TGB phases in chiral swallow‐tailed liquid crystals with a methyleneoxy linking group

Abstract

A homologous series of chiral swallow‐tailed materials with a methleneoxy linking group, 1‐ethylpropyl (S)‐2‐{6‐[4‐(4‐alkoxyphenyl)benzyloxy]‐2‐naphthyl}propionates, EmPNP (m = 8–12), has been synthesized for investigation. Polarizing optical microscopy observations demonstrated that the materials exhibit a N* phase and two frustrated phases: the twist grain boundary smectic A* (TGB_A*) and smectic C* (TGB_C*) phases. All of the materials exhibit a wide TGB phase temperature range. The spontaneous polarization and apparent tilt angle of the TGB_C* phase for compounds in surface stabilized geometry in 5 µm homogeneously aligned cells were also measured and reported.

Notes

^aThe enthalpy of the N*–TGB_A* transition was added to that of the I–N* transition.

^bThe enthalpy was too small to be measured.

^cTransition temperature determined by switching current behaviour at cooling rate 5°C min⁻¹.