An ultralong room-temperature phosphorescent material based on the combination of small singlet-triplet splitting energy and H-aggregation.

Compound AI-N-Cz was conveniently synthesized, and it exhibited ultralong room-temperature phosphorescence (RTP) with a lifetime of 775 ms, which was more than 400 times the RTP lifetime of its isomer AI-Cz (1.9 ms). The ultralong RTP of AI-N-Cz might be due to the combination of small singlet-triplet splitting energy (ΔEST) and H-aggregation, and this could be an efficient strategy for the further design of ultralong organic room-temperature materials.