A novel dimeric discotic liquid crystal based on anthraquinone

A novel dimer based on the disc-like anthraquinone core-bis1-(4-nitrobenzyloxy)-2,3,6,7-tetrapentyloxy-9,10-anthraquinon-5-oxy]do and its corresponding monomer 1-hexyloxy5-(4-nitrobenzyloxy)-2,3,6,7-tetrapentyloxy-9,10-anthraquinone, have been synthesized and characterized. X-ray diffraction studies show that this novel dimer exhibits a hexagonal columnar phase (Col_h) with correlation among the molecular cores along the column. The Col_h phase of the dimer exists over a very wide temperature range, extending from 176°C down to at least 60°C (the lowest temperature reached in DSC), whereas the monomer exhibits a Col_h phase at high temperature and a three-dimensionally ordered columnar phase (Col_x) at low temperature.