FLUOROALKYLATED DISCOTIC LIQUID-CRYSTALS

The concept of mesophase stabilization by partial fluorination of side chains has been extended to discotic systems. The mesophase structure is essentially unchanged, whereas the temperature range of the mesoph ase is strongly affected by the fluorinated side chains. Triphenylene substituted with only one partially fluorinated side chain exhibits a decrease of the clearing temperature, whereas for symmetrically substi tuted systems a broad range mesophase has been observed. This behaviou r can be attributed to a segregation of the incompatible parts of the molecule giving rise to a stabilized columnar structure for the symmet rical substitution pattern.