Mesogenic schiff base esters with terminal chloro group: Synthesis, thermotropic properties and X-ray diffraction studies

Sie Tiong Ha, Lay Khoon Ong, Yasodha Sivasothy, Guan Yeow Yeap, Hong Cheu Lin, Siew Ling Lee, Peng Lim Boey, Nilesh L. Bonde

Research output: Contribution to journalArticleResearchpeer-review

17 Citations (Scopus)

Abstract

A new homologous series of Schiff base esters comprising a terminal chloro substituent was studied. The chloro substituent contributes to the molecular polarizability, thus, affecting intermolecular interactions, hence, resulting in smectic polymorphism. The mesomorphic properties were studied using differential scanning calorimetry, polarizing optical microscopy and temperature-dependent X-ray diffractometry. Whilst the n-pentanoyloxy and n-heptanoyloxy derivatives exhibited enantiotropic smectogenic A and B phases, monotropic smectogenic A and B phases were observed in the nbutanoyloxy and n-hexanoyloxy derivatives. Enantiotropic smectogenic A and monotropic smectogenic B phases were observed in the n-octanoyloxy to n-hexadecanoyloxy derivatives. The highest member of this series, the n-octadecanoyloxy derivative, exhibited an enantiotropic smectogen A phase. The homologous members were compared with structurally related series to establish their chemical structure-mesomorphic behavior relationships.

Original languageEnglish
Pages (from-to)564-575
Number of pages12
JournalInternational Journal of Physical Sciences
Volume5
Issue number5
Publication statusPublished - May 2010
Externally publishedYes

Keywords

  • Schiff base ester
  • Smectic a
  • Smectic b
  • Thermotropic properties
  • X-ray diffraction

Cite this