Discotic liquid crystals through molecular self-assembly

We have created self-assembled disk-like aggregates of predictable stoichiometry which form discotic liquid crystalline phases. Attempts to assemble multiple molecules of one compound radially about a second acting as a template failed, presumably owing to the existence of a stable crystalline phase of the template. This difficulty was obviated by the choice of tetrakis(n-alkoxy)-6(SH)-phenanthridinon (1a-c), which were expected to form disk-like dimers by analogy with pyridones. All three of these compounds form columnar hexagonal liquid crystalline phases as shown by DSC, POM, and X-ray diffraction experiments. Infrared measurements show that la-e exist as hydrogen-bonded aggregates to temperatures well above their clearing points. Intercolumnar spacing and density considerations require the discotic entities to be dimers.