Darstellung und Struktur von [Cp2MoHLi(thf)]3 · Toluol

Synthesis and Crystal Structure of [Cp₂MoHLi(thf)]₃ · Toluene [Cp₂MoHLi]₄ reacts in THF/Toluene to the trimeric complex [Cp₂MoHLi(thf)]₃ · Toluene 1 . The structure of 1 was characterized by X-ray single crystal structure analysis. Space group P6₃, Z = 2, a = 1459.5(9) pm, c = 1182.3(8) pm. The central unit is represented by a Mo₃Li₃-hexagon. Each Mo-Atom is surrounded by two Cp-Ligands. One THF-Molecule is coordinated to each Li-atom. The Hydrogen-Ligand could not be located by the single crystal structure analysis.     

Synthese und Struktur eines Molybdän–Gadolinium-Heterometall-Komplexes Die Struktur von [Li(thf)4]2[Cp2MoSGdBr4(thf)]2

Synthesis and structure of a Molybdenum–Gadolinium Heterometallic Complex. The Structure of [Li(thf)₄]₂[Cp₂MoSGdBr₄(thf)]₂ [Cp₂MoHLi] reacts in THF with S and GdBr₃ to yield the tetranuclear heterobimetallic complex [Li(thf)₄]₂[Cp₂MoSGdBr₄(thf)]₂. The bonding situation and the structure of this compound were characterized by X-ray structure analysis (space group P1 (No. 2), Z = 1, a = 10.845(2) Å, b = 12.166(2) Å, c = 15.881(2) Å, α = 101.74(2)°, β = 97.62(2)°, γ = 103.97(2)°). Each S atom of the central Mo₂S₂-ring is coordinated by a GdBr₄(thf) fragment. Additionally each Mo atom is connected to two Cp ligands. This leads to a tetrahedral coordination of the Mo atoms and a octahedral coordination of the Gd ions.     

Neuartige Synthese eines Lanthanoidtrialkyls – Charakterisierung und Kristallstruktur von Yb(CH2tBu)3(thf)2

Novel Synthesis of a Lanthanide Trialkyl – Characterization and Crystal Structure of Yb(CH₂ t Bu)₃(thf)₂ The solvated ytterbium alkyl Yb(CH₂tBu)₃(thf)₂ ( 1 ) was obtained in moderate yield from the reaction of ytterbium metal with neopentyl iodide. Ruby‐red air‐sensitive crystals of 1 were characterized by melting point, elemental analysis, IR, NMR, and UV/Vis spectroscopy and by X‐ray crystallography. In the solid state the ytterbium atom shows a trigonal bipyramidal coordination with the neopentyl groups and the THF ligands occupying equatorial and axial positions, respectively.     

Synthese von Dimethoxyethan‐ und Tetrahydrofuran‐Komplexen der Selten‐Erd‐Nitrate – Festkörperstruktur von Pr(NO3)3(thf)4

Synthesis of Dimethoxyethane and Tetrahydrofuran Complexes of Rare‐Earth Nitrates – Solid State Structure of Pr(NO₃)₃(thf)₄ The solvated rare‐earth nitrates Ln(NO₃)₃(thf)_n (Ln = Pr, n = 4 ( 1 ); Ln = Ho ( 2 ), Yb ( 3 ), n = 3 and Ln(NO₃)₃(dme)₂; Ln = Pr ( 4 ), Ho ( 5 )) were obtained from Ln(NO₃)₃(H₂O)_x and HC(OCH₃)₃. Pale green thermally labile crystals of 1 were characterized by X‐ray crystallography. The praseodymium atoms in two independent monomeric molecules show capped trigonal prismatic and pentagonal bipyramidal coordination, respectively.     

Replacement of the Common Chromium Source CrCl3(thf)3 with Well-Defined [CrCl2(μ-Cl)(thf)2]2

CrCl₃(thf)₃ is a common starting material in the synthesis of organometallic and coordination compounds of Cr. Deposited as an irregular solid with no possibility of recrystallization, it is not a purity guaranteed chemical, causing problems in some cases. In this work, we disclose a well-defined form of the THF adduct of CrCl₃ ([CrCl₂(μ-Cl)(thf)₂]₂), a crystalline solid, that enables structure determination by X-ray crystallography. The EA data and XRD pattern of the bulk agreed with the revealed structure. Moreover, its preparation procedure is facile: evacuation of CrCl₃·6H₂O at 100 °C, treatment with 6 equivalents of Me₃SiCl in a minimal amount of THF, and crystallization from CH₂Cl₂. The ethylene tetramerization catalyst [iPrN{P(C₆H₄-p-Si(nBu)₃)₂}₂CrCl₂]⁺[B(C₆F₅)₄]⁻ prepared using well-defined [CrCl₂(μ-Cl)(thf)₂]₂ as a starting material exhibited a reliably high activity (6600 kg/g-Cr/h; 1-octene selectivity at 40 °C, 75%), while that of the one prepared using the impure CrCl₃(thf)₃ was inconsistent and relatively low (~3000 kg/g-Cr/h). By using well-defined [CrCl₂(μ-Cl)(thf)₂]₂ as a Cr source, single crystals of [(CH₃CN)₄CrCl₂]⁺[B(C₆F₅)₄]⁻ and [{Et(Cl)Al(N(iPr)₂)₂}Cr(μ-Cl)]₂ were obtained, allowing structure determination by X-ray crystallography, which had been unsuccessful when the previously known CrCl₃(thf)₃ was used as the Cr source.     

Synthesen und Strukturen der Titan(III)‐siloxane [Ti(OSiPh3)3(thf)2] und [Ti(OSiPh3)3(py)2]

Syntheses and Structures of the Titanium(III) Siloxanes [Ti(OSiPh₃)₃(thf)₂] and [Ti(OSiPh₃)₃(py)₂] The new titaniumtrioxysilanes [Ti(OSiPh₃)₃(thf)₂] ( 1 ) and [Ti(OSiPh₃)₃(py)₂] ( 2 ) have been obtained from the reaction of titaniumtrichloride with LiOSiPh₃ in the presence of the corresponding bases tetrahydrofurane (thf) and pyridine (py). From the crystal structures of both compounds it is evident that the titanium atoms are in the centres of trigonal‐bipyramidal coordination figures, with the donor atoms in axial positions. The compounds 1 and 2 have slightly different structures (mean values: 1 : Ti‐O(Si) 1.897(9), Ti‐O(C) 2.136(8) Å; 2 : Ti‐O 1.902(9), Ti‐N2.252(8) Å) and have a single absorption band in the visible region of the UV‐spectrum. The exchange of the thf‐ligands in 1 by pyridine (in high molar excess) seems to be hindered as deduced from UV‐spectroscopy.     

The first observation of the [Cp3Mn]- anion; structures of hexagonal [(eta 2-Cp)3MnK.1.5thf] and ion-separated [(eta 2-Cp)3Mn]2[Mg(thf)6].2thf

Hexagonal [(eta 2-Cp)3MnK.1.5thf] 1 and ion-separated [(eta 2-Cp)3Mn]2[Mg(thf)6].2thf 2 are obtained from reactions of CpK and Cp2Mg, respectively, with manganocene, Cp2Mn; they are the first complexes to be structurally characterised containing the [Cp3Mn]- anion.     

Na3AsSe3 und K3AsSe3 – Darstellung und Kristallstruktur

Na₃AsSe₃ and K₃AsSe₃ – Synthesis and Crystal Structure The compounds Na₃AsSe₃ and K₃AsSe₃ were synthesized by heating mixtures of As₂O₃ and the respective alkalicarbonate in a stream of hydrogen saturated by selenium at 750 °C. The structures were determined from X-ray single-crystal diffractometer data. Both compounds crystallize isostructural with Na₃AsS₃, space group P2₁3, Z = 4, lattice constants a = 8,925 (1) Å for Na₃AsSe₃ and a = 9,710(1) Å for K₃AsSe₃.