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Arikainen EO Boden N Bushby RJ Lozman OR Vinter JG Wood A 《Angewandte Chemie (International ed. in English)》2000,39(13):2333-2336
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Edwards DJ Jones JW Lozman O Ormerod AP Sintyureva M Tiddy GJ 《The journal of physical chemistry. B》2008,112(46):14628-14636
The solution and liquid crystalline phases formed by dissolution of the dye Edicol Sunset Yellow (ESY) in water have been examined using optical microscopy, multinuclear NMR (1H, 2H, 13C, 23Na), and X-ray diffraction. From the solution 1H and 13C spectra (particularly 13C), it is clear that the tautomeric form present in all these phases is the hydrazone, NH, structure, not the usually given azo, OH, form. Two chromonic mesophases occur: a nematic (N) phase at approximately 30-40 wt % and a hexagonal (M) phase at approximately 40-45 wt %. X-ray diffraction data show that the aggregates in the mesophases are single molecule stacks, with a typical spacing of approximately 3.5 angstroms, as expected for these systems. The NMR quadrupole splittings (2H2O, 23Na) are similar to those observed for surfactant lyotropic mesophases, suggesting that there are no water molecules or counter ions that are tightly bound to the ESY aggregates. An unusual feature of the X-ray diffraction pattern of the mesophases is the occurrence of diffuse off-axis reflections at approximately 6.8 angstroms. It is proposed that these arise from a head-to-tail packing of the molecules within the stacks. 相似文献
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2,3,6,7,10,11-Hexasubstituted triphenylenes have been synthesized that contain a mixture of hydrophobic (C6H13O) and hydrophilic (CH3OCH2CH2OCH2CH2O) side chains. At one extreme HAT6 (1a) (six hydrophobic chains) shows thermotropic behaviour and at the other TP6EO2M (1e) (six hydrophilic chains) shows lyotropic behaviour. Of the triphenylenes with a mixture of hydrophobic and hydrophilic side chains, only the triphenylene with one hydrophilic side chain and five hydrophobic side chains (1b) gives a thermotropic columnar phase. None of the others show liquid crystal behaviour. However, all of these triphenylenes form binary 1:1 compounds when mixed with PDQ9 (2a) and with PTP9 (2b). These CPI (complimentary polytopic interaction) stabilized compounds give thermotropic hexagonal columnar phases over wide temperature ranges. 相似文献
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Richard J. Bushby Julie Fisher Owen R. Lozman Stephan Lange John E. Lydon Sholto R. McLaren 《Liquid crystals》2006,33(6):653-664
Previous investigations of complementary polytopic interaction (CPI) columnar mesophases, in which the columns are built up of alternating hexaalkoxytriphenylene (HAT) and hexaphenyltriphenylene (PTP) molecules, concentrated mainly on the effect of variations in the structure of the HAT component. This investigation is concerned with the effect of variations in the structure of the PTP component and, in particular, variations in the position of an alkoxy side chain in the phenyl ring. Stable columnar mesophases are obtained when a hexyloxy substituent is placed in the meta- or para-position but not in the ortho-position. In the case of the meta- and para-substituted systems, the two-component CPI columnar phases are stable over a considerably larger temperature range than the one-component HAT systems. The evidence suggests that unfavourable PTP/PTP stacking is as much a driving force for the formation of these mixed stacks as is favourable PTP/HAT stacking, but both need to be explained in terms of the sum of atomically dispersed van der Waals and coulombic interactions. On cooling from the isotropic into the Colh phase, the columnar phase based on a 1:1 mixture of hexakis(hexyloxy)tripenylene and the meta-hexyloxy-substituted PTP gives an unusual texture consisting of 'viking-axe'-shaped structures. 相似文献
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Neville Boden Richard J. Bushby Gareth Headdock Owen R. Lozman Andrew Wood 《Liquid crystals》2013,40(1):139-144
We have synthesized new discogens based on polyphenylated triphenylene, polyphenylated azatriphenylene and hexabenztrinaphthylene. A procedure for the extension of the aromatic core by Suzuki coupling is described, which minimizes competitive reductive dehalogenation. 相似文献
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Richard J. Bushby Julie Fisher Owen R. Lozman Stephan Lange John E. Lydon Sholto R. McLaren 《Liquid crystals》2013,40(6):653-664
Previous investigations of complementary polytopic interaction (CPI) columnar mesophases, in which the columns are built up of alternating hexaalkoxytriphenylene (HAT) and hexaphenyltriphenylene (PTP) molecules, concentrated mainly on the effect of variations in the structure of the HAT component. This investigation is concerned with the effect of variations in the structure of the PTP component and, in particular, variations in the position of an alkoxy side chain in the phenyl ring. Stable columnar mesophases are obtained when a hexyloxy substituent is placed in the meta‐ or para‐position but not in the ortho‐position. In the case of the meta‐ and para‐substituted systems, the two‐component CPI columnar phases are stable over a considerably larger temperature range than the one‐component HAT systems. The evidence suggests that unfavourable PTP/PTP stacking is as much a driving force for the formation of these mixed stacks as is favourable PTP/HAT stacking, but both need to be explained in terms of the sum of atomically dispersed van der Waals and coulombic interactions. On cooling from the isotropic into the Colh phase, the columnar phase based on a 1:1 mixture of hexakis(hexyloxy)tripenylene and the meta‐hexyloxy‐substituted PTP gives an unusual texture consisting of ‘viking‐axe’‐shaped structures. 相似文献
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