Synthesis and physical properties of novel liquid crystals containing 2,3-difluorophenyl and 1,3-dioxane units
作者:Gui-Xiang Sun、Bing Chen、Hong Tang、Shou-Yi Xu
DOI:10.1039/b210765a
日期:2003.3.19
Three series of liquid crystalline materials have been synthesized: 2-(2,3-difluoro-4-alkoxyphenyl)-5-(4-alkylphenyl)-1,3-dioxanes (m,On-DFPPD), 2-(2,3-Difluoro-4-alkoxyphenyl)-5-(2-fluoro-4-alkylphenyl)-1,3-dioxanes (m,On-DFPFPD) and 2-(2,3-Difluoro-4-alkoxyphenyl)-5-(2,3-difluoro-4-alkylphenyl)-1,3-dioxanes (m,On-DFPDFPD). Their mesmorphic properties were observed and measured by polarizing optical microscopy and differential scanning calorimetry. The dielectric anisotropy (Δε) and birefringences (Δn) of some target compounds were determined. Most of these compounds exhibit a wide temperature range smectic A phase and/or a wide temperature range nematic phase with negative dielectric anisotropy (Δε) and low birefringences (Δn).
我们合成了三个系列的液晶材料:2-(2,3-二氟-4-烷氧基苯基)-5-(4-烷基苯基)-1,3-二氧杂环(m,On-DFPD)、2-(2,3-二氟-4-烷氧基苯基)-5-(2-氟-4-烷基苯基)-1、3-二氧杂环戊烷(m,On-DFPFPD)和 2-(2,3-二氟-4-烷氧基苯基)-5-(2,3-二氟-4-烷基苯基)-1,3-二氧杂环戊烷(m,On-DFPDFPD)。通过偏振光学显微镜和差示扫描量热法观察和测量了它们的中间形态特性。还测定了一些目标化合物的介电各向异性(Δε)和双折射(Δn)。这些化合物中的大多数都表现出具有负介电各向异性(Δε)和低双折射(Δn)的宽温度范围共晶 A 相和/或宽温度范围向列相。