multiple bodipy derivatives with 1,3,5-triazine as core: balance between fluorescence and numbers of bodipy units

The multiple bodipy derivatives could exhibit higher fluorescence than mono-bodipy derivatives but also might produce the stronger aggregation-induced quenching effect. it is important to investigate the relationship between fluorescence and numbers of bodipy units. in this work, series of multiple bodipy derivatives 2–5 with 1,3,5-triazine as core were designed and synthesized in high yields. a subtle balance between the fluorescence enhancement of multiple bodipy units and fluorescence quenching based on h-aggregation of multiple bodipy units was observed for these multiple bodipy derivatives. compound 3 bearing two bodipy units with triazine as core presented the strongest fluorescence emission and highest fluorescence quantum yield. compound 3 was successfully applied in viscosity measurement, exhibiting the linear relationship between fluorescence intensity (or steady-state emission anisotropy) and viscosity.