Aggregation-induced emission active thermally-activated delayed fluorescence materials possessing N-heterocycle and sulfonyl groups

Abstract

Novel thermally-activated delayed fluorescence (TADF) materials 2Cz2SB and 2Mi2SB, possessing N-heterocycle and arylsulfonyl groups, were synthesized and their photophysical properties in solution and the solid state were characterized. 2Cz2SB and 2Mi2SB exhibit typical TADF characteristics and aggregation-induced emission or crystallization-induced emission behaviour. Specifically, they display a blueshift of photoluminescence wavelength and an increase in photoluminescence quantum yield (Φ_PL) in the aggregate and solid states, owing to suppression of thermal deactivation. The results of time-resolved IR analysis suggest that aggregate and solid state promoted suppression of geometrical changes in the excited state causes the observed increases in Φ_PL.