SRX Chemistry

SRX Chemistry / 2010 / Article

Research Article | Open Access

Volume 2010 |Article ID 534608 | 14 pages | https://doi.org/10.3814/2010/534608

Effect of Molecular Structure on the Phase Behavior of Ternary Mixtures Made from Unsymmetrical 1,4-Phenylene bis 4-Substituted Benzoates

Received08 Aug 2009
Revised25 Sep 2009
Accepted08 Oct 2009
Published18 Jan 2010

Abstract

Ternary mixtures formed from components of the five series of unsymmetrical 1,4-phenylene bis-4-substituted benzoates (Ina--e), in which the substituent (X) alternatively changed from CH3O,CH3, Cl, NO2, and CN, respectively, while, within each homologous series, the length of the terminal alkoxy group varies between n=6, 8, or 14 carbons, were prepared and characterized for their mesophase behaviour. Transition temperatures of the mixtures prepared were measured by differential scanning calorimetry and the phases identified by polarized-light microscopy.

References

  1. M. M. Naoum, G. Hohne, H. Seliger, and E. Happ, “Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their binary mixtures. I. 4-hexadecyloxyphenyl-4-carboxybenzoate and 4-carboxyphenyl-4-hexadecyloxybenzoate,” Liquid Crystals, vol. 23, no. 5, pp. 653–658, 1997. View at: Publisher Site | Google Scholar
  2. M. M. Naoum, G. R. Saad, R. I. Nessim, T. A. Abdel-Aziz, and H. Seliger, “Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their binary mixtures. II. 4-hexadecyloxyphenyl arylates and aryl 4-hexadecyloxy benzoates,” Liquid Crystals, vol. 23, no. 6, pp. 789–795, 1997. View at: Publisher Site | Google Scholar
  3. M. M. Naoum, G. R. Saad, R. I. Nessim, and T. A. Abdel-Aziz, “Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their binary mixtures III. Binary mixtures of alkoxyphenyl arylates and arylalkoxybenzoates,” Liquid Crystals, vol. 25, no. 2, pp. 165–173, 1998. View at: Publisher Site | Google Scholar
  4. M. J. S. Dewar and J. P. Schroeder, “p-Alkoxy- and p-carbalkoxybenzoates of diphenols. A new series of liquid crystalline compounds,” Journal of Organic Chemistry, vol. 30, no. 7, pp. 2296–2300, 1965. View at: Publisher Site | Google Scholar
  5. M. J. S. Dewar and R. S. Goldberg, “Role of p-phenylene groups in nematic liquid crystals,” Journal of the American Chemical Society, vol. 92, no. 6, pp. 1582–1586, 1970. View at: Publisher Site | Google Scholar
  6. S. L. Arora, J. L. Fergason, and T. R. Taylor, “Molecular structure and liquid crystallinity. Phenylene bis(alkoxybenzoates),” Journal of Organic Chemistry, vol. 35, no. 12, pp. 4055–4058, 1970. View at: Publisher Site | Google Scholar
  7. S. A. Haut, D. C. Schroeder, and J. P. Schroeder, “Liquid crystals. II. Unsymmetrical p-phenylene di-p-n-alkoxybenzoates,” Journal of Organic Chemistry, vol. 37, no. 9, pp. 1425–1428, 1972. View at: Publisher Site | Google Scholar
  8. M. M. Naoum, R. I. Nessim, G. R. Saad, and T. Y. Labeeb, “Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their mixtures XII. Binary mixtures of homologues of unsymmetrical 1,4-phenylene bis(4-substituted benzoates),” Liquid Crystals, vol. 30, no. 2, pp. 165–172, 2003. View at: Publisher Site | Google Scholar
  9. M. M. Naoum, R. I. Nessim, G. R. Saad, and T. Y. Labeeb, “Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their mixtures XI. Binary mixtures of unsymmetrical 1,4-phenylene bis-(4-substituted benzoates),” Liquid Crystals, vol. 29, no. 7, pp. 929–943, 2002. View at: Publisher Site | Google Scholar
  10. M. M. Naoum, T. Y. Labeeb, E. Happ, and H. Seliger, “Effect of molecular structure on the phase behavior of some liquid crystalline compounds and their mixtures X. Unsymmetrical 1,4-phenylene-bis-(4-substituted benzoates),” Thermochimica Acta, vol. 391, no. 1-2, pp. 151–158, 2002. View at: Publisher Site | Google Scholar
  11. M. M. Naoum, A. A. Mansour, and A. A. Bayoumy, “Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their mixtures VII. Ternary mixtures of enantiotropes,” Liquid Crystals, vol. 27, no. 2, pp. 243–247, 2000. View at: Publisher Site | Google Scholar
  12. J. Van der Veen, “The influence of terminal substituents upon the nematic-isotropic transition temperature,” Journal de Physique Colloques, vol. 36, pp. C1-375–C1-377, 1975. View at: Google Scholar
  13. M. M. Naoum, R. I. Nessim, G. R. Saad, and T. A. Abdel-Aziz, “Effect of molecular structure on the phase behaviour of some liquid crystalline compounds and their binary mixtures IV. Dependence of Tc on the anisotropy of polarizability of the aryl-X bond,” Liquid Crystals, vol. 25, no. 1, pp. 73–83, 1998. View at: Publisher Site | Google Scholar

Copyright © 2010 Refaat I. Nessim. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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