抄録
We found a triphenylene mesogen having six azobenzene moieties with ester linkage exhibits both calamitic and discotic mesophses as photo-induced isothermal as well as thermal phase transitions. In order to discuss on the effect of linkage groups on the bimesomorphism, two types of ether-linkage derivatives were prepared to clarify the thermal and photoinduced phase transitions. It was found that only one rod-like smectic A phase is observed in one derivative, while the other show some LC phases. The phase transition temperatures are decreased by ca. 7.5 or 16.5 ℃ in comparison to the ester linkage one. This is due to the increase of the flexibility at the linkage parts. The isothermal phase transition of ether derivatives between liquid crystal and Isotropic phases were observed by controlling the intensity of UV light.
