Liquid Crystal Materials with Sulfur Atoms Incorporated in the Principal Structure III. Trans and Cis Isomers of New Liquid Crystal Material: 2-(<i>p</i>-Substituted phenyl)-5-alky 1-1,3-dithianes
作者:Yuichiro Haramoto、Hiroyoshi Kamogawa
DOI:10.1246/bcsj.58.477
日期:1985.2
p-substituents produced less cis isomers than that with the cyano group, which seems to indicate the establishment of an equilibrium in the formation reaction between trans and cis isomers. Several electro-optic properties of trans- and cis-2-(p-cyanophenyl)-5-alkyl-1,3-dithianes were determined by using them as a dopant of mixture of liquidcrystals. Mixture added with trans isomers was superior to that added
2,5-二取代的 1,3-二噻烷的反式和顺式异构体是通过对取代的苯甲醛和二硫醇的酸催化硫缩醛化合成的。反式和顺式异构体的 13C-NMR 化学位移鉴定结果表明异构现象发生在 1,3-二噻烷环的 5 位。带有给电子 p 取代基的苯甲醛比带有氰基的苯甲醛产生更少的顺式异构体,这似乎表明在反式和顺式异构体之间的形成反应中建立了平衡。反式和顺式-2-(对氰基苯基)-5-烷基-1,3-二噻烷的几种电光性质通过将它们用作液晶混合物的掺杂剂来确定。添加反式异构体的混合物在几个方面优于添加顺式异构体的混合物。
Haramoto, Y.; Kamogawa, H., Molecular Crystals and Liquid Crystals Science and Technology, Section A: Molecular Crystals and Liquid Crystals, 1994, vol. 241, p. 1 - 8
2-(p-Substituted phenyl)-5-alkyl-1,3-dithianes, newliquidcrystals, were synthesized by the thioacetalization of the corresponding aldehydes and dithiols. These compounds have characteristic supercooling states, exhibit monotropic liquidcrystal phases even in the case of long terminal alkyl substituents. The mesomorphic characteristics of these compounds were different from those of the corresponding