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Structure Analysis. (structure + analysis)

Distribution by Scientific Domains
Chemistry100%

Kinds of Structure Analysis.

  • crystal structure analysis.
    		•
  • x-ray crystal structure analysis.
    		•

    Selected Abstracts

    Synthesis and Structure of Aminopyridinato-Stabilized Yttrium and Lanthanum Amides and Their Reactivity towards Alkylaluminium Compounds

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 3 2009
    Christian Döring
    Abstract A series of aminopyridinato-stabilized (amido)lanthanide complexes has been synthesized and characterized. The bulky aminopyridines (2,6-diisopropylphenyl)[6-(2,4,6-triisopropylphenyl)pyridin-2-yl]amine (1a) and [6-(2,4,6-triisopropylphenyl)pyridin-2-yl](2,4,6-trimethylphenyl)amine (1b) were introduced by amine elimination reaction with [Ln{N(SiHMe2)2}3(thf)2] (Ln = Y, La, thf = tetrahydrofuran, Me = methyl) to obtain the corresponding mono(aminopyridinato) complexes. Single-crystal X-ray analyses were carried out for the yttrium derivatives. The complexes are not able to undergo coordinative chain transfer polymerization with ethylene in the presence of alkylaluminium compounds as the corresponding dialkyl complexes do. Investigations of the reactions of the lanthanide aminopyridinato complexes with triethylaluminium or diisobutylaluminium hydride reveal a fast transfer of the aminopyridinato ligand to the aluminium atom. The products of this transfer reaction are aminopyridinato-stabilized dialkylaluminium compounds. One example of these aluminium complexes was characterized by X-ray crystal structure analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

    Reactivity of InCp* Towards Transition Metal Carbonyl Clusters: Synthesis and Structural Characterization of the Rh6(CO)16,x(InCp*)x Mixed-Metal Cluster Compounds, x = 1,2

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 22 2007
    Elena V. Grachova
    Abstract With [Rh6(CO)15(InCp*)], the first example of a transition metal carbonyl cluster with a coordinated InCp* (Cp* = C5Me5) fragment in the ligand environment is reported. This cluster with direct Rh,In bonds forms in the reaction of the hexanuclear carbonyl rhodium cluster Rh6(CO)15(NCMe) with InCp* under mild conditions. This is characterized by means of IR and NMR spectroscopy and crystal structure analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

    First Examples of Ternary Lanthanide 2,2,-Diphenyldicarboxylate Complexes: Hydrothermal Syntheses and Structures of Lanthanide Coordination Polymers of 2,2,-Diphenyldicarboxylic Acid and 1,10-Phenanthroline

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2003
    Yibo Wang
    Abstract In the four new lanthanide coordination polymers {[La2(2,2,-dpdc)3(phen)(H2O)]·2H2O}n (1), [Eu2(2,2,-dpdc)3(phen)(H2O)2]n (2), {[Ln2(2,2,-dpdc)3(phen)2(H2O)2]·4H2O}n [Ln = Tb (3), Yb (4)] (2,2,-dpdc = 2,2,-diphenyldicarboxylate, phen = 1,10-phenanthroline), prepared by hydrothermal synthesis, the 2,2,-dpdc dianion affords tetradentate, pentadentate, and hexadentate coordination modes. Complex 1 is a two-dimensional network of infinite 1-D chains assembled through ,,, interactions, with nine- and ten-coordinate La3+, and arranged in wave-like layers. In 2, Eu3+ possesses nine- and ten-coordinate geometries bridged by 2,2,-dpdc ligands to give a 3-D structure. The isomorphous complexes 3 and 4, in which Tb3+ and Yb3+ ions are both nine-coordinate, have two-dimensional structures of 1-D zigzag chains stacked via hydrogen bonds and ,,, interactions of phen molecules. The high-resolution emission spectrum of 2 shows two Eu3+ ion sites, which is consistent with the results of the X-ray crystal structure analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    Direct Synthesis of (PhSe)4Ge and (PhTe)4Ge from Activated Hydrogenated Germanium , Crystal Structure and Twinning of (PhTe)4Ge

    EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2003
    Sabine Schlecht
    Abstract The germanium chalcogenolates (PhSe)4Ge and (PhTe)4Ge were synthesized from activated hydrogenated germanium (Ge*) and diphenyldiselenide or diphenylditelluride, respectively. (PhTe)4Ge is the first homoleptic organotellurolate of germanium. It was characterized spectroscopically and by X-ray crystal structure analysis. (PhTe)4Ge crystallizes in the monoclinic space group P21/c with a = 12.8018(14), b = 9.1842(9), c = 23.690(3) Å and , = 105.458(8)°. The molecules show a tetrahedral GeTe4 core. Weak Te-Te interactions connect neighbouring tetrahedra to infinite helices along [010]. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    Asymmetric Homoaldol Reactions with Cyclohex-2-enyl N,N -Diisopropylcarbamate: Kinetic Resolution, Elucidation of the Stereochemical Course and Applications in the Synthesis of Hexahydroisobenzofuran-4-(1H)-ones

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2007
    Jochen Becker
    Abstract Enantio-enriched cyclohex-2-enyl N,N -diisopropylcarbamate (5) is stereospecifically deprotonated by sec -butyllithium/(,)-sparteine (9) to form the configurationally stable lithium complex 7·9. A kinetic resolution of rac - 5 by n -butyllithium/(,)-sparteine (9) yielded (R)- 5 with up to 99,% ee. Electrophilic substitution with tin electrophiles proceeds in a anti -SE, fashion as shown by chemical correlations. The synthesized allylstannanes 10 undergo a highly stereospecific TiCl4 -mediated homoaldol reaction with various aldehydes, yielding syn -configured homoaldol products 12. These were transferred into all - cis -configured hexahydroisobenzofuran-4(1H)-ones 22 by BF3·OEt2 -mediated reactions with aldehydes. The configurations of several products were determined by X-ray structure analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]

    Synthesis of optically active hydroxyphosphonates

    HETEROATOM CHEMISTRY, Issue 2 2008
    Irina Guliaiko
    The reduction of dimenthyl ketophosphonates with sodium borohydride involves asymmetric induction at the ,-carbon atom, resulting in a small excess of the (R)-enantiomer of the ,-hydroxyphosphonate formed. A higher ee purity was achieved if the reduction of chiral dimenthyl ketophosphonates was carried out by the chiral complex of NaBH4 - L -proline, owing to the double asymmetric induction at the ,-carbon atom. The hydroxyphosphonates obtained were isolated in a diastereomerically pure state and were transformed to the optically active, free hydroxyalkylphosphonic acids. The (R)-configuration of one of them was proved by X-ray crystal structure analysis. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:133,139, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20391 [source]