| 초록 |
Fluorinated liquid crystals of fused ring systems with positive dielectric anisotropy for TFT, are reviewed and the current works on new fluorinated naphthalenes and fluorinated chromans with negative dielectric anisotropy for VA-LCD are presented. We designed and synthesized new liquid crystalline trifluoronaphthalene and difluorochroman derivatives. For their preparation, we developed some important technologies such as a ring formation, a selective fluorination and an aromatization. The transition temperatures and the physical properties of some series of trifluoronaphthalenes and difluorochroman are compared, and the relationships with chemical structures are discussed. Both the 1,7,8-trifluoronaphthalenes and the 7,8-difluorochromans exhibit large absolute value of dielectric anisotropy (Δε) and are useful components to reduce the driving voltage of VA-LCD. |
