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Robin D. Rogers Matthew M. Benning Lynn K. Kurihara Kevin J. Moriarty Marvin D. Rausch 《Journal of organometallic chemistry》1985,293(1):51-60
A reaction between (η5-C5Me5)TiCl3 and C5H5Tl in benzene solution has afforded (η5-C5Me5)(η5-C5H5)TiCl2 (I) in quantitative yield. (η5-C5Me5)(η5-C5H5)HfCl2 (III) has been prepared in 83% yield from a reaction between (η5-C5Me5)HfCl3 and C5H5Na·DME in refluxing toluene solution. The crystal and molecular structures of (η5-C5Me5)(η5-C5H5TiCl2 (I), (η5-C5Me5)(η5-C5H5)ZrCl2 (II) and (η5-C5Me5)(η5-C5H5HfCl2 (III) have been determined from X-ray data measured by counter methods. The three compounds are isostructural, crystallizing in the orthorhombic space group Pnma. The cell constants are: (I): a 9.873(1), b 12.989(3), c 11.376(4) Å and Dcalc 1.45 g cm?3 for Z = 4; (II): a 9.930(3), b 13.231(9), c 11.628(3) Å and Dcalc 1.58 g cm?3 for Z = 4; (III): a 9.938(1), b 13.156(2), c 11.582(2) Å and Dcalc 1.97 g cm?3 for Z = 4. In each case the metal atom resides on a crystallographic mirror plane which bisects both cyclopentadienyl rings and the ClMCl bond angle. The MCl bond lengths are 2.3518(9) for I, 2.4421(9) for II and 2.415(1) Å for III. The metal—cyclopentadienyl and metal—pentamethylcyclopentadienyl bond distances average 2.38(5) and 2.42(2) Å for I, 2.50(4) and 2.53(2) Å for II, and 2.48(4) and 2.50(1) Å for III respectively. 相似文献
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Robin D. Rogers Lynn K. Kurihara Matthew M. Benning 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(5):645-658
The reaction of UO2(ClO4)·nH2O with 15-crown-5 and 18-crown-6 in acetonitrile yielded the title complexes. [UO2(OH2)5] [ClO4]2·3(15-crown-5)·CH3CN crystallizes in the triclinic space groupPT with (at–150°C)a=8.288(6),b=12.874(7),c=24.678(7) Å, =82.62(4), =76.06(5), =81.06(5)°, andD
calc=1.67 g cm–3 forZ=2 formula units. Least-squares refinement using 6248 independent observed reflections [F
o5(F
o)] led toR=0.111. [UO2(OH2)5] [ClO4]2·2(18-crown-6)·2CH3CN·H2O is orthorhombicP212121 with (at–150 °C)a=12.280(2),b=17.311(7),c=22.056(3) Å,D
calc=1.68 g cm–3,Z=4, andR=0.032 (3777 observed reflections). In each complex the crown ether molecules are hydrogen bonded to the water molecules of the pentagonal bipyramidal [UO2(OH2)5]2+ ions, each crown ether having exclusive use of two hydrogen atoms from one water molecule and one hydrogen from another water molecule. In the 15-crown-5 complex the remaining hydrogen bonding interaction is between one of the water molecules and one of the perchlorate anions. The solvent molecule has a close contact between the methyl group and a perchlorate anion suggesting a weak interaction. There are a total of three U-OH...OClO3 hydrogen bonds to the two perchlorate anions in [UO2(OH2)5] [ClO4]2·(18-crown-6)·2CH3CN ·H2O. The remaining coordinated water hydrogen bond is to the uncoordinated 2H2O molecule, which in turn is hydrogen bonded to a perchlorate oxygen atom and an acetonitrile nitrogen atom. One solvent methyl group interacts with an anion, the other with one of the 18-crown-6 molecules. Unlike the 15-crown-5 structure, the hydrogen bonding in this complex results in a polymeric network with formula units joined by hydrogen bonds from one of the solvent molecules and the uncoordinated water molecule.
Supplementary data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82051 (37 pages).For Part 10, see reference [1]. 相似文献
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Electroconvection of liquid crystals does not only lead to a large variety of spontaneously formed patterns, but these patterns can also be used as a template for the fabrication of polymer surfaces exhibiting a periodic bold relief. Here, a useful room-temperature nematic mixture consisting of two photostable liquid crystals and a photosensitive cross-linker is presented. Its stability diagram in the frequency-voltage plane, the influence of monomer concentration and the topography of the resulting polymer surfaces are described. 相似文献
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The title compounds were recently demonstrated to be useful as luminescent electron transport materials in organic light emitting diodes. Here, we present studies of the fluorescence of the homologues with chain lengths between 2 and 10 carbon atoms. Dilute solutions of the investigated compounds show absorption in the range between 410 and 490 nm and fluorescence between 475 and 555 nm. However, the columnar phase of the pure compounds exhibits fluorescence at considerably larger wavelength (550-650 nm) and gives larger fluorescence lifetimes. This behaviour can be explained by the formation of excimers in the mesophase. The phase transitions to the liquid crystal state are associated with a distinct change of the fluorescence intensity. 相似文献
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Anuhar Osorio Tobias Schmidt Kamen Beronov Judith Forstner Rainer Benning Antonio Delgado 《PAMM》2009,9(1):723-724
In the presented work the basis of a novel method for detecting foreign solid inclusions in closed glass bottles and cans containing liquid food are presented. The new method is based on an automatic recording and analysis of multi-contact oscillatory signals of the food-container-particle (F-C-P) system. In this work, two different active mechanisms for positioning the foreign particles next to the wall of the bottle are studied and relevant numerical simulations are presented. In the first case, a bottle filled with water moves linearly with constant acceleration, while in the second case the bottle rotates around its longitudinal axis at a constant angular velocity. The obtained numerical results permit the selection of optimal locations for the detection system components. (© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献