High birefringent reactive discotic liquid crystals based on asymmetrical triphenylene with phenyl-acetylene moieties

ABSTRACT

Triphenylene (TP)-based liquid crystals, a category of discotic liquid crystals (DLCs), are easy to synthesise, thermally stable and can undergo self-assembly. A new DLC compound, 2,7,10-tris[4-(6-acryloyloxyhexyloxy)benzoate]-3,6,11-tris[(4-hexylphenyl)ethynyl]-triphenylene, was obtained with a 49% yield using catechol as a starting material and features acetylene groups on its TP core. This material can form films with high birefringence through its cross-linkable acrylate ends. Here, we synthesised this new compound and characterised it using nuclear magnetic resonance spectroscopy, mass spectrometry and elemental analysis. The thermal behaviour was also investigated using differential scanning calorimetry and polarised optical microscopy. This new asymmetric TP-based DLC compound exhibited a nematic liquid-crystalline phase between −20 and 170°C and formed an optical anisotropic film with a high birefringence (Δn = 0.21–0.25).

Graphical Abstract

KEYWORDS:

• High birefringence
• discotic liquid crystals
• asymmetrical triphenylene

Acknowledgements

This work was supported by the Technology Innovation Industrial Program funded by the Ministry of Trade, Industry & Energy [Grant Number 10052667, Korea] and the National Research Council of Science and Technology for Creative Convergence Research Project [Grant Numbers SKM1509 and KRICT], project No. KK-1602-D00.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Ministry of Trade, Industry and Energy [Grant Number: 10052667] and the National Research Council of Science and Technology: [Grant Numbers: SKM1509 and KK-1602-D00].