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Articles by Seiji Ujiie
Total Records ( 2 ) for Seiji Ujiie
  Akira Mori , Masashi Hashimoto and Seiji Ujiie
  Two ring systems constructed by a cyanotropone ring and a benzoyl group with a mono-, di-, and tri-alkoxyl group, linked by an ester or amide group, and the corresponding benzenoids were synthesised to investigate mesomorphic properties. Both troponoid esters and amides with a monoalkoxybenzoyl group and the corresponding benzenoids had smectic A phases. Troponoid esters and amides with a di- and trialkoxybenzoyl group exhibited smectic A and hexagonal columnar phases, respectively. However, the corresponding benzenoids with a di- and trialkoxybenzoyl group did not exhibit any mesophases. Interestingly, only the mesomorphic troponoid amides with a trialkoxybenzoyl group showed gelling ability. Non-mesomorphic troponoid amides with a trialkoxybenzoyl group, troponoid amides with mono- and dialkoxyl groups, all troponoid esters and all benzenoid esters and amides were not gelators. It was observed that gel formation is strongly related to the formation of a hexagonal columnar phase. An X-ray diffraction study of octanol gels showed that hexagonal packing is involved in gel formation. NMR titration experiments and IR spectral observation of octanol gels supported the fact that intramolecular hydrogen bonding between the tropone carbonyl and the NH group made the core part flat to induce effective π-π interactions, which are driving forces of gelling ability.
  Akira Moria , Tomohiko Itoh , Hisashi Taya , Kanji Kubo , Seiji Ujiie , Ute Baumeister , Siegmar Diel and Carsten Tschierske
  Mesomorphic properties of three-ring systems such as 2,5-dibenzoyloxytropones, 5-benzoylamino-2-benzoyloxytropones and 2,5-dibenzoylaminotropones with 4-alkoxy, 3,4-dialkoxy, and 3,4,5-trialkoxy groups on the benzoyl groups were investigated together with those of the corresponding benzenoids. Derivatives with two monoalkoxybenzoyl groups showed nematic and smectic A and C phases. Troponoid tetracatenars with two dialkoxybenzoyl groups had hexagonal columnar phases except for troponoids with two ester-connecting groups, whereas the corresponding benzenoids with two dialkoxybenzoyl groups were non-mesomorphic. All troponoid hexacatenars with two trialkoxybenzoyl groups formed hexagonal columnar phases. With the exception of benzenoid hexacatenars with two ester-connecting groups, the benzenoid hexacatenars showed hexagonal and tetragonal columnar phases. These mesomorphic properties were discussed from the standpoint of the difference of the core structure and the connecting group, where the amide-connecting group played a role to induce and enhance mesomorphic properties through hydrogen bonding.
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