標題: Synthesis of cyclopentyloxy terphenyl liquid crystals with negative dielectric anisotropy
作者: Lee, Tien-Hsin
Chen, Jiun-Tai
Hsu, Chain-Shu
應用化學系
Department of Applied Chemistry
關鍵字: negative dielectric;cyclopentyl end group;terphenyl liquid crystals;2,3-ortho-difluorophenyl
公開日期: 2-一月-2015
摘要: Liquid crystalline materials possessing negative dielectric anisotropy (Delta epsilon) have attracted considerable attention because they can be used to formulate eutectic mixture for several display applications. The negative Delta epsilon can be achieved by introducing a lateral polar substituent onto the mesogen core of a liquid crystalline material, and fluorine atoms are usually used because of the small size and high electronegativity. 2,3-ortho-Difluoro substituent liquid crystals exhibit stable and profound physical properties such as the low viscosity, strong negative Delta epsilon, and high solubility. To avoid the decrease of the mesophase range, 2,3-ortho-difluorophenyl is often placed next to the terminal chain. In this paper, we have synthesised a new series of 2,3-ortho-difluoroterphenyl liquid crystals with a negative dielectric anisotropy. Ether oxygen is introduced to the structure because it can further increase the lateral dipole moment. 3-Alkylcyclopentane end group decreases both the melting point and the viscosity, which makes it an appropriate substituent for negative Delta epsilon 2,3-ortho-difluoroterphenyl liquid crystals. The mesomorphic properties as well as the optical anisotropies of the synthesised liquid crystals are discussed in this paper. All compounds in the series are found to possess highly negative dielectric anisotropy, wide mesophase ranges; therefore, they have a great potential to formulate eutectic mixture for liquid crystal displays.
URI: http://dx.doi.org/10.1080/02678292.2014.965763
http://hdl.handle.net/11536/124218
ISSN: 0267-8292
DOI: 10.1080/02678292.2014.965763
期刊: LIQUID CRYSTALS
Volume: 42
起始頁: 104
結束頁: 112
顯示於類別:期刊論文