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Meiyappan Muthuraman Jean‐Franois Nicoud Muriel Bagieu‐Beucher 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(9):1077-1078
The title compound, alternatively sodium pyridin‐2‐olate trihydrate, Na+·C5H3N2O3?·3H2O, crystallizes in the P space group. It is made up of edge‐shared chains of NaO6 octahedra with five water molecules and one 5‐nitro‐2‐pyridonate anion. Four of these water molecules are bicoordinating, involved in connecting the adjacent octahedra, and the fifth is coordinated to only one octahedron. The crystal structure is stabilized by a network of strong O—H?O and O—H?N interactions. The organic moieties occupy the space between the chains with an antiparallel alignment. 相似文献
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In this article, the overall methodology used to determine the working flow-rates of a true moving bed (TMB) processing langmuirian isotherms compounds is explained. Then it is applied to different ternary configurations (4+4, 5+4, 8 or 9 zones TMB) in order to characterize their performances. Finally the results obtained on all the configurations are compared on a given example. This comparison allows the choice of the more suitable configuration to be used for a given set of compounds. 相似文献
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George S Nangia A Lam CK Mak TC Nicoud JF 《Chemical communications (Cambridge, England)》2004,(10):1202-1203
Crystalline nitrodiphenyl ureas adopt the N-H...O tape alpha-network only when stabilization accrues from the I...O(2)N or C[triple bond]C-H...O(2)N synthon, otherwise the ureanitro motif is preferred; soft, weak interactions can direct polar self-assembly in strong N-HO hydrogen-bonded crystals. 相似文献
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D. Haristoy S. Mery B. Heinrich L. Mager J. F. Nicoud D. Guillon 《Liquid crystals》2013,40(3):321-328
A series of [1]benzothieno[3,2-b][1]benzothiophene-2,7-dicarboxylate derivatives consisting of a flat, conjugated aromatic moiety containing sulphur hetero-atoms and substituted by terminal chains - ethyl, decyl, Z-4-decenyl or 2-(2-butoxyethoxy)ethyl - has been synthesized. These materials exhibit a smectic liquid crystalline phase, the stability of which was found to be strongly dependent on the length and the nature of the terminal chains. In the mesophase, the molecular arrangement within the smectic layer is characterized by a local stacking of the rigid parts similar to that found in discotic columnar systems. Finally, clear photoconductive behaviour was found in mechanically aligned samples of these liquid crystals. 相似文献
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Felder D Heinrich B Guillon D Nicoud JF Nierengarten JF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(19):3501-3507
Cyclotriveratrylene (CTV) derivatives substituted with 9 (1) or 18 (2) long alkyl chains have been prepared. Whereas no liquid crystalline behavior has been observed for 1, the CTV derivative 2 has mesomorphic properties. Indeed, at room temperature compound 2 exhibits a nematic phase characterized by cybotactic groups with a local lamello-columnar order. Both CTV derivatives 1 and 2 are able to form supramolecular complexes with C60 in the solid state. In both cases, the 2:1 host-guest species have been obtained as brown compounds. No liquid crystalline behavior was observed for the supramolecular complex [C60 is included in (1)2]. In contrast, observation of the brown product obtained from C60 and the CTV derivative 2 directly after preparation by polarized optical microscopy revealed a fluid birefringent phase at room temperature. When the sample is heated above 70 degrees C, the birefringence of the texture under the microscope disappears and the X-ray diffraction pattern is transformed into a pattern characteristic of a cubic phase. For the first time in thermotropic liquid crystals, the space group of this cubic phase can be assigned as I4(1)32. 相似文献
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Felder D Gallani JL Guillon D Heinrich B Nicoud JF Nierengarten JF 《Angewandte Chemie (International ed. in English)》2000,39(1):201-204
In spite of a molecular mass of 7704.6 g mol(-1), third-generation compound G3 (shown schematically; Z=C(8)H(17)) is able to form stable Langmuir films. In a systematic study, the amphiphilic properties of the corresponding dendrimers of first (G1) and second generation (G2), with one and two peripheral fullerene units, respectively, were investigated and a model could be proposed for the multilayer films obtained from G1. 相似文献
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Subbiah Meenakshisundaram RM. Sockalingam 《Journal of molecular catalysis. A, Chemical》2000,160(2):269-275
Catalytic activity of Os(VIII) in the oxidation of some twenty organic sulfides with sodium salt of N-chlorobenzenesulfonamide (CAB) has been investigated in alkaline (pH8.7) t-butanol–water (1:1 v/v) medium. Significant retarding influence of [OH−] on the reactivity is exhibited. The catalysed reaction is strongly accelerated in the presence of Hg(II). Imperfections are observed in the linear Hammett relationship in the case of –NO2 substituents. 相似文献
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The thermotropic phase transitions and the mesophase structure of two long-chain alkyl pyridinium halides are described. From small angle X-ray diffraction, optical microscopy, differential scanning calorimetry and dilatometry, the single liquid-crystalline phase found in each material is identified as smectic A. It is argued that the molecules within a layer are oriented alternately and packed in an interdigitated fashion, with the anions sandwiched between the pyridinium rings. 相似文献
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Yannick Rio Jean-Franois Nicoud Jean-Luc Rehspringer Jean-Franois Nierengarten 《Tetrahedron letters》2000,41(52):10207-10210
Triethylene glycol terminated poly(aryl ether) dendritic branches with an aldehyde function at the focal point have been prepared and attached to C60 by a 1,3-dipolar cycloaddition. 相似文献