Synthesis of new wide nematic diaryl-diacetylenes containing thiophene-based heteromonocyclic and heterobicyclic structures,and their birefringence properties |
| |
Authors: | Yuki Arakawa Shunpei Nakajima Koichi Sakajiri Susumu Kawauchi Junji Watanabe |
| |
Institution: | Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Tokyo, Japan |
| |
Abstract: | New monocyclic and bicyclic thiophene-based diaryl-diacetylene liquid crystal (LC) materials were synthesised and demonstrated to exhibit wide enantiotropic nematic phases. One thiophenyl-benzene derivative, in particular, displayed a stable nematic phase across a temperature range of over 100°C. The birefringence properties of the compounds were measured using a multiple-beam interference (MBI) method, with the highest value found to be for the same thiophenyl-benzene molecule (Δn = 0.57, 550 nm) at 10°C above the crystal-to-nematic transition temperature. Furthermore, the effects of the cyclic structure on the mesomorphic behaviours, transition temperatures, and birefringence properties were investigated in detail from both experimental and theoretical viewpoints. |
| |
Keywords: | diacetylene thiophene birefringence nematic phase |
|
|