Development and application of Diels-Alder adducts displaying AIE properties

Exploring organic reactions to construct novel molecules with aggregation-induced emission (AIE) features is an essential branch of AIE research. The fast-paced application of AIE materials in various disciplines, including photoelectricity, molecular biology, medicine, and materials science, has led to an ever-growing need for new AIE molecules. Unlike the synthesis of most “earlier generations” of AIE fluorogens (AIEgens) that require tedious and harsh reactions, chemists now shift their synthetic focus to a selection of reliable and straightforward reactions. The Diels-Alder reaction has been overlooked in this field. Herein, we report a catalyst-free Diels-Alder reaction between 1,3-diphenylisobenzofuran and a series of electron-deficient alkynes to create AIEgens. Photophysical properties of our synthesized 1,3,4-triphenyl-1,4-dihydro-1,4-epoxynaphthalene (ENAP) derivatives are studied systematically, manifesting their AIE characteristics and structure-fluorescence property relationships. Finally, we highlight the diverse applications of some selected ENAP derivatives in latent fingerprint detection, cell imaging, and bacterial staining.