Effect of the number of chiral mesogenic units and their spatial arrangement in dopant molecules on the stabilisation of blue phases

Abstract

To investigate the effect of the number of chiral mesogenic units and their spatial arrangement in dopant molecules on the induction of blue phases (BPs), and widening the temperature ranges of these phases, six benzene derivatives possessing (cholesteryloxycarbonyl)pentyloxy groups (monosubstituted (1), 1,2-disubstituted (2), 1,3-disubstituted (3), 1,4-disubstituted (4), 1,2,3-trisubstituted (5) and 1,3,5-trisubstituted (6) compounds) were prepared. Their helical twisting powers (HTPs) in 4-cyano-4′-pentylbiphenyl (5CB) were proportional to the number of the chiral mesogenic units in each molecule. Furthermore, the minimum amount of the chiral dopant necessary for the induction of BPs was almost inversely proportional to its HTP value in this series.

Keywords:

• chiral nematic liquid crystal
• chiral dopant
• helical twisting power
• blue phase

Funding

This work was supported by Japan Society for the Promotion of Science KAKENHI [grant numbers 24655166, 25288088].