Multifunctional Hydrazone‐Based AIEgens Enabled by Hydrogen‐Halogen Interaction

Abstract Stimuli‐responsive molecules with dynamic covalent bonds show physicochemical changes in response to external stimuli but also exhibit active molecular motions and poor luminescent properties. Hence, the manipulation and balance of dynamic and static behaviors are crucial for the development of multifunctional materials. In this work, a series of hydrazone‐based compounds with aggregation‐induced emission characteristics and hydrogen‐halogen interactions are designed and synthesized. Among them, TPAHPyCl showed the highest quantum yield of 54.0% and morphology‐dependent mechanochromic properties due to the strong chlorine‐hydrogen interactions and other multiple intermolecular interactions in the aggregate state. With the help of the turn‐on emission response to the non‐polar environment of lipid droplets, TPAHPyCl is also utilized for high‐resolution latent fingerprint detection and intracellular lipid‐droplet imaging, demonstrating multiple functions with dynamic and static properties. This work highlights the role of halogen‐hydrogen interactions and provides a new strategy to develop stimuli‐responsive materials with dynamic and static features.