Liquid-crystalline phase behavior in a zwitterionic tetraazapentacene

Andrew E. Riley, Gregory W. Mitchell, Panayiotis A. Koutentis, Michael Bendikov, Piotr Kaszynki, Fred Wudl, Sarah H. Tolbert

Research output: Contribution to journalArticle

27 Citations (Scopus)


A 5,7-dioctadecylquinoxalinophenazine zwitterion 1 has been investigated to determine its thermal phase behavior. A combination of differential scanning calorimetry (DSC), variable temperature low- and high-angle X-ray diffraction (XRD), and deuterium solid-state NMR spectroscopy were used to characterize the different phases of the tetraazapentacene 1. This molecule is found to exist in a variety of crystalline solid phases between room temperature and 167 °C. with different room-temperature phases resulting from crystallization from solution compared with cooling from the melt. Interestingly, the molecule exhibits liquid-crystalline behavior at high temperatures, between 167 °C and 186 °C, above which it becomes an isotropic fluid. The presence of liquid-crystalline behavior in a zwitterionic system opens up the potential for the use of these or related molecules in optoelectronic switching.

Original languageEnglish
Pages (from-to)531-540
Number of pages10
JournalAdvanced Functional Materials
Issue number7
Publication statusPublished - Jul 1 2003

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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    Riley, A. E., Mitchell, G. W., Koutentis, P. A., Bendikov, M., Kaszynki, P., Wudl, F., & Tolbert, S. H. (2003). Liquid-crystalline phase behavior in a zwitterionic tetraazapentacene. Advanced Functional Materials, 13(7), 531-540.