Department of Organic Chemistry, Institute of Chemical Technology, CZ-166 28 Prague 6, Czech Republic. ; Tel: +420220444182.
Institute of Physics, Academy of Science of the Czech Republic, Na Slovance 2, CZ-182 21 Prague 8, Czech Republic.
Beilstein J Org Chem. 2014 Apr 7;10:794-807. doi: 10.3762/bjoc.10.75. eCollection 2014.
Bent-shaped mesogens possessing a biphenyl as a central core have been synthesized and the role of the terminal chain and the orientation of the ester as a linkage group have been investigated. For the studied molecular core we have established that both parameters play an important role for the mesomorphic properties. The polyfluoroalkyl terminal chain supports the formation of mesophases, and the introduction of a chiral lactate terminal chain destabilizes mesophases for the first type of mutual orientation of ester groups, attached to the central core. On the contrary, for the opposite orientation of esters, the terminal chain has no effect on the mesomorphic properties, and columnar phases have been found for all compounds. A unique phase sequence has been found for the mesogen with the fluorinated chain. A generalized tilted smectics, SmCG, have been observed in a temperature interval between two different lamellar SmCP phases and characterized by X-ray and dielectric measurements. The dielectric spectroscopy data are unique and presented for the first time in the SmCG phase providing new information about the molecular dynamics.
已合成了具有联苯作为中心核的弯曲状介晶，并研究了末端链和作为连接基团的酯的取向的作用。对于所研究的分子核心，我们已经确定这两个参数对于介晶性质都起着重要作用。多氟烷基末端链支持介相的形成，而手性乳酸酯末端链的引入会使第一种酯基团的相互取向的介相失稳，连接到中心核上。相反，对于酯的相反取向，末端链对介晶性质没有影响，并且已经发现所有化合物都具有柱状相。具有氟化链的介晶具有独特的相序列。在两种不同的层状 SmCP 相之间的温度间隔内观察到了广义倾斜的向列相 SmCG，并通过 X 射线和介电测量进行了表征。介电光谱数据是独特的，并且首次在 SmCG 相中呈现，为分子动力学提供了新的信息。
