Poster 71 New Discotic Triphenylene Derivatives exhibiting a Cholesteric Blue Phase and Ferroelectric Switching in Columnar Mesophases

Since a very early stage of discotic liquid crystal research, triphenylene derivatives are known to be useful materials for the study of discotic liquid crystals. Recently, their importance as photoconducting materials was recognized [1]. Blue phases had only been observed in binary mixtures [2, 3]. It took over ten years to experimentally verify [4] J. Prost’s prediction of ferroelectricity in tilted columnar phases of chiral materials [5] and there is still only one other example of a ferroelectrically switchable columnar phase [6]. Based on works published by Goodby et al. [7, 8], we synthesized a number of symmetrically substituted chiral and achiral discotic triphenylene derivatives with phenylene units in the side chains (see table 1). Most of them show columnar phases and additionally compound 1 exhibits a cholesteric and a blue phase as well. Introducing strongly polarising lateral substituents (Cl, NO2) in the side chains, a stabilisation of the columnar mesophases was observed.