Unsymmetry effect of hexa-peri-hexabenzocoronenes on columnar mesophase behaviour

To address the effects of molecular symmetry on the phase of columnar liquid crystals, a series of unsymmetry (C-1) and symmetry (D-3h) hexa-peri-hexabenzocoronene derivatives was prepared. Compounds 3 and 4, as well as a mixture of compounds 3+4, all had a significantly lower melting temperature and clearing temperature than high-symmetry compounds (D-6h), and all results show a strong dependence on molecular symmetry. [GRAPHICS] .