A Columnar Liquid-Crystal Phase Formed by Hydrogen-Bonded Perylene Bisimide J-Aggregates.

A new perylene bisimide (PBI) dye self-assembles through hydrogen bonds and π-π interactions into J-aggregates that in turn self-organize into liquid-crystalline (LC) columnar hexagonal domains. The PBI cores are organized with the transition dipole moments parallel to the columnar axis, which is an unprecedented structural organization in π-conjugated columnar liquid crystals. Middle and wide-angle X-ray analyses reveal a helical structure consisting of three self-assembled hydrogen-bonded PBI strands that constitute a single column of the columnar hexagonal phase. This remarkable assembly mode for columnar liquid crystals may afford new anisotropic LC materials for applications in photonics.