Synthesis and Characterization of New Main Chain Liquid Crystalline Coumarin Compound with Ester Moiety

Ester기를 갖는 새로운 주쇄형 액정 coumarin 화합물의 합성 및 특성분석

  • Lee, Jong-Back (Department of Chemical Engineering, Dongeui University) ;
  • Kang, Byung-Chul (Department of Chemical Engineering, Dongeui University) ;
  • Lee, Gang-Choon (Department of Chemical Engineering, Dongeui University) ;
  • Lee, Dong-Jin (Korea Institute of Ceramic Engineering & Technology) ;
  • Hideyuki, Kihara (Nanotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST))
  • Published : 2009.12.31

Abstract

4-(6-bromohexyloxy)benzoic acid was synthesized from benzyl 4-Hydroxybenzoate and 1,6-dibromohexane. It was reacted with hydroquinone to obtain a new mesogenic ester having an bromine group. One kind of new photoresponsive coumarin compound was prepared by the reaction of mesogenic ester with coumarin sensitive to the ultraviolet. Structures of the compound were identified by FT-IR and $^1H$-NMR spectroscopies. Their phase transition temperatures and thermal stability were also investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM) and x-ray diffraction analysis. From optical polarizing microscopy, the prepared compound was found to show enantiotropic liquid crystallinity with smectic and nematic textures.

References

  1. 이신두, '액정' 전파과학사, 1994
  2. 최이준, 진정일 '액정고분자' 문운당, 2001
  3. J. Salamone, 'Polymetric Materials', ed. by C. D. Eisenbach, p. 6957, Boca Raton, New York, 1996
  4. P. J. Collings, 'Liquid crystals', ed. by P. J. Collings, p. 3, Princeton University Press, 1990
  5. P. J. Collings, M. Hird, 'Introduction to Liquid crystals', Taylor & Francis Ltd, London, 1997
  6. J. I. Jin, S. Antoun, C. Ober, and R. W. Lenz, 'Thermotropic Liquid Crystalline Polyesters with Rigid or Flexible Spacer Groups', Polym. J., 12, 132 (1980) https://doi.org/10.1002/pi.4980120403
  7. H. Kihara, and N. Tamaoki, 'In situ Photochemical Conversion from Cinnamoyl-functionalized Liquid -Crystalline Monomers to Liquid-Crystalline Dimers', Liquid Crystals, 34, 1337 (2007) https://doi.org/10.1080/02678290701697454
  8. R. S. Trenor, A. R. Shultz, B. J. Love, and T. E. Long, 'Coumarins in Polymers: From Light Harvesting to Photo- Cross-Linkable Tissue Scaffolds', Chem. Rev., 104, 3059 (2004) https://doi.org/10.1021/cr030037c
  9. X. YU, D. Scheller, O. Rademacher, and T. Wolff, 'Selectivity in the Photodimerization of 6-Alkylcoumarins', J. Org. Chem., 68, 7386 (2003) https://doi.org/10.1021/jo034627m
  10. N. K. Mal, M. Fujiwara, and Y. Tanaka, 'Photocontrolled Reversible Release of Gust Molecules from Coumarin-modified Mesoporous Silica', Nature, 421, 350 (2003) https://doi.org/10.1038/nature01362
  11. Y. Tian, E. Akiyama, Y. Nagase, A. Kanazawa, O. Tsutsumi, and T. Ikeda, 'Liquid Crystalline Coumarin Polymers', Macromol. Chem. Phys., 201, 1640 (2000) https://doi.org/10.1002/1521-3935(20000901)201:14<1640::AID-MACP1640>3.0.CO;2-Z
  12. P. O. Jackson and M. O'Neill, 'An Investigation of the Role of Cross-Linking and Photodegradation of side-Chain Coumarin Polymers in the Photoalignment of Liquid Crystals', Chem. Mater., 13, 694 (2001) https://doi.org/10.1021/cm0011413
  13. J. B. Lee, T. Kato, T. Yoshida, and T. Uryu, 'Synthesis and Liquid Crystalline Properties of Thermotropic Polyurethanes Prepared from 1,4-Diisocyanates and 4,4´-Bis(ω-hydroxyalkoxy) biphenyls', Macromolecules, 26, 4989 (1993) https://doi.org/10.1021/ma00071a001
  14. J. B. Lee, T. Kato, S. Ujiie, K. Iimura, and T. Uryu, 'Thermotropic Polyurethanes Prepared from 2,5-Tolylene Diisocyanates and 1,4-Bis($\omega$-hydroxyalkoxy)benzenes Containing No Mesogenic Unit', Macromolecules, 28, 2165 (1995) https://doi.org/10.1021/ma00111a010
  15. D. J. Lee, J. B. Lee, N. Koide, E. Akiyama, and T. Uryu, 'Liquid Crystallinity of Thermotropic Para-Type Home- and Copolyurethanes containing Biphenylene Mesogen and Their Blends', Macromolecules, 31, 975 (1998) https://doi.org/10.1021/ma970866y
  16. H. M. Jeong, J. B. Lee, S. Y. Lee, and B. K. Kim, 'Shape Memory Polyurethane Containing Mesogenic Moiety', J. of Materials Sci., 35, 279 (2000) https://doi.org/10.1023/A:1004728814128
  17. J. B. Lee, 'Thermal Properties of Liquid-Crystalline Polyurethanes Containing Biphenylene Mesogen', Key Engin. Mater., 321, 1385 (2006) https://doi.org/10.4028/www.scientific.net/KEM.321-323.1385
  18. J. B. Lee, K. H. Lee, and B. C. Kang, 'Synthesis and Characterization of Thermotropic Liquid Crystalline Polyurethanes', Elastomer, 41, 108 (2006)