Discotic mesogens were synthesized by esterification of 1,3,5-tris(4-hydroxy- benzoyloxy)benzene with 3,4,5-trialkyloxybenzoic acids in DCC/DMAP/THF. These derivatives were studied by optical microscopy, differential scanning calorimetry and powder X-ray diffractometry. Optically uniaxially negative columnar phases were observed for derivatives having dodecyloxy and hexadecyloxy chains. Hexagonal packing of columns was observed from the results of X-ray diffraction. However, the diameter of the column is less than the molecular dimension indicating the interdigitations of peripheral chains of the neighboring columns.
Molecular crystals and liquid crystals 411, pp.313-318