Long-Range Charge Transportation Induced Organic Host-Guest Dual Color Long Persistent Luminescence

Long persistent luminescence (LPL) can store light energy in excited states and gradually release it as light. Organic host-guest systems provide a good platform for LPL, and single-color LPL is often achieved while multicolor LPL is challengeable. Here host-guest supramolecular complexes are presented with dual LPL emissions: thermally activated delayed fluorescence (TADF) (>= 100 ms) and room temperature phosphorescence (RTP). A space charge transfer from alpha-cyclodextrin to diphenylacetylene (DPA) with long-range transportation (2.32 mm) carrier along DPA strand in the supramolecular complexes is attributed to generate the TADF and RTP. Fortunately, these supramolecular complexes are readily fabricated from alpha-cyclodextrin and DPA or DPA derivatives. The gradient color is observed after removing UV excitation. Furthermore, the hydrophobic property inside alpha-cyclodextrin makes the LPL appear by water shedding and disappear by organic solvent infiltration, showing the character of a "switch." This host-guest space charge transfer strategy paves a way to design LPL materials.