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961.
962.
Syntheses and Crystal Structures of the Nitrido‐chloro‐molybdates [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 and [Li(12‐Crown‐4)(NMoCl4)]2 · 2 CH2Cl2 Both the title compounds as well as [Li(12‐crown‐4)2]+MoNCl4– were made from MoNCl3 and the chlorides MgCl2 and LiCl, respectively, in dichloromethane suspensions in the presence of tetrahydrofuran and 12‐crown‐4, respectively. They form orange‐red moisture‐sensitive crystals, which were characterized by their IR spectra and partly by crystal structure analyses. [Mg(THF)4{NMoCl4(THF)}2] · 4 CH2Cl2 ( 1 ): space group C2/m, Z = 2, lattice dimensions at –50 °C: a = 1736.6(1), b = 1194.8(1), c = 1293.5(2) pm; β = 90.87(1)°; R1 = 0.037. In 1 the magnesium ion is coordinated octahedrally by the oxygen atoms of the four THF molecules and in trans‐position by the nitrogen atoms of the two [N≡MoCl4(THF)]– ions. [Li(12‐crown‐4)(NMoCl4)]2 · 2 CH2Cl2 ( 2 ): space group P 1, Z = 1, lattice dimensions at –70 °C: a = 930.4(1), b = 957.9(1), c = 1264.6(1) pm; α = 68.91(1)°, β = 81.38(1)°, γ = 63.84(1)°; R1 = 0.0643. 2 forms a centrosymmetric ion ensemble in the dimeric cation of which, i. e. [Li(12‐crown‐4)]22+, the lithium ions on the one hand are connected to the four oxygen atoms each of the crown ether molecules in a way not yet known; and in addition, each of the lithium ions enters into a intermolecular Li–O bond with neighboring crown ether molecules under formation of a Li2O2 four‐membered ring. The two N≡MoCl4– counterions are loosely coordinated to one oxygen atom each of the crown ether molecules with Mo–O distances of 320.2 pm. 相似文献
963.
Heiko Schirmer Michael Duetsch Frank Stein Thomas Labahn Burkhard Knieriem Armin de Meijere 《Angewandte Chemie (International ed. in English)》1999,38(9):1285-1287
A novel mode of reaction towards arylethynes is shown by the β-trimethylsilyl-substituted α,β-unsaturated Fischer carbene complexes 1 . A mixture of the isomeric, highly substituted spiro[4.4]nonatrienes 2 and 3 is formed by the formal insertion of three alkyne molecules and subsequent cyclization (see scheme). Such selective triple insertions of alkynes into ethenylcarbene complexes have not been previously observed. 相似文献
964.
David Scheschkewitz Matthias Menzel Matthias Hofmann Paul von Ragu Schleyer Gertraud Geiseler Werner Massa Klaus Harms Armin Berndt 《Angewandte Chemie (International ed. in English)》1999,38(19):2936-2939
Remarkably short distances to the ring plane are shown by the η5-bound lithium ions in the first compound with a triply negatively charged five-membered ring, 1 , which was obtained by reduction of 2 with lithium. R=CH(SiMe3)2, Dur=2,3,5,6-tetramethylphenyl. 相似文献
965.
966.
Gelling agents based on polysaccharides have become extremely important in the food industry. As more and more products like soups and sauces have become available in lyophilized form, thickeners have to be added to give a controlled consistency to the finished meal. A capillary electrophoretic method has been developed to investigate the monosaccharide composition of hydrolyzed thickeners. 2-Aminoanthracene was used as a derivatization reagent to allow sensitive fluorescence detection. This system was applied to a set of standard thickeners as well as to food samples. 相似文献
967.
968.
Dr. Dominique Bruns Dr. Daniel Merk Dr. Karthiga Santhana Kumar PD Dr. Martin Baumgartner Prof. Dr. Gisbert Schneider 《ChemistryOpen》2019,8(10):1303-1308
Constructive machine learning aims to create examples from its learned domain which are likely to exhibit similar properties. Here, a recurrent neural network was trained with the chemical structures of known cell-migration modulators. This machine learning model was used to generate new molecules that mimic the training compounds. Two top-scoring designs were synthesized, and tested for functional activity in a phenotypic spheroid cell migration assay. These computationally generated small molecules significantly increased the migration of medulloblastoma cells. The results further corroborate the applicability of constructive machine learning to the de novo design of druglike molecules with desired properties. 相似文献
969.
The liquid-solid Al/Ni diffusion couple was successfully fabricated by annealing at 1373?K for 48?h followed by water-quenching. Cross-sectional scanning and transmission electron microscopic analyses show that the multilayered diffusion zones comprise the following sequence of layers: γ-Ni(Al) | γ′-Ni3Al | β′-NiAl | Ni-rich β-NiAl | β-NiAl. The Ni-rich β-NiAl upon quenching undergoes a martensitic transformation from β (B2) to β′ (L10). The β′ martensite is found to be internally twinned on the {111}<112>system. The volume changes and strains due to martensitic phase transformation, the precipitation of γ′-Ni3Al from γ-Ni(Al) and lattice mismatch between Ni-rich β-NiAl and β-NiAl in the Al/Ni diffusion couple are quantitatively determined. The cuboidal γ′ phase coherently precipitates cube-on-cube in γ-Ni(Al). Composition fluctuations existing in the supersaturated solid solution γ-Ni(Al), provide sufficient driving force for the precipitation and facilitate nucleation and growth of the γ′ phase under isothermal annealing. 相似文献
970.
Chemical Sensing: Incorporating Copper Nanoclusters into Metal‐Organic Frameworks: Confinement‐Assisted Emission Enhancement and Application for Trinitrotoluene Detection (Part. Part. Syst. Charact. 6/2017) 下载免费PDF全文