The location of benzothiazole on the skeleton of rofecoxib defines an AIEgen and its potential application as multifunctional materials

Aggregation-induced emission (AIE) fluorescent molecules with unique photoelectric properties have received extensive attention due to the wide range of applications. In this study, a novel benzothiazole-rofecoxib-based luminogen, o-RBZ , was constructed by integrating the benzothiazole unit into the rofecoxib scaffold. It showed an obvious AIE property, which was investigated and elucidated clearly by systematic experimental and theoretical research. According to single-crystal X-ray and Hirshfeld surface analysis, the highly twisted structure of o-RBZ and restricted-stacking may allow for bright emission in the solid state. Meanwhile, the theoretical calculation revealed that small oscillator strengths ( f  = 0.06) and a large root mean square deviation (RMSD) were mainly responsible for the large non-radiative transition rate and the suppression of luminous efficacy in DMSO. Furthermore, o-RBZ displayed apparent solvatochromism, mechanochromism, and lipid droplets-specific imaging properties (Pearson's correlative coefficient value of 0.94, low cell cytotoxicity). These findings suggest that AIE-active o-RBZ has the potential to be developed as a multi-functional material for mechanical-force sensors and lipid droplets imaging probes.