Long-Range Charge Transport-Induced Color and Lifetime Tunable Afterglow Emission of Host-Guest Complexes

In a host-guest system, thetraditional conceptto achieveroom temperature phosphorescence (RTP) is to stabilize the long-livedtriplet state by the host matrix. The host reduces the non-radiativetransition of guests and interaction with oxygen but seldom participatesin excited state generation. In this work, the space through chargetransfer (STCT) and long-range charge transport between & alpha;-cyclodextrin(& alpha;-CD) and diphenylacetylene (DPA) and its derivatives induceultralong room temperature phosphorescence and thermally activateddelayed fluorescence (TADF) emission. The charge transfer processplays an essential role in regulating the lifetime and color of afterglowemission. The tunable color and lifetime of afterglow emission couldbe realized by changing the guest's electronegativity. In addition,the host-guest complexes are readily fabricated by self-assembly.Inspired by multiple color and lifetime as well as the "switch"property of afterglow emission control by self-assembly and disassembly,the host-guest complexes exhibit potential application in rewritableink, anti-counterfeiting, and information encryption.