Klaus Eichele Publication Abstracts 2011

 

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[UP]	C. Nickl, K. Eichele, D. Joosten, T. Langer, F. M. Schappacher, R. Pöttgen, U. Englert, L. Wesemann: 1,1,1-Tris(distanna-closo-dodecaborat)stannat - ein tripodaler Zinnligand Angew. Chem. 2011, 123, 5886-5889. DOI 10.1002/ange.201100936

Zinnhaltiger Dreibeiner: Der erste tripodale Zinnligand wurde aus 1,2-Distanna-closo-dodecaborat und Zinn(II)-chlorid synthetisiert. Er besteht aus drei Äquivalenten Cluster und einem zentralen Zinnatom und bildet ein Gerüst aus sieben Zinnatomen. Seine Koordinationsfähigkeit wurde anhand der Reaktion mit [Cu(CH3CN)4]PF6 gezeigt. Dabei entsteht ein zweikerniger Kupferkomplex, dessen Dikupfereinheit verzerrt oktaedrisch von zwei Sn7-Liganden umgeben ist.

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[UP]	C. Nickl, K. Eichele, D. Joosten, T. Langer, F. M. Schappacher, R. Pöttgen, U. Englert, L. Wesemann: 1,1,1-Tris(distanna-closo-dodecaborate)stannate: A Tripodal Tin Ligand Angew. Chem. Int. Ed. 2011, 50, 5766-5769. DOI 10.1002/anie.201100936

Tin tripod: Starting from 1,2-distanna-closo-dodecaborate and tin(II) chloride, the first tripodal tin ligand was prepared. It is made up of three clusters and one central tin atom that build a frame of seven tin atoms. The coordination ability is illustrated by reaction with [Cu(CH3CN)4]PF6: a binuclear copper complex is formed surrounded by two Sn7 ligands.

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[UP]	K. Eichele, A.-R. Grimmer: Phosphorus-31 and Vanadium-51 Solid-State Nuclear Magnetic Resonance Spectroscopy of beta-Vanadyl Phosphate - Effects of Homo- and Heteronuclear Spin-Spin, Electrostatic, and Paramagnetic Interactions Can. J. Chem. 2011, 89(7), 870-884. DOI 10.1139/v11-025

Field-dependent ³¹P solid-state NMR studies demonstrate that the line shape in spectra of beta-VOPO₄ depends on ⁵¹V-³¹P direct and indirect spin-spin interactions (M₂ (⁵¹V, ³¹P) = 101(23) × 10⁶ rad² s^-2, ²J_iso (⁵¹V, ³¹P) = 48(5) Hz) and, to a lesser extent, on ³¹P chemical shift anisotropy (δ_iso = -10.4(2), Ω = δ₁₁ - δ₃₃ = 22(2) ppm) and ³¹P-³¹P interactions (M₂ (³¹P, ³¹P) = 6.7(1) × 10⁶ rad² s^-2). In contrast, homonuclear dipolar interactions play an important role for the field and spinning rate dependent ³¹P spin-lattice relaxation via paramagnetic impurities (T₁ = 20-60 s). Vanadium-51 magic-angle spinning NMR spectra indicate a sizeable chemical shift anisotropy (δ_iso = -754(1), δ₁₁ = -336(10), δ₂₂ = -344(6), δ₃₃ = -1581(8) ppm) and nuclear quadrupole interaction (χ = 1.5(1) MHz, η = 0.35(5)); the principal axis systems of both interactions are clearly not coincident, with an angle of 35(5)° between the greatest component of the electric field gradient tensor and ?₃₃.

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[UP]	M. Stroebele, K. Eichele, H.-J. Meyer: Phosphorus-Centered and Phosphinidene-Capped Tungsten Chloride Clusters Eur. J. Inorg. Chem. 2011, 4063-4068. DOI 10.1002/ejic.201100122

Black crystalline powders of W₆PCl₁₇ and W₄(PCl)Cl₁₀ were obtained after reducing WCl₆ with red phosphorus at 370 and 500 °C. The crystal structures were determined by single-crystal and powder X-ray diffraction analyses. The structure of W₆PCl₁₇ is represented by a phosphorus-centered hexanuclear tungsten cluster, whose (W₆PCl₁₁)Cl₄^aCl_4/2^a-a chains form a hexagonal stick packing structure. The structure of W₄(PCl)Cl₁₀ is represented by a Jahn-Teller distorted tetranuclear tungsten cluster that is interconnected into a layered [W₄(mu₄-PCl)Cl₆ⁱ]Cl_8/2^a-a structure containing a chloro-phosphinidene ligand. Solid-state ³¹P magic-angle spinning (MAS) NMR spectra, electronic structures, and magnetic properties are reported.

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[UP]	A. Wagenpfeil, C. Nickl, H. Schubert, K. Eichele, M. A. Fox, L. Wesemann: 1,2-Carbagerma-closo-dodecaborate as a Germanium Ligand in Coordination Chemistry - Synthesis, Structure and Reactivity Eur. J. Inorg. Chem. 2011(22), 3349-3356. DOI 10.1002/ejic.201100310

A much improved synthesis for the carbagerma-closo-dodecaborate anion [GeCB₁₀H₁₁]^- is described in the form of [Bu₃NH][GeCB₁₀H₁₁] (1). In reactions with transition metal electrophiles, three transition metal complexes {[Bu₃NH][(C₆H₆)Ru(Cl)₂(GeCB₁₀H₁₁)] (2), [Bu₃NH][Cp*Ir(Cl)(GeCB₁₀H₁₁)₂] (3) and [Me₃NH][(PPh₃)₂Ir(CO)(GeCB₁₀H₁₁)₂] (4)} with metal-germanium bonds were synthesized. The carbagermaborate anion, in the form of the salt [Et₃NH][GeCB₁₀H₁₁], and the coordination compounds 2-4 were structurally characterized by single-crystal X-ray diffraction. Computations were carried out for the anions in 1-4 to aid NMR assignments.

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[UP]	H. Schubert, J.-A. Dimmer, F.-R. Küchle, K. Eichele, L. Wesemann: Homoleptic Coinage Metal Compounds of Group(IV)heteroborates Inorg. Chem. 2011, 50, 664-670. DOI 10.1021/ic102118n

This article describes the synthesis and characterization of the first silver complex with the germylene [GeB11H11]2- and coinage metal complexes with the stannylene ligand [SnB11H11]2-. Starting materials like CuCl, AuCl(Me2S), and AgNO3 were used to give mononuclear (3 and 4), dinuclear (5), hexanuclear (6), and heptanuclear (7) coordination compounds: [Et4N]5[Cu(CH3CN)(SnB11H11)3] (3), [Et4N]5[Ag(SnB11H11)3] (4), [Et4N]6[{Au(SnB11H11)2}2] (5), [Et4N]6[{Ag(GeB11H11)}6] (6), and [Et4N]9[Ag7(SnB11H11)8] (7). In case of the oligonuclear compounds 5-7 silver and gold aggregation was observed under formation of metal-metal bonds. Furthermore, the germa-closo-dodecaborate is found in a hitherto unknown µ3-bridging coordination mode connecting three silver atoms. The new compounds were characterized by single crystal X-ray diffraction and in the case of 3-6 also by NMR spectroscopy and elemental analysis.

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[UP]	S. Fleischhauer, K. Eichele, I. Schellenberg, R. Pöttgen, L. Wesemann: Cobalt, Rhodium, Iridium, and Ruthenium Carbonyl Complexes with Stanna-closo-dodecaborate: 103Rh NMR, 119Sn Mössbauer Spectroscopy, and Solid-State 119Sn NMR Organometallics 2011, 30, 3200-3209. DOI 10.1021/om200301v

Depending on the stoichiometry stanna-closo-dodecaborate [SnB11H11]^2- reacts with the dimeric carbonyl complex [Rh(CO)2Cl]2 to give a dinuclear rhodium coordination compound with bridging tin ligands, [Et3MeN]6[Rh2(CO)4(SnB11H11)4] (1), or a pentagonal-bipyramidal complex, [Et4N]5[Rh(CO)2(SnB11H11)3] (2), with the carbonyl ligands in axial position. The analogous iridium and cobalt complexes [Et4N]5[Ir(CO)2(SnB11H11)3] (3) and [Me4N]5[Co(CO)2(SnB11H11)3] (4) exhibit a pentacoordinated structure with the tin ligands in axial positions. The dimeric ruthenium chlorocarbonyl complex [Ru(CO)3Cl2]2 reacts with four equivalents of the tin nucleophile to give the octahedrally coordinated ruthenium complex [Et3MeN]4[Ru-cis-(CO)2-cis-Cl2-trans-(SnB11H11)2] (5). The synthesized coordination compounds were characterized by X-ray crystal structure analysis, by 103Rh, 119Sn, and 11B NMR spectroscopy in solution, and in the case of the rhodium complexes 1 and 2 by 119Sn solid-state NMR and 119Sn Mössbauer spectroscopy.