The synthesis of 1,4-disubstituted bicyclo[2.2.2]octanes exhibiting wide-range, enantiotropic nematic phases
作者:George W. Gray、Stephen M. Kelly
DOI:10.1039/p29810000026
日期:——
The 1,4-disubstituted bicyclo[2.2.2]octane ring has been incorporated in certain cyano-substituted systems to produce series of mesogens exhibiting wide-range nematic phases. 1-(4-Cyanophenyl)- and 1-(4′-cyanobiphenyl-4-yl)-4-n-alkylbicyclo[2.2.2]octanes are colourless stable materials, whose nematic phases are of low birefringence and of positive dielectric anisotropy. This combination of properties
1,4-二取代的双环[2.2.2]辛烷环已被并入某些氰基取代的系统中,以产生一系列具有宽范围向列相的液晶元。1-(4-氰基苯基)-和1-(4'-氰基联苯-4-基)-4-正烷基双环[2.2.2]辛烷是无色稳定的材料,其向列相具有低双折射和正介电各向异性。这些特性的结合使得这些材料的共晶混合物对电光显示设备具有吸引力,尤其是那些涉及胆甾型-向列相变模式的材料。这些液晶元的液晶转变温度要高于具有1,4-二取代苯环或反式的类似液晶元的液晶转变温度。-1,4-二取代的环己烷环代替1,4-二取代的双环[2.2.2]辛烷环。因此,这些化合物证明了双环[2.2.2]辛烷环具有产生令人感兴趣的向列物质的能力。