Helical arrangement of a hydrogen-bonded columnar liquid crystal induced by a centered triphenylene derivative bearing chiral side-chains

A hydrogen-bonded helical columnar liquid crystal was synthesized, in which the helical structure is induced by a centered triphenylene derivative bearing chiral side-chains. The triphenylene derivative, 2,6,10-tris(carboxymethoxy)-3,7,11-tris((S)-(-)-2-methyl-1-butanoxy) triphenylene (TPC4(S)), and a dendric amphiphile, 3,5-bis-(3,4-bis-dodecyloxy-benzyloxy)-N-pyridine-4-yl-benzamide (DenC12), were mixed in a 1:3 ratio to obtain a complex, TPC4(S)-DenC12. Analyses by ¹H-NMR spectroscopy, diffusion ordered spectroscopy (DOSY), CD spectroscopy, infrared (IR) spectroscopy, polarized optical microscopy (POM), differential scanning calorimetry (DSC), and X-ray diffractometry revealed that TPC-4(S)-DenC12 self-assembles to form helical columnar stacks in solution and a helical columnar liquid crystal in bulk. The hydrogen bonding between TPC4(S) and DenC12 is essential for the helical columnar organization, and the preference for a one-handed helical conformation is likely derived from the steric interaction between the chiral side-chains and the dendric amphiphiles in the packing of the hydrogen-bonded columnar assemblies.