Search Results
Crystal structures of two ansa-titanocene tri-fluoro-methane-sulfonate complexes bearing the Me2Si(C5Me4)2 ligand
2016, Kessler, Monty, Godemann, Christian, Spannenberg, Anke, Beweries, Torsten
The crystal structures of two ansa-titanocene tri-fluoro-methane-sulfonate complexes bearing the Me2Si(C5Me4)2 ligand are reported, namely [di-methylbis-(η5-tetra-methyl-cyclo-penta-dien-yl)silane](tri-fluoro-methane-sulfonato-κ2O,O')titanium(III) toluene monosolvate, [Ti(CF3O3S)(C20H30Si)]·C7H8, 1, and chlorido-[di-methyl-bis-(η5-tetra-methyl-cyclo-penta-dien-yl)silane](tri-fluoro-methane-sulfonato-κO)titanium(IV), [Ti(CF3O3S)(C20H30Si)Cl], 2. Both complexes display a bent metallocene unit, the metal atom being coordinated in a distorted tetra-hedral geometry, with the tri-fluoro-methane-sulfonate anion acting as a bidentate or monodentate ligand in 1 and 2, respectively. In 1, weak π-π stacking inter-actions involving the toluene solvent mol-ecules [centroid-to-centroid distance = 3.9491 (11) Å] are observed.
Crystal structure of 1-hydroxy-2,2,6,6-tetramethylpiperidin-1-ium trifluoromethanesulfonate
2015, Godemann,Christian, Spannenberg, Anke, Beweries, Torsten
In the cation of the title salt, C9H20NO+·CF3O3S-, the six-membered heterocyclic ring displays a chair conformation. In the crystal, centrosymmetric pairs of cations and anions are linked by N-H...O and O-H...O hydrogen bonds to form rings with a R44(14) graph-set motif.
Crystal structure of 1,1,2,2-tetramethyl-1,2-bis(2,3,4,5-tetramethylcyclopenta-2,4-dien-1-yl)disilane
2015, Godemann,Christian, Spannenberg, Anke, Beweries, Torsten
The molÂecular structure of the title compound, C22H38Si2, features a trans arrangement of the cycloÂpentaÂdienyl rings to avoid steric strain [C-Si-Si-C torsion angle = -179.0 (5)°]. The Si-Si bond length is 2.3444 (4) Ã…. The most notable interÂmolecular interÂactions in the molÂecular packing are C-H...[pi] contacts that lead to the formation of wave-like supraÂmolecular chains along the b axis.
A Comparative Study on the Thermodynamics of Halogen Bonding of Group 10 Pincer Fluoride Complexes
2019, Joksch, Markus, Agarwala, Hemlata, Ferro, Monica, Michalik, Dirk, Spannenberg, Anke, Beweries, Torsten
The thermodynamics of halogen bonding of a series of isostructural Group 10 metal pincer fluoride complexes of the type [(3,5-R2-tBuPOCOPtBu)MF] (3,5-R2-tBuPOCOPtBu=κ3-C6HR2-2,6-(OPtBu2)2 with R=H, tBu, COOMe; M=Ni, Pd, Pt) and iodopentafluorobenzene was investigated. Based on NMR experiments at different temperatures, all complexes 1-tBu (R=tBu, M=Ni), 2-H (R=H, M=Pd), 2-tBu (R=tBu, M=Pd), 2-COOMe (R=COOMe, M=Pd) and 3-tBu (R=tBu, M=Pt) form strong halogen bonds with Pd complexes showing significantly stronger binding to iodopentafluorobenzene. Structural and computational analysis of a model adduct of complex 2-tBu with 1,4-diiodotetrafluorobenzene as well as of structures of iodopentafluorobenzene in toluene solution shows that formation of a type I contact occurs. © 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.
Synthesis and crystallographic characterization of [2,2-bisÂ(η5-pentaÂmethylÂcycloÂpentaÂdienÂyl)-3,4-bis(triÂmethylÂsilÂyl)-2-zirconaÂfuran-5-one-κO5]triisobutylÂaluminium
2018-3-27, Burlakov, Vladimir V., Bogdanov, Vyacheslav S., Arndt, Perdita, Spannenberg, Anke, Rosenthal, Uwe, Beweries, Torsten, Shur, Vladimir B.
The crystal structure of the title zwitterionic zirconocene complex containing a furanÂone unit, [AlZr(C10H15)2(C4H9)3(C9H18O2Si2)], is reported. On reacting a zirconaÂfuranÂone with two equivalents of HAl(i-Bu)2, disproportionation of the Lewis acid results in the formation of a triisoÂbutylÂaluminium fragment, Al(i-Bu)3, which coordinates to the exocyclic carbonyl O atom of the zirconaÂfuranÂone ring. Single-crystal X-ray diffraction reveals that the zirconaÂfuranÂone ring remains intact with coordination of the aluminium to the exocyclic O atom. One of the i-butyl groups is disordered over two sets of sites, with an occupancy ratio of 0.731 (3):0.269 (3).
1-Titanacyclobuta-2,3-diene-an elusive four-membered cyclic allene
2019, Reiß, Fabian, Reiß, Melanie, Bresien, Jonas, Spannenberg, Anke, Jiao, Haijun, Baumann, Wolfgang, Arndt, Perdita, Beweries, Torsten
The synthesis of an unusual 1-metalla-2,3-cyclobutadiene complex [rac-(ebthi)Ti(Me3SiC3SiMe3)] (rac-ebthi = rac-1,2-ethylene-1,1′-bis(η5-tetrahydroindenyl)), a formal metallacyclic analogue of a non-existent four-membered 1,2-cyclobutadiene, is described. By variation of the cyclopentadienyl ligand of the titanocene precursor it was possible to stabilise this highly exotic compound which selectively reacts with ketones and aldehydes to yield enynes by oxygen transfer to titanium. Analysis of the bonding and electronic structure of the metallacycle shows that the complex is best described as an unusual antiferromagnetically coupled biradicaloid system, possessing a formal Ti(iii) centre coordinated with a monoanionic radical ligand. © 2019 The Royal Society of Chemistry.