Competition among intermolecular interactions induces unusual phase separation in a single compound

Abstract

We prepared a homologous series of liquid crystal trimers in which two cyanobiphenyl units and one octafluorobiphenyl unit were connected via flexible spacers, and investigated their phase transition behavior depending on the parity of the methylene spacer. All trimers showed a nematic phase. The trimers possessing odd-numbered spacers were found to exhibit phase separation, i.e., N–Cry and/or Iso–Cry, whereas those possessing even-numbered spacers did not show such an unusual phase coexistence. We discuss the structure–property relationship in the trimers.