Substituent Effects in Organic Luminogens with Room Temperature Phosphorescence

Organic room temperature phosphorescence (RTP) materials have attracted much attention for their potential applications in various areas. Many diverse molecular design strategies have been proposed to achieve efficient intersystem crossing (ISC) and stable triplet excited states of organic materials. Among them, the introduction of substituents with different types, linkage positions and amounts, can play a key role in moderating the RTP effect resulting from their tunable electronic properties and steric hindrance. Minor differences between substituents can change the molecular packing in aggregated states significantly, facilitating improved RTP performance with rational design. This Concept reviews the relationship between substituent effects, aggregated structure and RTP properties by the systematic investigation of organic luminogens bearing different substituents. The aim of this Concept is to aid researchers so as to accelerate the development of RTP materials by providing insight into the internal mechanism and reviewing efficient strategies through the introduction of suitable substituents.