New mesogen with thermotropic cubic phase: 3,4,5‐tris‐(11,11,12,12,13,13,14,14,15,15,16,16,16‐tridecafluorohexadecyloxy)benzoic acid

A new mesogen, 3,4,5‐tris(11,11,12,12,13,13,14,14,15,15,16,16,16‐tridecafluoro‐hexadecyloxy)benzoic acid, with a thermotropic cubic phase was synthesized. The phase behaviour of the fluorinated compound and its corresponding non‐fluorinated analogue was investigated by differential scanning calorimetry, polarizing optical microscopy, and synchrotron small‐angle X‐ray diffraction. The fluorinated compound, which contains three partially perfluorinated alkoxy moieties and one carboxylic acid group capable of forming hydrogen bonding, exhibits a very interesting sequence of isotropic, cubic and hexagonal columnar phases, whereas its non‐fluorinated compound does not have a liquid crystalline phase. The cubic phase exists over a wide temperature range (from ～200°C to ～30°C on cooling) and is hence amenable to various physical measurements and potential applications. The ability to self‐assemble molecules into ordered superstructure via both partially perfluorinated chains and hydrogen bonding provides new insight for the development of novel liquid crystalline materials.