AColumnar Liquid-Crystal Phase Formed by Hydrogen-Bonded Perylene Bisimide J-Aggregates

A new perylene bisimide (PBI) dye self-assembles through hydrogen bonds and p-p 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 pconjugated columnar liquid crystals. Middle and wide-angle Xray analyses reveal a helical structure consisting of three selfassembled 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.