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

Abstract

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.

Keywords:

• blue phase
• temperature range
• 2,5-disubstituted 1,3,4-oxadiazoles
• molecular parameters

Acknowledgements

This work was supported by National Natural Science Fund for Distinguished Young Scholar (Grant No. 51025313), National Natural Science Foundation (Grant Nos. 50973010, 51173003, 51272026 and 51273022), The Major Project of Chinese Ministry of Education (Grant No. 313002), National Natural Science Foundation Youth Fund of China (Grant No. 61007016) and The Fundamental Research Funds for the Central Universities of China (Grant No. FRF-TP–12–035A). The project listed in our paper provide financial support for our experiment. Dr. Ling Wang, Wanli He, Meng Wang, Xingwu Chen and Prof. Huai Yang are mainly in charge of the preparations of BPLC mixtures, analyzing and summarizing the experimental data as well as discussing and writing the paper. Mr. Jian Sun and Prof. Meiju Wei are mainly in charge of the computational calculation of molecular structures of all bent-shaped compounds.