Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
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Conformational Study of Liquid Crystalline Polymer: Theoretical Studies

  • Lee, Mi-Jung (Department of Chemistry, Kunsan National University) ;
  • Kim, Dong-Hee (Department of Chemistry, Kunsan National University)
  • Published : 2006.01.20
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Abstract

The relaxed torsional potential of a liquid crystalline polymer containing an ester functional group in a mesogenic unit (hereafter 12-4 oligomer) has been calculated with the ab initio self-consistent-field using 6-31G$^*$ basis set. GIAO^{13}C NMR chemical shifts also have been calculated at the B3LYP/6-31G$^*$ level of theory for each conformational structure obtained from torsional potential calculation. The results show that the phenyl ring-ester linkages are coplanar with the dihedral angle of about 0$^{\circ}$ and the ring-ring linkages in the biphenyl groups are tilted with the dihedral angle of around 43-44$^{\circ}$ in the lowest energy conformer. The biphenyl ring has a comparatively lower energy barrier of internal rotation potential in the ring-ring than that of phenyl ring-ester. The ^{13}C chemical shifts of carbonyl carbons were found to move to upfield due to $\pi$ -conjugation with phenyl ring and slightly affected about 0.5 ppm by dihedral angle of the ring-ring linkage.

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References

  1. Lee, M.; Oh, N. K. J. Mater. Chem. 1996, 6, 1079 https://doi.org/10.1039/jm9960601079
  2. Yu, S. C.; Choi, Y.; Yu, K. H.; Yu, J.; Choi, H.; Kim, D. H.; Lee, M. Macromolecules 2000, 33, 6527 https://doi.org/10.1021/ma991933m
  3. Lee, M.; Cho, B. K.; Kim, H.; Yoon, J. Y.; Zin, W. C. J. Am. Chem. Soc. 1998, 120, 13258 https://doi.org/10.1021/ja9823619
  4. Lee, M.; Cho, B. K.; Oh, N. K.; Zin, W. C. Macromolecules 2001, 34, 1987 https://doi.org/10.1021/ma001938f
  5. Birner, P.; Kugler, S.; Simon, K.; Naray-Szabo, G. Mol. Cryst. Liq. Cryst. 1982, 80, 11 https://doi.org/10.1080/00268948208071018
  6. Hummel, J. P.; Flory, P. J. Macromolecules 1999, 13, 479 https://doi.org/10.1021/ma60075a004
  7. Lesien, J.; Boeffel, C.; Spiess, H. W.; Yoon, D. Y.; Sherwood, M. H.; Kawasumi, M.; Percec, V. Macromolecules 1995, 28, 6937 https://doi.org/10.1021/ma00124a033
  8. Ishida, H.; Kaji, H.; Horii, F. Macromolecules 1997, 30, 5799 https://doi.org/10.1021/ma9703261
  9. Kurusu, H.; Ookubo, T.; Tuchiya, H.; Ando, I.; Watanabe, J. J. Mol. Struct. (Theochem) 2001, 574, 153 https://doi.org/10.1016/S0166-1280(01)00647-9
  10. Kim, D. H.; Pang, S.; Lee, S. H.; Yu, S. C.; Choi, H. S.; Han, O. H. Bull. Korean Chem. Soc. 2001, 22, 1289
  11. Kim, D. H.; Eun, H. M.; Choi, H. S. Bull. Korean Chem. Soc. 2000, 21, 148
  12. Wang, B.; Fleischer, U.; Hinton, J. E.; Pulay, P. J. Comput. Chem. 2001, 22, 1887 https://doi.org/10.1002/jcc.1139
  13. Wang, B.; Hinton, J. E.; Pulay, P. J. Comput. Chem. 2002, 23, 492 https://doi.org/10.1002/jcc.10044
  14. Fisch, M. J.; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.; Robb, M. A.; Cheeseman, J. R.; Zakrzewski, V. G.; Montgomery, J. A., Jr.; Stratmann, R. E.; Burant, J. C.; Dapprich, S.; Millam, J. M.; Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J.; Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo, C.; Clifford, S.; Ochterski, J.; Petersson, G. A.; Ayala, P. Y.; Cui, Q.; Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.; Foresman, J. B.; Cioslowski, J.; Ortiz, J. V.; Baboul, A. G.; Stefanov, B. B.; Liu, G.; Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.; Fox, D. J.; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.; Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; Johnson, B.; Chen, W.; Wong, M. W.; Andres, J. L.; Gonzalez, C.; Head-Gordon, M.; Replogle, E. S.; Pople, J. A. Gaussian 98, Revision A.7; Gaussian, Inc.: Pittsburgh, PA, 1998
  15. Becke, A. J. Chem. Phys. 1993, 98, 5648 https://doi.org/10.1063/1.464913
  16. Cacelli, I.; Prampolini, G.. Chem. Phys. 2005, 314, 283 https://doi.org/10.1016/j.chemphys.2005.03.003
  17. Ditchfield, R. Mol. Phys. 1974, 27, 789 https://doi.org/10.1080/00268977400100711
  18. Imase, T.; Kawauchi, S.; Watanabe, J. J. Mol. Struct. 2001, 560, 275 https://doi.org/10.1016/S0022-2860(00)00762-6
  19. Almenningen, A.; Bastiansen, O.; Fernholt, L.; Cyvin, S. J.; Smadal, S. J. Mol. Struc. 1985, 128, 59 https://doi.org/10.1016/0022-2860(85)85041-9
  20. Eaton, V. J.; Steele, D. J. Chem. Soc., Faraday Trans. 1973, 2, 1601
  21. Tashiro, K.; Hou, J.; Kobayashi, M.; Inoue, T. J. Am. Chem. Soc. 1990, 112, 8273 https://doi.org/10.1021/ja00179a009
  22. Carreira, L. A.; Towns, T. G. J. Mol. Struct. 1977, 41, 1 https://doi.org/10.1016/0022-2860(77)80034-3
  23. Akiyama, M.; Watanabe, T.; Kakihara, M. J. Phys. Chem. 1986, 90, 1752 https://doi.org/10.1021/j100400a005
  24. Karpfen, A.; Choi, C. H.; Kertesz, M. J. Phys. Chem. 1997, 101, 7426 https://doi.org/10.1021/jp971606l

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