Effects of symmetrically 2,5-disubstituted 1,3,4-oxadiazoles on the temperature range of liquid crystalline blue phases: a systematic study

Four series of symmetrically 2,5-disubstituted 1,3,4-oxadiazoles with different lateral substituents and terminal alkoxy chain length were synthesised and characterised. Then, all these bent-shaped compounds were separately doped into the blue phase (BP) liquid crystal host and their effects on the BP range of the host were investigated, which shows that the BP ranges varied greatly with the difference in the structure of 2,5-disubstituted 1,3,4-oxadiazoles and their doped concentration. Moreover, in order to explore the influence of the inherent molecular geometry and properties of the bent-shaped molecules on the stability of BPs, the molecular structures of all the compounds were studied by using the theory of density functional theory, and the optimised structural parameters of the molecules were calculated at the B3LYP/6-31G* level.