2B02 Novel Triphenylene Mesogens Showing the Phase Transitions Accompanied with Rod-Disc Alternation of Molecular Shape

Abstract

A new triphenylene mesogen was synthesized, which has six alkyloxyazobenzenes as the peripheral substitutes. The microscopic observation of optical textures indicated that this compound exhibits a hexagonal columnar (Col_h) mesophase, evidenced by the XRD pattern. However, it also shows a transient mesophase with the formation of "batonnet" texture on rapid cooling from the isotropic liquid which isothermally transitions to a Col_h mesophase. A contact method using a well-known smectic mesogen indicated that this phase is assigned to be SmA phase. These results strongly indicate that this mesogen changes the molecular shape in a manner of rod-disc alternation through the phase transition between Col_h and SmA phases.