Mechanistic insights into diversified photoluminescence behaviours of BF<sub>2</sub> complexes of <i>N</i>-benzoyl 2-aminobenzothiazoles
Zheng He, Yan-Xue Li, Wen-Chao Xiong, Xing-Cong Wang, Shan‐Shan Gong, Shouzhi Pu, Rongwei Shi, Qi Sun
Abstract
energy gap in the region approaching minimun energy conical intersection (MECI) led to the generation of a dark state in BFBB-1. The small energy barrier to access the dark-state region makes the resulting fast internal conversion a competitive channel for excited-state deactivation. In contrast, the presence of EDGs in BFBB-2 and 4 inhibits this pathway, thereby resulting in intense fluorescence emissions in solution. In addition, crystallographic analysis illustrated that the F atoms perpendicular to the polyheterocycle promoted a slipped face-to-face packing mode and enhanced intermolecular interactions. The efficiencies of their solid-state emissions are mainly affected by the degree of π-π overlaps.