Crystals (Feb 2019)

Thermotropic Liquid-Crystalline Properties of Viologens Containing 4-n-alkylbenzenesulfonates

  • Pradip K. Bhowmik,
  • Anthony Chang,
  • Jongin Kim,
  • Erenz J. Dizon,
  • Ronald Carlo G. Principe,
  • Haesook Han

DOI
https://doi.org/10.3390/cryst9020077
Journal volume & issue
Vol. 9, no. 2
p. 77

Abstract

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A series of viologens containing 4-n-alkylbenzenesulfonates were synthesized by the metathesis reaction of 4-n-alkylbenzenesulfonic acids or sodium 4-n-alkylbezenesulfonates with the respective viologen dibromide in alcohols. Their chemical structures were characterized by Fourier Transform Infrared, 1H and 13C Nuclear Magnetic Resonance spectra and elemental analysis. Their thermotropic liquid-crystalline (LC) properties were examined by differential scanning calorimetry and polarizing optical microscopy. They formed LC phases above their melting transitions and showed isotropic transitions. As expected, all the viologen salts had excellent stabilities in the temperature range of 278⁻295 °C as determined by thermogravimetric analysis.

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