Strongly Fluorescent Hydrogel as a Blue-Emitting Nanomaterial: An Approach toward Understanding Fluorescence−Structure Relationship

Amide-linked tripyridine derivative 1 and its dipyridine analogue 2 as a reference were synthesized, and their self-assembled behaviors were characterized at different pH values. Surprisingly, 1 was gelated in water and emitted strong blue color, whereas 2 was not gelated in any solvent and emitted no fluorescence. The unique gelation capability of 1 is attributed to the cooperative effects of π−π stacking and intermolecular hydrogen bonding interactions.