Strategy for the increasing the solid-state fluorescence intensity of pyrromethene–BF2 complexes

In this study, we attempted to increase the fluorescence quantum yield of pyrromethene–BF2 complex (BODIPY) in the solid state by introducing bulky groups as substituents at the boron atom. Although the BF2 complex did not exhibit any fluorescence in the solid state (Φf = 0.00), the B(OMe)2, B(OPh)2, and BPh2 complexes did show solid-state fluorescence with quantum yields of 0.02, 0.04, and 0.22, respectively.