Direct demonstration of triplet excimer in purely organic room temperature phosphorescence through rational molecular design

摘要

Organic luminogens with room temperature phosphorescence(RTP)have been paid great attention and developed rapidly for their wide application values.Until now,the internal mechanism and source of phosphorescence are still obscure,especially for the relationship between molecular dimer and RTP emission.Hence,we designed and synthesized eight phenothiazine 5,5-dioxide derivatives to directly reveal how the monomer and dimer in packing affect the RTP behavior.Dimers with strongπ-πstacking(θ<20.66°;d<3.86A)lead to pure triplet excimer emission,while those with weakπ-πstacking(27.02°<θ<40.64°;3.84A