Thermotropic Liquid Crystalline Behaviors of 4-{4'-(nitrophenylazo)phenoxy}alkanoic Acids and 4-{4'-(nitrophenylazo)phenoxy}alkanoyl Chlorides

4-{4'-(니트로페닐아조)펜옥시}알칸 산들 그리고 4-{4'-(니트로페닐아조)펜옥시}알카노일 클로라이드들의 열방성 액정 거동

  • Jeong, Seung Yong (Department of Polymer Science and Engineering, Dankook University) ;
  • Ma, Yung Dae (Department of Polymer Science and Engineering, Dankook University)
  • 정승용 (단국대학교 고분자공학과) ;
  • 마영대 (단국대학교 고분자공학과)
  • Received : 2008.06.11
  • Accepted : 2008.08.03
  • Published : 2008.10.10

Abstract

Two kinds of nitroazobenzene derivatives: 4-{4'-(nitrophenylazo)phenoxy}alkanoic acids (NAAn, n = 2~8, 10, number of methylene units in the alkyl chain) and 4-{4'-(nitrophenylazo)phenoxy}alkanoyl chlorides (NACn, n = 2~8, 10) were synthesized, and their thermotropic liquid crystalline behaviors were investigated. NAA6 formed an enantiotropic nematic phase, while the remainders, except NAA2, showed monotropic nematic phases. Isotropic-nematic transition temperature ($T_{iN}$) and change of entropy (${\Delta}S$) at $T_{iN}$ for both of NAAn and NACn varied by the change of n, and pronounced odd-even effects of n were also observed. However, the $T_{iN}$ and ${\Delta}S$ values of NAAn were much higher than those of NACn. This fact may be attributed to the hydrogen bonding between carboxyl groups. Thermal properties and degree of order in the mesophase and the magnitude of the odd-even effects of both NAAn and NACn were significantly different from those reported for 4-(alkoxy)-4'-nitroazobenzenes. It was discussed in terms of the differences in the molecular anisotropy and the temperature-dependent flexibility of the substituted groups.

두 종류의 니트로아조벤젠 유도체들, 즉 4-{4'-(니트로페닐아조)펜옥시}알칸 산(NAAn, n = 2~8, 10, 알킬 사슬 중의 메틸렌 기의 수) 그리고 4-{4'-(니트로페닐아조)펜옥시}알카노일 클로라이드(NACn, n = 2~8, 10)을 합성함과 동시에 이들의 열방성 액정의 거동을 검토하였다. NAA6은 쌍방성 네마틱 상을 형성하는 반면 NAA2을 제외한 나머지 유도체들은 단방성 네마틱 상을 형성하였다. NAAn 그리고 NACn이 나타내는 액체 상에서 네마틱 상으로의 전이온도($T_{iN}$) 그리고 $T_{iN}$에서의 엔트로피 변화(${\Delta}S$)는 n의 변화에 따라 현저한 홀수-짝수 효과를 나타냈다. 그러나 NAAn의 $T_{iN}$ 그리고 ${\Delta}S$는 n이 동일한 NACn의 $T_{iN}$ 그리고 ${\Delta}S$ 값에 비해 대단히 높았다. 이러한 사실은 카복실 그룹간에 작용하는 수소결합력에 의해 초래되는 것으로 생각된다. NAAn 그리고 NACn이 나타내는 액정 상의 열적 안정성과 질서도 그리고 홀수-짝수 효과는 4-(알콕시)-4'-니트로아조벤젠들에 대해 보고되어 있는 결과와는 현저히 달랐다. 이러한 특성을 분자의 이방성 그리고 온도에 의존하는 치환기 그룹의 유연성 차이 견지에서 검토하였다.

Keywords

References

  1. O. Nuyken, Encyclopedia of Polymer Science and Engineering eds. A. Klingsberg, J. Muldoon, and A. Salvatore, 2, 157, John wiley & Sons, New York (1995)
  2. X, Xie, A. Natansohn, and P. Rochon, Chem. Mater., 5, 403 (1993) https://doi.org/10.1021/cm00028a003
  3. L. Brehmer, Polymer Sensors and Actuators, eds, Y. Osada and D. De Rossi, 62, Springer-Verlag, Berlin (2002)
  4. V. Shibaev, A. Bobrovsky, and N. Boiko, Prog. Polym. Sci., 28, 729 (2003) https://doi.org/10.1016/S0079-6700(02)00086-2
  5. S. M. Harwood, K. J. Toyne, J. W. Goodby, M. Parsely, and G. W. Gray, Liq. Cryst., 27, 443 (2000) https://doi.org/10.1080/026782900202624
  6. B. Bahadur, Handbook of Liquid Crystals, eds. D. Denuus, J. Gooolby, G. W. Gray, H-W. Spiess, and V. Vill, 2A, 257, Wiley- VCH, Weinheim-New York (1998)
  7. A. E. Blatch and G. R. Luckhurst, Liq. Cryst., 27, 755 (2000) https://doi.org/10.1080/026782900202237
  8. P. A. Henderson, A. G. Cook, and C. T. Imrie, Liq. Cryst., 31, 1427 (2004) https://doi.org/10.1080/02678290412331298067
  9. T. Niori, S. Adachi, and J. Watanabe, Liq. Cryst., 19, 139 (1995) https://doi.org/10.1080/02678299508036731
  10. A. V. Mallia and N. Tamaoki, Chem, Mater., 15, 3237 (2003) https://doi.org/10.1021/cm034127+
  11. K. N. Kim, E.-D. Do, Y.-W. Kwon, and J.-I. Jin, Liq. Cryst., 32, 229 (2005) https://doi.org/10.1080/02678290412331329305
  12. J.-W. Lee, Y. Park, J.-I. Jin, M. F. Achard, and F. Hardouin, J. Mater. Chem., 13, 1367 (2003) https://doi.org/10.1039/b211932c
  13. S. W. Cha, J.-I. Jin, M. Laguerre, M. F. Achard, and F. Hardouin, Liq. Cryst., 26, 1325 (1999) https://doi.org/10.1080/026782999203995
  14. T. Fukuda, Y. Tsujii, and T. Miyamoto, Macromol. Symp., 99, 257 (1995)
  15. A. N Cammidge and R. J. Bushby, Handbook of Liquid of Crystals, eds. D. Demus, J. Goodby, G.-W. Spiess, and V. Vill, 2B, 693, Wiley-VCH, Weinheim-New York (1998)
  16. J. W. Goodby, Liq. Cryst., 25, 25 (1998)
  17. S.-Y. Jeong and Y.-D. Ma, J. Korean Ind. Eng. Chem., 18, 475 (2007)
  18. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 31, 58 (2007)
  19. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 30 338 (2006)
  20. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 31, 356 (2007)
  21. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 32, 169 (2008)
  22. S.-Y. Jeong and Y.-D. Ma, Industrial Technology Research Paper (Dan-kook University), 8, 69 (2007)
  23. N. Laurent, D. Lafont, F. Deumoulin, P. Boullanger, G. Makenzie, P. H. J. Kouwer, and J. W. Goodby, J. Am. Chem. Soc., 125, 15499 (2003) https://doi.org/10.1021/ja037347x
  24. C. Wu, Q. Gu, Y. Huang, and S. Chen, Liq. Cryst., 30, 733 (2003) https://doi.org/10.1080/0267829031000115005
  25. M. Muller and R. Zentel. Macromol. Chem. Phys., 201, 2055 (2000) https://doi.org/10.1002/1521-3935(20001001)201:15<2055::AID-MACP2055>3.0.CO;2-P
  26. E. Yashima, J. Noguchi, and Y. Okamoto, Macromoleules, 28, 8368 (1995) https://doi.org/10.1021/ma00128a054
  27. S.-Y. Jeong and Y.-D. Ma, Polymer(Korea), 31, 37 (2007)
  28. C. T. Imrie and F. E. Karasz, Macromoleules, 26, 545 (1993) https://doi.org/10.1021/ma00055a021
  29. J.-H. Liu and P.-C. Yang, J. Appl. Polym. Sci., 91, 3693 (2004) https://doi.org/10.1002/app.13614
  30. S. Kurihara, K. Iwamoto, and N. Nonaka, Polymer, 39, 3565 (1998) https://doi.org/10.1016/S0032-3861(97)10268-3
  31. C. T. Imrie, T. Schleek, F. E. Karasz, and G. S. Attard, Macromoleules, 26, 539 (1993) https://doi.org/10.1021/ma00055a020
  32. T. Kodaira, M. Endo, and M. Kurachi, Macromol. Chem. Phys., 199, 2329 (1998) https://doi.org/10.1002/(SICI)1521-3935(19981001)199:10<2329::AID-MACP2329>3.0.CO;2-G
  33. M. Li, E. Zhou, J. Xu, and X. Chen, J. Appl. Polym. Sci., 60, 2185 (1996) https://doi.org/10.1002/(SICI)1097-4628(19960620)60:12<2185::AID-APP16>3.0.CO;2-6
  34. J. Franek, Z. J. Jedllinsky, and J. Majunsz, Handbook of Polymer Synthesis, ed. H. R. Kircheldorf, Part B, 1281, Marcel Dekker, Inc., New York (1992)
  35. M. Sato and M. Mizoi, Polym. J., 36, 607 (2004) https://doi.org/10.1295/polymj.36.607
  36. M. Sato, M. Mizoi, and Y. Uemoto, Macromol. Chem. Phys., 202, 3634 (2001) https://doi.org/10.1002/1521-3935(20011201)202:18<3634::AID-MACP3634>3.0.CO;2-J
  37. S. Kumaresan and P. Kanan, J. Polym. Sci.; Part A: Polym. Chem., 41, 3188 (2003) https://doi.org/10.1002/pola.10910
  38. S. Yin, H. Xu, X. Su, G. Li, Y. Song, J. Lam, and B. Tang, J. Polym. Sci.; Part A: Polym. Chem., 44, 2346 (2006) https://doi.org/10.1002/pola.21355
  39. K. Yamaoka, T. Kaneko, J. P. Gong, and Y. Osada, Macromolecules, 34, 1470 (2001) https://doi.org/10.1021/ma001493v
  40. L. Chen, S.-G. Li, Y.-P. Zhao, Y.-C. Wang, and Q.-W. Wang, J. Appl. Polym. Sci., 96, 2163 (2005) https://doi.org/10.1002/app.21675
  41. Z. Zheng, J. Xu, Y. Sun, J. Zhou, B. Chen, Q. Zhang, and K. Wang, J. Polym. Sci.; Part A: Polym. Chem., 44, 3210 (2006) https://doi.org/10.1002/pola.21398
  42. G. W. Gray, Liquid Crystals and Plastic Crystals, eds. G. W. Gray and P. A. Winsor, 1, 103, Ellis Harwood, Chichester, England (1974)
  43. G. W. Gray, The Molecular Physics and Liquid Crystals, eds G. R. Luckhurst, and G. W. Gray, 1, Academic Press, New York (1979)
  44. C. T. Imrie and G. R. Luckhurst, Handbook of Liquid Crystals, eds. D. Demus, H, Goodby, G. W. Gray, H.-W. Spiess, and V. Vill, 2B, 801, Wiley-VCH, Weinheim-New York (1998)
  45. P. J. Collings and M. Hird, Introduction to Liquid Crystals, eds. G. W. Gray, G. W. Goodby, and A. Fukuda, 43, Taylor and Franics Ltd., London (1997)
  46. E. M. Barrall and J. F. Johnson, Liquid Crystals and Plastic Crystals, eds. G. W. Gray and P. A. Winsor, 2, 254, Ellis Harwood, Chichester, England (1974)
  47. G.-Y Yeap, W.-S. Ooi, Y. Nakamura, and Z. Chen, Mol. Cryst. Liq. Cryst., 381, 169 (2002) https://doi.org/10.1080/713738733
  48. M Studenovsky, Z. Sedlakova, G. Wang, S. Nespurek, K. Janus, O. P. Boiko, and F. Kajzar, Macromol. Symp., 212, 399 (2004)
  49. S.-Y. Jeong and Y.-D. Ma, unpublished results
  50. J.-I. Jin, Mol. Cryst. Liq. Cryst., 267, 249 (1995) https://doi.org/10.1080/10587259508034002
  51. S. Chandrasekhar, Liquid Crystals, 17, Cambridge University Press, New York (1992)
  52. E. Chiellini and M. Laus, Handbook of Liquid Crystals, eds. D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess, and V. Vill, 3, 26, Wiley-VCH, Weinheim-New York (1998)
  53. W. Maier, A. Saupe, and Z. Naturforsch, 13a, 564 (1958)
  54. W. Maier, A. Saupe, and Z. Naturforsch, 14a, 882 (1959)
  55. W. Maier, A. Saupe, and Z. Naturforsch, 15a, 287 (1960)
  56. F. Dowell and D. E. Martire, J. Chem. Phys., 68, 1094 (1979) https://doi.org/10.1063/1.435787
  57. P. A. Henderson and C. T. Imrie, Macromolules, 38, 3307 (2005) https://doi.org/10.1021/ma0502304