Ordering properties of columnar discotic triazines containing three pendant triphenylenes with four or five fluorinated tails

Abstract

Two series of discotic columnar liquid crystals were prepared and investigated, consisting of a triazine core to which three triphenylenes (HATs) are attached, connected via a flexible variable spacer containing a triazole group. The triphenylenes have five pentafluoropentyloxy tails or four pentafluoropentyloxy tails and one methoxy group. The compounds with four fluorinated tails on the HAT groups show a lamellar-columnar phase (Col_lam), whereas a compound with five fluorinated tails on the HAT groups shows a hexagonal-columnar (Col_h) phase. Small differences in the steric properties and fluorophobic effects can therefore have a strong influence on the ordering of the molecules in the liquid crystalline phase.

Keywords:

• columnar lamellar
• azide-alkyne click
• fluorinated
• triphenylenes

Acknowledgements

F. Claassen and P. Geutjes are thanked for their help with obtaining the mass spectra and NMR spectra, respectively. This research forms part of the research programme of the Dutch Polymer Institute (DPI), Project #681.