Room Temperature Phosphorescence from Organic Materials: Unravelling the Emissive Behaviour of Chloro?Substituted Derivatives of Cyclic Triimidazole

Purely organic luminophores that exhibit room temperature phosphorescence (RTP) are receiving an ever-growing attention. The design of efficient RTP materials and the understanding their emissive behaviour, however, remain a challenging task. Herein, to gain further insights into metal-free RTP, we report synthesis, characterization, photophysical study chloro-derivatives [1,2-a:1?,2?-c:1??,2??-e][1,3,5]triazine or cyclic triimidazole (TT). Mono- (1Cl), di- (2Cl) tri-chloro-TT (3Cl) derivatives prepared by mild chlorination with N-chlorosuccinimide (NCS). three compounds characterized aggregation-induced emission (AIE) comprising dual fluorescence multiple phosphorescences, whose origin is disclosed crystal structure analysis together accurate DFT/TDDFT calculations. Comparison previously reported bromine iodine TT reveals new chlorinated as best performing halogenated AIE members family.