Achieving Persistent and Efficient Blue Phosphorescence by Doping Electron‐Deficient Benzenes Into Poly(Acrylic Acid)

Purely organic blue room‐temperature phosphorescent materials are scarce. In this work, ten blue RTP film materials are designed and synthesized by doping electron‐deficient benzene derivatives into poly(acrylic acid) (PAA). Noteworthy, the phosphorescence performance of the simple benzenes doped in PAA is superior to that in polyvinyl alcohol (PVA). The phosphorescence lifetime of 4‐cyanobenzoic acid methyl ester@PAA reaches up to 1486.2 ms. A high phosphorescence quantum efficiency of 23.3% is achieved in dimethyl terephthalate@PAA film. Theoretical calculations indicate that excellent phosphorescence performance is attributed to stronger electrostatic interactions between guests and PAA. Finally, the applications of the phosphorescent films in anti‐counterfeiting are demonstrated by inkjet printing and embroidering.