Dynamic Arene‐Perfluoroarene Interactions Enable Programmed Vapofluorochromism in a Single Cocrystal

ABSTRACT

Multicolor luminescent solids that undergo sequential switching in response to a single stimulus are highly desirable yet seldom realized. Here, we report a single cocrystal system of 9,10‐bis(phenylethynyl)anthracene (BPEA) and octafluoronaphthalene (OFN) that exhibits three‐stage vapofluorochromism upon solvent vapor exposure, with the emission color evolving from green to orange and finally to yellow. This sequential transition arises from programmed, affinity‐governed OFN sublimation. The 1:1 phase (B ₁ O ₁ ) emits green, partial OFN loss generates a metastable 2:1 phase (B ₂ O ₁ ) emitting orange, and complete removal restores pure BPEA with yellow fluorescence. The disassembly process is effective across various solvent vapors, highlighting its general applicability. Our findings unveil the dynamic potential of arene‐perfluoroarene interactions beyond static assembly and provide a new pathway to programmable multi‐state luminescence switching in a single material with a single stimulus.