Triphenylene deriveatives with six alkoxyazobenzenne moieties at the periphery connected by ester linkages are unique liquid crystals which exhibit bimesomorphism of calamitic and discotic mesophases on both thermotropic and photo-induced manners. The alkyl homologues were found to show two types of mesomorphy depending on the chain length where one sees the mesomorphism change with a gap of phase transition parameters such as transition enthalpies. The optical texture observations indicate two types of conformers with lath-like and rod-like shapes of molecules exist in the SmA phase and the rod-to-disc shape change on cooling leads to characteristic change of optical textures for the aligned samples. XRD measurements with highly brilliant synchrotron irradiation for the aligned samples support the proposal conformation types and an averaged conformers of which shape is of neither rod- and lath-like even in the isotropic liquid phase.
