Tailoring the photophysical properties of organic fluorophores and their applications
Due to their excellent spectroscopic properties (i.e. relatively large molar absorption coefficients, narrow emission bands and high fluorescence quantum yields), high photochemical and chemical stabilities, and the facile alteration of their photophysical properties by molecular design, 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes are among the most popular organic fluorophores and have been widely employed as labeling reagents in molecular biology, lasing medium in liquid solution dye lasers, and chemosensors or molecular probes. In this talk, we present a systematic study of the substituents at the periphery of BODIPY dyes, in particular that of the meso substituent, to elucidate the factors that govern the optical properties in solution and the solid states, and the formation of emissive aggregates in this family of fluorophore. Several new BODIPYs can be added to the previously reported 1,3,5,7-tetramethyl-8-trifluoromethyl derivative in the list of those forming J-aggregates, in addition to other dyes that are emissive in the solid state without forming J-aggregates. Based on our findings of optical properies of meso-substituted BODIPY dyes, the fluorescence-sensory applications will be presented.