Nonconjugated Hyperbranched Polyether Emitting Ultralong Room Temperature Phosphorescence with Tunable Emission and Afterglow

Development of a nonconjugated room temperature phosphorescence (RTP) system with a lifetime longer than 1 s remains a challenge. Here, we report a nonconjugated RTP polymer composed of amide-terminated hyperbranched polyether cross-linked with boric acid, whose phosphorescence lifetime can reach up to 2.40 s with a maximum absolute quantum yield of 26.5%. Moreover, their phosphorescent emission wavelength can be tuned from 517 to 585 nm by changing the excitation wavelength from 300 to 480 nm, while the afterglow color can be regulated from blue to yellow-red. Particularly, the nonconjugated RTP polymer exhibits a dual stimulus response to humidity and temperature, so it is expected to find applications in anti-counterfeiting. The present study provides a strategy to design an RTP system with tunable emission and prolonged afterglow.