Two new chiral liquid crystals of schiff-base type have been synthesized.This series of compounds contain α-chloro acidic ester chain prepared from commercially available L-valine.Both of the compounds exhibit tilted...Two new chiral liquid crystals of schiff-base type have been synthesized.This series of compounds contain α-chloro acidic ester chain prepared from commercially available L-valine.Both of the compounds exhibit tilted smectic phases;their phase transitions were studied using DSC and polarized optical microscopy;the influence of intramolecular hydrogen bonds on the phase behavior was studied as well.展开更多
A chiral liquid crystal crown ether containing diaza-18-crown-6 was synthesized with the help of CPK atomic model and in the meantime a nonchiral liquid crystal crown ether of alike structure was also synthesized for ...A chiral liquid crystal crown ether containing diaza-18-crown-6 was synthesized with the help of CPK atomic model and in the meantime a nonchiral liquid crystal crown ether of alike structure was also synthesized for comparison, indicating that only the former was asymmetric. The present work represents the first attempt of the investigation in chiral liquid crystal crown ether, thus providing basis for further research into problems as such.展开更多
A new series of chiral shish-kebab type liquid crystal block copolymers that form the smectic C(Sc*) phase was synthesized by solution polycondensation. The copolymers were characterized by GPC, DSC, TG, POM, X-ray di...A new series of chiral shish-kebab type liquid crystal block copolymers that form the smectic C(Sc*) phase was synthesized by solution polycondensation. The copolymers were characterized by GPC, DSC, TG, POM, X-ray diffraction and polarimeter. The copolymers 7 entered into liquid crystal phase whin they were heated to their melting temperatures (T-m) and the copolymers 8 were in liquid crystal phase at room temperature with low viscosities. The smectic sanded texture or focal-conic texture were observed on POM. All the chiral block copolymers showed high optical activity. No racemization has happened. Temperature-variable X-ray diffraction study together with POM and polarimetric analysis realized that they are chiral smectic C(Sc*) phase. Thus we offer in this report the first example of shish-kebab type liquid crystal block copolymers that form a chiral smectic C(Sc*) phase. The variation of melting and isotropization temperatures with molecular structure was also discussed.展开更多
文摘Two new chiral liquid crystals of schiff-base type have been synthesized.This series of compounds contain α-chloro acidic ester chain prepared from commercially available L-valine.Both of the compounds exhibit tilted smectic phases;their phase transitions were studied using DSC and polarized optical microscopy;the influence of intramolecular hydrogen bonds on the phase behavior was studied as well.
文摘A chiral liquid crystal crown ether containing diaza-18-crown-6 was synthesized with the help of CPK atomic model and in the meantime a nonchiral liquid crystal crown ether of alike structure was also synthesized for comparison, indicating that only the former was asymmetric. The present work represents the first attempt of the investigation in chiral liquid crystal crown ether, thus providing basis for further research into problems as such.
基金This work was supported by the National Natural Science Foundation of China (No. 29674025) and the Natural Science Foundation of Henan Province.
文摘A new series of chiral shish-kebab type liquid crystal block copolymers that form the smectic C(Sc*) phase was synthesized by solution polycondensation. The copolymers were characterized by GPC, DSC, TG, POM, X-ray diffraction and polarimeter. The copolymers 7 entered into liquid crystal phase whin they were heated to their melting temperatures (T-m) and the copolymers 8 were in liquid crystal phase at room temperature with low viscosities. The smectic sanded texture or focal-conic texture were observed on POM. All the chiral block copolymers showed high optical activity. No racemization has happened. Temperature-variable X-ray diffraction study together with POM and polarimetric analysis realized that they are chiral smectic C(Sc*) phase. Thus we offer in this report the first example of shish-kebab type liquid crystal block copolymers that form a chiral smectic C(Sc*) phase. The variation of melting and isotropization temperatures with molecular structure was also discussed.
