Brilliant BODIPY-Fluorene Copolymers with Dispersed Absorption and Emission Maxima

Four systems 1a-1d were prepared to investigate the optical properties of copolymers comprised of polyfluorene doped with BODIPY-based fluors. The underlying hypothesis was energy harvested via the strong absorptivity of the major component, fluorene, would be primarily emitted from the BODIPY parts at much higher wavelengths. Optimization of the polymerization process as a function of the mol % of BODIPY indicated that the brightest polymers were formed when approximately 4 fluorene units were copolymerized with every BODIPY precursor. These polymers were cast into nanoparticles of ca. 40 nm diameter. Treatment of clone 9 rat liver cells with suspensions of these particles resulted in uptake without encapsulation in lysosomes, or organelle targeting.