Enhanced Solid‐State Luminescence of Supramolecular Tessellation Assemblies Through Förster Resonance Energy Transfer From Counterions

The development of straightforward strategies for constructing supramolecular tessellations with enhanced solid‐state luminescence has attracted growing interest in supramolecular chemistry and luminescent materials. Herein, we report the formation of diverse supramolecular tiling patterns by combining electron‐deficient bipyridinium‐based cationic macrocycles with either naphthalene‐1‐sulfonate or naphthalene‐2‐sulfonate counterions directly. Single‐crystal X‐ray diffraction reveals distinct tessellated superstructures assembled from 3,3′‐bipyridinium macrocycles, stabilized by a network of electrostatic interactions, hydrogen bonding, π···π stacking, and CH···π interactions. These assemblies exhibit red‐shifted and enhanced solid‐state fluorescence, attributed to Förster resonance energy transfer (FRET) between the macrocycles and their aromatic counterions. Crystallographic and computational studies provide molecular‐level insights into the noncovalent forces governing both the assembly process and luminescence enhancement. This work establishes a facile design strategy for constructing luminescent supramolecular tessellations and offers a deeper understanding of their structure–property relationships.