Synthesis and characterization of a trefoil-shaped liquid crystal based on 1,3,5-triazine with carbazole groups

A trefoil-shaped liquid crystal containing an aromatic hetero-nucleus has been synthesized by the reaction of cyanuric chloride with 3,6-didecanoyl carbazole ( DDC). The molecular structure was characterized by H-1 NMR and C-13 NMR spectroscopy, mass spectroscopy and elemental analysis. The core consists of 1,3,5- triazine directly linked to three carbazole groups. The trefoil-shaped conformation is suggested by molecular modelling. The mesophase was investigated using DSC, X-ray diffraction and polarizing optical microscopy. The X-ray diffraction pattern of a sample cooled slowly from the isotropic state showed sharp peaks in the small angle and wide angle regions implying the existence of a columnar phase with inter- and intra-columnar ordering. An unusual reticular texture similar to a cholesteric texture was observed.