Aggregation-induced emission of boryl substituted phenothiazine: synthesis and applications in fluoride ion sensing†

BN-containing molecules have attracted great attention in the past few decades due to their intriguing electronic and optoelectronic properties. Herein, three novel functionalized donor–acceptor (D–A) type luminophores, i.e., aminoboranes containing phenothiazyl substituents 4a, 4b, and 4c with similar structures, were obtained. These aminoborane derivatives showed good air/moisture stability and lower LUMO energy levels than those of CN-containing compound 4d. The results revealed that these aminoborane derivatives exhibited interesting photophysical behavior including aggregation-induced emission (AIE). More importantly, the addition of fluoride ions to diarylboryl–phenothiazines induced a rapid change in the emission color from blue to yellow accompanied by strong intensity changes. Compared to the BN-containing compounds, the CN-containing compound 4d did not show any evident AIE properties and fluoride ion sensing characteristics.