Search Results

Now showing 1 - 7 of 7
  • Item
    Crystal structure of diethyl (E)-2-[(benzofuran-2-yl)methylidene]succinate
    (Chester : International Union of Crystallography, 2015) Schirmer, Marie-Luis; Spannenberg, Anke; Werner, Thomas
    The title compound, C17H18O5, was synthesized by a base-free catalytic Wittig reaction. The mol­ecule consists of a diethyl itaconate unit, which is connected via the C=C double bond to a benzo­furan moiety. The benzo­furan ring system (r.m.s. deviation = 0.007 Å) forms dihedral angles of 79.58 (4) and 12.12 (10)° with the mean planes through the cis and trans eth­oxy­carbonyl groups, respectively. An intra­molecular C-H...O hydrogen bond involving the O atom of the benzo­furan moiety is observed. In the crystal, mol­ecules are linked into ribbons running parallel to the b axis by C-H...O hydrogen bonds.
  • Item
    Crystal 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, Uwe
    The title compound, [Zr2(C10H15)4(C6H6N2)2]·C6H14, was obtained by the stoichiometric reaction of adipo­nitrile with [Zr(C10H15)2([eta]2-Me3SiC2SiMe3)]. Intra­molecular nitrile-nitrile couplings and deprotonation of the substrate produced the (1-imino-2-enimino)­cyclo­pentane ligand, which functions as a five-membered bridge between the two metal atoms. The ZrIV atom exhibits a distorted tetra­hedral coordination sphere defined by two penta­methyl­cyclo­penta­dienyl ligands, by the imino unit of one (1-imino-2-enimino)­cyclo­pentane and by the enimino unit of the second (1-imino-2-enimino)­cyclo­pentane. The cyclo­pentane ring of the ligand shows an envelope conformation. The asymmetric unit contains one half of the complex and one half of the hexane solvent mol­ecule, both being completed by the application of inversion symmetry. One of the penta­methyl­cyclo­penta­dienyl 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 mol­ecules are packed into rods extending along [100], with the solvent mol­ecules located in between. The rods are arranged in a distorted hexa­gonal packing.
  • Item
    Crystal 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, 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.
  • Item
    Crystal 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, Torsten
    The mol­ecular structure of the title compound, C22H38Si2, features a trans arrangement of the cyclo­penta­dienyl rings to avoid steric strain [C-Si-Si-C torsion angle = -179.0 (5)°]. The Si-Si bond length is 2.3444 (4) Å. The most notable inter­molecular inter­actions in the mol­ecular packing are C-H...[pi] contacts that lead to the formation of wave-like supra­molecular chains along the b axis.
  • Item
    Synthesis and crystallographic characterization of [2,2-bis­(η5-penta­methyl­cyclo­penta­dien­yl)-3,4-bis(tri­methyl­sil­yl)-2-zircona­furan-5-one-κO5]triisobutyl­aluminium
    (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 furan­one unit, [AlZr(C10H15)2(C4H9)3(C9H18O2Si2)], is reported. On reacting a zircona­furan­one with two equivalents of HAl(i-Bu)2, disproportionation of the Lewis acid results in the formation of a triiso­butyl­aluminium fragment, Al(i-Bu)3, which coordinates to the exocyclic carbonyl O atom of the zircona­furan­one ring. Single-crystal X-ray diffraction reveals that the zircona­furan­one 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).
  • Item
    Crystal structure of 1-hydroxy-2,2,6,6-tetramethylpiperidin-1-ium trifluoromethanesulfonate
    (Chester : International Union of Crystallography, 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.
  • Item
    Crystal 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.