Rubicene, an Unusual Contorted Core for Discotic Liquid Crystals

Abstract

Rubicene, an unusual contorted polycyclic aromatic hydrocarbon, was realized to function as a novel core fragment for discotic liquid crystals. The central π-conjugated motif was prepared from dialkoxyiodobenzene via Sonagashira coupling followed by pentannulation and Scholl cyclodehydrogenation. The synthesized rubicene derivatives were found to be thermally stable and exhibit enantiotropic columnar mesophases. The columnar arrangement of these derivatives has been validated using polarising optical microscopy, differential scanning calorimetry & small-angle X-ray scattering.

Keywords: Columnar hexagonal phase; Contorted polycyclic aromatic hydrocarbon; Discotic liquid crystal; Homeotropically alignment; Rubicene.