Synthesis and liquid crystal properties of triphenylene liquid crystals bearing polymerisable acrylate and methacrylate groups

Abstract

The synthesis and liquid crystalline properties of some new triphenylene discotics bearing pendant acrylate groups are described. Mesophase behaviour is found to be sensitive to the number and position of substituents, the linking chain length, and to change between acrylate and methacrylate termini. Investigation of the isomerically pure triphenylene acrylate and methacrylate derivatives showed that the molecular symmetry also has a modest effect on mesophase behaviour. Unsurprisingly columnar phases are formed only when all substituent chains are of comparable length and methacrylates are far superior to simple acrylate termini, probably due to favourable space filling in the mesophase.

Keywords:

• triphenylenes
• acrylates
• unsymmetrically substituted triphenylenes
• discotics
• columnar mesophases
• isomers

Acknowledgements

X. Kong would like to acknowledge funding from China Scholarship Council, Ministry of Education. We would like to thank the EPSRC National Mass Spectrometry Service Centre (Swansea). This work is supported in part by NSFC (20674004), ISTCP (2008DFA61420), BMSTC (Z090803044009001), and FRFCU (2009JBZ019-1).