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Mesomorphic Properties of the Heterocyclic Analogs of Benzylidene-4-Amino-4′-Methoxybiphenyl

  • William R. Young
  • Ivan Haller
  • Larry Williams

Abstract

In order to ascertain the effect of heterocyclic rings on liquid crystal stability, a series of Schiff bases derived from 4′-methoxy-4-biphenylamine and aromatic heterocyclic aldehydes has been prepared. The ability of each compound to form a liquid crystal phase, either by melting the crystal or cooling the isotropic liquid, has been determined, and the appropriate heat of transition and corresponding entropy change have been measured by differential scanning calorimetry. The results will be discussed in terms of geometrical considerations, substituent effects, and intermolecular interactions.

Keywords

Schiff Base Heterocyclic Ring Liquid Crystal Phase Anhydrous Potassium Carbonate Heterocyclic Analog 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Footnotes

  1. 1.
    G. W. Gray, Molecular Structure and the Properties of Liquid Crystals ( Academic Press, New York, 1962 ).Google Scholar
  2. 2.
    Several heterocyclic mesomorphic materials have been reported. See, for example, Reference 1, p. 157.Google Scholar
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    L. F. Trefilova and I. Y. Postovskii, Doklady Akad. Nauk S.S.S.R., 114, 116 (1957).Google Scholar
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    Reference 1, pp. 131–133.Google Scholar
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    We are indebted to Prof. G. W. Gray for providing his synthetic scheme.Google Scholar
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    C. Ivanov and I. Panaiotov, Doklady Akad. Nauk S.S.S.R., 93, 1041 (1953).Google Scholar
  11. 11.
    Compound I has a reported nematic range of 174–176° (Reference 1, p. 133). Compound X is a monotropic nematic liquid crystal’. Compound XI has a reported melting point of 126–127° (Reference 3). The authors are unaware of reports concerning the remainder of the Schiff bases listed in Table I. C = crystal, N = nematic phase, I = isotropic liquid.Google Scholar
  12. 12.
    Molecular shapes for compounds I and VIII-XIII are very similar. No broadening is detected on Dreiding models.Google Scholar
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    E. M. Barrall, R. S. Porter, and J. F. Johnson, Molec. Crystals, 3, 299 (1968).CrossRefGoogle Scholar
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    R. M. Acheson, An Introduction to the Chemistry of Heterocyclic Compounds, Second Edition (Interscience Publishers, London, 1967), pp. 63–64, 93, 120.Google Scholar
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    Reference 1, pp. 161–163.Google Scholar
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    M. H. Palmer, The Structure and Reactions of Heterocyclic Compounds ( Edward Arnold Ltd., London, 1967 ), p. 255.Google Scholar
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    N. A. Lange, Editor, Handbook of Chemistry, Ninth Edition (Handbook Publishers, Inc., Sandusky, Ohio, 1956), pp. 1323, 1358.Google Scholar
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    This aromaticity difference is attributed to sulfur 3-d orbital participation. See Reference 16, p. 257.Google Scholar
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    Reference 1, pp. 148–155.Google Scholar

Copyright information

© Plenum Press, New York 1970

Authors and Affiliations

  • William R. Young
    • 1
  • Ivan Haller
    • 1
  • Larry Williams
    • 1
  1. 1.IBM Watson Research CenterYorktown HeightsUSA

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