A series of novel tolane-type liquid crystals with amide group as terminal group have been prepared. The terminal amide groups were modified, and the influence of these structural parameters on liquid crystal phases was investigated by polarizing optical microscope （POM） and differential scanning calorimetry （DSC）. Three of these new compounds exhibit nematic phase, good thermal stabilities. In general, these liquid crystals with amide as end groups have high melting points and phase transition temperatures, which result from the hydrogen bonds. Based on theoretical calculations, these new molecules with strong electron donating amide as end group have narrower HOMO-LUMO energy gap and higher dipole moment than tolane.
Hong ZhangFengying HongDezhao ZhuZhengce XiaHongxiang WuHui WangZhuo Zeng
Two series of novel tolane-type liquid crystals （LCs） comprising of hydrogen-bonded organic acids were synthesized. The formation of dimerized H-bond LCs was confirmed by IR spectroscopy, and mesomorphic properties of the LCs were investigated by differential scanning calorimetry （DSC） and polarizing optical microscopy （POM）. It was found that the end groups of the liquid crystals as well as the unsaturated rigid core had effect on the mesomorphic properties.
Dong Yu Zhao Qing Yong Meng Xiao Peng Cui Huai Yang
