Rational design of red AIEgens with a new core structure from non-emissive heteroaromatics† †Electronic supplementary information (ESI) available: Materials and methods, synthetic procedures, biological experiment, structural characterization, crystallographic date, cyclic voltammetry curves, computational details, UV-vis and PL spectra, SEM and TEM image characterization of nanoparticles and cell imaging. CCDC 1822148 and 1822244. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8sc02810a

This work provides a new strategy to design heterocycle-containing AIEgens from non-emissive heteroaromatics and promotes their applications for long-term lysosome imaging.
The development of new aggregation-induced emission (AIE) systems is a hot research topic, from which functional materials with diversified structures and properties are derived. Here, based on rare, non-emissive and highly electron-withdrawing heteroaromatics of 1,4,5,8-tetraazaanthracene (TAA), experimental and theoretical studies reveal that attaching phenyl rotors to TAA is crucial to creating a new N-type AIE core structure. Furthermore, by covalent attachment of electron-donating aromatic amines to the peripheries of the AIE core, red AIEgens could be obtained readily, which exhibit excellent photostability for long-term lysosome tracking. This work not only provides a new strategy to design heterocycle-containing AIEgens from non-emissive heteroaromatics but also stimulates more their applications as bio-imaging materials.