Synthesis and characterization of a trefoil-shaped liquid crystal based on1,3,5-triazine with carbazole groups

A trefoil-shaped liquid crystal containing an aromatic hetero-nucleus has b een synthesized by the reaction of cyanuric chloride with 3,6-didecanoyl ca rbazole ( DDC). The molecular structure was characterized by H-1 NMR and C- 13 NMR spectroscopy, mass spectroscopy and elemental analysis. The core con sists of 1,3,5- triazine directly linked to three carbazole groups. The tre foil-shaped conformation is suggested by molecular modelling. The mesophase was investigated using DSC, X-ray diffraction and polarizing optical micro scopy. The X-ray diffraction pattern of a sample cooled slowly from the iso tropic state showed sharp peaks in the small angle and wide angle regions i mplying the existence of a columnar phase with inter- and intra-columnar or dering. An unusual reticular texture similar to a cholesteric texture was o bserved.