Siloxane-terminated phenylpyrimidine liquid crystal hosts
Siloxane-terminated phenylpyrimidine liquid crystal hosts
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DOI：
10.1039/b700972k
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发表时间：
2007-06-14
影响因子：
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通讯作者：
Lemieux, Robert P.
中科院分区：
文献类型：
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作者：
Li, Li;Jones, Christopher D.;Lemieux, Robert P.
我们报告的合成和表征的三聚氰胺封端的液晶与2-苯基嘧啶核心，形成部分双层SmA和SmC相。可变温度测量的近晶层间距的粉末X-射线衍射相结合的光学倾斜角的测量和观察的双折射率的变化，通过偏振光学显微镜显示，三硅氧烷端基导致这些化合物的SmA-SmC过渡到更多的“德弗里斯样”相比，非硅氧烷类似物。一种这样的化合物，2-（4-（11-（1，1，1，3，3，5，5-七甲基三甲氧基）十一烷氧基）苯基）-5-（1-氯辛氧基）嘧啶（3），其特征在于最大层收缩率仅为1.6%，并且可以被认为是真正的de弗里斯材料。
We report the synthesis and characterization of trisiloxane-terminated liquid crystals with 2-phenylpyrimidine cores that form partially bilayered SmA and SmC phases. Variable temperature measurements of smectic layer spacings by powder X-ray diffraction combined with measurements of optical tilt angles and observations of birefringence changes by polarized optical microscopy reveal that the trisiloxane end-group causes the SmA-SmC transition of these compounds to be more 'de Vries-like' when compared to a non-siloxane analogue. One such compound, 2-(4-(11-(1,1,1,3,3,5,5-heptamethyltrisitoxanyl)undecyloxy)phenyl)-5-(1-chlorooctyloxy)pyrimidine (3), is characterized by a maximum layer shrinkage of only 1.6% and may be considered a bona fide de Vries material.