An Easily Accessible Ionic Aggregation‐Induced Emission Luminogen with Hydrogen‐Bonding‐Switchable Emission and Wash‐Free Imaging Ability

Ionic fluorophores are powerful tools for the study of environmental science and bio-imaging. However, traditional ionic dyes usually require long synthetic steps and suffer from a quenching effect caused by aggregation. A water-soluble ionic aggregation-induced emission luminogen called DBTA is presented, which is readily accessed by a one-step reaction. The switchable emission manipulated by hydrogen bonding provided solid evidence for the restriction of intramolecular motions as the mechanism of aggregation-induced emission. DBTA can not only differentiate solvents with different H-bond donor acidities but also capable of wash-free imaging in living HeLa cells and fish larva.