Chiral salicylaldimine-based liquid crystals in which the (S)-2-octyloxyl tail close to or far from the salicylaldimine core possesses a frustrated blue phase and an antiferroelectric SmC*A phase.
The effects of molecular structure and functional group of a rodlike Schiff base mesogen on blue phase stabilization in a chiral system
作者:Chiung-Cheng Huang、Yu-Chang Huang、Wei-Cheng Hsieh、Yen-Jung Chen、Shi-Kai Jiang、Bo-Hao Chen、I.-Jui Hsu、Jey-Jau Lee
DOI:10.1039/c8nj04493g
日期:——
(type I) and –NC– (type III) linkages were prepared. These mesogens possessed either difluoro substitutions at the inner-core position of the phenyl ring or hydroxy group to form intramolecular hydrogen bonding with an ester or/and imine linkage. When the appropriate concentration of chiral additive is doped into them, the incorporation of two fluoro substituents is more useful for blue phase (BP) stabilization
power into the racemic Schiff base mesogen possessing ester linkage. Cubic BPI and BPII can be confirmed by reflectance spectra and POM. The results of reflectance spectra indicate that the binary mixture composed of salicylaldimine-based mesogens and S811 easily exhibits a supercooling effect and induces BPI. However, only BPII can be observed in all binary mixtures containing Schiff base mesogens. On
New Liquid Crystalline Homologous Series Exhibiting the Smectic C Phase
作者:Sakumitsu Sakagami
DOI:10.1246/bcsj.60.1153
日期:1987.3
A liguid crystalline homologous series of N-[4-(4-alkoxybenzoyloxy)benzylidene]-4-butylanilines and their hydroxyl derivatives at the 2-position were synthesized, and then the liquid-crystalline-phase transitions were determined using a differential scanning calorimeter and a polarizing microscope. All of the members exhibit a nematic phase, and a smectic C phase can be observed for the homologues
A series of copper(II) complexes with tridentate Schiff bases, obtained by the 1:1 condensation of a 4-(p-n-alkoxybenzoyloxy)salicylaldehyde and an aminoalcohol have been prepared and characterized, where the n-alkoxy group is n-propyloxy, n-butyloxy, n-hexyloxy, n-octyloxy, n-hexadecyloxy or n-octadecyloxy and the aminoalcohol is 2-aminoethanol, 3-aminopropanol, (R)- or (S)-2-amino-4-methylpentanol. The nineteen complexes thus synthesized can be classified into two groups, A and B; group A contain a 3-aminopropanol residue and B one of the remaining aminoalcohol residues. Group A members are reddish violet and almost diamagnetic, and it is deduced that these molecules are rod-like in shape and involve a binuclear Cu2O2 central core; group B are blue and paramagnetic, and likely to have a tetranuclear Cu4O4 central core of cubane-like structure and overall disc-like molecular shape. Polarized microscopic, differential scanning calorimetry, and heating X-ray diffractometry measurements were made to study the thermotropic mesomorphism. Polymorphic transitions have been characterized for representative complexes from groups A and B.