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- ItemCrystal structure of diethyl (E)-2-[(benzofuran-2-yl)methylidene]succinate(Chester : International Union of Crystallography, 2015) Schirmer, Marie-Luis; Spannenberg, Anke; Werner, ThomasThe title compound, C17H18O5, was synthesized by a base-free catalytic Wittig reaction. The molÂecule consists of a diethyl itaconate unit, which is connected via the C=C double bond to a benzoÂfuran moiety. The benzoÂfuran ring system (r.m.s. deviation = 0.007 Ã…) forms dihedral angles of 79.58 (4) and 12.12 (10)° with the mean planes through the cis and trans ethÂoxyÂcarbonyl groups, respectively. An intraÂmolecular C-H...O hydrogen bond involving the O atom of the benzoÂfuran moiety is observed. In the crystal, molÂecules are linked into ribbons running parallel to the b axis by C-H...O hydrogen bonds.
- ItemCrystal structure of bis{μ2-[(2-iminocyclopentylidene)methylidene]azanido-κ2 N:N'}bis[(η5-pentamethylcyclopentadienyl)zirconium(IV)] hexane monosolvate(Chester : International Union of Crystallography, 2015) Becker, Lisanne; Spannenberg, Anke; Arndt, Perdita; Rosenthal, UweThe title compound, [Zr2(C10H15)4(C6H6N2)2]·C6H14, was obtained by the stoichiometric reaction of adipoÂnitrile with [Zr(C10H15)2([eta]2-Me3SiC2SiMe3)]. IntraÂmolecular nitrile-nitrile couplings and deprotonation of the substrate produced the (1-imino-2-enimino)ÂcycloÂpentane ligand, which functions as a five-membered bridge between the two metal atoms. The ZrIV atom exhibits a distorted tetraÂhedral coordination sphere defined by two pentaÂmethylÂcycloÂpentaÂdienyl ligands, by the imino unit of one (1-imino-2-enimino)ÂcycloÂpentane and by the enimino unit of the second (1-imino-2-enimino)ÂcycloÂpentane. The cycloÂpentane ring of the ligand shows an envelope conformation. The asymmetric unit contains one half of the complex and one half of the hexane solvent molÂecule, both being completed by the application of inversion symmetry. One of the pentaÂmethylÂcycloÂpentaÂdienyl ligands is disordered over two sets of sites with a refined occupancy ratio of 0.8111 (3):0.189 (3). In the crystal, the complex molÂecules are packed into rods extending along [100], with the solvent molÂecules located in between. The rods are arranged in a distorted hexaÂgonal packing.
- ItemCrystal structures of two ansa-titanocene tri-fluoro-methane-sulfonate complexes bearing the Me2Si(C5Me4)2 ligand(Chester : International Union of Crystallography, 2016) Kessler, Monty; Godemann, Christian; Spannenberg, Anke; Beweries, TorstenThe 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.
- ItemCrystal structure of 1,1,2,2-tetramethyl-1,2-bis(2,3,4,5-tetramethylcyclopenta-2,4-dien-1-yl)disilane(Chester : International Union of Crystallography, 2015) Godemann,Christian; Spannenberg, Anke; Beweries, TorstenThe 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.
- ItemSynthesis and crystallographic characterization of [2,2-bisÂ(η5-pentaÂmethylÂcycloÂpentaÂdienÂyl)-3,4-bis(triÂmethylÂsilÂyl)-2-zirconaÂfuran-5-one-κO5]triisobutylÂaluminium(Chester : International Union of Crystallography, 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).
- ItemCrystal structure of 1-hydroxy-2,2,6,6-tetramethylpiperidin-1-ium trifluoromethanesulfonate(Chester : International Union of Crystallography, 2015) Godemann,Christian; Spannenberg, Anke; Beweries, TorstenIn 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.
- ItemCrystal structure of tricarbonyl(N-diphenylphosphanyl-N,N'-diisopropyl-P-phenylphosphonous diamide-κ2 P,P')cobalt(I) tetracarbonylcobaltate(-I) toluene 0.25-solvate(Chester : International Union of Crystallography, 2014) Dura, L.; Spannenberg, A.; Beweries, T.The asymmetric unit of the title compound, [Co(C24H30N2P2)(CO)3][Co(CO)4]·0.25C7H8, consists of two crystallographically independent cations with similar conformations, two anions, and one-half of a toluene molecule disordered about an inversion centre. In the cations, a Co/P/N/P four-membered slightly bent metallacycle is the key structural element. The pendant NH group is not coordinated to the CoI atom, which displays a distorted trigonal-bipyramidal coordination geometry. Weak interionic hydrogen bonds are observed between the NH groups and a carbonyl group of the tetrahedral [Co(CO)4]- anions.