periodic DFT studies of Rb(2)PtH(6) and Rb(2)PtD(6)

The present work has provided a complete set of assignments for the vibrational spectrum of Rb(2)PtH(6) and Rb(2)PtD(6). To confirm the assignments, a periodic density functional theory (DFT) code has been applied to the analysis of the inelastic neutron scattering (INS) spectrum of an ionic material for the first time. The work has also provided an explanation for the unusual infrared spectrum of the potassium salt. The most significant aspect of the work is the use of the momentum transfer information provided by an INS chopper spectrometer. The straightforward method employed for the analysis of the data is applicable to any molecular system (organic or inorganic) and demonstrates the potential of these instruments for chemistry. Periodic DFT was also used to study the other A(2)PtH(6) (A = alkali metal) including, the at present, unknown Li salt, which is found to be stable. The DFT studies have also highlighted the crucial role of the cation in removing charge from the transition metal and "hydride" ligand. It is suggested that this is a general occurrence.     

High spin spectroscopy of 139Pr

The high spin states in N=80 ¹³⁹Pr have been investigated by in-beam γ-spectroscopic techniques following the reaction ¹³⁰Te (¹⁴N, 5n) reaction at E=75 MeV, using a gamma detector array, consisting of seven 23% compton-suppressed high purity germanium detectors and a multiplicity ball of fourteen bismuth germanate elements. Based on γ-γ coincidence data, the level scheme of ¹³⁹Pr has been considerably extended up to 7.2 MeV excitation. Tentative spin-parity assignments are done for the newly proposed levels on the basis of the DCO ratios corresponding to strong gates and the available information from the earlier light ion experiments.