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Novel Thermotropic Liquid Crystals with Lateral Aryl Substituent

Author Affiliations

  • 1Department of Applied Chemistry; Faculty of Technology and Engineering, The M.S. University of Baroda, Vadodara -390 001, Gujarat, INDIA

Res.J.chem.sci., Volume 4, Issue (9), Pages 22-26, September,18 (2014)

Abstract

A novel mesogenic homologous series 4 - carbethoxy 2’, 4’–bis (4”-n-alkoxy benzoyloxy) azobenzenes has been synthesized by fixing a rigid 4- carbethoxy phenyl azo group to a resorcinol moiety and both the phenolic hydroxyl groups are esterified by 4-n alkoxy benzoyl groups. The lower homologues of the series exhibit monotropic smectic mesophases whereas the higher homologues exhibit enantiotropic smectic mesophases. The synthesized compounds were characterized by a combination of elemental analysis and IR and NMR spectroscopy. Their mesomorphic properties are discussed and compared with those of structurally related homologous series. The impact of the lateral aryl segment on mesomorphism is also discussed.

References

  1. Colling P.J. and Hird M., Introduction to Liquid Crystals - Chemistry and Physics, Taylor & Francis; London, UK, 48 (1997)
  2. Kumar S., Experimental Study of Physical Properties and Phase Transitions, Cambridge University Press, Cambridge (2001)
  3. Naoum M.M., Mansour A.A. and Bayoumy A.A., Facile synthesis and mesomorphic properties of 4- hydroxybutyl4-(4-alkoxybenzoyloxy) benzoate mesogens, Liq. Cryst., 27, 177-181 (2000)
  4. Naoum M M., Mansour A.A. and Bayoumy A.A., Effect of molecular structure on the phase behavior of some liquid crystalline compounds and their mixtures V-II, Ternary mixtures of enantiotrops, Liq. Cryst., 27, 243-247 (2000)
  5. Naoum M.M., Nessim R.I. and Labeeb T.Y., Liq. Cryst., 27, 889-895 (2000)
  6. Ruslim C., and Ichimura K., Z- isomers of azobenzene highly compatible with liquid crystals, Chem. Lett., 789-790 (1998)
  7. Kozlovsky M.V., Shibaev V.P., Stakhanov A.I., Weyrauch T., and Iaase W.I., A new approach to photorecording based on hindering the TGBA*-Sm A* phase transition in photochromic, Liq. Cryst., 24, 759-767 (1998)
  8. Shibaev V.P., Kostomin S.A., and Ivanov S.A., Chiral Liquid Crystal Polymers In Polymers as Electro Optically and Photo-Optically Active Media, V.P. Shibaev (Ed), Springer: Berlin, 37 (1996)
  9. Ikeda T. and Tsutsumi O., Optical Switching and Image storage by means of azobenzene liquid crystal film, Science, 268, 1873 (1995)
  10. Anderle K. and Wendorff J., Holographic recording using liquid crystalline side chain polymers, Mole. Cryst. Liq. Cryst., 243, 51-75 (1994)
  11. Janossy I. and Lloyd A.D., Low power optical reorientation in dyed nematics, Mol. Cryst. Liq. Cryst., 203, 77-84 (1991)
  12. Dixit S. and Vora R.A. Azomesogens having a lateral hydroxy substituent, Mol.Cryst.Liq.Cryst., 501, 43-52 (2009)
  13. Dixit S. and Vora R.A., Novel azoester compounds with a lateral methyl substituent, Mol.Cryst.Liq.Cryst., 592, 133-140(2014)
  14. Imrie C. and Taylor L., The preparation and properties of low molar mass liquid crystals possessing lateral alkyl chains, Liq. Cryst., 1-10 (1989)
  15. Baumeister U., Kosturkiewicz Z. Hartung H., Demus D. and Weissflog W., Thermotropic liquid crystalline compound with lateral long chain substituent, crystal and molecular structure of mesogenic 4-ethoxy 3-(4-ethoxy phenyliminomethyl)-4‘-(4-methoxybenzoyloxy) azobenzenes, Liq. Cryst., 7(2), 241-249 (1990)
  16. Berdage P., Bayle J.P., Ho M.S. and Fung B.M., New laterally aromatic branched liquid crystal materials with large nematic ranges, Liq. Cryst., 14, 667- 674 (1993)
  17. Vora R.A., Prajapati A.K. and Kevat J.B., Mesogenic properties and the effect of 1,2,4-trisubstitution on the central benzene nucleus of a three ring mesogen, Liq. Cryst. 28, 7, 983- 989 (2001)
  18. Dave J.S. and Vora R.A., In Liquid Crystals And Ordered Fluids Edited By J. F.Johnson and R.S. Porter (Plenum Press, New York), 477 (1970)
  19. Vogel A.I., In Text Book Of Practical Organic Chemistry, thEdn. ELBS and Longman group, 946 (1989)
  20. Ganatra K.J., and Bhoya U.C., Study of homologous series of azomesogens with lateral aromatic branch, Mole Cryst. Liq. Cryst., 487, 110-116 (2008)
  21. Gray G.W., In Molecular Structure and Properties of Liquid Crystals, Academic Press, London, (1962)