Nonaromatic polymer-deep eutectic solvent complexes with ultralong room-temperature and high-temperature phosphorescence

Ultralong organic phosphorescence (UOP) and especially high-temperature phosphorescence (HTP) are difficult to be achieved in pure organic nontraditional luminogens (NTLs). Herein, we develop a strategy to prepare UOP materials by solvent exchange of an NTLs-based hydrogel with a deep eutectic solvent (DES), followed by wet annealing. The obtained polyacrylamide-DES complexes exhibit afterglows up to 9.5 s, room-temperature phosphorescence (RTP) lifetimes up to 622.5 ms, and high phosphorescence quantum yields of 17.6%. Excitingly, they also exhibit HTP with a lifetime of 366.2 ms even at 120°C and exhibit highly stable UOP in organic solvents. DESs form strong hydrogen bonding with the polymer matrix, the heavy atom effect of bromine in the DESs promotes the occurrence of RTP, and the rigidified and stable structures enable the HTP of the complexes. This work provides a universal strategy for preparing non-aromatic UOP materials for wide applications.