New Electron‐Donor/Acceptor‐Substituted Tetraphenylethylenes: Aggregation‐Induced Emission with Tunable Emission Color and Optical‐Waveguide Behavior

Abstract Herein, we report the synthesis of new tetraphenylethylene derivatives 1 , 2 , 3 , 4 , 5 that feature electron‐donating (methoxy) and ‐accepting (dicyanomethane) groups as AIE‐active molecules with tunable emission colors. The crystal structures of compounds 3 and 4 are described and the intermolecular interactions within their crystals agree with the observation that they exhibit strong solid‐state emission. Compounds 1 , 2 , 3 , 4 exhibit typical AIE behavior and their emission maxima are red‐shifted in the order: 1 < 2 < 3 < 4 . Such red‐shifts are ascribed to the fact that intramolecular interactions between the electron donor and the electron acceptor become stronger with increasing number of methoxy groups. The solid‐state emission colors of compounds 1 , 2 , 3 , 4 are successfully tuned from yellow‐green to red. Compound 5 shows AIE behavior, but its emission is only slightly enhanced after aggregation and its solid shows a low quantum yield. Furthermore, microplates of compound 3 exhibit 2D optical‐waveguide behavior.