Chiral Diazatriptycene Exhibiting Acid-Induced Ternary Circularly Polarized Luminescence Switching and Crystal Morphology Changes

Doubly N-doped triptycene 2,6-diazatriptycene 1 was synthesized as the first example of triptycene-bearing intrinsic chirality in its core. The resolved enantiomers exhibited an acid-induced ternary circularly polarized luminescence (CPL) switching behavior, enabling on/off and +/− control, with a dissymmetry factor (g_lum) of approximately 10⁻³. Density functional theory calculations indicated that these ternary CPL changes were derived from modulation of through-space conjugation within the triptycene skeleton. In addition, single-crystal X-ray analysis of 1 and the salt 1•(TfOH)_n revealed the presence of herringbone arrangements, trimer clusters, chiral porous tubes, and 2D charge-segregated array structures. These results demonstrate that precise change of the molecular assembly can be achieved using N-doped chiral triptycene facilitated by ionic hydrogen bonding and donor-acceptor π-π stacking.