Room-temperature fluorescent liquid crystalline dimers based on discotic 1,3,4-oxadizole

A series of liquid crystalline dimers DOXD-n (n = 6–10) based on discotic 1,3,4-oxadiazole have been synthesised and its thermal properties have been investigated by means of polarised optical microscopy, differential scanning calorimetry, variable-temperature X-ray diffraction and thermogravimetric analyses. Most of the dimers display a discotic nematic phase or a hexagonal columnar phase at room temperature and exhibit photoluminscence in solution, in solid state and in liquid crystalline phase. The relationship between the properties and states of the matter is discussed briefly. Notably, the fluorescent intensity in liquid crystalline state decreased apparently compared to that in solid state due to the self-quenching aggregates.