Aggregation-dependent room temperature phosphorescence based on different polymorphs of 1,2,3-triazole derivates

Abstract

It is significant and challenging to control the molecular packing in the aggregated state during the molecular design stage. Herein, a series of C4, C5 and N2-trisubstituted triazole derivatives have been designed to explore the relationship between packing modes and room temperature phosphorescence (RTP) properties. By introducing different substituents, these derivatives reveal different RTP properties and inherent mechanisms. TRA-H and TRA-F both have distinct crystalline polymorphs cultured by the evaporation of different mixed organic solvents. The lifetime of their RTP emissions exhibit distinct results due to the different packing modes in the aggregation state. Through careful analysis of experimental results, coupled with theoretical calculations, it is found that efficient intermolecular interactions between the adjacent triazoles, combined with the long-range orderly packing mode in the aggregated state are conducive to the longer phosphorescence lifetime.